Unit 4 AOS 1 Immunity SAC preparation

active immunity

immunity produced by exposure to an antigen, as a result of the immune response

adaptive immunity

the ability to recognize and remember specific antigens and mount an attack on them

agglutination

Clumping of microorganisms or cells, typically due to an antigen-antibody interaction.

antibody

An antigen-binding immunoglobulin, produced by B cells, that functions as the effector in an immune response.

antigen

substance that triggers an immune response

antigen presenting cells

dendritic cells, macrophages, B cells

artificial immunity

acquired through a medical procedure such as a vaccine or injected antibodies/plasma B cells

B lymphocytes

form in the bone marrow and release antibodies that fight bacterial infections

bacteria

single-celled organisms that lack a nucleus; prokaryotes

Basophils

A circulating leukocyte that produces histamine.

cell-mediated response

The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against virus infected cells.

cellular barriers

commensal micro-organisms

chemical barriers

Proteins that destroy pathogens at the body's surface.

clonal expansion

the rapid multiplication of B or T cell clones after activation by an antigen

clonal selection

The process by which an antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen.

complement proteins

a number of different types of proteins found in the blood that opsonise, cause lysis, and attract phagocytes to invading pathogens

cytokines

Chemicals released by the immune system communicate with other cells.

Cytotoxic T cells

destroy pathogens and release chemicals called cytokines

Degranulation

the emptying of granules from the interior of a mast cell into the extracellular environment.

dendritic cells

antigen-presenting cells in the skin

Eosinophils

a white blood cell containing granules that are readily stained by eosin.

epidemic

A widespread outbreak of an infectious disease.

fever

elevated body temperature

First line of defense

intact skin, mucous membranes and their secretions, normal microbiota

fungal pathogens

Eukaryotes species with chitin cell walls that can cause disease in plants and/or animals

Granulocytes

A group of leukocytes containing granules in their cytoplasm; mast cells, eosinophils, basophils.

Granzymes

enzymes that attack proteins of target cells and induce apoptosis

Helper T cells

T cells that help the immune system by increasing the activity of Cytotoxic T cells, B cells and stimulating the suppressor T cells

herd immunity

The resistance of a group to an attack by a disease to which a large proportion of the members of the group are immune

histamine

Chemical stored in mast cells that triggers dilation and increased permeability of capillaries.

humoral response

The branch of acquired immunity that involves the activation of B cells and that leads to the production of antibodies, which defend against bacteria in body fluids.

inflammatory response

nonspecific defense reaction to tissue damage caused by injury or infection, characterized by redness, heat, swelling, and pain

innate immunity

Immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens.

interferon

Protein produced by cells in response to being infected by a virus; helps other cells resist the virus.

Interleukins

proteins (cytokines) that stimulate the growth of B and T lymphocytes

lymphatic system

Composed of a network of vessels, ducts, nodes, and organs. Provides defense against infection.

lymph nodes

Bean-shaped filters that cluster along the lymphatic vessels of the body. They function as a cleanser of lymph as wells as a site of T and B cell activation

Macrophages

phagocytize foreign substances and help activate helper T cells

mast cells

Cells that release chemicals (such as histamine) that promote inflammation.

membrane attack complex

the complex of terminal complement proteins that forms a pore in the membrane of the target cell, damaging the membrane and leading to cell lysis.

memory B cells

Produced during a B cell response, but are not involved in antibody producing during the initial infection; are held in reserve for the rest of your life in case you encounter that pathogen again.

Memory T cells

Remember antigen and quickly stimulate immune response on reexposure

MHC 1 proteins

Found on all nucleated cells; necessary for cell recognition

MHC 2 proteins

occur only on APCs and display only foreign antigens

naïve B cells

B cells that have the ability to produce an antigen specific antibody but which wait in the lymph nodes until their particular antigen comes along and activates them

natural immunity

acquired as part of normal life experiences

Natural killer cells

A type of white blood cell that can kill tumor cells and virus-infected cells; an important component of innate immunity.

Neutralisation

antibody binds to toxin / pathogen and prevents it from damaging host cells

neutrophils

The most abundant type of white blood cell. Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.

opsonisation

a process in which a pathogen is coated with antibodies and/or complement and marked for phagocytosis

pandemic

Disease that occurs over a wide geographic area and affects a very high proportion of the population.

passive immunity

the short-term immunity that results from the introduction of antibodies from another person or animal.

pathogen

A disease causing agent

perforin

a protein, released by killer cells of the immune system, that destroys targeted cells by creating lesions like pores in their membranes.

phagocytes

a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

physical barriers

skin and mucous membranes

Plasma B cells

When the B cell is activated to divide by mitosis it gives a clone of plasma cells which produce and secrete the specific antibody that exactly fits the antigen on the pathogen's surface.

primary exposure

First exposed to a pathogen

primary lymphoid tissue

bone marrow and thymus

Prions

infectious proteins

Proliferation

rapid increase in numbers

Protist pathogens

Eukaryotic cellular pathogen eg. Malaria

second line of defense

protective cells and fluids; inflammation and phagocytosis - nonspecific

secondary exposure

A second exposure to the same infective agent

secondary lymphoid tissues

-Filter lymph

-Lymph nodes, spleen, and mucosa-associated lymphoid tissue (MALT)

T cell receptor

Antigen receptors on a T cell. Unlike antibodies, T cell receptors are never produced in a secreted form.

T lymphocytes

mature in thymus

third line of defense

adaptive immunity

Transmission

Transfer, such as of a disease, from one person to another

vaccination

injection of an attenuated form of a pathogen to produce immunity

Virus

A tiny, nonliving particle that invades and then reproduces inside a living cell.