22-23 - Specific Immune Response: MHC & T Cell Recognition Flashcards
Which of the following statements is true and paired with the correct location (cell or humoral)…
a) B-lymphocytes and antibodies (cell mediated)
b) B and T lymphocytes (cell mediated)
c) B lymphocytes and antibodies (humoral)
d) T lymphocytes and antibodies (cell mediated)
Which of the following statements is true and paired with the correct location (cell or humoral)…
a) B-lymphocytes and antibodies (cell mediated) (This is humoral)
b) B and T lymphocytes (cell mediated) (only B)
c) B lymphocytes and antibodies (humoral)
d) T lymphocytes and antibodies (cell mediated) (Antibodies is incorrect)
In addition to killing virus infected cells, what other function do cytotoxic T cells perform?
Modulating the activity of other cells (e.g. B cells and T helper cells)
T cell receptors (TCR) are found:
a) In the T cell cytoplasm
b) In the T cell nucleus
c) On the T cell surface
d) On the T cell surface and in the cytoplasm
T cell receptors (TCR) are found:
a) In the T cell cytoplasm
b) In the T cell nucleus
c) On the T cell surface
d) On the T cell surface and in the cytoplasm
MHC stands for…
Major Histocompatibility Complex
MHC perform which two functions in relation to antigens?
Processing and presentation
MHC proteins can be divided into two groups…
Class I and Class II
Which of the following is a function of TCRs?
a) recognise unprocessed antigens presented by MHC
b) present unprocessed antigens for MHC
c) recognise antigens presented by MHC
d) present processed antigens for MHC
Which of the following is a function of TCRs?
a) recognise unprocessed antigens presented by MHC
b) present unprocessed antigens for MHC
c) recognise antigens presented by MHC
d) present processed antigens for MHC
Class I MHC is found on which cell types…
All nucleated cells (i.e. all cells except RBCs)
Class II MHC is expressed by which type of cell?
Antigen presenting cells (APCs)
Describe the key structural difference between MHC classes I & II…
MHC Class I has one transmembrane domain, whereas MHC Class II has two
The recognition of MHC/peptide (antigen) complexes by other cells enables which 3 immune functions?
- Destruction of virus infected cells
- Activation of macrophage
- Activation of B cells
Pair the receptors with their respective functions…
- Presentation of extracellular antigens
- Recognition of presented antigens
-
Presentation of intracellular antigens
a. MHC Class I
b. MHC Class II
c. TCR
Pair the receptors with their respective functions…
- Presentation of extracellular antigens b. MHC Class II
- Recognition of presented antigens c. TCR
- Presentation of intracellular antigens a. MHC Class I
Outline the process of presenting antigens of extracellular origin (4)…
- Antigen is uptaken into intracellular vesicle (endosome)
- Acidification activates proteases in endosome
- Vesicles fuse with MHC Class II vesicles
- Presentation
Name 3 types of antigen presenting cell (APC)…
- Dendritic cells (main APC)
- Macrophages
- B Cells
Describe the process of killing an infected cell, starting with recognition of MHC bound antigen fragments…
- MHC CI presents fragment of intracellular antigen
- Cytotoxic T cell binds to infected cell via MHC CI
- Perforin and granzymes involved in killing mechanism
Helper T cells (TH) perform which two functions?
Recognition of MHC CII presentation
Regulation of other cells via cytokines and cell-to-cell interactions
There are __ main types of helper T cell (TH)
There are 5 main types of helper T cell (TH)
Other than the 5 main types there are also naive T cells (TH0). Where are they found?
In the thymus
TH1 cells help macrophages eliminate…
Intracelleluar pathogens (which persist in macrophage vesicles)
TH2 cells recruit cells to target…
Extracellular parasites (e.g. helminths)
(cells such as eosinophils, mast cells and basophils)
TH2 cell secrete the cytokine ______ , which promotes killing of extracellular parasites by promoting production of ____ isotype and increasing expression of ________.
TH2 cell secrete the cytokine Interleukin 4 (IL-4) , which promotes killing of extracellular parasites by promoting production of IgE isotype and increasing expression of MHC Class II.
TH17 help kill ________ _______ & _____ via ____________ . They also recruit and recruit __________ .
TH17 help kill extracellular bacteria & fungi via antimicrobial peptides. They also recruit and recruit neutrophils.
TFH (Follicular helper) are involved in both Type 1 and Type 2 responses. They stimulate…
B cell differentiation and production of class-switched antibodies
Treg inhibits and regulates T cell activation to suppress the immune response. This is important in preventing…
Autoimmunity
What are the differences between the humoral vs cell-mediated adaptive immune response?
Humoral involves B lymphocytes and antibodies
Cell-mediated involves T lymphocytes
What do TCRs recognise?
MHC-antigen complexes
What kind of response is associated with TH2 cells?
Type 2
MHC molecules are encoded by which genes?
HLA genes:
- MHC I - HLA A, B, C
- MHC II - HLA DP, DQ, DR
MHC molecules are:
a) glycoproteins
b) proteins
c) glycolipids
d) polysaccharides
MHC molecules are:
a) glycoproteins
b) proteins
c) glycolipids
d) polysaccharides
The Ig-like domain of MHC I consists of which subunits?
α2, α3, α1 and β2-microglobulin
The Ig-like domain of MHC II consists of which subunits?
α1, α2, β1, β2
What is the function of the invariant chain in MHC II?
To keep the binding site clear for the peptide
MHC genes are expressed in what way, which provides what advantage?
Co-dominantly, which allows more combinations of peptides to be presented.
CD4+ cells are _______.
CD8+ cells are _______.
CD4+ cells are T helper cells (TH).
CD8+ cells are Cytotoxic T cells (CTL).
What co-receptor is present on the surface of helper T cells?
CD4
HLA genes are among the most…
Polymorphic in the human genome
Which MHC class has the highest number of different HLA proteins?
Class I
HLA stands for…
Human Leucocyte Antigen
(They are the type of MHC present in humans)
