2024 Update of the RECOVER-Adult Long COVID Research Index.

Importance: Classification of persons with long COVID (LC) or post-COVID-19 condition must encompass the complexity and heterogeneity of the condition. Iterative refinement of the classification index for research is needed to incorporate newly available data as the field rapidly evolves.

Objective: To update the 2023 research index for adults with LC using additional participant data from the Researching COVID to Enhance Recovery (RECOVER-Adult) study and an expanded symptom list based on input from patient communities.

Rapid biphasic decay of intact and defective HIV DNA reservoir during acute treated HIV disease.

Despite antiretroviral therapy (ART), HIV persists in latently-infected cells (the HIV reservoir) which decay slowly over time. Here, leveraging >500 longitudinal samples from 67 people living with HIV (PLWH) treated during acute infection, we developed a mathematical model to predict reservoir decay from peripheral CD4 + T cells. Nonlinear generalized additive models demonstrated rapid biphasic decay of intact DNA (week 0-5: t ~ 2.

Infection-associated chronic conditions: Why Long Covid is our best chance to untangle Osler's web.

The recognition of Long Covid has renewed efforts to understand other infection-associated chronic conditions (IACCs). Here, we describe how studies of Long Covid and other IACCs might inform one another. We argue for the importance of a coordinated research agenda addressing these debilitating illnesses.

Early Viral Dynamics Predict HIV Post-Treatment Control After Analytic Treatment Interruption.

Background: A key research priority for developing an HIV cure strategy is to define the viral dynamics and biomarkers associated with sustained post-treatment control. The ability to predict the likelihood of sustained post-treatment control or non-control could minimize the time off antiretroviral therapy (ART) for those destined to not control and anticipate longer periods off ART for those destined to control.

Methods: Mathematical modeling and machine learning were used to characterize virologic predictors of long-term virologic control using viral kinetics data from several studies in which participants interrupted ART.

Measurement of circulating viral antigens post-SARS-CoV-2 infection in a multicohort study.

Objectives: To determine the proportion of individuals with detectable antigen in plasma or serum after SARS-CoV-2 infection and the association of antigen detection with postacute sequelae of COVID-19 (PASC) symptoms.

Methods: Plasma and serum samples were collected from adults participating in four independent studies at different time points, ranging from several days up to 14 months post-SARS-CoV-2 infection. The primary outcome measure was to quantify SARS-CoV-2 antigens, including the S1 subunit of spike, full-length spike, and nucleocapsid, in participant samples.

Mechanisms of long COVID and the path toward therapeutics.

Long COVID, a type of post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC) defined by medically unexplained symptoms following infection with SARS-CoV-2, is a newly recognized infection-associated chronic condition that causes disability in some people. Substantial progress has been made in defining its epidemiology, biology, and pathophysiology. However, there is no cure for the tens of millions of people believed to be experiencing long COVID, and industry engagement in developing therapeutics has been limited.

Sirolimus reduces T cell cycling, immune checkpoint marker expression, and HIV-1 DNA in people with HIV.

Key HIV cure strategies involve reversing immune dysfunction and limiting the proliferation of infected T cells. We evaluate the safety of sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, in people with HIV (PWH) and study the impact of sirolimus on HIV-1 reservoir size and HIV-1-specific immunity in a single-arm study of 20 weeks of treatment in PWH on antiretroviral therapy (ART). Sirolimus treatment does not impact HIV-1-specific CD8 T cell responses but leads to a significant decrease in CD4 T cell-associated HIV-1 DNA levels at 20 weeks of therapy in the primary efficacy population (n = 16; 31% decline, p = 0.

Recall and Appraisal of the Risks, Benefits, and Objectives of Interrupting HIV Treatment in an HIV Cure-Related Study.

The goal of HIV cure research is to either eliminate HIV from the body or durably suppress it in the absence of antiretroviral therapy (ART). This research often requires participants to interrupt ART. However, there are numerous risks associated with ART interruptions and therefore it is critical to understand how people with HIV (PWH) who participate recall the elements of consent, to safeguard their rights and welfare.

Brief Report: Low-Dose Methotrexate Does Not Affect Measures of HIV-1 Persistence in Individuals With Chronically Treated HIV-1 Infection.

