Structure Function Immunoglobulins

Immunoglobulin's are glycoprotein molecules that are produced by plasma cells in response to an immunogen and function as antibodies. definition

Plasma cell

All immunoglobulins have four chain structures as their basic unit Two identical light chains Two identical heavy chains Disulfide bonds The number on inter-chain disulfide bonds varies among different immunglobulin molecules Variable and Constant regions Hinge region Basic Structure

Variable and Constant region Basic Structure

The hinge area gives it flexibility IgG

THREE DIMENSIONAL IMAGE OF THE IMMUNOGLOBULIN SHOW THAT IT IS NOT STRAIGHT AS DEPICTED ON THE PREVIOUS SLIDES. RATHER, IT IS FOLDED INTO GLOBULAR REGIONS EACH OF WHICH CONTAINS INTRA-CHAIN DISULFIDE BONDS. THESE REGIONS ARE CALLED DOMAINS

Immunoglobulin Types IgG -Gamma Heavy Chains IgM -Mu Heavy Chains IgA -Alpha Heavy Chains IgD -Delta Heavy Chains IgE -Epsilon Heavy Chains These differences are based on the amino acid sequences in the constant region of the heavy chains Immunoglobulin Types

IgG and IgM are most commonly used in Blood Banking IgM Type of Antibody IgG and IgM are most commonly used in Blood Banking

Function of IgG Antibodies This is the most versatile because it can carry out all of the functions of immunoglobulin molecules 75% of serum immunoglobulins are IgG The only type that can have Placental transfer Fixes complement Binds to Macrophages, monocytes, PMN’s and some lymphocytes Most significant Antibodies in Blood Banking Function of IgG Antibodies

Function of IgM Antibodies Exists as a pentamer Third most common serum immunoglobulin IgM is the first made by the fetus and the first to be made by virgin B cells when it is stimulated by an antigen Good at binding complement Good at agglutination, can react at room temperature Good at clumping microorganisms for eventual elimination Function of IgM Antibodies

Function of the IgA Antibodies IgA is the 2nd most common serum immunoglobulin IgA is the major class of immunoglobulins in secretions- tears, saliva, mucous, clostrum Does not fix complement It has another protein associated with it called the secretory piece or T piece that protects it when being transported across mucosa. Function of the IgA Antibodies

IgD and IgE IgD found in very small amounts in blood Its function is unclear Possibly can serve as a receptor on the B cell IgE is the least common in the blood Binds to Eosinophils, Basophils and mast cells Involved in the allergic reactions, help in diagnosis of allergies IgD and IgE

A killer cell activated by an antibody One function of IgG

Primary and Secondary Response Primary response Occurs after first exposure to antigen IgM detectable in 3-4 days IgG detectable in 1 -2 weeks IgM measurement can indicate if Acute infection Secondary Response Re-exposure of Antigen Antibody production increases rapidly IgG reaches higher levels than in primary response IgG remains detectable in the serum or plasma for months to years Primary and Secondary Response

Primary and Secondary response Vaccine example

The wonders of Antibodies Anitbodies have recognition, specificity and memory This project was funded at $3,000,000 (100% of its total cost) from a grant awarded under the Trade Adjustment Assistance Community College and Career Training Grants, as implemented by the U.S. Department of Labor’s Employment and Training Administration. Rogue Community College is an equal opportunity employer/program. Auxiliary aids and services, alternate form and language services are available to individuals with disabilities and limited English proficiency free of cost upon request.   This work is licensed under a Creative Commons Attribution 4.0 International License. The wonders of Antibodies