Jan. 25 (UPI) -- New research by the University College London has discovered the method the HIV virus uses to infect macrophages, which could potentially lead to a cure for HIV.
Macrophages are a type of white blood cell vital to the function of the immune system. Macrophages have an antiviral protein called SAMHD1, which can prevent HIV from replicating. However, when SAMHD1 is turned off, the virus is able to infect macrophages by penetrating its protective protein barrier.
"We knew that SAMHD1 is switched off when cells multiply, but macrophages do not multiply so it seemed unlikely that SAMHD1 would be switched off in these cells," Professor Ravindra Gupta of UCL Infection & Immunity and senior author of the study, said in a press release. "And yet we found there's a window of opportunity when SAMHD1 is disabled as part of a regularly-occurring process in macrophages."
Researchers do not know why SAMHD1 gets switched off but think it might happen so damaged DNA can be repaired.
"Other viruses can disable SAMHD1, but HIV cannot," Dr. Petra Micochova, lead author of the study, said in a press release. "Our work explains how HIV can still infect macrophages, which are disabling SAMHD1 by themselves."
Researchers also learned how to prevent HIV from infecting macrophages by treating the cells with HDAC inhibitors.
The study found that when a macrophage is infected, it continually makes the HIV virus and that by stopping this process at the point of infection, it could prevent the spread of the disease.
"Our findings could help explain why some people undergoing anti-retroviral therapy for HIV continue to have HIV replication in the brain, as the infected cells in the brain are typically macrophages," Gupta said. "While this is a barrier to achieving control of HIV in just a minority of patients, it may more importantly be a barrier to a cure."
The study was published in the EMBO Journal.
