The Potential of
Attenuated Mycobacterium tuberculosis or BCG Vaccines
to Enhance Oral SIV Acquisition
in Infant Macaques
IAS Meeting-Vancouver
July 22, 2015
No Disclosures
Kristina De Paris, PhD
UNC Chapel Hill
Prevention of Mother-To-Child-Transmission of HIV-1
+ Tuberculosis
Infection rate: 3% of children / year
Median age: 12-15 mo.
HIV-TB co-infection: 30-50%
Breast milk transmission of HIV-1
- administration at birth (PO / ID)
- immunogenic
- risk of dissemination in HIV+ infants
BCG
Pediatric HIV-TB Combination Vaccine
Auxotroph rMtb-HIV vaccines, administered at birth, may
present a safe alternative to BCG that could protect against oral
HIV-1 acquisition and TB infections.
An auxotroph mutant of human-adapted M. tuberculosis H37Rv
(i) is attenuated for replication and pathogenicity,
(ii) can be manipulated for increased immunogenicity, and
(iii) modified to express HIV antigens.
mc26435: ΔleuCDΔpanCDΔsecA2:pSIV Gag/pSIV Env/pSIV Pol
Jensen et al., 2012 and 2013
Repeated Low-Dose Oral Challenge Model (SIVmac251)
Mock Vaccine (Group A)
Log10 SIV RNA copies/ml Plasma
06/04
10
08/12
9
108
107
- recapitulate repeated
exposure to HIV-1 in
breast-feeding infants
- start at 9 weeks of age
106
105
Vaccine Efficacy:
104
sterilizing immunity
or
partial efficacy
(No. of SIV exposures)
103
102
101
1
2
3
4
5
6
7
No. of SIV Exposures
8
9
10
Probability of infection / exposure = 0.246
n=15
Challenge Outcome in Vaccinated Infant Macaques
rMtb-SIV/ rMtb-SIV
rMtb-SIV/ MVA-SIV
Mtb-SIV/MVA-SIV Vaccine
109
Log10 SIV RNA copies/ml Plasma
Log10 SIV RNA copies/ml Plasma
Mtb-SIV/Mtb-SIV Vaccine
108
107
106
105
104
4/6
103
102
101
9
11
13
15
17 19 21 24
Age (weeks)
29
- rMtb-SIV at birth (PO)
- homologous boost (ID): wk. 3
34
109
108
107
106
105
104
7/8
103
102
101
9
11
13
15
17 19 21 24
Age (weeks)
29
34
- single rMtb-SIV at birth (PO)
- heterologous boost (IM): wks. 3+6
Vaccine-induced Enhancement of Infection?!
Repeat and Confirm:
109
15/19
Independent of:
108
107
106
strain,
route,
boost, and
SIV inserts.
105
104
Mtb
103
Mtb-SIV/Mtb-SIV
Mtb-SIV/MVA-SIV
102
101
BCG (ID)
1
2
3
4
5
6
7
No. of SIV Exposures
8
9
Probability of infection / exposure:
Mtb vaccines 0.340
BCG
0.353
10
BCG Vaccine (ID)
Log10 SIV RNA copies/ml Plasma
Log10 SIV RNA copies/ml Plasma
Mtb
Vaccine
Mtb Vaccine
(PO)
109
108
107
106
105
6/7
104
103
102
101
1
2
3
4
5
6
7
No. of SIV Exposures
8
9
10
Oral SIV Acquisition
Probability of Infection
90
Biological Significance
80
70
1.4-fold risk enhancement
NS
60
50
40
Mean Exposure to SIV Infection
30
10
Mock
Mtb
BCG
20
10
0
0
1
2
3
4
5
6
7
No. of SIV Exposures
8
STAT Trivia:
To detect a 1.65-fold higher risk
with 80% power,
45 animals/group are required.
