HIV-specific broadly neutralizing antibodies are promising
Combined antiretroviral therapy (ART) has revolutionized the treatment and prevention of HIV infection. Taken daily, it suppresses the virus or reduces the risk of infection (PrEP) to near zero. However, a violation of the systematic use of medication almost always leads to an increase in viral load. The reason for this is the existence of hidden “reservoirs” of HIV.
Knowing this, scientists in many countries do not stop trying to develop a technique to counter the virus, which, along with greater efficiency, will provide for avoiding lifelong therapy.
Recent preclinical and clinical studies have demonstrated that immunotherapy can be an alternative or adjuvant for ART, because widely neutralized HIV-specific antibodies (bNab) detected by specialists in addition to preventing the penetration of viral strains in the body can also clear it of infected cells and significantly improve the immunity to HIV
As part of the Seattle Retrovirus and Opportunistic Infections (CROI) Conference, Michel Nussenzweig presented a report on the challenges and prospects for studying HIV-specific bNabs.
According to him, the problem of working with antibodies is that they are far from being formed by all PLHIV. Mutations are an extremely long process, therefore, to solve this problem, scientists began to clone universally active antibodies, which subsequently received the name of widely neutralized (bNabs).
This method is similar to the development of a vaccine, Nussenzweig explained.
Conducting experiments on rodents, experts have received very encouraging results. Having different goals, the antibodies did not interfere with each other and increased the efficiency of immunity.
Macaque observations gave similar results. The introduction of antibodies to primates 3 days after infection allowed them to reach an undetectable viral load (HV) after an average of 100 days. At the same time, 4 of the 30 monkeys demonstrated control over HH and CD4 for a long time. Obviously, similar mechanisms can be traced in cancer immunotherapy, the speaker suggested.
Currently, several antibodies are undergoing clinical trials at once. Not all of them demonstrate similar effectiveness, but it is already clear that the use of bNabs combinations will be a promising direction. For example, this approach promises to be useful if the carrier of the virus develops resistance to one of the antibodies.
Dr. Nussenzweig explained that bNabs has one significant advantage over antiretroviral therapy: widely neutralizing antibodies, acting like a vaccine, make a person’s immune system work harder, thereby increasing its resistance to the virus.
Concluding the review of studies, the scientist once again drew the attention of the conference participants to the fact that despite the noticeable progress in the study of antibodies, experts still have quite a lot of questions about the mechanism of action of bNabs (pharmacokinetics) and the safety of their use.
But in any case, he noted, this direction does not cease to remain promising, and researchers have something to work on and where to go.