ESSENTIALS

Unit

6 Antibodies

ESSENTIALS

OF HUMAN

ANATOMY

& PHYSIOLOGY

Monoclonal Antibodies

�Prepared for clinical testing or diagnostic

services

�Produced from a single cell line

�Examples of uses

�Diagnosis of pregnancy�Diagnosis of pregnancy

�Treatment for exposure to hepatitis and rabies

Antibodies (Immunoglobulins) (Igs)

�Soluble proteins secreted by B cells

(plasma cells)

�Carried in blood plasma

�Capable of binding specifically to an

antigenantigen

Antibody Structure

�Four amino acid chains

linked by disulfide

bonds

�Heavy chains- 2

identical amino acid identical amino acid

chains

�Light chains- 2 identical

chains

�Specific antigen-binding

sites are present

Antibody Classes

�Each class has slightly different roles

�Five major immunoglobulin classes

� IgM- can fix complement

� IgA- found mainly in mucus

� IgD- important in activation of B cell� IgD- important in activation of B cell

� IgG- can cross the placental barrier

� IgE- involved in allergies

Antibody Function

�Inactivate antigens by:

�Complement fixation

�Neutralization

�Agglutination

�Precipitation�Precipitation

ANTIBODY FUNCTION ANIMATIONPRESS

TO PLAY

Antibody Function

Cellular Immune Response

�Cell-Mediated

�Antigens presented by macrophages to an immunocompetent T cell (antigen presentation)

�T cells must recognize nonself and self (double recognition)

�After antigen binding clones form

Cellular Immune Response

T Cell Clones

�Cytotoxic T cells�Specialize in killing infected cells

� Insert a toxic chemical (perforin)

CYTOTOXIC T CELLS ANIMATIONPRESS

TO PLAY

�Helper T cells�Recruit other cells to fight the invaders

� Interact directly with B cells

HELPER T CELLS ANIMATIONPRESS

TO PLAY

T Cell Clones

�Suppressor T cells

�Release chemicals to suppress the activity of T and B cells

�Stop the immune response to prevent uncontrolled activity

�A few members of each clone are memory

cells

Summary of the Immune Response