dont know at all Flashcards
L4- decreased oxygen tension impact?
link to L16- Hypoxia shifts macrophages to an M1 phenotype which is pro-inflammatory. this enhances their ability to secrete pro-inflammatory cytokines: TGF-alpha and IL-6. Amplifies inflammation.
prolongs neutrophil survival and ROS production?
L4- what activates mast cells?
link to L3- Activated by c5a/c3?
L7- immune synapse?
Different types of Immune Synapses (stimulatory synapses):
Th cell + B cell
Naïve T cell + APC
B cell + APC
Lytic Immune synapses
- CD8 cytotoxic T cell + Infected cell
Advantages of immune synapses:
IS stabilises cell-cell contacts to allow more receptors to bind to their ligands
Increased stability of the synapse facilitates signalling by lower affinity antigens
Physical separation of activating and inhibitory molecules
Directed secretion of cytokines and other molecules (secretory synapse)
L7- what are ITAMS?
ITAM (Immunoreceptor Tyrosine-based Activation Motif) in their cytoplasmic domains
ITAM contains tyrosine residues that can be phosphorylated for downstream signalling.
Cognate (specific) antigen binds to immunoglobulin causing signalling.
L7- What do CD79a and CD79b do?
CD79a and b help:
Bring BCR to cell surface
Regulate BCR movement
Key Concept
The immunoglobulin needs CD79a/b to:
Signal
Move to cell surface
Initiate immune response
L7- B and T cell changes upon activation?
When activated more of blast cells? (possible link to L12) Enter cell cycle, bigger, condensation of chromatin to facilitate more gene transcription, expand rough and smooth er to produce more proteins. Divide up to 4 times a day which drives clonal expansion. B cells become antibody secreting cells. Effector t cell has condensed chromatin, produce cytokines: cd4 or cd8.memory cells look like small resting lymphocytes.
L7- what does syk stand for and what family do FYN, LYN BLK belong to? what does the phosphorylation of ITAMS cause?
Src Kinases: Sarcoma (src) pro-oncogene family members
Antigen-Induced Activation:
Syk (Spleen Tyrosine Kinase)
phosphorylating ITAMS leads to Trans-phosphorylation occurs due to:
Clustered BCR proximity
Neighboring cells in close contact
Syk kinases phosphorylate neighboring Syk molecules
L8- how do ROS kill?
Oxidative burst initiated by enzyme nox2 (NADPH oxidase 2) triggers cascade where different radicals of oxygen are produced. Nox2 is multisubunit enzyme complex assembles in membrane, nadph is its cofactor, nadph delivers a electron that is transferred through the membrane on a moleculcular oxugen leading to a super reactive superoxide. Immediatley react with proteins , ipids, dna , rna other radicals. Oxidate everything so destory function of molecule. Superoxide spontaneously or mediated by superoxide dis? To form h2o2 and mpo enzyme convert h2o2 to hocl.
L8- what are the antimicrobial peptides and proteases in neutrophil granules?
Neutrophil granules contain antimicrobial peptides and proteases like LL-37, cathepsin G (CG), and azurocidin, which also act as chemoattractants, recruiting immune cells to infection sites.
L9- TCR diversity in segments vs innate?
T cell receptor: cd4 t cell with its co receptor and its signalling domains at the bottom.
Innate Receptors (e.g., Toll-like receptors - TLRs):
These receptors are germline-encoded as complete, functional genes without requiring recombination.
for tcr there are multiple copies of the gene segments. For the alpha chain there are over 100 different variable parts and over 50 joining (J) And for beta chain there are over multiple copies of the segments of genes that make up the tcr. This is how you get diversity of the tcr. (one of the reasons)
