Lymphocytes I Flashcards
Describe Innate immunity.
Consists of germline encoded receptors that recognize pathogens. Response is fast and non-specific; no memory (p.193)
What types of cells are involved in innate immunity?
Neutrophils, macrophages, dendritic cells, natural killer cells (lymphoid origin), and complement (p.193)
Describe adaptive immunity.
Consists of receptors that undergo V(D)J recombination during lymphocyte development to recognize pathogens. Response is slow on first exposure but memory response is faster and more robust (p.193)
What types of cells are involved in adaptive immunity?
T cells, B cells, circulating antibody (p.193)
What types of genes encode MHC?
HLA (human leukocyte antigen) genes (p.194)
What is the function of MHC class I and II?
To present antigen fragments to T cells and to bind TCRs (p.194)
What three haplotypes are associated with MHC I?
HLA-A, HLA-B, HLA-C (p.194)
To what does MHC I bind?
TCR and CD8 (p.194)
On what types of cells is MHC I expressed?
All nucleated cells (p.194)
On what types of cells is MHC I not expressed?
On RBCs (p.194)
How is antigen loaded onto MHC I?
Antigen is loaded in the RER with mostly intracellular peptides (p.194)
To what does MHC I pair?
Pairs with B2-microglobulin (p.194)
What is the function of B2 microglobulin-MHC I binding?
Aids in MHC I transport to cell surfact (p.194)
What type of immunity is mediated by MHC I?
Viral immunity (p.194)
What three haplotypes are associated with MHC II?
HLA-DR, HLA-DP, HLA-DQ (p.194)
To what does MHC II bind?
CD4 cells and TCR (p.194)
On what types of cells is MHC II expressed?
Expressed only on antigen presenting cells (p.194)
How is antigen loaded onto MHC II?
Antigen is loaded following release of the invariant chain in an acidified endosome (p.194)
By what mechanisms do NK cells induce apoptosis?
Through perforin and granzymes NK cells induce apoptosis of virally infected and tumor cells (p.194)
What cell type is the only lymphocyte member of the innate immune system?
Natural Killer (NK) cells (p.194)
What four types of cytokines enhance NK cell activity?
IL-2, IL-12, IFN-b, IFN-a (p.194)
What induces an NK cell to kill?
Exposure to a nonspecific activation signal on a target cell and/or absence of class I MHC on the target cell surface (p.194)
What are the four general functions of B cells?
To make antibody, to assist in type I hypersensitivity (allergy) reactions, to assist in cytotoxic and immune complex (types II and III) hypersensitivity, and to function in hyperacute and humorally mediated acute and chronic organ rejection (p.195)
What type of B cells opsonize bacteria and neutralize viruses?
What type of B cells opsonize bacteria and neutralize viruses?
