Biology subjects

Cyktor, J.

Publications and source records attributed to Cyktor, J..

3 recordsLinked to original sources

bioRxiv2024

Single-cell analyses reveal that monocyte gene expression profiles influence HIV-1 reservoir size in acutely treated cohorts

Elimination of latent HIV-1 is a major goal of AIDS research but the host factors determining the size of these reservoirs are poorly understood. Here, we investigated whether differences in host gene expression modulate the size of the HIV-1 reservoir during suppressive ART. Peripheral blood mononuclear cells (PBMC) from fourteen individuals initiating ART during acute infection who demonstrated effective viral suppression but varying magnitude of total HIV-1 DNA were characterized by single-cell RNA sequencing (scRNA-seq). Differentially expressed genes and enriched pathways demonstrated increased monocyte activity in participants with undetectable HIV-1 reservoirs. IL1B expression in CD14+ monocytes showed the greatest fold difference. The inverse association of IL1B with reservoir size was validated in an independent cohort comprised of 38 participants with different genetic backgrounds and HIV-1 subtype infections, and further confirmed with intact proviral DNA assay (IPDA(R)) measurements of intact HIV-1 proviruses in a subset of the samples. Modeling interactions with cell population frequencies showed that monocyte IL1B expression associated inversely with reservoir size in the context of higher frequencies of central memory CD4+ T cells, implicating an indirect effect of IL1B via the cell type well established to be a reservoir for persistent HIV-1. Signatures consisting of co-expressed genes including IL1B were highly enriched in the "TNF signaling via NF-{kappa}B" geneset. Functional analyses in cell culture revealed that IL1B activates NF-{kappa}B, thereby promoting productive HIV-1 infection while simultaneously suppressing viral spread, suggesting a natural latency reversing activity to deplete the reservoir in ART treated individuals. Altogether, unbiased high throughput scRNA-seq analyses revealed that monocyte IL1B variation could decrease HIV-1 proviral reservoirs in individuals initiating ART during acute infection.

immunology↗

bioRxiv2022

Reduction of the HIV-1 reservoir in T cells from persons with HIV-1 on suppressive antiretroviral therapy using expanded natural killer cells ex vivo

Treatment with latency-reversing agents (LRAs) alone has been ineffective in reducing HIV-1 reservoirs in persons with HIV-1 (PWH) on antiretroviral therapy (ART), due to inefficiencies in reservoir reactivation and adaptive immune responses. However, NK cells that are activated with cytokines may be able to target HIV-1 reservoirs more efficiently. To study the therapeutic potential of NK cells, we expanded blood NK cells from multiple donors ex vivo into CD56brightCD16+ "eNK" cells using artificial antigen presenting cells (aAPCs) expressing membrane-bound IL21. eNK cells express multiple activating receptors and are highly cytotoxic against specific target cells. eNK cells can also kill HIV-infected CD4 T cells via antibody dependent cell-mediated cytotoxicity (ADCC) using broadly neutralizing antibodies against HIV-1 Env gp120/gp41. Importantly, eNK cells from PWH on ART efficiently killed autologous HIV-1+ T cells reactivated by a combination of vorinostat (SAHA) and IL-15 or an IL-15 superagonist (N-803), as detected by declines in proviral load, inducible HIV-1 mRNA, and virus release. Adoptive immunotherapy with eNK cells is therefore a promising approach to reduce the latent HIV-1 reservoir in PWH when combined with LRA treatment. Author SummarySuccessful antiretroviral therapy (ART) eliminates progression to AIDS by reducing HIV to nearly indetectable levels by routine clinical measurements of blood samples. However, more sensitive DNA and RNA measurements show that most persons on ART retain a reservoir of long lived latently infected cells, which remain undetected by the immune system while no HIV is being produced. In nearly all cases, ART interruption results in a rebound of HIV production and spread, requiring an immediate return to ART. Currently the goal of HIV eradication is to achieve a "functional cure", where HIV reservoirs are reduced to the point where ART can be interrupted indefinitely, and low levels of infected cells remaining can be controlled by the immune system. Our eradication strategy combines HIV latency-reversing agents (LRAs), ex vivo expansion of natural killer (NK) cells, and enhancement of specificity and killing of infected cells with broadly neutralizing antibodies against HIV. In this study, we have demonstrated that NK cells from person living with HIV can be isolated and expanded ex vivo into "eNK" cells that kill HIV-infected cells without killing uninfected cells, especially when broadly neutralizing antibodies are present, and can significantly reduce HIV reservoirs after LRA treatment.

immunology↗

bioRxiv2020

HIV-specific T-cell responses reflect substantive in vivo interactions with infected cells despite long-term therapy

Antiretroviral therapies (ART) durably suppress HIV replication to undetectable levels - however, infection persists in the form of long-lived reservoirs of infected cells with integrated proviruses, that re-seed systemic replication if ART is interrupted. A central tenet of our current understanding of this persistence is that infected cells are shielded from immune recognition and elimination through a lack of antigen expression from proviruses. Efforts to cure HIV infection have therefore focused on reactivating latent proviruses to enable immune-mediated clearance, but these have yet to succeed in driving reductions in viral reservoirs. Here, we revisited the question of whether HIV reservoirs are predominately immunologically silent from a new angle, by querying the dynamics of HIV-specific T-cell responses over long-term ART for evidence of ongoing recognition of HIV-infected cells. We show that T-cell responses to autologous reservoir viruses persist over years, and that the maintenance of HIV-Nef-specific responses was uniquely associated with residual frequencies of infected cells. These responses disproportionately exhibited a cytotoxic, effector functional profile, indicative of recent in vivo recognition of HIV-infected cells. These results indicate substantial visibility of the HIV reservoir to T-cells on stable ART, presenting both opportunities and challenges for the development of therapeutic approaches to curing HIV infection.

immunology↗