Exam 2 Flashcards
Microbial protein antigens are mainly captured by….
dendritic cells
Where are captured antigens concentrated and immune responses initiated?
lymph nodes
MHC Class 1 proteins are recognized by what cells?
CD8+ cells
MHC Class 2 proteins are recognized by what cells?
CD4+ cells
What MHC molecules trigger immediate cell apoptosis?
MHC Class 1
How are antigens for display by MHC Class 1 molecules created?
ubiquinated and broken down by proteosome into peptide fragments
Where in the cell do antigen fragments first meet MHC Class 1 molecules?
transported to ER by TAP
In order for an MHC molecule to trigger an effector response in CD4+ or CD8+ cells, it must present antigens along with a….
costimulator
Mucosal epithelial cells express MHC Class ___ molecules. These mobilize _________ lymphocytes to combat the infection.
- one
- cytotoxic T
What types of antigens are recognized by antibodies and not T Cell receptors?
polysaccharides
What types of antigens are recognized by T cell receptors?
protein/peptide antigens
What two mechanisms do activated T cells use to activate antigen presenting B cells to proliferate and differentiate?
- CD40 ligand
- cytokine secretion (CD40 engagement cytokines)
IL-2 release is stimulated by what? IL-2 causes what?
- triggered by CD28 activation by B7
- IL-2 causes T-Cell proliferation
What is the most important costimulator for naive T cell activation?
B7 ligand
What stimulates the production of B7 molecules?
-components of the innate immune system recognizing PAMPs with TLRs. Antigen presentation without TLR activation means it it likely self antigen
What costimulator interaction is needed to stimulate macrophage killing functions when CD4+ effector T cell is bound to MHC Class II presented antigens?
-CD40 ligand on the T cell binding to CD40 on the macrophage
What is the function of CD4+ Th1 helper T lymphocytes? What is the cytokine?
- activation of macrophages against intracellular pathogens
- IFN gamma
What is the function of CD4+ Th2 helper T lymphocytes? What are the cytokines?
- activation of eosinophils for attack of helminths
- IL-4, IL-5, IL-13
What is the function of CD4+ Th17 helper T lymphocytes? What are the cytokines?
- activation of neutrophils against extracellular pathogens
- IL-17, IL-22
What is the mechanism for cell destruction of CD8+ T Cells?
Granzyme B and Perforin
What pathogens inhibit phagosomal lysosomal function?
mycobacterium
What anatomic region is normally only protected by humoral immune responses?
intestinal lumen
