a localized region on the surface of an antigen that is chemically recognized by antibodies; also called antigenic determinant
any substance or organism that provokes an immune response (produces immunity) when introduced into the body
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
That region of antibodies that varies from one antibody to another even within one class
the protective mechanisms that provide specific protection against certain types of bacteria or toxins
The normal situation whereby a person’s immune system does not respond to constituents of the person’s body.
taking a vaccine as a precaution against contracting a disease
to weaken or reduce in force, intensity, effect, quantity, or value
any disease-producing agent (especially a virus or bacterium or other microorganism)
a type of cell death in which the cell uses specialized cellular machinery to kill itself
proteins that act as biological catalysts
any substance (as a toxin or enzyme) that stimulates the production of antibodies
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.
a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response
That part of the Ab molecule that is the same for all Ab of one class within an isotype
process whereby opsonins make an invading microorganism more susceptible to phagocytosis
Microorganisms that reside in or on the body without causing disease
any substance that can cause an allergy
the act of making immune (especially by inoculation)
A toxin treated so as to destroy its toxicity, but still capable of inducing formation of antibodies on injection
degree of pathogenicity
an act exempting someone
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.