Nelson- Hypersensitivity Flashcards
What is innate immunity?
Pre-existing, non-specific defense mechanism, present prior to infection. Evolved to recognize PAMPS and DAMPS and protect individual from infection.
What is adaptive immunity?
Reactive mechanisms stimulated by specific microb capable of recognizing microbial and non-microbial substances.
What are some of the component of innate immunity?
Epithelial barriers phagocytic cells Eosino, Baso, mast NK Plasma proteins (complement)
What are the two types of adaptive immunity?
Humoral- extracellular microbes and toxins
Cell-mediated- intracellular microbes, tumor cells
What are naive lymphocytes?
mature lymphocytes which haven’t yet encountered the antigen they’re specified for
What are activated lymphocytes? (2 type)
differentiate into effector cells that eliminate the pathogen and memory cells that are reactivated upon second exposure.
Function of CD4 T cell
Secrete cytokines, help B cells become plasma cells
Function of CD8 T cell
kill virus infected cells, neoplastic and donor graft cells
Function of B lymphocyte
differentiate into plasma cells that produce IG to kill encapsulated bacteria and act as APCs w/ CD4 cells
Function of NK
kill virus infected and neoplastic cells
release IFNy
Function of macrophage
phagocytosis and cytokine production
APCs for T cells
Function of DC
APCs to T cells
What are generative lymphoid organs?
Sites where T and B lymphocytes mature and become competent to respond to antigens
What are peripheral lymphoid organs?
Sites where the adaptive IR is initiated (lymph nodes and spleen)
B cells in follicles
T cells in paracortical regions
HLA-A, B and C genes code for what class of MHC. What does that MHC do?
MHC I
Display proteins derived from the cytoplasm
Recognized by CD8 T lymphocytes and NK cells
HLA-DP, DQ, DR genes code for what class of MHC. What does that MHC do?
MHC II
Display antigens that have been internalized into vesicles
Recognized by CD4 T lymphocytes
What are the two reasons we do HLA testing?
Diseases are associated w/ the inheritance of HLA alleles. HLA testing is used to determine disease risk.
HLA testing is also used in transplantation work up. Close matches increase chances of graft survival.