Immunology Chapter 1: Overview of the Immune System

Flashcards covering the historical perspective, fundamental concepts, components, and dysfunctions of the immune system based on Kuby Immunology 8th Edition Chapter 1.

Immunity

The state of protection against foreign pathogens or substances (antigens).

Immunis

The Latin term meaning “exempt,” which is the source of the English word immunity.

Thucydides

An ancient historian who wrote in $430\text{ BC}$ about a plague in Athens where those who recovered could safely nurse the ill due to ihrer immunity.

Vaccination

A practice that prepares the immune system to eradicate an infectious agent before it causes disease.

Humoral immunity

A component of the immune system that combats pathogens via antibodies produced by B cells.

Passive immunity

A type of immunity achieved by transferring antibodies between individuals.

Cell-mediated immunity

Immune response involving primarily T lymphocytes that can eradicate pathogens, clear infected self-cells, or aid other cells.

B-cell receptors (BCRs)

Surface-bound immunoglobulins on B cells that recognize specific antigens and are generated by random gene segment rearrangements.

T-cell receptors (TCRs)

Receptors on T cells that bind specific peptides presented by MHC molecules.

Pathogens

Disease-causing organisms which fall into four major categories: Viruses, Bacteria, Fungi, and Parasites.

PRRs

Pattern recognition receptors; germ-line encoded recognition molecules that bind to PAMPs.

PAMPs

Pathogen-associated molecular patterns; generic molecules found on many different types of pathogens, such as peptidoglycan.

Clonal selection

The process where a B or T cell interacting with its specific antigen is selected and activated to proliferate into many identical clones.

Tolerance

The mechanism that ensures the immune system avoids destroying host tissue by keeping anti-self-recognition molecules from circulating.

Innate immunity

The fast ($minutes$ to $hours$), first line of defense that is nonspecific and utilizes germ-line–encoded recognition molecules.

Adaptive immunity

A highly specific immune response using B and T lymphocytes that is slower to develop ($5\text{--}6$ days) but provides memory.

Cytokines

Signal molecules produced by innate immune responses that stimulate and direct adaptive immune responses.

Primary response

The immune response initiated upon the first exposure to a specific antigen.

Secondary response

A faster, more significant, and better immune response initiated upon subsequent exposure to the same antigen, stimulated by memory lymphocytes.

Immunodeficiency

A dysfunction of immunity involving the loss of immune function, categorized as either primary (genetic) or secondary (acquired).

Opportunistic infections

Infections, such as oral thrush, that can occur in people with impaired immune responses.

Microbiome

Commensal organisms that live in and on the body without causing harm and function in metabolic and immune balance.

Homeostasis

The metabolic and immune balance maintained by the interaction between the host and the microbiome.

Dysbiosis

An imbalance in the microbiome caused by dietary changes or environmental factors that leads to immune overstimulation and inflammation.