5.2.2 Virus – Host Interactions

5.2.2 Virus Host Interactions

The reactions that occur in host in response to viral infections are summarized below:

Host Effector Functions in Viral Infections

Host Defense

Effector

Target of Effector

Early nonspecific responses

Fever

Phagocytosis

Inflammation

NK cell activity

Interferon

Virus replication

Virus

Virus replication

Virus-infected cell

Virus replication,

immunomodulation

Immune responses mediated by cells

Cytotoxic T lymphocytes

Activated macrophages

Lymphokines

ADCC

Virus infected cell

Virus, Virus-infected cell

Virus-infected cells, immunomodulation

Virus-infected cell

Humoral immune responses

Antibody

Antibody+ complement

Virus, Virus-infected cell

Virus, Virus-infected cell

Virus – virus interactions:

A virus-virus interaction (VVI) a measurable difference in the course of infection of one virus as a result of a concurrent or prior infection by a different species or strain of virus. A concurrent infection may include infection of the same cell by two or more virus species, or two viruses may infect different cell types within one organism and produce measurable VVIs. Measurable differences include changes in tissue permissiveness or tropism, viral replication, patterns of progeny production and release, latency, pathology including immunopathology, and immunological responses. The simple case of a prior viral infection conferring protective immunity against future infections with an immunologically identical virus is well known in vertebrates.

Last modified: Tuesday, 27 December 2011, 12:58 PM