Macrophage migration inhibitory factor
John A. Baugh, PhD; Richard Bucala, MD, PhD
Macrophage migration inhibitory factor (MIF) has been proposed to be the physiologic counter-regulator of glucocorticoid
action within the immune system. In this role, MIF’s position
within the cytokine cascade is to act in concert with glucocorticoids to control both the “set point” and the magnitude of the
inflammatory response. As well as overriding the immunosuppressive effects of glucocorticoids, it is now well established that
MIF has a direct proinflammatory role in inflammatory diseases,
such as sepsis, rheumatoid arthritis, and glomerulonephritis. The
A
fter nearly four decades of research into the activity of macrophage migration inhibitory
factor (MIF), it is noteworthy
that we can review the protein mediator
MIF under the heading “novel molecules
and mechanisms in critical care medicine.” Although a variety of functions
have been attributed to MIF, recent investigations appear to provide more questions than answers. With the increased
sophistication of molecular biology and
gene knockout techniques, however, we
are beginning to establish a firm understanding of MIF’s role in immune homeostasis. MIF has features of a cytokine,
a hormone, and an enzyme, and although
its exact mechanism of action is still incompletely understood, it has become
well established that MIF is a critical mediator of the innate and acquired immune
response.
History
Inhibition of macrophage migration
was recognized as far back as the late
1950s to be associated with immune cell
From the Picower Institute for Medical Research,
Manhasset, NY.
Studies in the authors’ laboratory were supported
by funds from National Institutes of Health grants
1R01-AI35931 and 1R01-AI42310, the Manning Foundation, the Arthritis Foundation, and The Picower Institute for Medical Research.
Address requests for reprints to: Richard Bucala,
MD, PhD, The Picower Institute for Medical Research,
350 Community Drive, Manhasset, NY 11030. E-mail:
rbucala@picower.edu
Copyright © 2002 by Lippincott Williams & Wilkins
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
functions of MIF within the immune system are both unique and
diverse, and although a unified molecular mechanism of action
remains to be elucidated, there have been significant advances in our
understanding of how MIF affects cellular processes. This review
discusses the pathogenic role of MIF in inflammatory disease and
highlights the novel structural, functional, and mechanistic properties of MIF. (Crit Care Med 2002; 30[Suppl.]:S27–S35)
KEY WORDS: macrophage migration inhibitory factor; inflammation; sepsis; acute respiratory distress syndrome; glucocorticoids
activation. The name MIF was coined by
the ability of an unspecified factor to inhibit the random migration of cultured
guinea pig peritoneal exudate macrophages in capillary tube assays. By 1966,
Bloom and Bennett (1) and David (2)
independently characterized this activity
to be a soluble factor produced by activated T lymphocytes. During the subsequent 20 yrs, MIF activity was also found
to correlate with general macrophage activation functions, including adherence,
spreading, phagocytosis, and enhanced
tumoricidal activity (3–5). These early investigations relied on crude conditioned
media from activated T cells as a source
of MIF, so observations were rendered
imprecise by the fact that certain other
mediators, such as interleukin-4 and interferon-␥, could also contribute to inhibitory effects on macrophage migration. These investigations were finally put
on a more firm molecular footing by the
cloning of a unique complementary DNA
(cDNA) for human MIF (6), although a
more precise analysis of the biological,
biochemical, and biophysical properties
of MIF had to await the preparation of
pure recombinant MIF and specific, neutralizing antibodies.
A separate line of investigation that was
aimed at identifying novel mediators that
could regulate glucocorticoid action at the
systemic level led to the discovery of an
apparently novel 12.5-kDa protein released
by cells of the anterior pituitary gland. On
purification and sequencing, it was determined that this protein was the murine
homolog of MIF (7). Further studies in ro-
dents indicated that the pituitary release of
MIF was an integral part of the host’s systemic stress response. When mice received
an intraperitoneal injection of lipopolysaccharide (LPS), there was a dramatic fall in
the pituitary content of MIF, a concomitant
increase in plasma levels of MIF, and a
gradual elevation of MIF messenger RNA
(mRNA) expression in pituitary tissues (7–
9). Circulating MIF levels in animals were
also observed to rise 3– 4 hrs after exposure
to handling-induced stress, similar to the
more classically described stress-related increases in circulating adrenocorticotrophic
hormone (ACTH) and glucocorticoid levels
(8). MIF was, thus, “rediscovered” as a pituitary-derived mediator of systemic stress
responses (reviewed by Bucala (10)).
Given the prior association of MIF
with delayed-type hypersensitivity and
immune cell activation, it was somewhat
surprising that MIF was released from the
same pituitary cell type that secretes
ACTH, a mediator that stimulates the adrenal secretion of glucocorticoids-potent
anti-inflammatory hormones. In addition
to being secreted from the pituitary, MIF
was then found to be released from immune/inflammatory cells as a consequence of glucocorticoid stimulation (8,
11). Recombinant MIF was shown to
“override” or counter-regulate the immunosuppressive effects of glucocorticoids
on immune/inflammatory cell activation
and proinflammatory cytokine release (8,
12, 13). An emerging body of data presently indicates that MIF’s position within
the cytokine cascade is to act in concert
with glucocorticoids to control the “set
S27
point” of the immune and inflammatory
responses (10).
MIF Structure
The cDNA for MIF encodes a 115amino acid protein with an apparent molecular weight of 12.5 kDa that has no
significant sequence homology to any
other protein. The unique structure of
both rat and human MIF has recently
been defined using radiographic crystallography (14, 15). The amino acid sequences of human and murine MIF share
90% identity, and this is reflected in almost identical three-dimensional crystal
structures. Crystal structure studies have
shown that MIF exists as a homo-trimer,
with each monomer consisting of two
antiparallel ␣-helices and six ␤-strands.
Thus, three ␤-sheet domains are surrounded by six ␣-helices to form a central
barrel with open ends (Fig. 1). The barrel
structure contains a solvent-accessible
channel that varies from 4 Å to 15 Å in
diameter and is predominantly lined with
hydrophilic atoms. Electrostatic potential
mapping indicates that the core of the
barrel structure is positively charged and
could possibly interact with negatively
charged moieties. The ability of MIF
monomers to interact in vivo has been
verified recently using a yeast two-hybrid
protein interaction system (J. A. Baugh
unpublished results, and Reference 16).
Enzymatic Activity of MIF
The three-dimensional structure of
MIF is unlike that of any other cytokine
or pituitary hormone and defines a new
protein superfamily. The only known proteins that display any structural similarity to MIF are dopachrome tautomerase
(17) the prokaryotic enzymes: 4-oxalocrotonate tautomerase, 5-carboxymethyl2-hydroxymuconate isomerase (CHMI),
and chorismate mutase (15).
MIF has been reported to possess different catalytic activities: D-dopachrome
tautomerase (18), phenylpyruvate (and
hydroxyphenylpyruvate)
keto-enol
isomerase (19), and thiol-protein oxidoreductase (20). Therefore, MIF not only
Figure 1. Three-dimensional structure of macrophage migration inhibitory factor trimer showing
solvent accessible channel.
