Overview and antibodies Flashcards
(49 cards)
Role of Immune system
host defense Discriminate self form non self (tolerance) Loss of tolerance leads to autoimmunity
Chemical barriers
lysozyome in secretions (splits cell walls of the Gm+ bacteria) Spermine in semen( prevents growth of Gm+ bacteria) Acid pH of the stomach(prevents colonization of bacteria
physical barriers to prevent pathogen entry
intact skin mucosal linings
Properties of antigens
-are foreign(NON-SELF) -chemically complex -molecular weight of 6Kd - has a particular sequence that is recognized by receptors on cells of the immune system called a Epitope/antigenic determinante/Determinant
Characteristics of adaptive immunity
-specific -memory- (you save cells so that your body will know how to deal with it) -lag time (for first encounter due to time for T Cell and B cell to change) -adaptivity(faster response with more exposure
Characteristics of innate immunity
not exquisitely specific -no memory -no lag time -no adaptivity
Cells of innate immunity
basophils, dendritic cells, eosinophils, mast cells, monocytes, macrophages, NKC, Neutrophils
Cells of adaptive immunity
B cells CD8+ T cells, CD4+ tcells and its subsets (Thp, 0,1,2,3,17, nTreg, a/iTreg
Primary immune tissue
Bone marrow- hematopoiesis of both myeloid and lymphod cells, ome cells emerge from bone marrow as precursors and differentiate in other tissue Thymus- progenitor t cells from bone marrow differentiate into naive mature cells in thymus ( nTregs, Thp, and pCTL)
Secondary Immune tissue
Lymph nodes, tonsils, adenoids, spleen, mucosa associated tissues MALT, GALT
MALT
unencapsulated tissues underlying mucosal areas -follicle associated lymphoid epithelium is a region without mucus -M cells located in the FAE -Mcells transport microbes to the lamina propria via vesicles - Lamina propria: phagocytes, dendritic cells lymphocytes are located here - organized aggregates in GALT are called Peyer’s patches GALT and BALT ( Broncus)
Intial site of primary immune response
depends on the route of pathogen Blood- spleen lymph- lymph nodes Mucosa- MALT GI tract- GALT
Cytokines
small peptides secreted mainly by activated leukocytes - critical for all aspects of immnity
Chemokines
smal peptides that induce leukocyte accumulation in tussues that have unique disulphide bonds
chemoattractant molecules
attract cells to a particular region without unique disulphide bonds
complement components
family of proteins that facilitate elimination of microorganisms particularly extracellular bacteria, proteins, activated by cleavage
antibodies
antibody isotypes Ig M, D, G, E , A which correpsond to Mu, Delta, Gamma, Epsilon, and Alpha are polypeptides, that are bifunctonal molelcues that bind antigen.
monomeric antibody
two identical light chains covelently linked to two identical heavy chains with each chain witha varible region and a constant region
dimeric, trimeric and pentameric forms
two three or five monomeric units
light chain constant regions
kappa or lambda
isotypes
IgA, IgD, IgE, IgG, and IgM with 5 different heavy chain constant regions named alpha, delta, epsilon, gamma, or mu
subclasses
antibodies have small differences in amino acid sequences in heavy chian constant region, unique properties ( IgG1, IgG2 , IgG3, IgG4, and IgA1, IgA2
allotypes
polymorphisms within an IgG or IgA constnat regions (Gm or Am)
bifunctional molecules
antigen binding site in variable region confers specificity, biological activity in the constnat region confers different roles for isotypes
