Highlights of Immune System

Topic Outline Overview of the Immune System 1 st and 2 nd lines of Defense The Immune System  B cells  The antibody & antibody diversity  Vaccinations  Breast Feeding  Diagnostic applications  T cells  Allergies

Lines of Defense Physical and Chemical Immune system 3 rd line 1 st and 2 nd lines

First line of defense

Second line of defense  Inflammation  Phagocytic cells  complement

3 rd line of defense “The Immune System”

Summary Lines of Defense INNATE ACQUIRED

Immune System B cells T cells

Lymph nodes are contain high concentrations lymphocytes

Let’s look more closely at the B lymphocytes

B Cell: humoral or antibody mediated immunity ANTIBODIES=IMMUNOGLOBULINS Humoral Immunity  Matures in bone marrow  Moves to lymph nodes (& other locations)  Secretes antibodies “as plasma cell”  Also creates “memory” B cells B-lymphocyte

CLONAL SELECTION

Different classes of immunoglobulins or antibodies IgM IgG IgA IgD IgE

Antibody Diversity

Antibody genes are composed of segments V J C

Somatic Recombination unology/Flash/somaticrecomb.html unology/Flash/somaticrecomb.html

How are vaccinations related to immunity? Active and Passive

Active Vaccinations: Antibody Production Memory Cells!

Immune Benefits of Breast Feeding IgA’s

The next part gets tricky Onto T Cells

All T cells require cell to cell contact

CD8+ CD4+ MHC=major histocompatibility complex: gene found on chromosome 6

Tissue Transplantation MHC proteins differ between individuals

Helper T Cell and MHC II Antigen presentation

Cytotoxic T Cell and MHC I Antigen presentation CD8+ cell

Cytotoxic T cell= CD8+

B lymphocytes source of antibodies Overview of T lymphocytes

Cancer cell being attacked by cytotoxic T cells After release of perforin

Allergies B cell also directly stimulated IgE