University:
York University
Course:
SC/BIOL 3120 | Immunobiology
Academic year:

2023
Views:

166

Pages:

2
Author:

Niklas

What role do antibodies play? They recognize antigen very specifically They promote effector activity in response to the antigen Antibodies have NO direct effector activity The variable regions/domains are responsible for antigen bindingThe constant regions/domains are responsible for effector activityHinge region flexibilityCarbohydrate ends (glycosylation) = more soluble in the blood Immunoglobulin (Ig) Domains: NOTE: Ig domain is NOT the same as an immunoglobulin So called Ig domain because it was first discovered on Ig and is one of the 30 components of Ig They are found all over - not just Ig Antibody binding site: Made up of the variable regions from both heavy and light chains Antigen can only bind if both chains are present Hyper variable regions: The three regions within the antibody responsible for all of the diversity Also called complementary determining regions (CDRs) Antibody diversity: The remaining Antibody Isotypes and Effector Functions Heavy ChainIgE Heavy ChainIgA Heavy ChainIgM Heavy ChainIgG Heavy ChainIgD There are also isotype subclasses (IgG1, IgG2, etc.) Differing heavy chains (isotypes) promote differing effector functions (Think signaling beacons) Remember that antibodies have no effector activity 6 categories of antibody effector function: neutralization doesn't kill/hurt BUT does stop it agglutination clumping immune complex opsonization complement fixation attaching complement to the pathogen. ADCC Antibody Dependent Cell mediated Cytotoxicity LADCC degranulation Complement activation and antibody dependent cell mediated cytotoxicity