<p>In a first, scientists have identified HIV reservoir cells where the virus can persist despite treatment, a finding that may pave the way for new therapies to effectively treat the disease.<br /><br />HIV cure research to date has focused on clearing the virus from T cells, a type of white blood cell that is an essential part of the immune system, researchers said.<br /><br />They found the virus persists in HIV-infected macrophages - large white blood cells found in tissues throughout the body including the liver, lung, bone marrow and brain.<br /><br />"These results are paradigm changing because they demonstrate that cells other than T cells can serve as a reservoir for HIV," said Jenna Honeycutt of University of North Carolina in the US.<br /><br />Researchers demonstrated the ability of tissue macrophages to support HIV replication in vivo in the total absence of human T cells.<br /><br />However, how macrophages would respond to antiretroviral therapy (ART) and whether macrophages represented a reservoir for HIV after treatment were unknown.<br /><br />Using a humanised myeloid-only mouse (MoM) model devoid of T cells, researchers showed that ART strongly suppresses HIV replication in tissue macrophages.<br /><br />Yet when HIV treatment was interrupted, viral rebound was observed in one third of the animals. This is consistent with the establishment of persistent infection in tissue macrophages, researchers said.<br /><br />"The fact that HIV-infected macrophages can persist means that any possible therapeutic intervention to eradicate HIV might have to target two very different types of cells," Honeycutt said.<br /><br />"This is the first report demonstrating that tissue macrophages can be infected and that they respond to antiretroviral therapy," Honeycutt said.<br /><br />"In addition, we show that productively infected macrophages can persist despite ART; and most importantly, that they can reinitiate and sustain infection upon therapy interruption even in the absence of T cells - the major target of HIV infection," she said.<br /><br />The study was published in the journal Nature Medicine. <br /></p>
<p>In a first, scientists have identified HIV reservoir cells where the virus can persist despite treatment, a finding that may pave the way for new therapies to effectively treat the disease.<br /><br />HIV cure research to date has focused on clearing the virus from T cells, a type of white blood cell that is an essential part of the immune system, researchers said.<br /><br />They found the virus persists in HIV-infected macrophages - large white blood cells found in tissues throughout the body including the liver, lung, bone marrow and brain.<br /><br />"These results are paradigm changing because they demonstrate that cells other than T cells can serve as a reservoir for HIV," said Jenna Honeycutt of University of North Carolina in the US.<br /><br />Researchers demonstrated the ability of tissue macrophages to support HIV replication in vivo in the total absence of human T cells.<br /><br />However, how macrophages would respond to antiretroviral therapy (ART) and whether macrophages represented a reservoir for HIV after treatment were unknown.<br /><br />Using a humanised myeloid-only mouse (MoM) model devoid of T cells, researchers showed that ART strongly suppresses HIV replication in tissue macrophages.<br /><br />Yet when HIV treatment was interrupted, viral rebound was observed in one third of the animals. This is consistent with the establishment of persistent infection in tissue macrophages, researchers said.<br /><br />"The fact that HIV-infected macrophages can persist means that any possible therapeutic intervention to eradicate HIV might have to target two very different types of cells," Honeycutt said.<br /><br />"This is the first report demonstrating that tissue macrophages can be infected and that they respond to antiretroviral therapy," Honeycutt said.<br /><br />"In addition, we show that productively infected macrophages can persist despite ART; and most importantly, that they can reinitiate and sustain infection upon therapy interruption even in the absence of T cells - the major target of HIV infection," she said.<br /><br />The study was published in the journal Nature Medicine. <br /></p>