10) MHC Flashcards
3 main Ag recognition molecules in the immune system
- TCR
- sIg
- MHC
2 main functions of MHC in T-cell response
- establish library of T-cells during development
- activation of mature T cells
2 best known MHC molecules
- human (HLA)
- mouse (H2)
MHC similar to Ig
MHC I
divided into 3 independent loci (A, B, C)
MHC I
3 variable portions of MHC I
𝛼1
𝛼2
𝛼3
invariant portion of MHC I
β2 microglobulin
MHC I AA length
8-9
binds to β2 microglobulin of MHC I
CD8
each individual expresses —- MHC I molecules
6
(2 HLA-A, 2 HLA-B, and 2 HLA-C)
subdivided into DP and DR
coding region for MHC II
consists of parallel transmembrane 𝛼 and β chains
MHC II
MHC II AA length
12-25
binds to invariant β region of MHC II
CD4
MHC II always expressed on…
B cells
dendritics
thymic epithelials
can be induced to express MHC II
T-cells
macros
group of complement factors found in serum
MHC III
what kind of Ag does MHC II present?
exogenous
internalized by endocytosis or phagocytosis
what kind of Ag does MHC I present?
endogenous
synthesized within the cell
MHC — presents antigens found in vaccines with a non-infectious viral particle
II
parameters to consider when trying to elicit an immune response
- amount of Ag
- timing of exposure
- route of entry
immunogenicity depends on…
- complexity of Ag/more epitopes
- foreign
- large enough
added to enhance immunogenicity of vaxx
adjuvant
time before Ab is detectable in serum
latent phase
(1-2 weeks)