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WALKER BIOLOGY CLUB MEETING & GUEST SPEAKER!!. Dr. Janice Swab, a world-traveling evolutionary biologist will be speaking! Come hear about “Following Darwin [and not following Darwin] in the Southern Hemisphere!” January 23, 2008 5:00 p.m. in Room 210. Pizza & Drinks Provided!.
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WALKER BIOLOGY CLUB MEETING & GUEST SPEAKER!! Dr. Janice Swab, a world-traveling evolutionary biologist will be speaking! Come hear about “Following Darwin [and not following Darwin] in the Southern Hemisphere!” January 23, 2008 5:00 p.m. in Room 210 Pizza & Drinks Provided!
Campbell Pre-Med Allied Health “ We’re here to help…” Welcome Back! Come join us for our first meeting of the semester! Thursday, Jan 24 @ 5:00PM Science Bldg. Room 210 Everyone is Welcome! CampbellPreMed@gmail.com
Announcements • Begin literature search! • Locate a minimum of 1 review article & 2 peer reviewed research articles. • Type out a reference list & have a copy of the papers turned in by Feb 4! • Worth a 10 pt quiz grade. • Exam 1: Mon, Jan 28 • Chapter 1
Antigen Presentation to T- cells continued
Antigen must be processed to be displayed on MHC. alpha beta alpha B-2 microglobulin
The Endogenous Pathway: • MHC class I • Endogenous Ag: • derived from pathogens that multiply intracellularly.
Exogenous Pathway • MHC class II • Exogenous antigen: • derived from pathogens that multiply outside of host cells or inside the phagolysosome.
T cells engage cells carrying the MHC with antigen. • TCR on CD4+ T cells engages APC with MHC class II molecules. • TCR on CD8+ T cells engages cells with MHC class I molecules. Immunology (kuby)
For successful T cell engagement of the APC: • TCR must recognize & bind to the MHC. • CD4 or CD8 must participate. • TCR must recognize & bind to the antigenic peptide.
The TCR on the CD4+ T cell engages the MHC class II molecule on APC! (Fig. 1.27 p. 25).
The TCR on CD8 + T cells interact with the MHC class I molecule & Ag. Toxic granules released Virally infected CHO cells. Fig. 1.26, p. 24
Clonal selection of the T cell leads to: Proliferation Differentiation into effecter cells: TH cells TC cells Differentiation into Memory cells What does the interaction of T cells with the APC accomplish?
Why do T cells need to undergo positive & negative Selection to achieve tolerance?
The Humoral Immune Response Activation of B cells
1. T Independent Antigens • Polysaccharides & LPS. • Crosslinks multiple Ig receptors. Fig. 16-14, nester Microbiology
2. T dependent antigens: • Costimulation by the interaction with Th2 cells is required! A strong B cell Response generally requires cytokine production from the Th2 cells. Fig. 1.21, Janeway (6th ed)
Clonal selection & clonal expansion Generally require Th2 cell assistance
Antibody Dependent Cell mediated Cytotoxicity (ADCC): NK cells (natural killer cells)- FcR (Fc receptors). Kills: tumor cells Pathogens cells infected with pathogens. perforin
Antibody Function: Fig. 1.29, 2nd ed Immune Complex formation
Ab can initiate complement activation by the classical pathway. http://www.bmb.psu.edu/courses/bisci004a/immune/activate.jpg
Overview of the two arms of adaptive immunity: Humoral Immunity & Cell Mediated Immunity.
Fig. 1.7, Immunology (kuby) 4th ed B cell internalizes Ag & now is an APC
Th2 cells Th1 cells • Fig. 1.13, p. 13, Immunology (kuby) 4th ed
Adaptive Immunity Demonstrates Primary & Secondary Responses:
Adaptive Immunity- Primary & Secondary Responses: p. 28, Parham
Mouse A receives skin grafts T cells demonstrate primary & secondary responses
Improper immune responses may lead to allergies or autoimmune disease.
