1. Pages 415-425

2.  Soluble proteins secreted by activated B cells or by their plasma- cell offspring (in response to an antigen)  They are capable of binding specifically with that antigen  Also known as immunoglobulins or Igs

3.  B lymphocyte activation and clonal selection:  First they bind to a specific antigen  clonal selection creates copies of the activated cell this is called the primary humoral response  most clones become antibody producing plasma cells  other clones become memory cells memory cells provide the secondary humoral response a much faster, effective, and more prolonged response © 2015 Pearson Education, Inc.

4. Primary response (initial encounter with antigen) Secondary response (can be years later) Activated B cells Plasma cells Secreted antibody molecules Secreted antibody molecules Plasma cells Clone of cells identical to ancestral cells Proliferation to form a clone Memory B cell Memory B cells Antigen Antigen binding to a receptor on a specific B cell (B cells with non-complementary receptors remain inactive) Subsequent challenge by same antigen results in more rapid response

5. Primary response Secondary response Antigen injected Antigen injected Relative antibody concentration in blood plasma Time (weeks) 0123456

6.  Active immunity  when B cells encounter antigens and produce antibodies  acquired naturally from infection or from vaccines Most vaccines contain dead or weakened pathogens © 2015 Pearson Education, Inc.

7.  Passive immunity (temporary protection)  Antibodies are obtained from an immune human or animal donor Naturally by mother to fetus via placenta; child via breast milk Artificially by way of an immune serum containing antibodies (antivenoms, antitoxins, gamma globulin)  No immunological memory is established

8.  Four amino acid chains linked by disulfide bonds to form a T- or Y- shaped molecule  Each polypeptide chain has a variable and a constant region Constant regions determine antibody function and class © 2015 Pearson Education, Inc.

10.  Five major immunoglobulin classes (MADGE): 1. IgM—can fix complement 2. IgA—found mainly in mucus 3. IgD—important in activation of B cell 4. IgG—can cross placental barrier; fixes complement 5. IgE—involved in allergies © 2015 Pearson Education, Inc.

11.  T lymphocytes are activated indirectly:  Antigens must be presented by APCs This is known as antigen presentation  T cell recognizes and binds to the antigen fragment  T cell also recognizes and binds to “self” glycoprotein on APC  Clonal selection occurs  Clones differentiate into various T cell classes © 2015 Pearson Education, Inc.

12.  Cytotoxic (killer) T cells  Binds, releases lethal chemicals that degrade membrane and digest proteins  Helper T cells  Direct/manage cloning, signal with APCs, release chemicals called cytokines which increase efficiency of response  Regulatory (suppressor) T cells  Release chemicals that slow down B and T cell activity; cease the response after removal of antigen  Memory cells  Remember each unique antigen  second response is harder, better, faster, stronger… that’s where Kanye got that song!!

13. HUMORAL (ANTIBODY-MEDIATED) ADAPTIVE IMMUNE RESPONSE CELLULAR (CELL-MEDIATED) ADAPTIVE IMMUNE RESPONSE Antigens displayed by infected cells activate Cytotoxic T cell Macrophage Antigen- presenting cell Antigen (1st exposure) Engulfed by Becomes Stimulates Free antigens directly activate B cell T cell Gives rise toStimulates Plasma cells Secrete Antibodies Memory B cells Defend against extracellular pathogens by binding to antigens and making them easier targets for phagocytes and complement. Stimulates Defend against intracellular pathogens and cancer by binding to and lysing the infected cells or cancer cells. Antigen (2nd exposure) Stimulates Memory T cells Stimulates Helper Memory T cell Gives rise to Active cytotoxic T cells

14.  Class II MHC: The main function of major histocompatibility complex (MHC) class II molecules is to present processed antigens which are derived from exogenous sources; they are critical for the initiation of the antigen-specific immune response.  T cell dependent antigens  http://highered.mheducation.com/sites/0072507470/student_view0/chapter22/ animation__t-cell_dependent_antigens__quiz_1_.html http://highered.mheducation.com/sites/0072507470/student_view0/chapter22/ animation__t-cell_dependent_antigens__quiz_1_.html  Clonal Selection  http://highered.mheducation.com/olcweb/cgi/pluginpop.cgi?it=swf::600::480::/ sites/dl/free/0073532215/788107/Clonal_Selection.swf::Clonal%20Selection http://highered.mheducation.com/olcweb/cgi/pluginpop.cgi?it=swf::600::480::/ sites/dl/free/0073532215/788107/Clonal_Selection.swf::Clonal%20Selection  Cell mediated Immunity  https://smartsite.ucdavis.edu/access/content/user/00002950/bis10v/media/ch2 3/cell_mediated.swf https://smartsite.ucdavis.edu/access/content/user/00002950/bis10v/media/ch2 3/cell_mediated.swf

15.  Major types of tissue grafts  Autografts—tissue transplanted on the same person most successful  Isografts—tissue from an identical person (twin)  Allografts—tissue from unrelated person most common  Xenografts—tissue from a different animal species (whole organs unsuccessful) © 2015 Pearson Education, Inc.

16.  Blood group and tissue matching is done  ensures the best match possible  Cell membrane antigens must have a 75% match (or better) to continue with transplant  immunosuppressive therapy follows © 2015 Pearson Education, Inc.