Long-term Persistent Elite HIV-controllers: The Right Model of Functional Cure

The HIV-1 reservoir landscape in persistent elite controllers and transient elite controllers

BACKGROUNDPersistent controllers (PCs) maintain antiretroviral-free HIV-1 control indefinitely over time, while transient controllers (TCs) eventually lose virological control. It is essential to characterize the quality of the HIV reservoir in terms of these phenotypes in order to identify the factors that lead to HIV progression and to open new avenues toward an HIV cure.METHODSThe characterization of HIV-1 reservoir from peripheral blood mononuclear cells was performed using next-generation sequencing techniques, such as full-length individual and matched integration site proviral sequencing (FLIP-Seq; MIP-Seq).RESULTSPCs and TCs, before losing virological control, presented significantly lower total, intact, and defective proviruses compared with those of participants on antiretroviral therapy (ART). No differences were found in total and defective proviruses between PCs and TCs. However, intact provirus levels were lower in PCs compared with TCs; indeed the intact/defective HIV-DNA ratio was significantly higher in TCs. Clonally expanded intact proviruses were found only in PCs and located in centromeric satellite DNA or zinc-finger genes, both associated with heterochromatin features. In contrast, sampled intact proviruses were located in permissive genic euchromatic positions in TCs.CONCLUSIONSThese results suggest the need for, and can give guidance to, the design of future research to identify a distinct proviral landscape that may be associated with the persistent control of HIV-1 without ART.FUNDINGInstituto de Salud Carlos III (FI17/00186, FI19/00083, MV20/00057, PI18/01532, PI19/01127 and PI22/01796), Gilead Fellowships (GLD22/00147). NIH grants AI155171, AI116228, AI078799, HL134539, DA047034, MH134823, amfAR ARCHE and the Bill and Melinda Gates Foundation.

Bibliometric and visualized analysis of elite controllers based on CiteSpace: landscapes, hotspots, and frontiers

Background

A unique subset of people living with HIV, known as elite controllers, possess spontaneous and consistent control over viral replication and disease progression in the absence of antiviral intervention. In-depth research on elite controllers is conducive to designing better treatment strategies for HIV. However, comprehensive and illuminating bibliometric reports on elite controllers are rare.

Methods

Articles on elite controllers were retrieved from the Web of Science Core Collection. A visualized analysis of this domain was conducted by CiteSpace software. Taking count, betweenness centrality, and burst value as criteria, we interpreted the visualization results and predicted future new directions and emerging trends.

Results

By December 31, 2022, 843 articles related to elite controllers had been published. The largest contributors in terms of country, institution, and author were the United States (485), Univ Calif San Francisco (87), and Walker B.D. (65), respectively. Migueles S.A. (325) and Journal of Virology (770) were the most cocited author and journal, respectively. Additionally, by summarizing the results of our CiteSpace software analysis on references and keywords, we considered that the research hotspots and frontiers on elite controllers mainly focus on three aspects: deciphering the mechanisms of durable control, delineating the implications for the development of treatments for HIV infection, and highlighting the clinical risks faced by elite controllers and coping strategies.

Conclusion

This study performed a bibliometric and visual analysis of elite controllers, identified the main characteristics and emerging trends, and provided insightful references for further development of this rapidly evolving and complex field.

HIV-2 as a model to identify a functional HIV cure

Two HIV virus types exist: HIV-1 is pandemic and aggressive, whereas HIV-2 is confined mainly to West Africa and less pathogenic. Despite the fact that it has been almost 40 years since the discovery of AIDS, there is still no cure or vaccine against HIV. Consequently, the concepts of functional vaccines and cures that aim to limit HIV disease progression and spread by persistent control of viral replication without life-long treatment have been suggested as more feasible options to control the HIV pandemic. To identify virus-host mechanisms that could be targeted for functional cure development, researchers have focused on a small fraction of HIV-1 infected individuals that control their infection spontaneously, so-called elite controllers. However, these efforts have not been able to unravel the key mechanisms of the infection control. This is partly due to lack in statistical power since only 0.15% of HIV-1 infected individuals are natural elite controllers. The proportion of long-term viral control is larger in HIV-2 infection compared with HIV-1 infection. We therefore present the idea of using HIV-2 as a model for finding a functional cure against HIV. Understanding the key differences between HIV-1 and HIV-2 infections, and the cross-reactive effects in HIV-1/HIV-2 dual-infection could provide novel insights in developing functional HIV cures and vaccines.

Proviral Quasispecies Diversity Is Not Associated With Virologic Breakthrough or CD4+ T Cell Loss in HIV-1 Elite Controllers

Elite controllers (EC) are able to control HIV-1 replication to extremely low levels (<50 HIV-1 RNA copies/mL) in the absence of antiretroviral therapy. However, some EC experience CD4⁺ T cell loss and/or lose their ability to control HIV-1 over the course of infection. High levels of HIV-1 env proviral diversity, activated T cells and proinflammatory cytokines were pointed out as relevant biomarkers for detection of EC at risk of virologic/immunologic progression. The aim of this study was to assess the importance of proviral diversity as a prognostic marker of virologic and/or immunologic progression in EC. To this end, we analyzed plasma viremia, total HIV DNA levels, T cells dynamics, and activation/inflammatory biomarkers in EC with low (EC_LD = 4) and high (EC_HD = 6) HIV-1 env diversity. None of EC_LD and EC_HD subjects displayed evidence of immunologic progression (decrease in absolute and percentage of CD4⁺ T cells) and only one EC_HD subject presented virologic progression (≥2 consecutive viral loads measurements above the detection limit) 2–5 years after determination of proviral env diversity. Despite differences in proviral genetic diversity, the EC_LD and EC_HD subgroups displayed comparable levels of total cell-associated HIV DNA, activated CD8⁺ T (CD38⁺HLA-DR⁺) cells and plasmatic inflammatory biomarkers (IP-10, IL-18, RANTES, PDGF-AA, and CTACK). These results indicate that the genetic diversity of the HIV-1 proviral reservoir is not a surrogate marker of residual viral replication, immune activation or inflammation, nor an accurate biomarker for the prediction of virologic breakthrough or CD4⁺ T cells loss in EC.