Glossary

adaptive

The adaptive immune defence refers to the tailoring of an immune response to the particular foreign invader. It involves differentiating self from non self and involves B cells and T cells (lymphocytes). A key feature of the adaptive immune system is memory. Repeat infections by the same virus are met immediately with a strong and specific response.

antigenic drift

Minor changes in antigens that occur as a pathogen mutates.

antigenic shift

Major changes in the antigens of a pathogen that result from reassortment of genes.

cytopathic

Description of the damage caused to host cells or tissues by a pathogen, often a virus.

gel electrophoresis

The separation of molecules (proteins or nucleic acids) in an electric field as a function of their size and charge.

genetic reassortment

The mixing of the genetic material of two species into new combinations in different individuals. Especially used to describe when two or more similar viruses, infecting the same cell, exchange genetic material to produce a new virus.

genome

The complete set of genes that an organism contains.

inflammation

A series of reactions, which bring cells and molecules of the immune system to sites of infection or damage. This appears as an increase in blood supply, increased vascular permeability and increased transendothelial migration of leukocytes.

non-adaptive

The non-adaptive immune defence (sometimes called the ‘innate’ or ‘humoral’ response) is a non-specific response and is generally the first line of immune defence, being active even before infection begins. Receptors on host cells detect uniquely viral components, such as double stranded RNA and viral glycoproteins, and trigger the release of cytokines.

T cells

Lymphocytes that differentiate primarily in the thymus and are central to the control and development of immune responses. The principle subgroups are cytotoxic T cells (Tc) and T helper cells (Th).