{"id":142,"date":"2008-10-30T12:41:44","date_gmt":"2008-10-30T11:41:44","guid":{"rendered":"http:\/\/localhost\/new\/htb\/?p=142"},"modified":"2013-08-23T13:51:36","modified_gmt":"2013-08-23T13:51:36","slug":"tenofovir-gel-as-a-rectal-microbicide-evidence-for-protection-and-priming-of-t-cell-responses-in-the-siv-challenge-model","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/142","title":{"rendered":"Tenofovir gel as a rectal microbicide: evidence for protection and priming of T-cell responses in the SIV challenge model"},"content":{"rendered":"<p><strong>Richard Jefferys, TAG<\/strong><\/p>\n<p><strong>The new PLoS Medicine features a study conducted by Martin Cranage and colleagues evaluating tenofovir gel as a potential rectal microbicide in the SIV challenge model. The researchers report that application of the gel two hours prior to exposure to the SIVmac251\/32H challenge virus protected six out of nine macaques. Of the remaining three, two showed lowered viral loads post-infection compared to controls. Interestingly, most of the protected animals also displayed detectable SIV-specific T cell responses even though sensitive assays could find no trace of virus.<\/strong><\/p>\n<p>The PLoS editor&#8217;s summary raises the concern that these SIV-specific T cells may be associated with enhanced susceptibility to infection upon re-exposure; however, Cranage et al note in their discussion that transient tenofovir treatment immediately post SIV infection has been shown to lead to induction of SIV-specific T cell responses, and macaques (<a href=\"http:\/\/jvi.asm.org\/\">http:\/\/jvi.asm.org\/cgi\/content\/full\/75\/21\/10187<\/a>) in this study subsequently resisted both homologous and heterologous SIV challenges. The question of whether the SIV-specific T cell responses observed in Cranage&#8217;s study have the potential to be protective can only be definitively addressed by another experiment in which the macaques are re-challenged with SIV.<\/p>\n<p>An additional implication of these data is that human trials of microbicides and pre-exposure prophylaxis (PrEP) should include monitoring for HIV-specific T cell responses.<\/p>\n<p>Source: TAG Basic Science Blog 06 Aug 2008 <a href=\"http:\/\/tagbasicscienceproject.typepad.com\/tags_basic_science_vaccin\/2008\/08\/tenofovir-gel-a.html\"><br \/>\nhttp:\/\/tagbasicscienceproject.typepad.com\/tags_bas ic_science_vaccin\/ 2008\/08\/tenofovir-gel-a.html<\/a><\/p>\n<p>Reference:<\/p>\n<p>Cranage M et al. Prevention of SIV Rectal Transmission and Priming of T Cell Responses in Macaques after Local Pre-exposure Application of Tenofovir Gel. PLoS Medicine Vol. 5, No. 8, e157 doi:10.1371\/journal.pmed.0050157<br \/>\n<a href=\"http:\/\/medicine.plosjournals.org\/perlserv\/?request=get-document&amp;doi=10.1371\/journal.pmed.0050157\">http:\/\/medicine.plosjournals.org\/perlserv\/ ?request=get-document&amp;doi=10.1371\/journal.pmed.0050157<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Richard Jefferys, TAG The new PLoS Medicine features a study conducted by Martin Cranage and colleagues evaluating tenofovir gel as a potential rectal microbicide in the SIV challenge model. The researchers report that application of the gel two hours prior &hellip;<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[],"class_list":["post-142","post","type-post","status-publish","format-standard","hentry","category-transmission-and-prevention"],"_links":{"self":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/142","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/comments?post=142"}],"version-history":[{"count":0,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/142\/revisions"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/media?parent=142"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/categories?post=142"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/tags?post=142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}