Cell biology and immunology
Lecture 1 first lecture - cytotoxicity and the study of the cell / recording_1
Biomaterial = any material used in the body to achieve a therapeutic or diagnostic purpose.
Can be used inside as well as outside the body
Biocompactibilty = ability of a biomaterial to perform its desired function with respect to a
medical therapy, without eleciting any underiable local or systemic effects in the recipient or
beneficiary of that therapy, but generating the most appropiate beneficial cellular or tissue
response in that specific situation, and optimising the clinically relevant performance of that
therapy
Cytoxciity = means something is toxic to the cyto/cell part
Cell culture = Proces by which cells are grown in controlled conditions outside of its native
environment
Types of cytotoxicity
1. Extract testing (37 C)
orange is median
Green is material
Cultured median is added
to the cell, so no adding of
cells to median
Energy source  mitochondria:
glucose + oxygen
2. Direct contact testing  hard to say if something is toxic
3. Indirect contrast testing
cultured well and disc with cells
Types of responses
1. Amputee response = metabolic response, originated from the mitochondria, uses
oxygen and glucose for ATP
2. Cell coloration – opposite is cell death
to the right (Volt):
the lower the concentration  the less toxic for the cells  more metabolic active the cells
become
fibronectin = formenend member of the extracellular matrix, protein, very adhesive meaning
cells like to bind to it
Lecture 2 - Cell study and visualization / recording_1
Cell deviation methods
Tumor cell
 Unlimited survival
 Unlimited deviation
Normal differentiated cell
 Limited survival change
 Limited deviation
Hybrid cells  best of both
 Powerful producer of biological factors
 For use of ea. Antibodies
spins really hard  larger parts will go down faster than lighter ones
Spins  different densities will go down, ea. nucleus heavy or mitochondria
different densities (gr/ml) different layers
Types of columns/matrices
Protein
 Building blocks
 Structure cell
PCR  separating protein mix based on molecular weight
Peptide = Protein cut into smaller pieces with enzymes
Mass spectrometry identify protein (fingerprints)
A detergent = a surfactant or a mixture of surfactants with cleansing properties when in
dilute solutions
- Often charged
- Remove lipids
Anisotropy = has preferred direct
Isotropy = no preferred direction
Lecture 3 - Cell signalling / recording_1
One signal can have different effect -same receptor- different intracellular signaling and
effector proteins, and therefore genes targeted
Types of cell surface receptors
1. Ion channel-coupled receptors
2. G-protein-coupled receptor
3. Enzyme-coupled receptors
Phosphorylation events drive the signal cascade – protein kinase activity switches a protein
towards another state, phosphatase activity does the opposite
Types of protein kinases
1. Majority: serine/threonine kinases
2. Other: tyrosine kinases
3. GTP: binding proteins
A double negative activation is a positive activation
dynamic range = what kind of concentrations lead to a response
persistence = how long does respond hold
signal processing / integration = how does cell combine different
signals at same time
Fast response  seconds minutes, protein only need to alter already existing proteins
Slow response  minutes hours, must make new proteins
G-protein receptors: neurotransmitters bind to receptor  instead of immediately opening
an ion channel  activation of intermediate protein called a G-protein  G-protein can
influence the opening of ion channels and also affect enzymes and activate intracellular
signaling molecules known as second messengers which can initiate signaling cascade within
cell
- Slower action
- Effect more widespread due to ability to influence molecules around a cell
Central theme in signaling:
Second messengers and enzymatic cascades amplify the signal. Inactivation mechanisms are
rapid
Lecture 4 - Mitochondria/ recording_1
Ras = Rat sarcoma virus, is a family of related proteins that are expressed in all animal cell
lineages and organs. All Ras protein family members belong to a class of protein called small
GTPase and are involved in transmitting signals within cells (cellular signal transduction).
- Lipid groups anchor the Ras to the membrane space
- Ras is needed for proliferation and differentiation
- In 30% of tumors Ras mutant is found
- Ras inactive  bound to GDP
- Ras active  GDP switched for GTP
Integrins are the principal receptors used by animal cells to bind to the extracellular
matrix.