S28
shares a three-dimensional architecture
with several microbial enzymes, but also
is itself an enzyme.
The dopachrome tautomerase activity
of MIF was serendipitously discovered
during the investigation of melanin biosynthesis, which involves the conversion
of 2-carboxy-2,3-dihydroindole-5,6-quinone (dopachrome) into 5,6-dihydroxyindole-2-carboxylic acid (DHICA). While
using D-dopachrome as a negative control
in this reaction for the natural substrate
L-dopachrome, two enzymes were purified from melanoma cell lysates that
could also convert D -dopachrome to
DHICA. One of these proteins turned out
to be MIF and the other a novel protein
designated D-dopachrome tautomerase.
MIF and D -dopachrome tautomerase
share 27% sequence identity (21). Among
MIF homologs, it can be seen that the
majority of residues are highly evolutionarily conserved (Fig. 2). Of particular interest, MIF shares sequence and structural similarities with 4-oxalocrotonate
tautomerase, CHMI, and D-dopachrome
tautomerase in that each protein has an
N-terminal proline that acts as a catalytic
base (22–25). The pKa of the N-terminal
proline is lowered by virtue of its position
within a hydrophobic environment. At
physiologic pH, the proline is uncharged
and a lone pair of electrons is available to
effect proton abstraction. A recently determined co-crystal structure of MIF with
hydroxyphenylpyruvate reveals that Pro-1
is positioned to function as a catalytic
base (26), and it has been shown that
replacement of Pro-1 with serine or glycine eliminates tautomerase activity (22,
23). Interestingly, in addition to Pro-1,
there are several other invariant residues
in the different MIF homologs that map
to areas adjacent to the hydrophobic
pocket. This would suggest a strong evolutionary pressure to preserve this structural domain (27).
MIF can also act as a phenylpyruvate
tautomerase, but neither hydroxyphenylpyruvate nor phenylpyruvate are likely
to be physiologic substrates for MIF because the measured Km values appear too
high compared with the concentration of
these substrates that is present endogenously (19, 28).
MIF also has a Cys-X-X-Cys motif that
is evolutionarily conserved and that is a
characteristic feature of thiol-protein oxidoreductases, such as thioredoxin (29)
and protein disulfide isomerase (30). Oxidoreductase activity is dependent on the
formation and reduction of a disulfide
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
Figure 2. Sequence alignment of macrophage migration inhibitory factor (MIF) homologs. *Key residues implicated in MIF enzymatic activities.
bridge between the two conserved cysteine residues. Based on these observations, recombinant MIF was assessed for
oxidoreductase activity and was found to
promote the reduction of the disulfides in
insulin and 2-hydroxyethyldisulfide (20).
Interestingly, the conserved Cys-X-XCys motif also has been proposed to be
important for the binding of MIF to the
thiol-specific antioxidant protein PAG
(16). PAG was identified as an interacting
partner for MIF in a yeast two-hybrid
screen and was shown to inhibit the Ddopachrome tautomerase activity of MIF.
Moreover, MIF binding to PAG was
shown to inhibit the antioxidant activity
of PAG in vitro, suggesting a possible role
for MIF in maintaining the redox status
of thiol-containing proteins (16).
Regardless of the compelling structural
and biochemical evidence for MIF’s catalytic activities, the physiologic importance
of such activities remains to be established.
Mutational analyses have not convincingly
linked the catalytic activity of MIF with
biological activity (22, 27, 31, cf 23]. A natural substrate for MIF enzymatic activity
also has yet to be convincingly identified.
Cellular Sources of MIF
Although MIF was first described as a
T lymphocyte product in 1966 (1, 2) and
then as a pituitary-secreted factor in 1993
(7), it is now known that several other
cell types are important sources of MIF.
During the course of studies with hypophysectomized mice, significant levels
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
of circulating MIF were detected during
the earliest phase of endotoxemia. This
indicated that significant LPS-sensitive
sources of MIF must exist in nonpituitary
tissue(s) and led directly to the identification of the monocyte/macrophage as an
important producer of MIF during the
innate immune response (32). Like anterior pituitary cells, macrophages contain
a significant amount of preformed MIF
within intracellular pools that can be rapidly released on stimulation. This is in
contrast to other proinflammatory cytokines, such as interleukin (IL)-1␤ and
tumor necrosis factor (TNF)-␣, that require de novo mRNA generation and protein synthesis before secretion is observed. MIF secretion from macrophages
is not only rapid but also occurs with LPS
concentrations that are 10- to 100-fold
lower than those required to induce
TNF-␣ production (32).
Rodent studies have established that pituitary corticotrophic cells, monocytes/
macrophages, and T cells are principal
sources of MIF production in vivo. MIF
protein also is expressed by eosinophils, endothelial and various epithelial cell types,
fibroblasts and muscle cells, and specific
cells within the endocrine system (Table 1).
MIF Secretion
MIF lacks a classic N-terminal leader
sequence and appears to be released from
cells via a nonconventional protein secretion pathway. This feature is shared by
several other mediators, such as IL-1, ba-
sic fibroblast growth factor, and cyclophilin, but the molecular details of this secretory process remain unexplained.
Immunocytochemical and immunohistochemistry techniques have shown that
MIF is contained within secretory vesicles
in corticotrophic cells of the anterior pituitary gland and that MIF protein accounts for approximately 0.05% of total
pituitary protein (7, 9). Within corticotrophic cells, MIF resides in specific granules, as well as in vesicles co-localized
with ACTH (9). MIF secretion from corticotrophic cells can be induced by in
vitro stimulation with corticotrophinreleasing factor (CRF) and requires lower
concentrations of CRF than those required to induce ACTH secretion (9). Interestingly, CRF also has been shown to
be a potent inducer of MIF transcription
in murine pituitary cells. A recent functional analysis of the murine MIF genepromoter region using primary rat pituitary cells and the pituitary cell line
AtT-20 demonstrated that CRF-induced
gene expression was dependent on a cyclic AMP responsive element binding protein (33).
