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Ferreira, I. A. T. M.

Publications and source records attributed to Ferreira, I. A. T. M..

3 recordsLinked to original sources

Dynamic Antigen Expression and Intrinsic CTL Resistance in HIV Reservoir Clones

Reservoirs of clonally expanded CD4+ T-cells harboring rebound-competent HIV proviruses persist lifelong during ART. Latency is considered the principal barrier to viral eradication and has resisted pharmacological reversal, yet it appears that sustained immune pressure may still erode reservoirs. Recent advances have yielded glimpses into these exceptionally rare reservoir-harboring cells, implicating intrinsic pro-survival properties in their persistence. Here, we isolate and characterize populations of authentic reservoir clones (ARCs) that robustly proliferate and accumulate while producing infectious virus, without overtly succumbing to viral cytopathic effects. At any given moment, only small fractions of ARCs expressed HIV proteins, a state remarkably unperturbed by potent TCR or mitogenic stimulation. Nevertheless, sustained co-culture with cytotoxic T-lymphocytes (CTL) revealed extensive time-integrated antigenic vulnerability, culling clonal expansion of some ARCs by >90%. Notably, a regulatory T-cell ARC displayed pronounced cell-intrinsic resistance to CTL - a longstanding hypothesis we now directly demonstrate - linked to low oxidative stress and reversed with desferoxamine, a hypoxic stress inducer and FDA-approved therapeutic. Overall, we provide novel insights into the vulnerabilities of reservoir clones to potent, sustained CTL pressure and highlight intrinsic resistance pathways as actionable therapeutic targets, opening opportunities for advancing immune-based HIV cure strategies.

immunology↗

HIV-1 expression is heterogeneous among clones of CD4+ T cells carrying authentic intact latent proviruses

Antiretroviral therapy suppresses HIV-1 infection but is not curative because it fails to eliminate a reservoir of intact latent proviruses that reside primarily in CD4+ T cells. This compartment is composed of rare T cells that predominantly express memory and effector memory markers. The lack of precise understanding of the latent compartment has made it challenging to develop curative strategies for HIV-1 infection. Here we report on the properties of CD4+ T cells clones carrying intact latent proviruses, expanded in vitro from single cells obtained from the reservoir of people living with HIV-1. The latent proviruses in the clones were integrated into ZNF genes, non-genic satellite and centromeric regions, frequently associated with latency. Notably, the transcriptome of the cultured clones resembled their cells of origin. Despite their descent from single cells, only a fraction of the cells ranging from 0.4-14% expressed relatively low levels of HIV-1 that did not measurably alter host gene transcriptome. Latency reversing agents (LRAs) variably increased the number and amount of expression per cell, but the effects were modest and clone and LRA specific. The results suggest that pharmacologic and immunologic approaches to clear the reservoir should be optimized to accommodate intra- and inter-clonal diversity.

immunology↗

Transcription of HIV-1 at sites of intact latent provirus integration

HIV-1 anti-retroviral therapy is highly effective but fails to eliminate a reservoir of latent proviruses leading to a requirement for life-long treatment. How the site of integration of authentic intact latent proviruses might impact their own or neighboring gene expression or reservoir dynamics is poorly understood. Here we report on proviral and neighboring gene transcription at sites of intact latent HIV-1 integration in cultured T cells obtained directly from people living with HIV, as well as engineered primary T cells and cell lines. Proviral gene expression was correlated to the level of endogenous gene expression under resting but not activated conditions. Notably, latent proviral promoters were 100-10,000X less active than in productively infected cells and had little or no measurable impact on neighboring gene expression under resting or activated conditions. Thus, the site of integration has a dominant effect on the transcriptional activity of intact HIV-1 proviruses in the latent reservoir thereby influencing cytopathic effects and proviral immune evasion.

immunology↗