Diseases of Immunity Pt 1 Flashcards
Innate Immunity definition
pre-esixting defense against pathogens
Components of innate immunity
barrier defense, neutrophils, dendritic cells, NK cells, complement proteins
Adaptive immunity definition
specific, programmed defense in response to ag presence
Components of adaptive immunity
lymphocytes!!!
Physical barriers of innate immunity
skin, ciliated epithelium in tracheobronchial tree
Chemical barriers of innate immunity
saliva, tears, gastric acid
Three main PRRs
Toll like receptors, NOD-like receptors, C-type lectin receptors
TLRs culminate on what transcription factors?
NF-kB and interferon regulatory factors
NOD-like receptors signal via what protein
inflammasome
Action of inflammasome
activates caspase-1 that cleaves precursor of IL-1 to biologically active form
C-type lectin receptors detect what?
Fungal glycans
Reactions of Innate immunity
inflammation, antiviral response, complement
Function of bone marrow in adaptive immunity
generation of lymphocyte stem cells and B cell maturation, primary site of hematopoiesis
Function of thymus in adaptive immunity
maturation of T lymphocytes
Function of lymph nodes in adaptive immunity
lymphocytes can interact with APCs and antigens in circulating lymph
Function of spleen in adaptive immunity
lymphocytes can interact with blood-borne antigens
Function of MALT in adaptive immunity
allow lymphocytes and plasma cells to be in the vicinity of antigens within mouth and intestinal tract
Cellular components of bone marrow
erythroid precursors, megakaryocytes, lymphocytes, neutrophils, adipocytes
T cell migration through the thymus
cortex to medulla
The medulla contains what types of cells?
Maturing T lymphocytes, dendritic APCs, Hassall corpuscles (squamous cell nests)
APCs interacting with lymphocytes in the lymph node trigger what cell processes?
t and b cell clonal expansion, b cell differentiation into plasma cells, migration of T cells and plasma cells into circulation
Role of Helper T cell in adaptive immunity
activate macrophages, inflammation, activation of T and B lymphocytes
Role of cytotoxic T cells in adaptive immunity
killing of infected cell
Role of regulatory T cell in adaptive immunity
suppression of immune response
What cells express MHC Class I?
All nucleated cells and platelets
What cells express MHC Class II?
antigen presenting cells
What antigens do MHC class I peptides recognize?
Intracellular (viral or tumor)
What antigens do MHC class II peptides recognize?
Extracellular (allergens or bacterial)
How are antigens processed to create MHC Class I peptides?
Ags broken down by proteasome and transported to ER where they are loaded into MHC and moved to the cell membrane
What cells recognize MHC Class I?
CD8 cytotoxic T cells
How are antigens processed to create MHC Class II peptides?
antigens are broken down by endolysosomal enzymes and vesicles form with the peptides and MHC II
What cells recognize MHC Class II?
CD4 helper T cells
Regions and chromosome that code for MHC?
6 regions on chromosome 6; HLA-A, HLA-B, HLA-C, HLA-DP, HLA-DQ, HLA-DR
Heterogeneity in HLA haplotypes can be recognized in what ways?
differences in fighting off illness, differences in allergic sensitivities
Clinical importance of HLA heterogeneity?
transplanted organs, associated autoimmune diseases