Susceptibility of XMRV to retroviral restriction factors


Senior Member
North West, England, UK
Could someone please explain the following to a layman?

Apologies if already posted.

Susceptibility of xenotropic murine leukemia virus-related virus (XMRV) to retroviral restriction factors

Xenotropic murine leukemia virus-related virus (XMRV) is a recently discovered gammaretrovirus that has been linked to prostate cancer and chronic fatigue syndrome. This virus is therefore an important potential human pathogen and, as such, it is essential to understand its host cell tropism. Intriguingly, infectious virus has been recovered from patient-derived peripheral blood mononuclear cells. These cells express several antiviral restriction factors that are capable of inhibiting the replication of a wide range of retroviruses, including other gamma retroviruses. This raises the possibility that, similar to HIV, XMRV may have acquired resistance to restriction. We therefore investigated the susceptibility of XMRV to a panel of different restriction factors. We found that both human APOBEC3 and tetherin proteins are able to block XMRV replication. Expression of human TRIM5α, however, had no effect on viral infectivity. There was no evidence that XMRV expressed countermeasures to overcome restriction. In addition, the virus was inhibited by factors from nonhuman species, including mouse Apobec3, tetherin, and Fv1 proteins. These results have important implications for predicting the natural target cells for XMRV replication, for relating infection to viral pathogenicity and pathology, and for the design of model systems with which to study XMRV-related diseases.


Could someone please explain the following to a layman?

Apologies if already posted.

The extract comes from a paper by groom.Once cells are infected by viruses the cells produce molecules aimed to repell the virus and to recruit elements of the immune system.they are called restrictive factors or restriction factors.

APOBEC3 and TETHERIN block XMRV but TRIM alpha does not.

ABOBEC3 and TETHERIN are found expressed in the cells that the WPI found XMRV in.Groom is slyly suggesting that there is something wrong with their results because the molecules in those cells would kill XMRV

.Other viruses of the same family as XMRV get over this by traveling about in the corridors between the cell walls and avoid the cytoplasm

The fact that trim alpha doesnt inhibit XMRV means that the virus can get past the front line of the immune system and begin replication before the main arsenal is alerted---it gives it a head start if you like.

this how aids establishes a hold so quickly.