Recent studies investigating the expression and secretion of MIF from rat
epididymal epithelial cells also have
shown the presence of MIF in vesicular
structures (34). Immunoelectron microscopy showed MIF immunoreactivity to be
confined to the cytoplasm, with no visible
activity seen within the Golgi complex or
the endoplasmic reticulum. MIF apS29
Table 1. Tissue/cellular distribution of macrophage migration inhibitory factor protein
Tissue Stimuli
References
Anterior pituitary
Corticotrophic cells—CRF, LPS
Immune system
Monocytes/macrophages—LPS, TNF-␣, IFN-␥, glucocorticoids
TSST-1, exotoxin A
T cells, (TH2 ⬎ TH1), mast cells—␣CD3, PMA/ionomycin, PHA
Eosinophils—PMA, C5a, IL-5
HL-60, myelomonocytic—LPS
Adrenal gland
Cortex-zona glomerulosa—LPS
Zona fasiculata
Lung
Bronchial epithelium—LPS
Alveolar macrophages
Kidney
Tubular and glomerular—LPS
Epithelial cells, endothelium
Central veins, Kuppfer cells—LPS
Mesangial cells—LPS, PDGF-AB, IFN-␥
Liver
Hepatocytes surrounding central veins, Kupffer cells—LPS
Pancreas
Islet ␤-cells glucose
Brain
Cortex, hypothalmus and cerebellum-neurons, glial cells, ependyma, astrocytes,
Telecephalon—LPS
Vasculature
Endothelial cells—LPS
7, 9
32
38
37, 80
55
81
43
43
54
81, 82
83
84
43
59
85–87
88, 89
CRF, corticotrophin-releasing factor; LPS, lipopolysaccharide; TNF, tumor necrosis factor; IFN,
interferon; TSST, toxic shock syndrome toxin-1; PMA, phorbol myristate acetate; PHA, phytohemagglutinin antigen; IL, interleukin; PDGF-AB, platelet-derived growth factor-AB.
peared to be concentrated in stereocilia at
the apical cell surface, and MIF-rich vesicles were observed to pinch off from the
plasma membrane. These structures may
account for MIF secretion from epididymal cells, but whether they represent a
generalized mechanism for MIF secretion
from immune and other cell types remains to be established.
Recent data from our laboratory
showed that human MIF interacts with
the vesicle docking protein p115, also
known as transcytosis-associated protein (J. A. Baugh et al., unpublished
data). Studies in p115-deficient yeast
(Uso-p1 knockout) have shown that
p115 is critical for protein secretion
(35). In mammalian cells, p115 is considered to be essential for vesicle trafficking between the endoplasmic reticulum and the Golgi complex (13, 36).
Whether p115 plays a role in MIF secretion remains to be established.
MIF in Adaptive Immunity
Although MIF was originally described
as a T-cell product involved in the delayed
type hypersensitivity response, the current view of MIF function favors a domiS30
nant role for MIF in the innate immune
response. MIF is nevertheless an important regulator of cognate immunity.
Stimulation of primary T cells with antiCD3 antibody or superantigen was found
to induce MIF mRNA expression and protein secretion (37, 38). Neutralization of
T-cell-derived MIF with specific anti-MIF
antibodies inhibited both anti-CD3 and
superantigen-induced IL-2 secretion and
reduced T-cell proliferation by 40% to
60% (37). In vivo, treatment of mice with
anti-MIF antibodies inhibits antigendriven T-cell proliferation and reduces
the expression of antigen-specific immunoglobulin G production (37). A role for
MIF in the shaping of the adaptive immune response is also supported by expression studies using TH1 and TH2 T-cell
subsets. In parallel to effects seen in vivo,
it was found that although both subsets
of T cells express MIF, secretion is predominantly increased in activated TH2
clones (37). Furthermore, studies using
MIF knockout mice (MIF-/-) revealed that
antigen-stimulated lymph node cells
from MIF-/- mice produce higher levels of
IL-4 and interferon (IFN)-␥ than those
from wild-type mice (39). These data
would favor a role for MIF in the devel-
opment of TH2-driven antibody production, at least in some settings.
MIF has recently been shown to play
an important role in the trafficking and
regulation of anti-tumor T lymphocytes
(40). In a mouse model of the cytokine
T-cell (CTL) response using the OVAtransfected tumor cell line EL4 (EG.7), it
was found that cultures of splenocytes
from EG.7-primed mice secrete high levels of MIF after antigen stimulation in
vitro (40). Immunoneutralization of MIF
in parallel splenocyte cultures resulted in
a significant increase in the CTL response
directed against EG.7 cells. Histologic examination of the EG.7 tumors from antiMIF-treated mice showed a prominent increase in both the CD4⫹ and CD8⫹ T
cells, as well as apoptotic tumor cells,
consistent with the observed augmentation of CTL activity in vivo by anti-MIF.
Increased CTL activity was associated
with enhanced expression of the common
␥c-chain of the IL-2 receptor, which mediates CD8⫹ T-cell survival (41), and was
accompanied by elevated IFN-␥ expression. Increased trafficking of CD8⫹ T
cells into tumor tissue was also demonstrated by the transfer of labeled cells
from anti-MIF-treated EG.7 tumorbearing mice into recipient tumorbearing mice (40).
MIF in Innate Immunity
Hypophysectomized mice show a hyperacute plasma MIF release response
when injected with endotoxin. These
studies established the monocyte/macrophage, which had previously been
thought to be the target of MIF action, to
be an important source of MIF in response to LPS (7). Monocytes and macrophages contain large quantities of preformed MIF that were readily released in
response to stimulation with LPS, Grampositive exotoxins (such as toxic shock
syndrome toxin-1), proinflammatory cytokines (TNF-␣, IFN-␥) (32), and malaria
pigment (42). On release from macrophages, MIF can exert potent autocrine
and paracrine effects, promoting cell activation and proinflammatory cytokine
release and overriding glucocorticoid action at the site of inflammation (8, 37). In
vivo studies in rats have shown that MIF
protein is released from the pituitary, adrenal gland, lung, liver, spleen, kidney,
and skin within 6 hrs of LPS injection
(43) (Table 1).
Treatment with recombinant MIF exacerbates LPS-induced toxicity, whereas
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
treatment with anti-MIF neutralizing antibodies rescues mice from lethal endotoxic shock (7) and reduces circulating
TNF-␣ levels by up to 50% (44). The
pivotal role played by MIF in the pathogenesis of endotoxic shock has recently
been confirmed by experiments carried
out in MIF-/- mice, in which a similar
degree of resistance to LPS lethality was
seen (45) as compared with MIF immunoneutralization (7).
MIF also has been shown to play an
important role in the pathogenesis of sepsis caused by Gram-negative bacteria
(44). Two models of bacterial peritonitis
were used, one involving intraperitoneal
injection of live Escherichia coli and the
other cecal ligation and puncture. In
both models, the development of peritonitis was accompanied by local elevations
in MIF expression in the peritoneum, followed by elevated systemic MIF levels
once the animals became bacteremic. In
a similar manner to that observed in the
endotoxic shock models, the addition of
recombinant MIF exacerbated lethality
and neutralization of MIF protected from
lethality because of bacterial peritonitis
(44). Of particular interest in the cecal
ligation and puncture model, mice were
still protected from lethality when antiMIF treatment was initiated as late as 8
hrs after the onset of infection. This is of
extreme importance in the clinical situation because treatment of septic shock in
humans is nearly always initiated after
symptoms are expressed and the infection
is well established. These data suggest
that an anti-MIF strategy may be particularly advantageous in the therapy of septic shock.
To investigate the possible mechanism
by which MIF contributes to the pathogenesis of sepsis, the cecal ligation and
puncture model was repeated in TNF-␣
knockout mice (TNF-␣-/-). TNF-␣-/- mice
are significantly immunocompromised
and are unable to mount an adequate
innate immune response to invading bacteria (46). TNF-␣-/- mice also were protected against septic death by anti-MIF
treatment (44), indicating that mechanisms other than modulation of TNF-␣
action must be involved.
