Báo cáo y học: Retroviral superinfection resistance

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài:"Retroviral superinfection resistance
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Báo cáo y học: "Retroviral superinfection resistance"Retrovirology BioMed Central Open AccessReviewRetroviral superinfection resistanceMicha Nethe, Ben Berkhout and Antoinette C van der Kuyl*Address: Dept. of Human Retrovirology, Academic Medical Centre, University of Amsterdam, Meibergdreef 15, 1105AZ Amsterdam, TheNetherlandsEmail: Micha Nethe - michanethe@hotmail.com; Ben Berkhout - b.berkhout@amc.uva.nl; Antoinette C van derKuyl* - a.c.vanderkuyl@amc.uva.nl* Corresponding authorPublished: 18 August 2005 Received: 18 April 2005 Accepted: 18 August 2005Retrovirology 2005, 2:52 doi:10.1186/1742-4690-2-52This article is available from: http://www.retrovirology.com/content/2/1/52© 2005 Nethe et al; licensee BioMed Central Ltd.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract The retroviral phenomenon of superinfection resistance (SIR) defines an interference mechanism that is established after primary infection, preventing the infected cell from being superinfected by a similar type of virus. This review describes our present understanding of the underlying mechanisms of SIR established by three characteristic retroviruses: Murine Leukaemia Virus (MuLV), Foamy Virus (FV), and Human Immunodeficiency Virus (HIV). In addition, SIR is discussed with respect to HIV superinfection of humans. MuLV resistant mice exhibit two genetic resistance traits related to SIR. The cellular Fv4 gene expresses an Env related protein that establishes resistance against MuLV infection. Another mouse gene (Fv1) mediates MuLV resistance by expression of a sequence that is distantly related to Gag and that blocks the viral infection after the reverse transcription step. FVs induce two distinct mechanisms of superinfection resistance. First, expression of the Env protein results in SIR, probably by occupancy of the cellular receptors for FV entry. Second, an increase in the concentration of the viral Bet (Between-env-and-LTR-1-and-2) protein reduces proviral FV gene expression by inhibition of the transcriptional activator protein Tas (Transactivator of spumaviruses). In contrast to SIR in FV and MuLV infection, the underlying mechanism of SIR in HIV-infected cells is poorly understood. CD4 receptor down-modulation, a major characteristic of HIV-infected cells, has been proposed to be the main mechanism of SIR against HIV, but data have been contradictory. Several recent studies report the occurrence of HIV superinfection in humans; an event associated with the generation of recombinant HIV strains and possibly with increased disease progression. The role of SIR in protecting patients from HIV superinfection has not been studied so far. The phenomenon of SIR may also be important in the protection of primates that are vaccinated with live attenuated simian immunodeficiency virus (SIV) against pathogenic SIV variants. As primate models of SIV infection closely resemble HIV infection, a better knowledge of SIR-induced mechanisms could contribute to the development of an HIV vaccine or other antiviral strategies. Page 1 of 13 (page number not for citation purposes)Retrovirology 2005, 2:52 http://www.retrovirology.com/content/2/1/52 ferent cell lines were found to express functional variantsIntroductionViral entry and replication is a complex process that of the ecotropic-, polytropic-, and xenotropic-MuLVinvolves multiple viral and host proteins. Many host gene receptors, which block infection by certain MuLV stra ...