9
No. of SIV Exposures
Percent Infected Animals
100
10
8
6
4
2
0
Mock
Mtb
BCG
Oral SIV Acquisition Risk
Probability of Infection
- enhanced infection risk
in two separate studies
90
80
70
60
50
40
Peak
PeakViremia
Viremia
30
Mock
Mtb
BCG
20
10
0
Log10 SIV RNA copies/ml Plasma
Percent Infected Animals
100
0
1
2
3
4
5
6
7
No. of SIV Exposures
8
…and increased peak viremia (BCG)
9
p=0.0270
9
p=0.0042
8
10
7
6
5
Mock
Mtb
BCG
Systemic Immune Activation (TOC)
MCP-1
MCP-1
100
p<0.050
37-plex (NHP)
MCP-1 [pg/ml]
80
- only 4 differ!
p<0.001
60
40
20
0
Mock
Mtb Vaccine
BCG
2.0
sCD163
sCD163
p=0.011
1.5
1.0
0.5
0.0
-0.5
Mock
Vaccine
Plasma sCD163 Ratio Wk 9: Wk 0
Plasma sCD14 Ratio Wk 9: Wk 0
sCD14
sCD14
2.5
p=0.0402
2.0
1.5
1.0
0.5
0.0
Mock
Vaccine
Increased Monocyte Activation + Function
50
p=0.0366
Blood and Tissues
Persistence up to 18 wks.!
p=0.0003
40
Monocytes/ Macrophages
30
20
10
0
CCR5
CCR5
CD69
CD69
TNF-a+ CD14+ (%)
CCR5+ or CD69+ CD14+ Cells (%)
Monocytes
102
72
42
12
12
TNF-a
p=0.0168
p=0.0256
Ax. LN
Subm.LN
p=0.0025
9
6
3
0
PBMC
PBMC
Tonsil
Ax.LN Subm.LN Tonsil
Target cells of mycobacteria: monocytes/ macrophages and DC
Vaccine-induced CD4+T Cell Activation
96
Increased SIV target cells at TOC?!
p=0.0038
72
48
( Ki67, CD69, PD-1 )
24
12
9
6
50
3
0
Ki-67
60
Mock
Mtb
BCG
Potential Viral Entry Sites
(16-18 wks.)
CD4+Ki67+T Cells (%)
Expression Ratio (Wk 9:Wk 0)
CCR5+CD4+ T
p=0.0001
p=0.0466
p<0.0001
40
30
20
20
15
10
5
0
Mock
Mtb
PBMC
PBMC
Mock
Mtb
Retropharyngeal LN
Mock
Mtb
Retrophar.LN Colon
Colon
Summary
Mtb- and BCG-based vaccines
 cause persistent immune activation of myeloid cells (monocytes/ mDC),
 increase the numbers of potential SIV/HIV target cells, and thereby
 may enhance risk of oral SIV/HIV acquisition, and
 alter challenge outcome as immune activation persists even post-challenge.
 Enhanced risk of oral SIV infection was not associated with genetic markers.
Supporting Evidence from HUMAN Studies
 BCG-induced “trained immunity” (Netea)
- epigenetic changes in monocytes enhance functional capacity
- increased responsiveness to mycobacterial and unrelated Ags for up to 1 yr!
consistent with the persistent increased functional capacity of
monocytes and mDC in vaccinated infant macaques
 BCG – risk factor for HIV?
- BCG vaccination in SA infants results in increased CCR5+CD4+T cells (Jaspan
- Mtb-exposed CD4+T cells show increased HIV-1 infection in vitro (Page)
consistent with increased CD4+T cell activation in blood and tissues of
infant macaques vaccinated with Mtb or BCG vaccines
Potential Health Impact
 TB vaccine development:
- auxotroph BCG and auxotroph Mtb strains, similar to our strain
- combination HIV-BCG vaccines are being tested
(Hanke, Joseph, Williamson)
Protective efficacy against TB infection
 BUT: Safety risk for pediatric population?
- increased susceptibility to oral HIV-1 infection
- increased morbidity due to higher viremia and
persistent immune activation
- include testing for immune activation in TB vaccine
safety assessment
THANK YOU to:
De Paris Lab
rMtb Vaccine
Kara Jensen
Michelle Larsen
Glenn Fennelly
Bill Jacobs
Uma Ranangathan
Myra dela Pena
Maggie Conner
Michael Mengual
Neelima Choudhary
Virology
Michael Hudgens
Katie Mollan
Mike Piatak
Jeff Lifson
LSUHSC
CNPRC
Koen Van Rompay
Veterinary Staff
Pam Kozlowski
Robert Wilson
Histology
Jake Estes
Carissa Lucero
Angela Amedee
NIH: R01 DE019064 and R01 DE019064-S1 to ML, GF, and KDP
NIH HIV/ AIDS and TB Program Officers