A segue is not just a dorky transportation device. Remember Mate Choice as an selective pressure in evolution?

Immunity Keeping the bad guys out, and destroying them if they breach the fortress

Immune System Overview: HIV and AIDS

Figure Pathogen Splinter Mast cell Macro- phage Capillary Red blood cells Neutrophil Signaling molecules Innate Immunity

Figure Pathogen Splinter Mast cell Macro- phage Capillary Red blood cells Neutrophil Signaling molecules Movement of fluid Innate Immunity

Figure Pathogen Splinter Mast cell Macro- phage Capillary Red blood cells Neutrophil Signaling molecules Movement of fluid Phagocytosis Innate Immunity

Figure 43.9 Cytoplasm of B cell Antigen- binding site B cell antigen receptor B cell Light chain Disulfide bridge Antigen- binding site Variable regions Constant regions Transmembrane region Heavy chains Plasma membrane C C C C V V V V Humoral Immunity

Figure Antibody Antigen receptor B cell Antigen Epitope Pathogen (a) B cell antigen receptors and antibodies Antibody C Antibody B Antibody A Antigen (b) Antigen receptor specificity Humoral Immunity

Figure 43.10b Antibody C Antibody B Antibody A Antigen (b) Antigen receptor specificity

Figure DNA of undifferentiated B cell DNA of differentiated B cell Recombination deletes DNA between randomly selected V segment and J segment Functional gene Transcription RNA processing Translation pre-mRNA mRNA Light-chain polypeptide Antigen receptor B cell Variable region Constant region 2341 Poly-A tail Cap V 39 J5J5 J5J5 V 37 V 38 V 39 V 37 V 38 V 39 V 40 J5J5 J5J5 J4J4 J3J3 J2J2 J1J1 Intron V C C C C C C C C C V V V V Example of Somatic Cell Recombination: Very cool!

Figure Antigen Antigen receptor Antibody Plasma cells (B-cell effector cells) Memory cells B cells that differ in antigen specificity

Figure Primary immune response to antigen A produces antibodies to A. Secondary immune response to antigen A produces antibodies to A; primary immune response to antigen B produces antibodies to B. Exposure to antigen A Exposure to antigens A and B Time (days) Antibody concentration (arbitrary units) Antibodies to A Antibodies to B

Figure 43.12a Displayed antigen fragment MHC molecule Antigen fragment Pathogen Host cell T cell T cell antigen receptor (a) Antigen recognition by a T cell

Figure Antigen- presenting cell Pathogen Antigen fragment Class II MHC molecule Accessory protein Antigen receptor Helper T cell Cytokines Humoral immunity Cell- mediated immunity B cell Cytotoxic T cell 321    

Cytotoxic T Cell in Action Actual video of cells

Figure Cytotoxic T cell 1 Accessory protein Class I MHC molecule Infected cell Antigen receptor Antigen fragment Mechanism of Action for Cytotoxic T Cells

Figure Cytotoxic T cell 12 Accessory protein Class I MHC molecule Infected cell Antigen receptor Antigen fragment Perforin Pore Gran- zymes Mechanism of Action for Cytotoxic T Cells

Figure Cytotoxic T cell 312 Accessory protein Class I MHC molecule Infected cell Antigen receptor Antigen fragment Perforin Pore Gran- zymes Released cytotoxic T cell Dying infected cell Mechanism of Action for Cytotoxic T Cells

Figure Pathogen 1 Antigen-presenting cell Antigen fragment Class II MHC molecule Antigen receptor Accessory protein Helper T cell Activation of a B cell in the humoral immune response

Figure Pathogen 12 Antigen-presenting cell Antigen fragment Class II MHC molecule Antigen receptor Accessory protein Helper T cell B cell Cytokines Activated helper T cell  Activation of a B cell in the humoral immune response

Figure Pathogen 312 Antigen-presenting cell Antigen fragment Class II MHC molecule Antigen receptor Accessory protein Helper T cell B cell Cytokines Activated helper T cell Memory B cells Plasma cells Secreted antibodies  Activation of a B cell in the humoral immune response

Figure Humoral (antibody-mediated) immune response Cell-mediated immune response Antigen (1st exposure) Engulfed by Antigen- presenting cell Helper T cell Memory helper T cells Antigen (2nd exposure) B cell Plasma cells Secreted antibodies Defend against extracellular pathogens Memory B cells Memory cytotoxic T cells Active cytotoxic T cells Defend against intracellular pathogens and cancer Cytotoxic T cell Key Stimulates Gives rise to          

In plain English:

The Universe Within If you’re really fit, lucky, and stubborn, this is what your immune system can do for you.

How a flu virus invades your cells Why is HIV so resistant to the immune system?

Figure Latency AIDS Helper T cell concentration Years after untreated infection Helper T cell concentration (in blood (cells/mm 3 ) Relative anti-HIV antibody concentration Relative HIV concentration

And now, Evolution! The amazing link between the Black Plague and HIV resistance.

Figure IgE Allergen Histamine Granule Mast cell What about histamines? redness swelling asthma itching

Emerging Infectious Diseases How the Dengue virus gets into a cell How HIV infects a cell How vaccines work