BIOL 453 Exam 1 Definitions

A Subunit (AB toxin)

Toxic enzyme which disrupts the host cell biology upon entering the cell’s cytoplasm.

B Subunit (AB toxin)

Binding part which binds to specific receptors of host cells, acting as a channel to deliver the toxin inside.

Edema factor

Forms an edema toxin.

Spikes cAMP, disrupts signaling and fluid accumulation.

Lethal factor

Forms a lethal toxin.

Cleaves kinases, prevents immune cells from surviving or communicating.

Capsule plasmid

Genetic element that contains genes used to build a bacterial capsule. Acts as an invisibility cloak.

Toxin plasmid

Genetic element contains genes for anthrax toxin proteins.

Variolation

The use of smallpox scabs to challenge healthy individuals, via inhalation or insertion into a small cut. Builds immunity against smallpox.

Discovered by Chinese physicians in the 1400s.

Serum

The fluid portion of blood, initially transferred as a whole from an immunized animal.

Passive immunity

Short-term conferred immunity to a non-immunized animal.

Immunoglobulins

Responsible for all immunological activity of antisera.

Also called antibodies, they are produced to identify and neutralize foreign invaders.

Gamma globulin

Specific fraction of serum that is responsible for all of the serum’s attributes.

Humoral immunity

Aspect of the adaptive immune system which protects the body by producing antibodies.

Active immunity

Administration of a vaccine, or thwarting a natural infection which results in antibody production.

Phagocytes

Cells in blood which undergo phagocytosis, or “eating” bacteria.

Lymphocytes

White blood cells which are responsible for cell-mediated and humoral immunity.

T lymphocytes

Responsible for cell-mediated immunity and originated from the Thymus.

B lymphocytes

Responsible for humoral immunity and developed in the bone marrow of mammals (or Busa of Fabricuis of birds).

Antigenic specificity

The recognition of specific antigens.

What’s meant by “diversity”?

Any antigen capable of eliciting an adaptive immune response.

Self/Non-self recognition

The reaction against antigens produced within the host which would be deleterious or fatal.

Immunogens

Substances or molecules which elicit an immune response.

Antigens

Substances which bind to receptors and antibodies.

Immunological diversity

The idea that T and B cell receptors are produced in random genetic recombination.

Clonal selection

T and B cells express receptors which complement immunogens selected for activation.

T helper cell (T_H)

Produces cytokines to activate and direct other immune cells. Activates T_C cells.

Cytotoxic T cell (T_C)

Specialized white blood cells which directly destroy cancerous or infected cells.

Pathogen Associated Molecular Patterns (PAMPs)

Surface marker found on pathogens that is unique to that disease-causing organism.

Pattern Recognition Receptors (PRRs)

Receptors which are recognized by the specific receptors of immune effector cells.

Innate immunity

PRRs recognize PAMPs to rapidly attack invading pathogens.

The first line of defense. No immunological activity.

Adaptive immunity

The recognition of pathogens with mutated PAMPs.

Is highly specific, requires T and B lymphocytes, and produces memory cells.

Complements

The complex array of proteins produced by the liver and macrophages.

Has many immunological properties. Part of the innate immune system.

Primary lymphoid organs

Organs which produce immune cells.

Immunocompetence and maturation.

Bone marrow

Promotes development of B cells and other immune cells.

Thymus

Promotes development of T cells, dendritic cells, and NK cells.

Secondary lymphoid organs

Organs which create a microenvironment to allow for antigen recognition.

Activation and differentiation, produces effector and memory cells.

Lymph nodes

Encounter antigens which have derived from tissues and organs.

Spleen

Encounter antigens which have derived from circulation.

Cytokines

Produced by T cells and hematopoietic stem cells (HSC).

Involved in communication and coordination.

Chemokines

Cytokines with a chemoattractant effect.

Attracts other cells to a site of production.

Phagocytic cells

Engulf, produce cytokines, initiate chemotaxis, and migrate to secondary lymphoid organs.

Primary exposure

The first encounter of an immunological challenge.

Initial IgM production for naive B cell, then IgG appearance.

Secondary exposure

Second encounter with a challenge.

Rapid IgG production from memory cells produced in primary response.

Phylaxis

Protection against infection or disease.

Usage of a vaccine with the purpose of “shielding.”

Anaphylaxis

An allergic reaction, anti-protection.

An inappropriate immune response to an immunological challenge.

Autoimmune disease

Self-reactive immune cells fail to undergo clonal deletion in maturation.

Result is immunological attack and host tissue damage.

Clonal deletion

The process of eliminating immature T or B lymphocytes, which could recognize and bind to the body’s own healthy cells.

Prevents the body from attacking itself.

Immune deficiency

Conditions which result in an inability to activate an immune response.

Primary immunodeficiency

A heritable defect.

Includes TCR or a cytokine mutation.

Secondary immunodeficiency

One derived from an exogenous source.

Can be disruption or damage caused by a biological agent (like a pathogen).

Selective IgA deficiency

The inability to produce IgA antibodies, which is normally dominant in mucosal secretions.

Still produces IgM and IgG.

Severe Combined Immunodeficiency (SCID)

The crippling of the humoral and cell-mediated branches of the immune systems. Impacts T and B cells.

Inability to develop immunological memory. Attenuated vaccines are harmful or fatal.

Human Immunodeficiency Virus (HIV)

An infectious agent capable of crippling the immune system.

Viral particles in blood drops, T cell population gradually declines with time, eventual clinical AIDS.

Major Histocompatibility Complex (MHC)

A group of genes which codes for proteins on cell surfaces.

Binds antigens and displays them on the surface so that T cells can recognize and initiate an immune response.