Chapter 14 Specific Immunity adaptive immunity Copyright 2006

Chapter 14 Specific Immunity (adaptive immunity) Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Adaptive Immunity § Adaptive immunity includes immunity due to: § Exposure to pathogens § Antibody transfer from mother § Vaccination § Injections of antibodies Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Dual Nature of Adaptive Immunity § Humoral immunity involves antibodies produced by B cells. § B cells recognize antigens by antibodies on the surface of the B cells. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Dual Nature of Adaptive Immunity § Cell-mediated immunity involves T cells. § T cells recognize antigens by T cell receptors (TCRs) on the T cell surface. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Antigenic Determinants § Antibodies recognize and react with antigenic determinants, called Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings , on an antigen.

Antibody Structure Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Ig. G antibodies § Monomer § 80% of serum antibodies § Fix complement § In blood, lymph, and intestine § Cross placenta, protects fetus and newborn § Enhance neutralize toxins and viruses Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings ;

Ig. M Antibodies § Pentamer § 5 -10% of serum antibodies § Fix complement § In blood, lymph, and on B cells § microbes; first Ab produced in response to infection Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Ig. A Antibodies § Dimer § 10 -15% of serum antibodies § In secretions § Mucosal protection Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Ig. D Antibodies § Monomer § Function not fully understood Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Ig. E Antibodies § Monomer § 0. 002% of serum antibodies § On mast cells, basophils, and in blood § Allergic reactions; lysis of parasitic worms Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Activation of B Cells MHC: Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Clonal Selection Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Activation of B Cells § T-independent antigen: § Provokes antibody production without T cell help. § T-dependent antigen: Requires T cell help Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

T-Dependent Antigens § Helper T (TH) cell recognizes antigen § Activated TH cells secrete cytokines Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

The Results of Ag-Ab Binding Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

T Cells § Helper T Cells (also referred to as , or TH , cells) § T cell receptors (TCRs): Recognize antigens and MHC II. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Activation of TH Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

T Cells § Cytotoxic T Cells (CD 8, TC) can differentiate into cytotoxic T lymphocytes (CTLs). § CTLs recognize Ag + MHC I. § CTLs induce apoptosis in target cell. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Destruction of infected cell by a CTL Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Antigen-Presenting Cells (APCs) § Digest antigen § Ag fragments are presented on surface of APC in association with MHC § B cells § Dendritic Cells § Macrophages Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Antigen-Presenting Cells § Activated macrophages: Macrophages stimulated by ingesting Ag or by cytokines. § They have increased and capabilities. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Extracellular Killing § Antibody-dependent cell-mediated cytotoxicity by: § Natural killer cells § Eosinophils § Macrophages Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Extracellular Killing Antibody-dependent cell-mediated cytotoxicity by eosinophils Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Immunological Memory § Antibody is the amount of Ab in serum. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Humoral and Cell-Mediated Immune System Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings