Lecture 23.txt

has variable and constant regions, alpha and beta chains, undergoes somatic recombination, only has ONE antigen binding site

have CD4 receptors, bind to MHC II receptors, secrete cytokines (mainly interluekins)

Receptor that helps Tcell receptor bind

secreted by Th Cells to cause Th cell proliferation; they then differentiate into memory T cells supressor T cells

have CD8 receptor, bind to MHC I, secrete perforin for apoptosis

helps T cell receptor bind to MHC I

secreted by Tc to kill infected cell by apoptosis

released by activated Tc cell to induce apoptosis

Binding of TCR to MHC and antigen; binding of CD 4 or 8 to MHC

binding of CD 28 to B7

produced once the phagocyte has bound a PaMP; ensures dendritic cells have seen a pathogen

receptor on Tcell which binds B7

stimulates the Tc cell as a second signal to activate a Tc cell

T cell that hasn't seen a pathogen

T cell that has bound to pathogen on MHC and CD28

must be stimulated by T cell to make antibodies

B cells that can proliferate without a Th cel by binding an antigen to many receptors n the B cell at once

T independent antigen is attached to a proein; b cell has typical response and makes antibodies and memory B cells

shut off immune response once the antigen is gone

reactivated just by binding the antigen; do not need to bind CD28/B7; last 5-10 years

occurs in thymus during T cell development to delete T cells that recognize self antigens

T cells must bind to MHC I in thymus to get nutrients to develop; if they don't they die

If binding to a self antigen in thymus occurs they die

Binds to the Fc part of an antibody bound to a pathogen; releases perforins to cause apoptosis

If a MHC I receptor is present on a cell, it isn't killed by NK cells