Antigen Capture and Presentation to Lymphocytes Flashcards
_____ protein displaced on surface of cells
MHC
_____ can recognize lipids, nucleic acids, and other types of molecules; mainly recognize proteins
Antibodies
___ t cells are involved in killing of infected cells
CD8+
Antigens are initially captured by ____ cells
Dendritic cells
Once antigens are captured, they are concentrated in ____ organs
Peripheral lymph organs
______: used in antigen presentation to naive T cells in the initiation of T cell responses to protein antigens (priming)
Dendritic cells
_____ are important for antigen presentation to by dendritic cells activate naive T cells
Costimulators
Besides dendritic cells, what are 2 other important APCs?
Macrophages and B lymphocytes
________ molecules are expressed on antigen-presenting cells and function to display peptides derived from protein antigens. Peptides bind to the molecules by anchor residues, which attach the peptides to pockets in the molecules. The receptor of every T cell recognizes some residues of the peptide and some (polymorphic) residues of the molecule.
Major histocompatibility complex (MHC)
_____ bind to the MHC molecules by anchor residues, which attach the peptides to pockets in the molecules.
Peptides
The receptor of every ____ recognizes some residues of the peptide and some (polymorphic) residues of the MHC molecule.
T cell
____ was originally founded via tissue graft matching
MHC
Polymorphic regions: a1 and a2
a3 binds T cell co-receptor
peptide-binding cleft for peptides 8-9 aa long
CD8+T cells
____ can only respond to antigen presented by MHC class I molecules
CD8+T cells
_____ can only respond to antigen presented by MHC class II molecules
CD4+T cells
Polymorphic regions: a1 and b1
a2and b2 binds T cell co-receptor
Peptide-binding cleft for peptides 10-30 aa long
CD4+T cells
Peptide-binding cleft for peptides 8-9 aa long in which T cell?
CD8+T cells
Peptide-binding cleft for peptides 10-30 aa long
CD4+T cells
T/F: Class I and class II MHC genes are the most polymorphic genes in the genome.
true
The total number of HLA alleles in the human population is estimated to be about ____ class I alleles and _____ class II alleles.
10,000 class I alleles and 3,000 class II alleles.
_____ expression of (MHC) alleles inherited from parents
Codominant
_____ genes: many different alleles are present in the population
Polymorphic genes
_______: both parental alleles of MHC gene are expressed
Co-dominant expression
____ feature of MHC molecules: many different peptides can bind to the same MHC molecule
broad specificity
____ feature of MHC molecules: class 1 and 2 MHC molecules display peptides from different cellular compartments
Peptides acquired during intracellular assembly
____ feature of MHC molecules: only peptide-loaded MHC molecules are expressed on the cell surface for recognition by T cells
Stable surface expression of MHC molecule requires peptide bond
____ feature of MHC molecules: MHC molecule displays bound peptide for long enough to be located by T cell
Very slow off-rate
______ recognize endogenous (cytosolic) antigen presented by MHC class I molecules on an infected cell
CD8+Cytotoxic T cells (CTLs)
______ exports peptides into ER to be recognized by MHC 1; also helps MHC 1 break free to be transported out to cell surface via golgi and exocytic vesicle
Tapasin
_______ recognize exogenous antigen presented by MHC class II molecules on a professional antigen presenting cell (APC)
CD4+ Helper T cells
Class I MHC-restricted cross-presentation of microbial antigens from infected cells by _____ cells
dendritic
Class ____ MHC effector functions: macrophage activation: killing of phagocytosed microbe; B cell antibody secretion: antibody binding to antigen
Class 2 MHC
Class ____ MHC effector functions: killing of antigen-expressing target cell
Class 1 MHC