Consistent with observations that
Gram-positive exotoxins induce secretion
of MIF from T cells and macrophages (38,
47), neutralization of MIF in toxic shock
syndrome toxin-1-treated mice protects
animals from toxic shock lethality (38).
Similarly, MIF-/- mice were resistant to a
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
lethal injection of staphylococcal enterotoxin B (44).
Neutralization of MIF on a cellular
level with antisense oligonucleotide strategies has been shown to reduce the endogenous expression of MIF and significantly reduce the secretion of TNF-␣ and
IL-6 from LPS-stimulated macrophages
(48). LPS-induced nuclear factor (NF)-␬B
activity and steady-state TNF-␣ mRNA
levels were also markedly reduced by antisense MIF treatment of macrophages.
By contrast, antisense MIF macrophages
exhibited normal responses to other inflammatory stimuli, including Grampositive bacteria (48). Investigations are
in progress to identify at which point in
the NF-␬B activation cascade MIF may
play a role.
Several studies have provided clinical
evidence for systemically elevated MIF expression during sepsis. In addition to
studies carried out by Calandra et al. (44),
Beishuizen and colleagues (49) serially
measured serum MIF, cortisol, plasma
ACTH, TNF-␣, and IL-6 in 40 critical care
patients during a period of 14 days or
until discharge or death. On day 1, MIF
levels were significantly elevated in septic
shock patients compared with multitrauma patients and normal controls.
Furthermore, the time-course of MIF expression in serum paralleled that of cortisol in the septic shock patients. A significant correlation also was observed
between elevated MIF levels at admission
and occurrence of death. Interestingly,
MIF levels were not elevated in nonseptic,
multitrauma patients (49). These data
were complemented by Joshi et al. (50),
who reported elevated MIF levels in multitrauma patients that correlated with
positive tests for bacterial cultures in
blood, urine, sputum, or at the wound
site.
MIF in Acute Lung Injury
Acute respiratory distress syndrome
(ARDS) is a life-threatening, hyperacute
inflammatory response that occurs in the
lungs after trauma or sepsis. Inflammatory cell activation and, in particular,
neutrophil activation have been implicated in the early stages of ARDS pathogenesis (51–53). As a consequence of this
overwhelming inflammatory response,
disruption of the alveolar/capillary interface occurs, leading to decreased arterial
oxygen tension, pulmonary capillary
pressure, and leakage of a protein-rich
fluid into the alveolar air spaces. Hypox-
emia, respiratory failure, and death
quickly ensue.
MIF is one of several proinflammatory
cytokines overexpressed in the alveolar
air space during ARDS. Donnelly et al.
(54) measured elevated levels of circulating and, more importantly, air spacelocalized MIF and demonstrated that a
significant source of MIF in the lung during ARDS was activated alveolar macrophages. Furthermore, ex vivo treatment
of alveolar macrophages from patients
with ARDS with exogenous MIF resulted
in an elevated expression of TNF-␣ and
IL-8. Conversely, treatment with antiMIF antibodies inhibited the expression
of these cytokines. Recent clinical studies
confirm these finding and show that increased MIF expression correlates with
the development of ARDS in septic patients (49).
In a rat model of lung injury, anti-MIF
treatment was shown to reduce the accumulation of activated neutrophils in the
lungs (55). Bronchoalveolar lavage samples from these animals were found to
contain significantly reduced levels of the
neutrophil chemoattractant macrophage
inflammatory protein-2. Because MIF is
not itself a chemoattractant for neutrophils (S. C. Donnelly, unpublished observations), these data suggest that MIF may
play a role in ARDS via up-regulation of
the neutrophil chemoattractant macrophage inflammatory protein-2 (55).
Further studies showed that MIF
could counter-regulate the anti-inflammatory effects of glucocorticoids on alveolar macrophage cytokine expression.
These data suggest that overproduction
of MIF in the lung during acute trauma
could lead to neutrophilia that is refractory to suppression by both endogenous
and therapeutic glucocorticoids. Clinical
treatment with anti-MIF strategies may
help reduce early neutrophil accumulation in ARDS and increase the effectiveness of glucocorticoid treatment.
Recently, human eosinophils derived
from atopic donors have been shown to
contain preformed stores of MIF and to
secrete MIF in response to relevant physiologic stimuli (IL-5 and C5a) (56). Eosinophils have been implicated as a key
cell type in the pathogenesis of allergic
inflammatory diseases, such as bronchial
asthma, allergic rhinitis, and atopic dermatitis (57, 58). Analysis of bronchoalveolar lavage samples from a cohort of
stable asthmatics revealed an elevated
level of MIF protein expression, and it is
suggested that the elevated numbers of
S31
eosinophils present in the alveolar air
spaces are responsible for its production.
The identification of eosinophils and, notably, the type II alveolar epithelial cells
(54) as additional cellular sources of MIF
highlights the potential importance of
MIF in allergic pulmonary inflammatory
disease.
Molecular Mechanism of Action
of MIF
There are substantial data to support
roles for MIF as an inflammatory cytokine, a neuroendocrine hormone, and a
catalytic enzyme. Nevertheless, the rank
order of these activities with respect to
the pathologic role of MIF in various inflammatory/immune diseases remains to
be established. A variety of data (7, 8, 23,
31, 37, 59 – 62) suggest that an interaction between MIF and a receptor on the
surface of target cells is essential for
MIF’s activities, but there remains little
information concerning the molecular
identity of this receptor.
MIF is directly proinflammatory by activating or promoting cytokine expression (TNF-␣ (32, 44), IL-1␤, IL-2 (37),
IL-6 (32, 39), IL-8 (60), IFN-␥ (37, 40)),
nitric oxide release (63), matrix metalloproteinase-2 expression (64, 65), and induction of the cyclooxygenase-2 pathway
(62) (Table 2). MIF also plays an important role in regulating both the set-point
and the direction of the inflammatory
response by counter-regulating the antiinflammatory and immunosuppressive
effects of glucocorticoids (Table 3). Specifically, MIF counteracts glucocorticoidinduced inhibition of inflammatory cytokine secretion in macrophages (TNF-␣,
IL-1␤, IL-6, IL-8) (32), T cells (IL-2 and
IFN-␥) (37), and synovial fibroblasts
(TNF-␣) (66). Although an MIF receptor
protein has yet to be described, several
lines of data have converged for how MIF
may induce signal transduction and modulate cell responses. In terms of cell signaling pathways, it has been found that in
many of the transformed and immortalized cell lines, a high endogenous level of
MIF expression may temper the effects of
exogenously added recombinant MIF. Recent studies by Mitchell et al. (62) show
that exogenously added recombinant MIF
as well as endogenously released MIF,
which is secreted as a consequence of
serum stimulation, induced the proliferation of quiescent fibroblasts. This response was associated with a sustained
activation of the p44/p42 ERK subfamily
S32
Table 2. In vitro and in vivo activities of macrophage migration inhibitory factor
References
In vitro
Phagocytosis of particles
Glucocorticoid counter-regulator
Promotes NO and TNF-␣ release from macrophages
Mediator of T-cell activation and antigen-specific immunity
Promotes insulin release from pancreatic ␤ cells
Suppression of inhibin release from Leydig cells
Suppression of erythroid progenitor development
Regulator of glycolysis
Mitogen for fibroblasts and endothelial cells
Promotes tumor cell proliferation
Promotes endothelial cell proliferation
In vivo
Disease progression/pathologies (experimental animal models)
Endotoxemia and exotoxemia
Delayed-type hypersensitivity reaction
Antigen-dependent T-cell activation
Arthritis–collagen-induced and adjuvant-induced
Glomerulonephritis
Tumor growth and angiogenesis
90
8, 37, 54
32, 75
37
59
91
42
60
62, 92
61, 92
88
7, 38, 44, 45
93
37
94, 95
81, 96
92, 88, 89
NO, nitric oxide; TNF, tumor necrosis factor.
