Poxviruses Flashcards

Flashcards covering key vocabulary and concepts related to poxviruses, their structure, replication, and medical perspectives.

Chordopoxvirinae

A subfamily of poxviruses that infect vertebrates; contains 18 genera.

Entomopoxvirinae

A subfamily of poxviruses that infect invertebrates; contains 4 genera.

Virion Structure

Oval or brick-shaped particles 200-400nm long with ridged external surface; complex structure with >100 virus-encoded proteins; resistant to degradation.

Extracellular Enveloped Virions (EEV)

Mature virion form containing 2 membranes.

Intracellular Mature Virions (IMV)

Mature virion form with only an inner membrane.

Poxvirus Genome

Linear dsDNA genome of 130-375kb, encodes ~200 proteins, flanked by inverted terminal repeat (ITR) sequences.

NCLDVs

Nucleocytoplasmic large DNA viruses that share a range of genes and replicate in the cytoplasm, independently of the cell nucleus.

Entry-Fusion Complex

Located in the outer membrane of vaccinia virus. Formed from 4 types of attachment proteins and 11 different fusion proteins and is required for attachment, membrane fusion and core entry.

Temporal Gene Expression

Poxvirus genes are expressed in phases: early, intermediate, and late, regulated by promoter consensus sequences and specific transcription factors.

Viroceptors

Secreted versions of cellular cytokine receptors used by poxviruses for immune evasion.

Virokines

Secreted molecules that are either agonistic or antagonistic ligands for host cellular receptors, used by poxviruses for immune modulation.

Smallpox

Caused by Variola virus; two forms: major (high mortality) and minor (low mortality); transmission via aerosolized droplets, direct contact, fomites.

Molluscum Contagiosum

Caused by Molluscipoxvirus; tropism for human keratinocytes; transmission via direct skin-skin contact; presents as skin blisters.

Mpox

Caused by Orthopoxvirus; symptoms similar to mild smallpox; zoonotic infection with rodent reservoir; transmission via direct contact with blood, bodily fluids, or lesions.

Tecovirimat

Antiviral that inhibits VP37 envelope wrapping protein, limiting EEV release and dissemination; used as a treatment for orthopoxviruses like mpox.