Lecture 24 - Genetics of the Immune System Flashcards
What is an Antigen?
Molecules that elicit an immune response
What is an Antibody?
Proteins that bind to antigens and mark them for destruction by phagocytic cells.
What is Humoral immunity?
B cells targeting circulating antigens for destruction by macrophages.
What is Cellular immunity?
Produced by T cells. Is directed against cells infected with a pathogen that is expressing a recognized antigen on the surface of the cell.
What is clonal selection?
after a specific antigen is recognized that T cell is mass produced to elicit an immune response against the pathogen.
What are immunoglobins?
glycoproteins produced by white blood cells AKA Antibodies.
What is antibody neutralisation?
neutralizing antiboides block parts of the surface of an antigen to render its attack ineffective.
What is antibody agglutination?
antibodies glue together foreign cells to be targeted by phagocytes
What is antibody Precipitation?
antibodies glue together serum-soluble antigens, forcing them to precipitate out of solution into clumps that can be targeted by phagocytes
What is antibody Complement activation?
antibodies that are latched onto a foreign cell encourage complement to attack it with a membrane attack complex. Which leads to lysis.
Antibody diversity is created by _____, which is possible because?
somatic recombination; differing combinatinos of light and heavy chains and high mutation rates.
Most T-cell receptors are composed of what?
Alpha and Beta polypeptide chains held together by disulfide bonds.
How are T cells activated?
binding both to a foreign antigen and to a histocompatibility antigen on the surface of a self-cell (MHC)
What are MHC antigens?
major function of MHCs is to bind to peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate t-cells.
What is transplant rejection?
when transplanted tissue is rejected by the recipient’s immune system, which destroys the transplanted tissue.
