AP Bio Ch. 43 Vocab

Acquired immunity

Acquired immunity

A specific immunity that tailors its attack to a specific antigen previously encountered. Its hallmarks are its ability to learn, adapt, and remember. ____________ takes time to develop after first exposure to a new antigen.

Acquired immunodeficiency

AIDS

Active immunity

Long-lasting immunity conferred by the action of B cells and T cells and the resulting B and T memory cells specific for a pathogen. _________ can develop as a result of natural infection or immunization.

AIDS

The symptoms and signs present during the late stages of HIV infection, defined by a specified reduction in the number of T cells and the appearance of characteristic secondary infections.

Allergens

A type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body.

Antibody

A protein secreted by plasma cells (differentiated B cells) that binds to a particular antigen; also called immunoglobulin. All ___________ have the same Y-shaped structure and in their monomer form consist of two identical heavy chains and two identical light chains.

Antigen

A substance that elicits an immune response by binding to receptors of B or T cells.

Antigen presentation

The process by which an MHC molecule binds to a fragment of an intracellular protein antigen and carries it to the cell surface, where it is displayed and can be recognized by a T cell.

Antigen receptor

The general term for a surface protein, located on B cells and T cells, that binds to antigens, initiating adaptive immune responses. The ____________ on B cells are called B cell receptors, and the antigen receptors on T cells are called T cell receptors.

Antigen-presenting cells

A cell that upon ingesting pathogens or internalizing pathogen proteins generates peptide fragments that are bound by class II MHC molecules and subsequently displayed on the cell surface to T cells. Macrophages, dendritic cells, and B cells are the primary __________.

Autoimmune disease

An immunological disorder in which the immune system turns against self.

B cell receptor

A transmembrane protein on the surface of a B cell which initiates a cascade of intracellular signalling leading to the internalization of antigen for processing and presentation to T cells.

B cells

The lymphocytes that complete their development in the bone marrow and become effector cells for the humoral immune response.

Cell-mediated immune response

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

Clonal selection

The process by which an antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen. The selected lymphocytes proliferate and differentiate into a clone of effector cells and a clone of memory cells specific for the stimulating antigen.

Complement system

A group of about 30 blood proteins that may amplify the inflammatory response, enhance phagocytosis, or directly lyse extracellular pathogens.

Cytokines

Any of a group of small proteins secreted by a number of cell types, including macrophages and helper T cells, that regulate the function of other cells, particularly immune cells. Examples include interferons and interleukins.

Cytotoxic T cells

A type of lymphocyte that, when activated, kills infected cells as well as certain cancer cells and transplanted cells.

Dendric cells

An antigen-presenting cell, located mainly in lymphatic tissues and skin, that is particularly efficient in presenting antigens to helper T cells, thereby initiating a primary immune response.

Effector cells

A lymphocyte that has undergone clonal selection and is capable of mediating an adaptive immune response.

Eosinophils

Immune system cell that secretes destructive enzymes and helps defend against multicellular pathogens.

Epitope

A small, accessible region of an antigen to which an antigen receptor or antibody binds.

Heavy chains

One of the two types of polypeptide chains that make up an antibody molecule and B cell receptor; consists of a variable region, which contributes to the antigen-binding site, and a constant region.

Helper T cells

A type of T cell that, when activated, secretes cytokines that promote the response of B cells (humoral response) and cytotoxic T cells (cell-mediated response) to antigens.

Histamine

A substance released by mast cells that causes blood vessels to dilate and become more permeable in inflammatory and allergic responses.

HIV

(human immunodeficiency virus) The infectious agent that causes AIDS. HIV is a retrovirus.

Humoral immune response

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

Immune system

An organism’s system of defenses against agents that cause disease.

Immunization

The process of generating a state of immunity by artificial means. In vaccination, an inactive or weakened form of a pathogen is administered, inducing B and T cell responses and immunological memory. In passive immunization, antibodies specific for a particular pathogen are administered, conferring immediate but temporary protection.

Immunodeficiency

Results from a failure or absence of elements of the immune system, including lymphocytes, phagocytes, and the complement system

Immunoglobulin

A protein secreted by plasma cells (differentiated B cells) that binds to a particular antigen. All __________ have the same Y-shaped structure and in their monomer form consist of two identical heavy chains and two identical light chains..

Inflammatory response

An innate immune defense triggered by physical injury or infection of tissue involving the release of substances that promote swelling, enhance the infiltration of white blood cells, and aid in tissue repair and destruction of invading pathogens.

Innate immunity

A form of defense common to all animals that is active immediately upon exposure to a pathogen and that is the same whether or not the pathogen has been encountered previously.

Interferons

A protein that has antiviral or immune regulatory functions. For example, _________ secreted by virus-infected cells help nearby cells resist viral infection.

Light chains

One of the two types of polypeptide chains that make up an antibody molecule and B cell receptor; consists of a variable region, which contributes to the antigen-binding site, and a constant region.

Lymphocytes

A type of white blood cell that mediates immune responses. The two main classes are B cells and T cells.

Macrophages

A phagocytic cell present in many tissues that functions in innate immunity by destroying microorganisms and in acquired immunity as an antigen-presenting cell.

Major histocompatibility complex

A host protein that functions in antigen presentation. Foreign ___________ molecules on transplanted tissue can trigger T cell responses that may lead to rejection of the transplant.

T cells

The class of lymphocytes that mature in the thymus; they include both effector cells for the cell-mediated immune response and helper cells required for both branches of adaptive immunity.

Thymus

A small organ in the thoracic cavity of vertebrates where maturation of T cells is completed.

Type 1 diabetes mellitus

An endocrine disease marked by an inability to maintain glucose homeostasis. The type 1 form results from autoimmune destruction of insulin-secreting cells; treatment usually requires daily insulin injections.

Vaccination

Treatment with a vaccine to produce immunity to a particular infectious disease or pathogen.

Mast cells

Immune system cell that secretes histamine; plays role in inflammatory response and allergies.

Memory cells

One of a clone of long-lived lymphocytes, formed during the primary immune response, that remains in a lymphoid organ until activated by exposure to the same antigen that triggered its formation. Activated ___________ mount the secondary immune response.

Monoclonal antibodies

Any of a preparation of antibodies that have been produced by a single clone of cultured cells and thus are all specific for the same epitope.

Natural killer cells

A type of white blood cell that can kill tumor cells and virus-infected cells as part of innate immunity.

Neutrophils

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

Passive immunity

Short-term immunity conferred by the transfer of antibodies, as occurs in the transfer of maternal antibodies to a fetus or nursing infant.

Phagocytosis

A type of endocytosis in which large particulate substances or small organisms are taken up by a cell. It is carried out by some protists and by certain immune cells of animals (in mammals, mainly macrophages, neutrophils, and dendritic cells).

Plasma cells

These develop from B lymphocytes (B cells), a type of white blood cell that is made in the bone marrow. They cells make antibodies to fight bacteria and viruses, to stop infection and disease.

Primary immune response

The initial adaptive immune response to an antigen, which appears after a lag of about 10 to17 days.

Rheumatoid arthiritis

An autoimmune and inflammatory disease, when that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body.

T cell receptor

A protein complex found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex molecules.