Background: People with HIV-1 often have chronic inflammation leading to severe non-AIDS morbidity and mortality. The AIDS Clinical Trials Group Study A5314 sought to lower inflammation with low-dose methotrexate (LDMTX). The primary study outcomes were reported previously but here we present the impact of LDMTX on multiple measures of HIV-1 persistence.

A Pooled Analysis of Eight Clinical Studies Suggests a Link Between Influenza-Like Symptoms and Pharmacodynamics of the Toll-Like Receptor-7 Agonist Vesatolimod.

Introduction: Vesatolimod is a Toll-like receptor-7 (TLR7) agonist in clinical development as part of a combination regimen for human immunodeficiency virus (HIV) cure. Influenza-like symptoms associated with TLR7-mediated immune activation have been reported in clinical trials of vesatolimod. Therefore, a broader understanding of the safety profile of vesatolimod and association with dose and mechanism of action will help inform future clinical studies.

Integrated epigenomic exposure signature discovery.

The epigenome influences gene regulation and phenotypes in response to exposures. Epigenome assessment can determine exposure history aiding in diagnosis. Here we developed and implemented a machine learning algorithm, the exposure signature discovery algorithm (ESDA), to identify the most important features present in multiple epigenomic and transcriptomic datasets to produce an integrated exposure signature (ES).

Early biological markers of post-acute sequelae of SARS-CoV-2 infection.

To understand the roles of acute-phase viral dynamics and host immune responses in post-acute sequelae of SARS-CoV-2 infection (PASC), we enrolled 136 participants within 5 days of their first positive SARS-CoV-2 real-time PCR test. Participants self-collected up to 21 nasal specimens within the first 28 days post-symptom onset; interviewer-administered questionnaires and blood samples were collected at enrollment, days 9, 14, 21, 28, and month 4 and 8 post-symptom onset. Defining PASC as the presence of any COVID-associated symptom at their 4-month visit, we compared viral markers (quantity and duration of nasal viral RNA load, infectious viral load, and plasma N-antigen level) and host immune markers (IL-6, IL-10, TNF-α, IFN-α, IFN-γ, MCP, IP-10, and Spike IgG) over the acute period.

HIV-1 control in vivo is related to the number but not the fraction of infected cells with viral unspliced RNA.

In the absence of antiretroviral therapy (ART), a subset of individuals, termed HIV controllers, have levels of plasma viremia that are orders of magnitude lower than non-controllers (NC) who are at higher risk for HIV disease progression. In addition to having fewer infected cells resulting in fewer cells with HIV RNA, it is possible that lower levels of plasma viremia in controllers are due to a lower fraction of the infected cells having HIV-1 unspliced RNA (HIV usRNA) compared with NC. To directly test this possibility, we used sensitive and quantitative single-cell sequencing methods to compare the fraction of infected cells that contain one or more copies of HIV usRNA in peripheral blood mononuclear cells (PBMC) obtained from controllers and NC.

Mechanisms and efficacy of small molecule latency-promoting agents to inhibit HIV reactivation ex vivo.

Drugs that inhibit HIV transcription and/or reactivation of latent HIV have been proposed as a strategy to reduce HIV-associated immune activation or to achieve a functional cure, yet comparative studies are lacking. We evaluated 26 drugs, including drugs previously reported to inhibit HIV transcription (inhibitors of Tat-dependent HIV transcription, Rev, HSF-1/PTEF-b, HSP90, Jak/Stat, or SIRT1/Tat deacetylation) and other agents that were not tested before (inhibitors of PKC, NF-κB, SP-1, or histone acetyltransferase; NR2F1 agonists), elongation (inhibitors of CDK9/ PTEF-b), completion (inhibitors of PolyA-polymerase), or splicing (inhibitors of human splice factors). To investigate if those drugs would vary in their ability to affect different blocks to HIV transcription, we measured levels of initiated, elongated, midtranscribed, completed, and multiply spliced HIV RNA in PBMCs from antiretroviral therapy-suppressed individuals following ex vivo treatment with each drug and subsequent T cell activation.