Table 3. Regulatory action of macrophage migration inhibitory factor in inflammation
Mechanism
Effect Reference
Antagonism of glucocorticoid suppression of cPLA2 expression—1arachidonic
acid, JNK activation, 1TNF-␣ expression
Antagonism of glucocorticoid induction of I␬B␣—NF-␬B activation
Direct interaction with Jab1—modulation of AP-1 activity, 2p27Kip1
62
73
74
cPLA2, cytoplasmic phospholipase A2; TNF, tumor necrosis factor; NF, nuclear factor; AP, activator
protein.
of mitogen-activated protein (MAP) kinases and was dependent on the activity
of protein kinase A. The ERK MAP kinase
signaling cascade results in the phosphorylation and activation of a number of
cytosolic proteins, such as P90rsk, c-myc,
and cytoplasmic phospholipase A 2
(cPLA2) (67). cPLA2 is a critical mediator
of inflammatory responses (68), and its
product, arachidonic acid, is the precursor for the synthesis of prostaglandins
and leukotrienes. Further studies went
on to show that MIF could induce the
phosphorylation and activation of cPLA2
and, ultimately, the release of arachidonic acid by an ERK- but not p38-MAP
kinase-dependent mechanism (62). Interestingly, cPLA2 is an important target for
the anti-inflammatory action of glucocorticoids, and the ability of MIF to activate
cPLA2 may be one mechanism by which
MIF regulates glucocorticoid action in
cells. In support of this hypothesis, MIF
was able to counter-regulate glucocorticoid inhibition of TNF-␣-induced arachidonic acid release from L929 fibroblasts
(62). Arachidonic acid also is required for
the activation of jun N-terminal kinase
and efficient translation of TNF-␣ mRNA,
providing another point of interaction between MIF and glucocorticoids.
Another possible mechanism by which
MIF may modulate inflammatory responses and counter-regulate the effects
of glucocorticoids is via NF-␬B activation. NF-␬B is an important regulator of
inflammatory cytokine gene expression
(69), and several lines of evidence suggest
that glucocorticoids may inhibit the production of inflammatory mediators, such
as TNF-␣, via modulation of NF-␬B activity. Glucocorticoids have been proposed
to inhibit binding of the p65 subunit of
NF-␬B to the transcriptional machinery
of target genes (70) and to induce I␬B
synthesis (71, 72). Elevation of cytoplasmic I␬B inhibits the ability of NF-␬B to
translocate to the nucleus, and inhibition
of NF-␬B p65 binding to DNA directly
prevents the expression of target genes.
Recent studies have shown that MIF inhibits the ability of glucocorticoids to induce I␬B synthesis in LPS-stimulated human peripheral blood mononuclear cells
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
T
he diverse actions
of macrophage migration inhibitory
factor (MIF) within the immune system are yet to be
fully understood, but it is
clear that MIF plays a pivotal role in the regulation of
both innate and adaptive
immunity.
(73). Thus, by blocking glucocorticoidinduced I␬B synthesis, MIF promotes the
translocation of NF-␬B into the nucleus,
where it activates proinflammatory cytokine and adhesion molecule expression.
Recent studies by Kleemann et al. (74)
also show that MIF may directly affect transcriptional activity of activator protein-1
(AP-1) responsive genes via an interaction
with Jab-1. AP-1 is a transcription factor
that binds DNA as a heteromeric complex
with the Fos and Jun oncoproteins, and it is
proposed that Jab-1 stabilizes the binding
of AP-1·c-jun complexes to AP-1 sites. By
using MIF as “bait” in a yeast two-hybrid
screen, they identified Jab-1, a coactivator
of AP-1, as a binding partner of MIF (74).
Jab-1 also binds and promotes the degradation of p27Kip1, a protein that halts the
cell-division cycle. The interaction of MIF
with Jab-1 was confirmed in vivo and was
shown to result in the inhibition of Jab-1
binding to c-jun, thus destabilizing the formation of activated AP-1 complexes. The
binding of MIF to Jab-1 resulted in reduced
degradation of p27Kip1, and MIF overexpression inhibited the growth-promoting
properties of Jab-1 in fibroblast cells (74).
Because AP-1 has been shown to be an
important regulator of several proinflammatory genes, these data at first appear to
conflict with the proinflammatory nature
described for MIF. Similarly, the cell
growth-promoting effects of MIF reported
by others (61, 62) would conflict with the
proposed role of MIF in the enhancement
of p27Kip1-regulated cell-cycle stasis. However, one characteristic feature of MIF action is its bell-shaped dose-response curve
with respect to several biological phenomena, such as its inhibition of macrophage
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
migration (75). This implies that low vs.
high levels of MIF may have distinct regulatory effects on cellular processes.
The cell growth-promoting properties of
MIF may indeed be an important mechanism by which MIF contributes to the pathology of various inflammatory diseases.
During the response to infection, the innate immune response is kept in check by
specialized counter-regulatory mechanisms, such as apoptosis or programmed
cell death (76). Exaggerated apoptosis in T
cells is a well-reported phenomenon during
sepsis and is thought to contribute to the
development of immune suppression (reviewed by Oberholzer et al (77)). Similarly,
defective apoptosis of activated macrophages may lead to a prolonged inflammatory response. Recent data published by
Hudson et al. (61) link the actions of MIF to
the inhibition of the tumor suppressor p53.
These data were extended by Mitchell et al.,
who recently showed that MIF sustains
macrophage survival and proinflammatory
function by suppressing activation-induced, p53-dependent apoptosis (Mitchell
et al., manuscript in preparation). Macrophage apoptosis has been proposed to be a
significant contributor to the depression of
the host immune response late in sepsis
(78, 79). A likely scenario can now be envisaged, whereby MIF’s role in the innate
immune response is to prolong the life
span and activity of monocytes/macrophages.
