Immune Mechanisms

Chapter 29

Immune Cells

B and T Cells

Innate Response: Phagocytosis of Bacillus megaterium

Toll Like Receptors: PAMP and PRR

Oxygen Dependent Killing in the Phagolysosome

Inhibiting Phagocytosis

1. Staphylococcus aureus carotenoids, Mycobacterium tuberculosis cell wall glycolipids :: absorb ROS.

2. Staphylococcus aureus, Streptococcus pyogenes :: leucocidins – toxins that kill phagocytes pus.

pyogenic = pus forming pathogens.

3. Streptococcus pneumoniae capsules, S. pyogenes M protein – inhibit phagocytosis.

Antibodies specific to capsules, M protein…overcome this escape mechanism…Ab dependent phagocytosis.

Adaptive Immune Response

Clicker Question:

Adaptive Immune Response

Clicker Question:

Adaptive Immune Response

Clicker Question:

Three Immune Characteristics

applies to bothAntibody Response

and Cellular Response

Immunogens

Proteins > Polysaccharides >>>>> DNA >>>lipids

Antigen Binding

Clicker Question:

Tcell Receptor and MHC and Ag Presentation

T-cell Receptor

MHC-I

MHC-II

Tcell Receptor Binds Ag Presented by MHC

TC cell = Cytotoxic T-cell TH cell = Helper T-cell.

TC Cells Killing

NK Cells

TH1 Cells Helpers

TH2 Cells Helpers

TH17 cells, secrete IL-17 and other cytokines to attrach Neutrophils to sites of infection…….independent of Ag contact (activated by dendritic cells)

Antibodies

IgG

Disulfide bonds circled in Red

Antibodies

IgG vs IgM

IgM (in blood)

Clicker Question:

IgA: Excreted to Mucosal Surfaces

Clicker Question:

Ig Light Chain Molecular Biology

Hey, we had this slide Last Class

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Complement Holes in Salmonella enterica

Complement is So Cool !

Complement is So Cool !

3 Pathways of Complement Activation