FDA approved anti-inflammatory drugs may have a positive impact on the HIV infected cells and their reservoir.
Highlights
- Anti-inflammatory medications such as tofacitinib and ruxolitinib can block viral production in HIV infected cells, prevent their transmission to other healthy cells and decay their viral reservoir
- The size of the HIV reservoir was found to be linked to the activity of Jak enzymes in the cells.
- Blocking Jak enzymes could impose a drought on the HIV reservoir.
"These are a very small number of immune cells that have the virus integrated into their genomes. These cells are completely undetectable by the immune system because the virus is dormant. But as soon as you stop treatment, the virus reactivates. Our results show you can kill these reservoir cells if you treat them with Jak inhibitors."
The new study included 37 people infected with HIV, but who have controlled the virus with antiretroviral drugs. The size of their residual reservoir - the number of cells with HIV integrated into their DNA - was linked to the activity of Jak enzymes in the cells. The research suggests blocking Jak enzymes could, in effect, impose a drought on the HIV reservoir. Laboratory experiments confirmed that Jak inhibitors prevent HIV spread to nearby, healthy cells.
Jak inhibitors block key pro-inflammatory cytokines that are dysregulated in certain diseases including autoimmune disorders such as rheumatoid arthritis. In blocking these inflammatory cytokines, Jak inhibitors restore the inflammatory state to a "normal" level observed in individuals without an inflammatory disorder.
Sékaly's foundational research into HIV reservoir persistence made him a natural collaborator for researchers at Emory with expertise in small molecule Jak inhibitors. Co-corresponding author on the study is Raymond F. Schinazi, Ph.D., DSc, a Frances Winship Walters Professor of Pediatrics and Director of the Laboratory of Biochemical Pharmacology at Emory University. Schinazi is also the director of the HIV Cure Scientific Working Group at the Emory University Center for AIDS Research. One of the study's three first authors, Christina Gavegnano, Ph.D. is an Assistant Professor in Dr. Schinazi's group. Schinazi and Gavegnano previously reported that Jak inhibitors demonstrate antiviral potency in human immune cells and that ruxolitinib can ameliorate HIV-associated encephalitis in a mouse model.
A key safety feature of Jak inhibitors in the study is that they are not globally immunosuppressive, but instead immunomodulatory. Said Sékaly, "Our results show how Jak inhibitors do not prevent the reservoir cells from responding to new infections."
Since Jak is overactive in HIV-infected cells, Jak inhibitors can specifically target inflammatory cytokines in the cells that cause them to activate and "reseed" nearby cells. HIV requires cellular activation to replicate efficiently. Blocking key inflammatory cytokines in HIV-infected cells with a Jak inhibitor creates an environment where the virus simply cannot replicate because it cannot properly activate the cell. The unique mechanism of action allows Jak inhibitors to block viral replication in infected cells, reduce the lifespan of reservoir cells (key markers such as Bcl-2 are down-regulated), and block expansion of the viral reservoir.
Explained Gavegnano, "Jak inhibitors are unique since they are highly selective agents that keep the lid on smoldering infection through anti-inflammatory properties. If the lid is on the smoldering fire long enough, it is our hope that the fire will be extinguished."
The study results have strengthened rationale for an ongoing, AIDS Clinical Trial Group (ACTG) Phase 2a multi-site trial to evaluate the safety, tolerability, and efficacy of ruxolitinib in HIV-infected individuals. "We are rigorously evaluating the effect of Jak inhibitors on key events that prevent the eradication of HIV in culture, animal models, and humans," said Gavegnano.
"We are also carefully monitoring safety.It is important to evaluate these agents from every possible angle, to ensure that we are delivering a safe and effective treatment. Our data to date provides a reason to explore the indication of HIV for Jak inhibitors carefully. We look forward to understanding how blocking residual inflammation in HIV-infected cells can impact the ultimate goal of a cure." continued Ms.Gavegnano.
References
- Christina Gavegnano , Jessica H. Brehm , Franck P. Dupuy.et.al. Novel mechanisms to inhibit HIV reservoir seeding using Jak inhibitors, PLOS Pathogens (2017).https://doi.org/10.1371/journal.ppat.1006740
Source-Eurekalert