UMMS Affiliation

Program in Molecular Medicine

Publication Date


Document Type



Immunology and Infectious Disease | Immunology of Infectious Disease | Immunoprophylaxis and Therapy | Infectious Disease | Microbiology


HIV-2 and SIVMAC are AIDS-causing, zoonotic lentiviruses that jumped to humans and rhesus macaques, respectively, from SIVSM-bearing sooty mangabey monkeys. Cross-species transmission events such as these sometimes necessitate virus adaptation to species-specific, host restriction factors such as TRIM5. Here, a new human restriction activity is described that blocks viruses of the SIVSM/SIVMAC/HIV-2 lineage. Human T, B, and myeloid cell lines, peripheral blood mononuclear cells and dendritic cells were 4 to > 100-fold less transducible by VSV G-pseudotyped SIVMAC, HIV-2, or SIVSM than by HIV-1. In contrast, transduction of six epithelial cell lines was equivalent to that by HIV-1. Substitution of HIV-1 CA with the SIVMAC or HIV-2 CA was sufficient to reduce HIV-1 transduction to the level of the respective vectors. Among such CA chimeras there was a general trend such that CAs from epidemic HIV-2 Group A and B isolates were the most infectious on human T cells, CA from a 1 degrees sooty mangabey isolate was the least infectious, and non-epidemic HIV-2 Group D, E, F, and G CAs were in the middle. The CA-specific decrease in infectivity was observed with either HIV-1, HIV-2, ecotropic MLV, or ALV Env pseudotypes, indicating that it was independent of the virus entry pathway. As2O3, a drug that suppresses TRIM5-mediated restriction, increased human blood cell transduction by SIVMAC but not by HIV-1. Nonetheless, elimination of TRIM5 restriction activity did not rescue SIVMAC transduction. Also, in contrast to TRIM5-mediated restriction, the SIVMAC CA-specific block occurred after completion of reverse transcription and the formation of 2-LTR circles, but before establishment of the provirus. Transduction efficiency in heterokaryons generated by fusing epithelial cells with T cells resembled that in the T cells, indicative of a dominant-acting SIVMAC restriction activity in the latter. These results suggest that the nucleus of human blood cells possesses a restriction factor specific for the CA of HIV-2/SIVMAC/SIVSM and that cross-species transmission of SIVSM to human T cells necessitated adaptation of HIV-2 to this putative restriction factor.


HIV-1, T cells, HIV-2, Human blood cells, Vector-borne diseases, Viral vectors, Vesicular stomatitis virus, SIV

Rights and Permissions

Copyright: © 2015 Pizzato et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

DOI of Published Version



PLoS Pathog. 2015 Jul 16;11(7):e1005050. doi: 10.1371/journal.ppat.1005050. eCollection 2015. Link to article on publisher's site

Journal/Book/Conference Title

PLoS pathogens

Related Resources

Link to Article in PubMed

PubMed ID


Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.