T and B cells recognize specific antigens, memory cells

red bone marrow

cytotoxic T cells, helper T cells

contains CD8 protein receptors on their surface and have X ray vision, able to see inside our bodies own cells simply by scanning their surface , hunt down and destroy cells that are infected with germs or that have become cancerous

contain CD4 protein receptors on their surface and orchestrate an immune response, Help activate B cells to secrete antibodies and macrophages to destroy ingested microbes , help activate cytotoxic T cells

cell mediated immunity, antibody mediated immunity

involves the production of cytotoxic T cells that directly attack invading pathogens, memory T cells are also produced

involves the production of B cells that transform into antibody making plasma cells, Antibodies (Ab) (immunoglobulins) circulate in extracellular fluids and B memory cells are also produced, Helper T cells aid immune responses of both types of adaptive immunity

the process by which a lymphocyte proliferates and differentiates in response to a specific antigen

effector cells- (the active helper T cells, active cytotoxic T cells, and plasma cells) result in destruction or inactivation of antigen, memory cells- do not participate in the initial immune response but are able to respond to a subsequent exposure

capable of producing an immune response , antibodies recognize certain epitopes on the antigen

proteins that are used as cell markers to flag self from non-self

help T cells recognize that an antigen is foreign

they are built into almost all body cells , used to present non-self proteins (from bacteria or viruses, for example) to cytotoxic T cells (used to recognize foreign antigens on inside of cell)

only found on surface of antigen-presenting cells (APCs) (used to recognize foreign antigens on outside of cell)

ingestion of the antigen, digestion of antigen into peptide fragments, fusion of vesicles, binding of peptide fragments to MHC-II molecules, insertion of antigen MCH-II complex into the plasma membrane

MHC-II

digestion of antigen into peptide fragments , synthesis of MHC-I molecules, antigen peptide fragments bind to MHC-I molecules, packaging of antigen MHC-I molecules into a vesicle, vesicle undergoes exocytosis and antigen MHC-I complexes are inserted into plasma membrane

MHC-I

antigen recognition- TCR with CD4 or CD8 protein, costinulation- T cell becomes activated only if it binds to foreign antigen and at the same time receives this costimulation signal

1. recognize exogenous antigen fragments associated MHC-II molecule at surface of APC, 2. costimulation, 3. once activated helper T cells undergo clonal selection , 4. quickly proliferate and differentiate into more active cytotoxic T cells and more memory cells

a large Y shape protein produced by plasma cells

2 heavy chains (450 amino acids), 2 light chains (220 amino acids)

disulfide bonds

gives an antibody it’s specificity

each class of antibody

responsible for the type of antigen-antibody reaction that occurs

lgG, lgA, lgM, lgD, lgE

lgG- Most abundant (80%); protects against bacteria and viruses by enhancing phagocytosis; only class of antibody to cross placenta from mother to fetus , lgA- Found in sweat, tears, saliva, mucus, breast milk; Makes up 10-15% of antibodies in blood; provides localized protection of mucous membranes against bacteria and viruses , lgM- 5-10% of all antibodies in blood; first antibody class to be secreted by plasma cells , lgD- Found on surfaces of B cells as antigen receptors; involved in activation of B cells; about 0.2% of antibodies in blood , lgE- Less than 0.1% in blood; located on mast cells and basophils; involved in allergic and hypersensitivity reactions; provides protection against parasitic worms