From Chronic Disease to Functional Cure: Two Landmark Nature Studies Reveal Path to HIV Remission

Since the advent of antiretroviral therapy (ART),HIV/AIDS has transformed from a fatal, incurable disease into a manageable chronic condition.However, ART is not a perfect cure. While it can potently suppress viral replication, it cannot eliminate the “viral reservoir” latent within the body. Once patients discontinue medication, viral rebound is almost inevitable within weeks. Therefore, patients must adhere to lifelong therapy, which not only poses risks of long-term side effects and financial burden but also carries persistent social stigma.

The scientific community has been committed to finding a“Functional Cure” Protocol, namely, to achieve long-term control of the virus through the patient’s own immune system without complete viral eradication, thereby eliminating the need for lifelong medication.

Recently, the top academic journal *Nature* published back-to-back landmark studies from the Ragon Institute and the University of California, San Francisco (UCSF), which not onlyAchieved Long-Term Drug Discontinuation Control in Some Patients in Clinical Trials, more importantly, they jointly reveal aKey Immune Mechanisms for Achieving a Functional Cure: A special subset of “stem-like” CD8+ T cells (stem-like CD8+ T cells).

Although these two studies employed different treatment regimens, both focused on leveraging broadly neutralizing antibodies (bNAbs) as a core therapeutic strategy and observed similarly encouraging results. The study led by David Collins’ team at the Ragon Institute analyzed blood samples from participants in four previous clinical trials. These patients received broadly neutralizing antibody therapy after discontinuing antiretroviral medication. The results showed that approximately 14% to 22% of participants maintained viral control for at least two months even after antibody levels declined.One of the “super controllers” even maintained low viral levels for over seven years without medication.

Meanwhile, the team led by Rachel Rutishauser at the University of California, San Francisco (UCSF), adopted a more aggressive combination strategy. They enrolled 10 patients in a “tripartite” immunotherapy regimen comprising an experimental HIV vaccine designed to enhance T-cell responses, a TLR9 agonist (Lefitolimod) aimed at “shocking” latent viral reservoirs and activating innate immunity, and two long-acting broadly neutralizing antibodies. Trial results showed thatSeven of the 10 participants achieved prolonged viral control.One patient, Tom Perrault, successfully maintained viral control for four months after discontinuing medication, a phenomenon that is extremely rare in previous single-intervention studies.

Why Do Some Patients Achieve Control While Others Experience Rapid Relapse?

The two teams conducted an in-depth analysis of the immune systems of “controllers” and were surprised to discover the same key signal:TCF-1+ CD8+ T cells.Typically, CD8+ T cells (cytotoxic T cells) responsible for killing viruses become exhausted during prolonged battles. However, research has identified a distinct population of CD8+ T cell precursors in patients who successfully control viral infection. These cells exhibit high expression of the transcription factor TCF-1 and possess stem cell-like properties. They are capable not only of self-renewal to ensure a sustained supply of cellular resources but also of rapid differentiation into highly cytotoxic effector T cells. When the virus attempts to rebound, this “special forces” cohort can rapidly proliferate and differentiate, thereby suppressing the virus once again.

David Collins vividlyCompare this process to a “relay race.”When patients discontinue antiretroviral therapy (ART), long-acting broadly neutralizing antibodies (bNAbs) in the body serve as the first line of defense, suppressing rapid viral rebound and buying valuable time for the immune system. During this buffer period, “stem-like” CD8+ T cells have sufficient time to mature and differentiate into large numbers of cytotoxic T cells. As bNAb levels gradually wane, the mature T cell army is already poised and ready, successfully taking over the baton in controlling the virus. Without the “head start” provided by bNAbs, the fast-replicating virus would quickly overwhelm the immune system, causing T cells to collapse before they could mount an effective response.

These two studies are consideredIt is a milestone in the field of HIV cure research.Previous cure cases (such as the "Berlin Patient") largely relied on high-risk hematopoietic stem cell transplantation, which is difficult to replicate and scale, whereas this study achieved similar immune control through pharmacological intervention.It points the way toward developing scalable “functional cure” therapies.Moreover, the discovery of TCF-1+ CD8+ T cells provides a clear monitoring biomarker for future clinical trials, enabling scientists to focus on developing drugs or vaccines that can specifically expand this cell population. Furthermore, research from UCSF indicates that a single modality may be insufficient to address the complex HIV reservoir, and future cure strategies are likely to be“Vaccines + Antibodies + Immunomodulators”combination punch.

Although the current study has a small sample size and not all patients responded, as Sharon Lewin, Director of the Peter Doherty Institute for Infection and Immunity, stated, this is an extremely important observation that allows the field to move forward. As the scientific community deepens its understanding of this population of “stem-like” T cells, we have reason to believe that achieving “drug-free control” of HIV through precise modulation of the body’s own immune system will no longer be an unattainable dream.