Myxoma virus expresses a TNF receptor homolog with two distinct functions.
Myxoma virus, a member of the poxvirus family of DNA viruses, encodes many virulence factors to combat and evade the host immune responses. Among the virus-encoded immuno-modulators is M-T2, a tumor necrosis factor receptor (TNF-R) homologue. M-T2 is secreted as monomeric and dimeric species that bind and inhibit rabbit TNF in a species-specific manner. Deletion analysis indicates that the anti-TNF function is mediated by the first three of four cysteine rich domains (CRDs) of M-T2. In addition, the intracellular form of M-T2 has the ability to block virus-induced apoptosis in lymphocytes, and the first two CRDs appear to be sufficient for this function. Although the mechanisms for the anti-TNF and anti-apoptotic functions of M-T2 are not yet fully defined, we postulate that these dual activities of M-T2 are mediated through different functional motifs and abrogate distinct cellular responses to virus infection.
Xu
X
X
Department of Microbiology and Immunology, University of Western Ontario and The John P. Robarts Research Institute, London, Ontario, Canada.
Nash
P
P
McFadden
G
G
D000595:Amino Acid Sequence; D000818:Animals; D008969:Molecular Sequence Data; D009233:Myxoma virus / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011213:Poxviridae Infections / Q000821:virology; D011817:Rabbits; D018124:Receptors, Tumor Necrosis Factor / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014412:Tumor Virus Infections / Q000821:virology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
C104612:M-T2 protein, Myxoma virus; D018124:Receptors, Tumor Necrosis Factor; D014764:Viral Proteins