Prediction of differential Gag versus Env responses to a mosaic HIV-1 vaccine regimen by HLA class I alleles.

class I variation has the strongest effect genome-wide on outcome after HIV infection, and as such, an understanding of the impact of polymorphism on response to HIV vaccination may inform vaccine design. We sought associations with HIV-directed immunogenicity in the phase 1/2a APPROACH vaccine trial, which tested vaccine regimens containing mosaic inserts in Ad26 and MVA vectors, with or without a trimeric gp140 protein. While there were no allelic associations with the overall cellular immune response to the vaccine assessed by ELISpot (Gag, Pol, and Env combined), significant associations with differential response to Gag compared to Env antigens were observed.

Tissue-based T cell activation and viral RNA persist for up to 2 years after SARS-CoV-2 infection.

The mechanisms of postacute medical conditions and unexplained symptoms after SARS-CoV-2 infection [Long Covid (LC)] are incompletely understood. There is growing evidence that viral persistence, immune dysregulation, and T cell dysfunction may play major roles. We performed whole-body positron emission tomography imaging in a well-characterized cohort of 24 participants at time points ranging from 27 to 910 days after acute SARS-CoV-2 infection using the radiopharmaceutical agent [F]F-AraG, a selective tracer that allows for anatomical quantitation of activated T lymphocytes.

HIV rebound in HIV controllers is associated with a specific fecal microbiome profile.

HIV infection is associated with gut dysbiosis, and microbiome variability may affect HIV control when antiretroviral therapy (ART) is stopped. The TLR7 agonist, vesatolimod, was previously associated with a modest delay in viral rebound following analytical treatment interruption in HIV controllers (HCs). Using a retrospective analysis of fecal samples from HCs treated with vesatolimod or placebo (NCT03060447), people with chronic HIV (CH; NCT02858401) or without HIV (PWOH), we examined fecal microbiome profile in HCs before/after treatment, and in CH and PWOH.

High-parameter phenotypic characterization reveals a subset of human Th17 cells that preferentially produce IL-17 against antigen.

Background: Interleukin-17-producing CD4 T cells contribute to the control of () infection in humans; whether infection with human immunodeficiency virus (HIV) disproportionately affects distinct Th17-cell subsets that respond to is incompletely defined.

Methods: We performed high-definition characterization of circulating -specific Th17 cells by spectral flow cytometry in people with latent TB and treated HIV (HIV-ART). We also measured kynurenine pathway activity by liquid chromatography-mass spectrometry (LC/MS) on plasma and tested the hypothesis that tryptophan catabolism influences Th17-cell frequencies in this context.

AMPLON: Amplifying DNA with Multiarm Priming and Looping Optimization of Nucleic Acid.

Nucleic acid amplification, the bedrock of biotechnology and molecular diagnostics, surges in applications-especially isothermal approaches-heightening the demand for advanced and precisely engineered methods. Here, a novel approach for amplifying DNA with multiarm priming and looping optimization of nucleic acid (AMPLON) is presented. AMPLON relies on a novel polymeric material with unique set of multiarm polyethylene glycol-DNA primers for efficient DNA amplification under isothermal conditions.

Autologous neutralizing antibody responses after antiretroviral therapy in acute and early HIV-1.

BACKGROUNDEarly antiretroviral therapy initiation (ARTi) in HIV-1 restricts reservoir size and diversity while preserving immune function, potentially improving opportunities for immunotherapeutic cure strategies. For antibody-based cure approaches, the development of autologous neutralizing antibodies (anAbs) after acute/early ARTi is relevant but is poorly understood.METHODSWe characterized antibody responses in a cohort of 23 participants following ARTi in acute HIV (<60 days after acquisition) and early HIV (60-128 days after acquisition).

Long COVID and post-acute sequelae of SARS-CoV-2 pathogenesis and treatment: A Keystone Symposia report.

In 2023, the Keystone Symposia held the first international scientific conference convening research leaders investigating the pathology of post-acute sequelae of COVID-19 (PASC) or Long COVID, a growing and urgent public health priority. In this report, we present insights from the talks and workshops presented during this meeting and highlight key themes regarding what researchers have discovered regarding the underlying biology of PASC and directions toward future treatment. Several themes have emerged in the biology, with inflammation and other immune alterations being the most common focus, potentially related to viral persistence, latent virus reactivation, and/or tissue damage and dysfunction, especially of the endothelium, nervous system, and mitochondria.