@article{JacobsBockSchuchetal.2012, author = {Jacobs, Graeme and Bock, Stefanie and Schuch, Anita and Moschall, Rebecca and Schrom, Eva-Maria and Zahn, Juliane and Reuter, Christian and Preiser, Wolfgang and Rethwilm, Axel and Engelbrecht, Susan and Krekau, Thomas and Bodem, Jochen}, title = {Construction of a high titer Infectious HIV-1 subtype C proviral clone from South Africa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76340}, year = {2012}, abstract = {The Human Immunodeficiency Virus type 1 (HIV-1) subtype C is currently the predominant subtype worldwide. Cell culture studies of Sub-Saharan African subtype C proviral plasmids are hampered by the low replication capacity of the resulting viruses, although viral loads in subtype C infected patients are as high as those from patients with subtype B. Here, we describe the sequencing and construction of a new HIV-1 subtype C proviral clone (pZAC), replicating more than one order of magnitude better than the previous subtype C plasmids. We identify the env-region for being the determinant for the higher viral titers and the pZAC Env to be M-tropic. This higher replication capacity does not lead to a higher cytotoxicity compared to previously described subtype C viruses. In addition, the pZAC Vpu is also shown to be able to down-regulate CD4, but fails to fully counteract CD317.}, subject = {HIV}, language = {en} } @article{SpannausHartlWoehrletal.2012, author = {Spannaus, Ralf and Hartl, Maximilian J. and W{\"o}hrl, Birgitta M. and Rethwilm, Axel and Bodem, Jochen}, title = {The prototype foamy virus protease is active independently of the integrase domain}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75370}, year = {2012}, abstract = {Background: Recently, contradictory results on foamy virus protease activity were published. While our own results indicated that protease activity is regulated by the viral RNA, others suggested that the integrase is involved in the regulation of the protease. Results: To solve this discrepancy we performed additional experiments showing that the protease-reverse transcriptase (PR-RT) exhibits protease activity in vitro and in vivo, which is independent of the integrase domain. In contrast, Pol incorporation, and therefore PR activity in the viral context, is dependent on the integrase domain. To further analyse the regulation of the protease, we incorporated Pol in viruses by expressing a GagPol fusion protein, which supported near wild-type like infectivity. A GagPR-RT fusion, lacking the integrase domain, also resulted in wild-type like Gag processing, indicating that the integrase is dispensable for viral Gag maturation. Furthermore, we demonstrate with a trans-complementation assays that the PR in the context of the PR-RT protein supports in trans both, viral maturation and infectivity. Conclusion: We provide evidence that the FV integrase is required for Pol encapsidation and that the FV PR activity is integrase independent. We show that an active PR can be encapsidated in trans as a GagPR-RT fusion protein.}, subject = {Medizin}, language = {en} }