Lymphocytes II Flashcards
What are the functions of IgG?
To opsonize bacteria and to neutralize viruses; to activate compliment (p.195)
What types of B cells activate compliment?
IgM and IgG (p.195)
What type of B cells sensitizes mast cells?
IgE (p.195)
What are the functions of IgE?
To sensitize mast cells; to mediate type I hypersensitivity allergic reactions (p.195)
What immunoglobin type mediates cytotoxic (type II) and immune complex (type III) hypersensitivity reactions?
IgG (p.195)
What is the function of CD4+ T cells?
To help B cells make antibody and produce cytokines to activate other cells of the immune system (p.195)
What is the function of CD8+ T cells?
To kill virus infected cells directly (p.195)
What class of immune cells is responsible for mediating delayed type hypersensitivity reactions (type IV)?
T cells (p.195)
What class of immune cells is responsible for mediating acute and chronic cellular organ rejection?
T cells (p.195)
What class of immune cells is responsible for mediating hyperacute and humorally mediated acute and chronic organ rejection?
B cells (p.195)
Where do T cell precursors get tagged with CD4+ and CD8+ T cell markers?
In the thymus (p.195)
Where do T cells with CD4+ and CD8+ tags differentiate into CD8+ or CD4+ T cells?
In the thymus (p.195)
Where do cytotoxic T cells kill virus infected, neoplastic cells, and donor graft cells?
In the lymph node (p.195)
What is the first signal in naiive T cell activation?
When foreign antigen is presented on MHC II and recognized by TCR on Th (helper) cells; Antigen is presented on MHC I to Tc cells (p.196)
What is the second signal in naiive T cell activation?
The interaction of B7 and CD28 causes a costimulatory signal (p.196)
What are the four steps in B cell activation and class swirtching?
1.) Helper T cell activation; 2.) B cell receptor mediated endocytosis; foreign antigen is presented on MHC II and recognized by TCR on Th cells (signal 1); 3.) CD40 receptor on B cell binds CD40 ligand on Th cell (signal 2); 4.) Th cell secretes cytokines that determine Ig class switching of B cells. B cell activates and undergoes class switching, affinity maturation, and antibody production (p.196)
What is the first signal in B cell activation and class switching?
B cell receptor mediated endocytosis; foreign antigen is presented on MHC II and recognized by TCR on Th cells (p.196)
What is the second signal in B cell activation and class switching?
CD40 receptor on B cell binds CD40 ligand on Th cell (p.196)
What is secreted by Th1 cells?
IFN y (p.196)
What is secreted by Th2 cells?
IL-4, IL-5, IL-10, IL-13 (p.196)
What is the primary function of Th1 cells?
To activate macrophages (p.196)
What is the primary function of Th2 cells?
To recruit eosinophils for parasite defense and to promote IgE production by B cells (p.196)
What inhibits the Th1 cell pathway?
IL-4 and IL-10 (both from Th2 cells) (p.196)
What inhibits the Th2 cell pathway?
IFN-y from Th1 cells (p.196)
What is the macrophage-lymphocyte interaction?
When activated lymphocytes (that release IFN-y) and macrophages (that release IL-1, TNFa) stimulate one another (p.196)