SUMMARY
The diverse actions of MIF within the
immune system are yet to be fully understood, but it is clear that MIF plays a
pivotal role in the regulation of both innate and adaptive immunity. Elevated
levels of MIF are expressed in sepsis,
ARDS, and in a number of autoimmune
pathologies, including rheumatoid arthritis and glomerulonephritis. Of particular interest, it has been established that
in animal models of sepsis, anti-MIF
treatment protects from lethality, even
when administered as late as 8 hrs after
the onset of infection. This unique feature of anti-MIF treatment could prove to
be highly beneficial in the therapy of human sepsis if effective inhibitors of MIF
action can be developed. Recent studies
have begun to delineate the functional
effects of MIF within disease, and a
greater understanding of these mechanisms will provide novel targeting strategies for the treatment of various immunopathologies. In addition to inhibiting
MIF’s direct proinflammatory action,
successful therapies will likely also increase the immunosuppressive and antiinflammatory properties of glucocorticoids, thereby decreasing the need for
long-term steroid therapy in chronic inflammatory conditions.
REFERENCES
1. Bloom BR, Bennett B: Mechanism of a reaction in vitro associated with delayed-type hypersensitivity. Science 1966; 153:80 – 82
2. David JR: Delayed hypersensitivity in vitro:
its mediation by cell-free substances formed
by lymphoid cell-antigen interaction. Proc
Natl Acad Sci U S A 1966; 56:72–77
3. Churchill WHJ, Piessens WF, Sulis CA, et al:
Macrophages activated as suspension cultures with lymphocyte mediators devoid of
antigen become cytotoxic for tumor cells.
J Immunol 1975; 115:781–786
4. Nathan CF, Karnovsky ML, David JR: Alterations of macrophage functions by mediators
from lymphocytes. J Exp Med 1971; 133:
1356 –1376
5. Nathan CF, Remold HG, David JR: Characterization of a lymphocyte factor which alters
macrophage functions. J Exp Med 1973; 137:
275–290
6. Weiser WY, Temple PA, Witek-Giannotti JS,
et al: Molecular cloning of a cDNA encoding
a human macrophage migration inhibitory
factor. Proc Natl Acad Sci U S A 1989; 86:
7522–7526
7. Bernhagen J, Calandra T, Mitchell RA, et al:
MIF is a pituitary-derived cytokine that potentiates lethal endotoxemia. Nature 1993;
365:756 –759
8. Calandra T, Bernhagen J, Metz CN, et al: MIF
as a glucocorticoid-induced modulator of cytokine production. Nature 1995; 377:68 –71
9. Nishino T, Bernhagen J, Shiiki H, et al: Localization of macrophage-migration inhibitory factor (MIF) to secretory granules
within the corticotropic and thyrotropic cells
of the pituitary-gland. Mol Med 1995;
1:781–788
10. Bucala R: MIF rediscovered: Cytokine, pituitary hormone, and glucocorticoid- induced
regulator of the immune response. FASEB J
1996; 10:1607–1613
11. Leech M, Metz C, Bucala R, et al: Regulation
of macrophage migration inhibitory factor by
endogenous glucocorticoids in rat adjuvantinduced arthritis. Arthritis Rheum 2000; 43:
827– 833
12. Santos L, Hall P, Metz C, et al: Role of macrophage migration inhibitory factor (MIF) in
murine antigen-induced arthritis: Interaction with glucocorticoids. Clin Exp Immunol
2001; 123:309 –314
13. Sapperstein SK, Lupashin VV, Schmitt HD,
et al: Assembly of the ER to Golgi SNARE
complex requires Uso1p. J Cell Biol 1996;
132:755–767
14. Suzuki M, Sugimoto H, Nakagawa A, et al:
S33
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
S34
Crystal structure of the macrophage migration inhibitory factor from rat liver. Nat
Struct Biol 1996; 3:259 –266
Sun HW, Bernhagen J, Bucala R, et al: Crystal structure at 2.6-angstrom resolution of
human macrophage migration inhibitory
factor. Proc Natl Acad Sci U S A 1996; 93:
5191–5196
Jung H, Kim T, Chae HZ, et al: Regulation of
macrophage migration inhibitory factor and
thiol-specific antioxidant protein PAG by direct interaction. J Biol Chem 2001; 276:
15504 –15510
Sugimoto H, Taniguchi M, Nakagawa A, et al:
Crystallization and preliminary X-ray analysis of human D-dopachrome tautomerase.
J Struct Biol 1997; 120:105–108
Rosengren E, Bucala R, Aman P, et al: The
immunoregulatory mediator macrophage
migration inhibitory factor (MIF) catalyzes a
tautomerization reaction. Mol Med 1996;
2:143–149
Rosengren E, Aman P, Thelin S, et al: The
macrophage migration inhibitory factor MIF
is a phenylpyruvate tautomerase. FEBS Lett
1997; 417:85– 88
Kleemann R, Kapurniotu A, Frank RW, et al:
Disulfide analysis reveals a role for macrophage migration inhibitory factor (MIF) as
thiol-protein oxidoreductase. J Mol Biol
1998; 280:85–102
Zhang M, Aman P, Grubb A, et al: Cloning
and sequencing of a cDNA encoding rat Ddopachrome tautomerase. FEBS Lett 1995;
373:203–206
Bendrat K, Al-Abed Y, Callaway DJ, et al:
Biochemical and mutational investigations
of the enzymatic activity of macrophage migration inhibitory factor. Biochemistry 1997;
36:15356 –15362
Swope M, Sun HW, Blake PR, et al: Direct
link between cytokine activity and a catalytic
site for macrophage migration inhibitory factor. EMBO J 1998; 17:3534 –3541
Stamps SL, Fitzgerald MC, Whitman CP:
Characterization of the role of the aminoterminal proline in the enzymatic activity
catalyzed by macrophage migration inhibitory factor. Biochemistry 1998; 37:
10195–10202
Subramanya HS, Roper DI, Dauter Z, et al:
Enzymatic ketonization of 2-hydroxymuconate: specificity and mechanism investigated by the crystal structures of two isomerases. Biochemistry 1996; 35:792– 802
Lubetsky JB, Swope M, Dealwis C, et al: Pro-1
of macrophage migration inhibitory factor
functions as a catalytic base in the
phenylpyruvate tautomerase activity.
Biochemistry 1999; 38:7346 –7354
Swope MD, Lolis E: Macrophage migration
inhibitory factor: Cytokine, hormone, or enzyme? Rev Physiol Biochem Pharmacol
1999; 139:1–32
Deutsch JC: Determination of p-hydroxyphenylpyruvate, p-hydroxyphenyllactate and tyrosine in normal human plasma by gas chromatography-mass spectrometry isotope-
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
dilution assay. J Chromatogr B Biomed Sci
Appl 1997; 690:1– 6
Takahashi N, Creighton TE: On the reactivity
and ionization of the active site cysteine residues of Escherichia coli thioredoxin.
Biochemistry 1996; 35:8342– 8353
Puig A, Lyles MM, Noiva R, et al: The role of
the thiol/disulfide centers and peptide binding site in the chaperone and anti-chaperone
activities of protein disulfide isomerase.
