The process of activation of the immune system in advance of the presence of a disease; is accomplished by administration of a vaccine.

Self markers that allow your body to recognize the cells that belong to you.

Enzyme in saliva and tears that kills certain kinds of bacteria.

A protein molecule released by a B cell or a plasma cell that binds to specific antigens.

A cell that displays antigen-MHC complexes on its surface and can trigger an immune response by lymphocytes.

Type of T lymphocyte that orchestrates cell-mediated immunity by direct contact with other immune cells and by releasing chemicals called lymphokines.

Disease-causing microorganism, such as a bacterium or virus.

An infectious misfolded protein that replicates by causing a normal protein in the infected animal to misfold, producing another one.

Overzealous immune response to an otherwise harmless substance.

A "killer T cell" that directly lyses foreign cells, cancer cells, or virus-infected body cells.

Pure preparations of identical antibodies produced in the laboratory by a colony of genetically identical cells.

Endocrine gland that contributes to immune responsiveness.

A strategy for causing the body to develop immunity to a specific pathogen.

Collective term for the defense activities of the immune system.

A condition in which the immune system attacks the body's own tissues.

A cell derived from a B cell lymphocyte specifically to mass-produce and release antibodies.

Lymphocytes responsible for cell-mediated immunity, which depends on the actions of several types of T cells

A white blood cell that matures in bone marrow and gives rise to antibody producing plasma cells.

White blood cell whose granules stain well with a basic dye; also will release histamine and other substances during inflammation.

A nonspecific defensive response of the body to tissue injury characterized by dilation of blood vessels and an increase in vessel permeability.

One of the three domains of life.

A substance or part of a substance (living or nonliving) that the immune system recognizes as foreign and activates the immune system and reacts with immune cells or their products, such as antibodies.

Immunity conferred by activated T cells, which directly lyse infected or cancerous body cells or foreign cells and release chemicals that regulate the immune response.

A complex group of cells, proteins, and structures of the lymphatic system that work together to provide the immune response.

Blood plasma proteins (gamma globulins) that play a crucial role in immunity; there are 5 classes.

Chemical that is able to provide some protection against virus invasion of the body by inhibiting viral reproduction.

Members of T cell and B cell clones that provide for immunologic memory.

Mechanism of defense in which B cells and plasma cells produce antibodies that bind to specific antigens.

The process of fighting an existing or anticipated infection by the administration of specific antibodies against the infective agent; the antibodies are isolated from a human or animal with immunity to the infective agent.

A substance that interferes with bacteria metabolism.

Any substance that triggers an allergic response.

Most abundant type of white blood cell that respond rapidly during an infection, surrounding and engulfing bacteria.

Antigens prepared in such a way that when injected or taken orally they induce active immunity without causing disease.

Small masses of tissue and lymphatic vessels that contain macrophages and lymphocytes, which remove microorganisms, cellular debris, and abnormal cells from the lymph before it is returned to the cardiovascular system.

A group of blood borne proteins which, when activated, enhance the inflammatory and immune responses and may lead to lysis of pathogens.

Granular white blood cell whose granules stain readily with a red stain called eosin.

Process by which phagocytes surround, engulf, and destroy foreign cells.

A noncellular infectious agent that can replicate only within a host cell.

A disease in which there is a severe loss of the body's cellular immunity, greatly lowering the resistance to infection and malignancy.

Substance produced by basophils and mast cells that causes vasodilation and increases vascular permeability.

Immune cell that detects foreign substances in the tissue spaces and release histamine to initiate a local inflammatory response against them.

A bacterial infection that killed an estimated 25-40% of the European population between 1348-1350.

Resistance to disease and pathogens.

A type of lymphocyte that can lyse and kill cancer cells and virus-infected body cells before the immune system is activated.

Body temperature that has risen above the normal set point (~37 C or 98.6 F); can indicate an illness.

Signaling molecules secreted by helper T cells; have a variety of functions, including promoting immune cell development, stimulating their activity and attracting them to an area of infection.

System consisting of lymphatic vessels, lymph nodes, and other lymphoid organs and tissues.

A lentivirus that causes the acquired immunodeficiency syndrome, a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive.