Immunology Study Guide

Epitope
a localized region on the surface of an antigen that is chemically recognized by antibodies; also called antigenic determinant

Immunogen
any substance or organism that provokes an immune response (produces immunity) when introduced into the body

Antibody
any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response

Variable Region
That region of antibodies that varies from one antibody to another even within one class

Specific Immunity
the protective mechanisms that provide specific protection against certain types of bacteria or toxins

Self Tolerance
The normal situation whereby a person’s immune system does not respond to constituents of the person’s body.

vaccination
taking a vaccine as a precaution against contracting a disease

attenuated
to weaken or reduce in force, intensity, effect, quantity, or value

Pathogen
any disease-producing agent (especially a virus or bacterium or other microorganism)

APOPTOSIS
a type of cell death in which the cell uses specialized cellular machinery to kill itself

enzymes
proteins that act as biological catalysts

antigen
any substance (as a toxin or enzyme) that stimulates the production of antibodies

mhc
Major Histocompatability complex, a set of proteins found on the plasma membranes of cells that help display antigen to T cells. MHC I is found on all cells and displays bits of proteins from within the cell; this allows T cells to monitor cell contents and if abnormal peptides are displayed on the surface, the cell is destroyed by killer T cells. MHC II is found only on macrophages and B cells. This class of MHC allows these cells (known as antigen presenting cells) to display bitts of “eaten” (phagocytosed or internalized) proteins on their surface, allowing the activation of helper Ts –> thus further activating immune response.

immunoglobulin
a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response

constant region
That part of the Ab molecule that is the same for all Ab of one class within an isotype

opsonization
process whereby opsonins make an invading microorganism more susceptible to phagocytosis

Normal Flora
Microorganisms that reside in or on the body without causing disease

Allergen
any substance that can cause an allergy

Immunization
the act of making immune (especially by inoculation)

Toxiod
A toxin treated so as to destroy its toxicity, but still capable of inducing formation of antibodies on injection

Virulence
degree of pathogenicity

Immunity
an act exempting someone

Perforin
one of the proteins released by cytotoxic T cells on contact with their target cells. It forms pores in the target cell membrane that contribute to cell killing.