J Biol Chem 1994; 269:19128 –19135
Hermanowski-Vosatka A, Mundt SS, Ayala
JM, et al: Enzymatically inactive macrophage
migration inhibitory factor inhibits monocyte chemotaxis and random migration.
Biochemistry 1999; 38:12841–12849
Calandra T, Bernhagen J, Mitchell RA, et al:
Macrophage is an important and previously
unrecognized source of macrophage-migration inhibitory factor. J Exp Med 1994; 179:
1895–1902
Waeber G, Thompson N, Chautard T, et al:
Transcriptional activation of the macrophage
migration-inhibitory factor gene by the corticotropin-releasing factor is mediated by the
cyclic adenosine 3',5'- monophosphate responsive element-binding protein CREB in
pituitary cells. Mol Endocrinol 1998; 12:
698 –705
Eickhoff R, Wilhelm B, Renneberg H, et al:
Purification and characterization of macrophage migration inhibitory factor as a secretory protein from rat epididymis: evidences
for alternative release and transfer to spermatozoa. Mol Med 2001; 7:27–35
Nakajima H, Hirata A, Ogawa Y, et al: A
cytoskeleton-related gene, uso1, is required
for intracellular protein transport in Saccharomyces cerevisiae. J Cell Biol 1991; 113:
245–260
Seemann J, Jokitalo EJ, Warren G: The role
of the tethering proteins p115 and GM130 in
transport through the Golgi apparatus in
vivo. Mol Biol Cell 2000; 11:635– 645
Bacher M, Metz CN, Calandra T, et al: An
essential regulatory role for macrophage migration inhibitory factor in T-cell activation.
Proc Natl Acad Sci U S A 1996; 93:
7849 –7854
Calandra T, Spiegel LA, Metz CN, et al: Macrophage migration inhibitory factor is a critical mediator of the activation of immune
cells by exotoxins of gram-positive bacteria.
Proc Natl Acad Sci U S A 1998; 95:
11383–11388
Satoskar AR, Bozza M, Rodriguez SM, et al:
Migration-inhibitory factor gene-deficient
mice are susceptible to cutaneous Leishmania major infection. Infect Immun 2001; 69:
906 –911
Abe R, Peng T, Sailors J, et al: Regulation of
the CTL response by macrophage migration
inhibitory factor. J Immunol 2001; 166:
747–753
Dai Z, Arakelov A, Wagener M, et al: The role
of the common cytokine receptor gammachain in regulating IL-2-dependent, activa-
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
tion-induced CD8⫹ T cell death. J Immunol
1999; 163:3131–3137
Martiney JA, Sherry B, Metz CN, et al: Macrophage migration inhibitory factor release
by macrophages after ingestion of Plasmodium chabaudi-infected erythrocytes: Possible role in the pathogenesis of malarial anemia. Infect Immun 2000; 68:2259 –2267
Bacher M, Meinhardt A, Lan HY, et al: Migration inhibitory factor expression in experimentally induced endotoxemia. Am J Pathol
1997; 150:235–246
Calandra T, Echtenacher B, Roy DL, et al:
Protection from septic shock by neutralization of macrophage migration inhibitory factor. Nat Med 2000; 6:164 –170
Bozza M, Satoskar AR, Lin G, et al: Targeted
disruption of migration inhibitory factor
gene reveals its critical role in sepsis. J Exp
Med 1999; 189:341–346
Echtenacher B, Falk W, Mannel DN, et al:
Requirement of endogenous tumor necrosis
factor/cachectin for recovery from experimental peritonitis. J Immunol 1990; 145:
3762–3766
Bacher M, Calandra T, Bernhagen J, et al:
MIF is an essential mediator of T-cell activation, is released from T-cells by glucocorticoids, and overrides glucocorticoid suppression of T-cell proliferation. J Cell Biol 1995;
1:64
Froidevaux C, Roger T, Martin C, et al: Macrophage migration inhibitory factor and innate immune responses to bacterial infections. Crit Care Med 2001; 29[7 Suppl]:
S13–S15
Beishuizen A, Thijs LG, Haanen C, et al:
Macrophage migration inhibitory factor and
hypothalamo-pituitary-adrenal function during critical illness. J Clin Endocrinol Metab
2001; 86:2811–2816
Joshi PC, Poole GV, Sachdev V, et al: Trauma
patients with positive cultures have higher
levels of circulating macrophage migration
inhibitory factor (MIF). Res Commun Mol
Pathol Pharmacol 2000; 107:13–20
Donnelly SC, Haslett C, Dransfield I, et al:
Role of selectins in development of adult
respiratory distress syndrome. Lancet 1994;
344:215–219
Powe JE, Short A, Sibbald WJ, et al: Pulmonary accumulation of polymorphonuclear
leukocytes in the adult respiratory distress
syndrome. Crit Care Med 1982; 10:712–718
Chollet-Martin S, Gatecel C, Kermarrec N, et
al: Alveolar neutrophil functions and cytokine levels in patients with the adult respiratory distress syndrome during nitric oxide
inhalation. Am J Respir Crit Care Med 1996;
153:985–990
Donnelly SC, Haslett C, Reid PT, et al: Regulatory role for macrophage migration inhibitory factor in acute respiratory distress syndrome. Nat Med 1997; 3:320 –323
Makita H, Nishimura M, Miyamoto K, et al:
Effect of anti-macrophage migration inhibitory
factor antibody on lipopolysaccharide-induced
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
pulmonary neutrophil accumulation. Am J Respir Crit Care Med 1998; 158:573–579
Rossi AG, Haslett C, Hirani N, et al: Human
circulating eosinophils secrete macrophage
migration inhibitory factor (MIF): Potential
role in asthma. J Clin Invest 1998; 101:
2869 –2874
Thomas LH, Warner JA: The eosinophil and
its role in asthma. Gen Pharmacol 1996;
27:593–597
Kay AB, Barata L, Meng Q, et al: Eosinophils
and eosinophil-associated cytokines in allergic inflammation. Int Arch Allergy Immunol
1997; 113:196 –199
Waeber G, Calandra T, Roduit R, et al: Insulin secretion is regulated by the glucosedependent production of islet beta cell macrophage migration inhibitory factor. Proc
Natl Acad Sci U S A 1997; 94:4782– 4787
Benigni F, Atsumi T, Calandra T, et al: The
proinflammatory mediator macrophage migration inhibitory factor induces glucose catabolism in muscle. J Clin Invest 2000; 106:
1291–1300
Hudson JD, Shoaibi MA, Maestro R, et al: A
proinflammatory cytokine inhibits p53 tumor suppressor activity. J Exp Med 1999;
190:1375–1382
Mitchell RA, Metz CN, Peng T, et al: Sustained mitogen-activated protein kinase
(MAPK) and cytoplasmic phospholipase A2
activation by macrophage migration inhibitory factor (MIF): Regulatory role in cell proliferation and glucocorticoid action. J Biol
Chem 1999; 274:18100 –18106
Bernhagen J, Calandra T, Mitchell RA, et al:
Purification and characterization of the cytokine macrophage- migration inhibitory
factor (MIF). FASEB J 1994; 8:A1417
Onodera S, Kaneda K, Mizue Y, et al: Macrophage migration inhibitory factor upregulates expression of matrix metalloproteinases in synovial fibroblasts of rheumatoid
arthritis. J Biol Chem 2000; 275:444 – 450
Meyer-Siegler K: Macrophage migration inhibitory factor increases MMP-2 activity in
DU-145 prostate cells. Cytokine 2000; 12:
914 –921
Leech M, Metz C, Hall P, et al: Macrophage
migration inhibitory factor in rheumatoid
arthritis: Evidence of proinflammatory function and regulation by glucocorticoids.