Mitochondria  energy conversion
- ATP production by oxidative phosphorylation
- In chloroplast by photosynthesis
- Has own DNA; encoding a subset of proteins, but they are not stand-alone
- Chemiosmotic coupling = energy store created by an electrochemical proton gradient
across the membrane
- Electron transport chain embedded in a membrane
- H+ protons flow back through ATP synthase membrane associated protein machine
- Buffering of redox potential in cytosol = recycling of electron acceptor NAD+
- Urea cycle = mitochondria in liver cells
Intermembrane space
- No difference in pH and ionic composition with cytoplasm  no electrochemical
gradient across the outer membrane
- In cristae ± 75 precent of membrane is protein  increases availability oxidative
phosphorylation
Fuel = fatty acids and pyruvate
Input Kreb cycle / citric acid cycle = acetyl CoA
Chemiosmotic coupling:
Electron generation carried by NADH  NADH transfers electrons into the electrontransport chain  proton gradient serves to generate ATP
Redox potential
Because of infinity electrons flow – (low) + (high)
In membrane cristae:
Lecture 5 - the foreign body response / recording_1
Biocompatibility = the ability of a material to perform with an appropriate host response in a
specific application
No immunotoxicity = implant must not elicit an adverse immune response from the host
Bio in earth = does not evoke response from the host , no interaction
Unwanted Foreign Body Reaction effects
1. Too early resorption of biomaterial → may lead to autologous tissue incompletely
restored
2. Implant loosening → eg hip prosthesis due to infection or wear and tear
3. Chronic inflammation → priming immune system or hyper-sensitivity
solutions:
1. Modification of the materials → eg coatings
2. Modification of the FBR → ‘downregulation’ of the inflammatory reaction
Step 1: protein adsorption
Protein coating = adsorption or proteins to a surface creates a new surface
until blue line = wound
healing
Bioreaction - short and long term
when stay horizontal = chronic wound healing
Implantation of biomaterial always followed by 2 types of inflammatory responses
1. Wound healing
2. Foreign body reaction
Lecture foreign body response continued / recording_1
Macrophages vs granulocytes (= can phagocytose and destroy infectious agents)
 Granulocytes  nucleus split up in multiples nuclei
 Macrophages  single round shape nucleus (can fuse together to form giant cell,
frustrated)
Giant cells:
- No role in phagocytoses
- Anti-inflammatory
Main players in FBR: macrophages and foreign body giant cells 
When macrophages encounter a foreign object too large to be phagocytosed, they fuse to
form larger ‘foreign body giant cells’
Macrophages
Cross-linked collagens with different FBR:
1. HDSC (zeemleer) complete degraded within one month
2. GDSC (zeemleer) hardly any degradation after one month
(Biomaterials can modulate own degradation time)
M-CSF macrophages colony stimulating factor  activating stem cells  activate forming
monocytes  more macrophages
MaFIA mouse
-
Macrophages and fibroblasts orchestrate the FBR in a joint fashion
Their response can be modulated
Their response must be taken seriously also when scaffolds are being used for RM
Lecture 6 - Macrophages / recording_1
Implantation of biomaterials gives inflammation
Implantation of a biomaterial is generally accompanied by two types of inflammatory
responses:
1. Wound healing process
2. Foreign body reaction
In vivo = in body
In vitro = in reageerbuis
Degradation of pTMC by macrophages
- Macrophages but not fibroblasts degrade pTMC in vitro (oxidative and enzymatic
degradation)
- Rates not always consistent with in vivo
- Oxidative = super anions
- Enzymatic = choleretic esterase
- Degradation by surface erosion
To create in vitro model  establishing the role of enzymes and reactive oxygen species in
an in vitro model of macrophages-mediated degradation of poly network films
Lecture 7 - Adaptive immunity / recording_1
Pattern recognition receptors  including toll-like receptors = pathogen-recognizing
receptors recognize PAMP’s located on cell surface or in endosome vesicles including inferno
b-signaling pathways
Lysosoom = afvalberg van de cel, breken afvalstoffen van cel af voor hergebruik of
uitscheiding
- Important inside macrophages for phagocytosis
Dendritic cells - are experts at immune
- Antigen components are trimmed to suitable sizes and displayed in conduction with
MHCs 1 and 2 on the surface of the antigen-representing cells
- MHC gene cluster yields both MHC class 1 and 2 molecules



All nucleated cells contain MHC 1
Only professional APCs (DC, macrophages, B cells) contain MHC 2  encage CD4+ to
amplify immune response
Intercellular signaling by chemokines and cytokines
Pathogen = foreign infectious microbes that cause sickness
Antigen = a molecule that induce a specific immune response
Antibody = y-shaped protein that are specific and match antigen  after connecting they
can be detected and destroyed by white blood cells
Innate – receptors with broad specificity
Adaptive – receptors with single specificity
T-helper (CD4+)  producing cytokines (control growth and activity of other immune
systems and blood cells like T helper cells) after negative feedback shut down immune
response and inflammation
Tc (CD8+)  kill virus-detected cells
B-cells development in bone marrow; B cell surface receptors is an antibody. Different
into plasma cells > antibody secretion
Antibodies = immunoglobins or Igs
MHC 1 = CD8 T cells
MCH 2 = CD4 T cells
Cell-based = memory cells stay in body after immune response
Spleen and lymph nodes  have lot of immune cells, memory cells, T cells
Adaptive immunity continued / recording_1
Cytosolic = antibodies ineffective here. NK cells and cytotoxic T cells role of Th cells and
infernos
Central tolerance  tolerance develops of signal strength, strong signal leads to inactivation
Peripheral tolerance  outside primary organs a plethora of mechanisms; anergy, apoptosis.
Ignorance, receptor editing
Stents and cell biology of the blood vessel wall / recording_1
Thrombosis / occluding vessel = when a blood clot forms in a vessel
1. Interior of the vessel
2. Neointima/ new part of vessel
3. Original vessel wall
Stem cells and tissue renewal / recording_1
Stem cells = cells from which all other cells with specialized functions are generated
Self-renewal = the ability to go through numerous cycles of cell division while maintaining
the undifferentiated state
potency / differentiation = the ability to differentiate into specialized cell types. Requires
stem cells to be totipotent or pluripotent, to be able to give rise to any mature cell type,
although multipotent or unipotent progenitor cells are sometimes referred to as stem cells
Classification:
1. Embryonic stem cells
2. Fetal stem cells – including amniotic stem cells (baby’s amniotic fluid/vruchtwater)
3. Umbilical stem cells (cord blood)
4. Adult stem cells (bone marrow, adipose tissue – vetweefsel, blood)
5. Induces pluripotent stem cells (iPS cells)
Stem cells 
- Immunological responses
- Stem cells niche (place where stem cells remain stem cells)
- Potential of (early) banking of cells
- Determination of phenotype i.e., differentiation state
Bone marrow