A collaborative team of researchers may have cracked the code behind the substantially reduced HIV viral loads detected in infected individuals of African descent. Viral load denotes the concentration of the virus present within an HIV-positive individual’s system.
Enhanced virus levels correlate with swifter disease advancement and increased transmission vulnerability. Multiple factors contribute to virus levels, diverging significantly among individuals living with HIV. Genetic composition is a pivotal determinant of these levels.
The African population harbors a unique genetic variant that yields a diminished viral load, thus reducing the transmission of the virus. This intrinsic mechanism curbs disease progression, as elucidated in a pioneering study featured in the esteemed scientific journal Nature.
The research consortium consisted of scientists hailing from the Canadian National Microbiology’s Public Health Agency, the Department of Medicine at the University of Cambridge, and London’s Imperial College.
This team’s tireless efforts spanned almost three decades, culminating in unprecedented findings. “Our success in identifying not only a new genetic variation but one specific to this population, associated with lower HIV viral loads, stems from meticulous analysis of an extensive African sample,” explained Paul McLaren, the lead author from the Public Health Agency.
Promisingly, these findings could revolutionize the quest for an HIV cure, a pursuit that has long proven elusive. HIV remains a formidable global public health challenge, claiming 40.4 million lives to date and continuing its spread across all nations.
Some regions report concerning upticks in new infections. At the close of 2022, an estimated 39.0 million individuals lived with HIV, with the World Health Organization revealing that two-thirds of these cases were concentrated in the African Region.
Experts lament the scarcity of information concerning the intricate link between DNA and HIV within African populations. Despite Africa enduring the brunt of the HIV epidemic, research disproportionately concentrates on European demographics.
“The imperative of comprehending the genetic role in HIV infection among African populations cannot be overstated. This continent, harboring over 25 million individuals living with HIV, bears a disproportionate burden of the virus,” emphasized these experts.
“While Africans endure the gravest impact of HIV infection, their representation in DNA-related studies remains woefully inadequate.”
Analyzing DNA samples from roughly 4,000 African individuals afflicted by the prevalent HIV-1 strain, researchers pinpointed a variation within chromosome 1 housing the CHD1L gene. This gene emerges as a hallmark among individuals boasting lower viral levels.
Renowned for its role in repairing damaged DNA, the specific relevance of CHD1L in reducing viral load prompts ongoing exploration. The researchers estimate that this variant is carried by between four to thirteen percent of individuals with African ancestry.
Researchers leveraged generated cell variants susceptible to HIV infection through stem cells, as the virus predominantly targets immune cells. Intriguingly, they observed that CHD1L activity was either suppressed or deactivated.
Surprisingly, while HIV replication within macrophages—a type of immune cell—increased upon CHD1L deactivation, no such effect manifested in T cells, where the majority of HIV replication occurs.
Lead researchers André Lever and Dr. Harriet Groom expressed that “the gene appears to play a crucial role in modulating virus levels within African populations. Although the mechanism remains to be unveiled, each revelation brings new insight into HIV control. We not only glean information about the virus but also about cellular dynamics.”
Dr. Groom further remarked, “The unexpected and intriguing connection between viral load and HIV replication within macrophages adds a new layer of complexity.”
Professor Manjinder Sandhu, co-author of the research at London’s Imperial College Faculty of Medicine, underscores that the battle against HIV remains a formidable challenge.
“A cure remains elusive, a preventive vaccine is yet to be discovered, and some individuals are still developing drug resistance. Clearly, the fight against the virus has a long road ahead, with over a million new infections reported annually,” Prof. Sandhu emphasized.
He emphasizes the urgent need for a comprehensive understanding of how the genetic variant controls HIV replication.