Arthritis Rheum 1999; 42:1601–1608
Denhardt DT: Signal-transducing protein
phosphorylation cascades mediated by Ras/
Rho proteins in the mammalian cell: The
potential for multiplex signalling. Biochem J
1996; 318:729 –747
Hayakawa M, Ishida N, Takeuchi K, et al:
Arachidonic acid-selective cytosolic phospholipase A2 is crucial in the cytotoxic action
of tumor necrosis factor. J Biol Chem 1993;
268:11290 –11295
Barnes PJ, Karin M: Nuclear factor-kappaB: A
pivotal transcription factor in chronic in-
Crit Care Med 2002 Vol. 30, No. 1 (Suppl.)
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
flammatory diseases. N Engl J Med 1997;
336:1066 –1071
De Bosscher K, Vanden Berghe W, Vermeulen L, et al: Glucocorticoids repress NFkappaB-driven genes by disturbing the interaction of p65 with the basal transcription
machinery, irrespective of coactivator levels
in the cell. Proc Natl Acad Sci U S A 2000;
97:3919 –3924
Scheinman RI, Cogswell PC, Lofquist AK, et
al: Role of transcriptional activation of I
kappa B alpha in mediation of immunosuppression by glucocorticoids. Science 1995;
270:283–286
Auphan N, DiDonato JA, Rosette C, et al:
Immunosuppression by glucocorticoids: inhibition of NF-kappa B activity through induction of I kappa B synthesis. Science 1995;
270:286 –290
Daun JM, Cannon JG: Macrophage migration
inhibitory factor antagonizes hydrocortisoneinduced increases in cytosolic IkappaBalpha.
Am J Physiol 2000; 279:R1043–R1049
Kleemann R, Hausser A, Geiger G, et al:
Intracellular action of the cytokine MIF to
modulate AP-1 activity and the cell cycle
through Jab1. Nature 2000; 408:211–216
Bernhagen J, Mitchell RA, Calandra T, et al:
Purification, bioactivity, and secondary
structure-analysis of mouse and human macrophage-migration inhibitory factor (MIF).
Biochemistry 1994; 33:14144 –14155
Ohmori Y, Hamilton TA: Regulation of macrophage gene expression by T-cell-derived
lymphokines. Pharmacol Ther 1994; 63:
235–264
Oberholzer C, Oberholzer A, Clare-Salzler M,
et al: Apoptosis in sepsis: A new target for
therapeutic exploration. FASEB J 2001; 15:
879 – 892
Williams TE, Ayala A, Chaudry IH: Inducible
macrophage apoptosis following sepsis is mediated by cysteine protease activation and
nitric oxide release. J Surg Res 1997; 70:
113–118
Ayala A, Urbanich MA, Herdon CD, et al: Is
sepsis-induced apoptosis associated with
macrophage dysfunction? J Trauma 1996;
40:568 –573
Chen H, Centola M, Altschul SF, et al: Characterization of gene expression in resting and
activated mast cells. J Exp Med 1998; 188:
1657–1668
Lan HY, Mu W, Yang NS, et al: De novo renal
expression of macrophage migration inhibitory factor during the development of rat
crescentic glomerulonephritis. Am J Path
1996; 149:1119 –1127
Lan HY, Yang NS, Brown FG, et al: Macrophage migration inhibitory factor expression in human renal allograft rejection.
Transplantation 1998; 66:1465–1471
Imamura K, Nishihira J, Suzuki M, et al:
Identification and immunohistochemical localization of macrophage migration inhibi-
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
tory factor in human kidney. Biochem Mol
Biol Int 1996; 40:1233–1242
Tesch GH, NikolicPaterson DJ, Metz CN, et
al: Rat mesangial cells express macrophage
migration inhibitory factor in vitro and in
vivo. J Am Soc Nephrol 1998; 9:417– 424
Bacher M, Meinhardt A, Lan HY, et al: MIF
expression in the rat brain: Implications for
neuronal function. Mol Med 1998; 4:217–230
Nishibori M, Nakaya N, Tahara A, et al: Presence of macrophage migration inhibitory
factor (MIF) in ependyma, astrocytes and
neurons in the bovine brain. Neurosci Lett
1996; 213:193–196
Suzuki T, Ogata A, Tashiro K, et al: Augmented expression of macrophage migration
inhibitory factor (MIF) in the telencephalon
of the developing rat brain. Brain Res 1999;
816:457– 462
Chesney J, Metz C, Bacher M, et al: An essential role for macrophage migration inhibitory factor (MIF) in angiogenesis and the
growth of a murine lymphoma. Mol Med
1999; 5:181–191
Shimizu T, Abe R, Nakamura H, et al: High
expression of macrophage migration inhibitory factor in human melanoma cells and its
role in tumor cell growth and angiogenesis.
Biochem Biophys Res Commun 1999; 264:
751–758
Onodera S, Suzuki K, Matsuno T, et al: Macrophage migration inhibitory factor induces
phagocytosis of foreign particles by macrophages in autocrine and paracrine fashion.
Immunology 1997; 92:131–137
Meinhardt A, Bacher M, McFarlane JR, et al:
Macrophage migration inhibitory factor production by Leydig cells: Evidence for a role in
the regulation of testicular function. Endocrinology 1996; 137:5090 –5095
Takahashi N, Nishihira J, Sato Y, et al: Involvement of macrophage migration inhibitory factor (MIF) in the mechanism of tumor
cell growth. Mol Med 1998; 4:707–714
Bernhagen J, Bacher M, Calandra T, et al: An
essential role for macrophage migration inhibitory factor in the tuberculin delayed-type
hypersensitivity reaction. J Exp Med 1996;
183:277–282
Mikulowska A, Metz CN, Bucala R, et al:
Macrophage migration inhibitory factor is
involved in the pathogenesis of collagen type
ii-induced arthritis in mice. J Immunol 1997;
158:5514 –5517
Leech M, Metz C, Santos L, et al: Involvement of macrophage migration inhibitory
factor in the evolution of rat adjuvant arthritis. Arthritis Rheum 1998; 41:910 –917
Lan HY, Mu W, Yang N, et al: Macrophage
migration inhibitory factor (MIF): A previously unrecognized kidney-derived cytokine
which participates in local macrophage accumulation and proliferation in the progression of rat anti-gbm glomerulonephritis.
Kidney Int 1997; 51:1313–1314
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