Unpredicted protective function of Fc-mediated inhibitory antibodies for HIV and SARS-CoV-2 vaccines.

Developing effective vaccines is necessary in combating new virus pandemics. For HIV and SARS-CoV-2, the induction of neutralizing antibodies (NAb) is important for vaccine protection; however, the exact mechanisms underlying protection require further study. Recent data emphasize that even Abs that do not exhibit neutralizing activity may contribute to immune defense.

Underdiagnosis of arbovirus infections in returned travelers in an area with growing circulation of Aedes albopictus in North-Eastern France.

Background: Vector-borne diseases such as malaria and arboviruses are common etiologies of post-travel fever.

Methods: After excluding malaria, we retrospectively analyzed the diagnosis of dengue virus (DENV), chikungunya virus (CHIKV), and zika virus (ZIKV) infections following recent travel by patients treated at the Strasbourg University Hospital between 2014 and 2023. Available serums (n = 35) sampled in 2023 were retrospectively tested for DENV, CHIKV, and ZIKV infections.

HIV Productively Infects Highly Differentiated and Exhausted CD4+ T Cells During AIDS.

Background: Throughout HIV infection, productively infected cells generate billions of viral particles and are thus responsible for body-wide HIV dissemination, but their phenotype during AIDS is unknown. As AIDS is associated with immunological changes, analyzing the phenotype of productively infected cells can help understand HIV production during this terminal stage.

Methods: Blood samples from 15 untreated viremic participants (recent infection, n=5; long-term infection, n=5; active opportunistic AIDS-defining disease, n=5) and 5 participants virologically controlled on antiretroviral therapy (ART) enrolled in the Analysis of the Persistence, Reservoir and HIV Latency (APRIL) study (NCT05752318) were analyzed.

Two Cases of Viral Re-suppression After M184V + R263K Selection on Dolutegravir/Lamivudine Without Treatment Modification.

Dolutegravir/lamivudine (DTG/3TC) has a high genetic barrier against the development of human immunodeficiency virus drug resistance. We report 2 cases of R263K + M184V mutations during DTG/3TC failure followed by viral suppression after adherence intervention without treatment change that we attribute to residual drug activity, reduced viral fitness, and robust immune competence.

Plasma SARS-CoV-2 RNA elimination and RAGE kinetics distinguish COVID-19 severity.

Objectives: Identifying biomarkers causing differential SARS-CoV-2 infection kinetics associated with severe COVID-19 is fundamental for effective diagnostics and therapeutic planning.

Methods: In this work, we applied mathematical modelling to investigate the relationships between patient characteristics, plasma SARS-CoV-2 RNA dynamics and COVID-19 severity. Using a straightforward mathematical model of within-host viral kinetics, we estimated key model parameters from serial plasma viral RNA (vRNA) samples from 256 hospitalised COVID-19 patients.

Antigen specificities of HIV-infected cells: A role in infection and persistence?

Antigen-experienced memory CD4 T cells are the major target of HIV infection and support both productive and latent infections, thus playing a key role in HIV dissemination and persistence, respectively. Here, we reviewed studies that have shown direct association between HIV infection and antigen specificity. During untreated infection, some HIV-specific cells host productive infection, while other pathogen-specific cells such as cytomegalovirus (CMV) and also contribute to viral persistence on antiretroviral therapy (ART).

HIV rapidly targets a diverse pool of CD4 T cells to establish productive and latent infections.

Upon infection, HIV disseminates throughout the human body within 1-2 weeks. However, its early cellular targets remain poorly characterized. We used a single-cell approach to retrieve the phenotype and TCR sequence of infected cells in blood and lymphoid tissue from individuals at the earliest stages of HIV infection.

Case Report: Evolution of Humoral and Cellular Immunity in Two COVID-19 Breakthrough Infections After BNT162b2 Vaccine.

Background: SARS-CoV-2 breakthrough infections after complete vaccination are increasing whereas their determinants remain uncharacterized.

Methods: We analyzed two cases of post-vaccination SARS-CoV-2 infections by α and β variants, respectively. For each participant both humoral (binding and neutralizing antibodies) and cellular (activation markers and cytokine expression) immune responses were characterized longitudinally.

Integrated immunovirological profiling validates plasma SARS-CoV-2 RNA as an early predictor of COVID-19 mortality.

Despite advances in COVID-19 management, identifying patients evolving toward death remains challenging. To identify early predictors of mortality within 60 days of symptom onset (DSO), we performed immunovirological assessments on plasma from 279 individuals. On samples collected at DSO11 in a discovery cohort, high severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA (vRNA), low receptor binding domain–specific immunoglobulin G and antibody-dependent cellular cytotoxicity, and elevated cytokines and tissue injury markers were strongly associated with mortality, including in patients on mechanical ventilation.

Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization.

The SARS-CoV-2 B.1.617 lineage was identified in October 2020 in India.

In-depth single-cell analysis of translation-competent HIV-1 reservoirs identifies cellular sources of plasma viremia.

Clonal expansion of HIV-infected cells contributes to the long-term persistence of the HIV reservoir in ART-suppressed individuals. However, the contribution from cell clones that harbor inducible proviruses to plasma viremia is poorly understood. Here, we describe a single-cell approach to simultaneously sequence the TCR, integration sites and proviral genomes from translation-competent reservoir cells, called STIP-Seq.

Single-cell TCR sequencing reveals phenotypically diverse clonally expanded cells harboring inducible HIV proviruses during ART.

Clonal expansions occur in the persistent HIV reservoir as shown by the duplication of proviral integration sites. However, the source of the proliferation of HIV-infected cells remains unclear. Here, we analyze the TCR repertoire of single HIV-infected cells harboring translation-competent proviruses in longitudinal samples from eight individuals on antiretroviral therapy (ART).

The multifaceted nature of HIV latency.

Although antiretroviral therapies (ARTs) potently inhibit HIV replication, they do not eradicate the virus. HIV persists in cellular and anatomical reservoirs that show minimal decay during ART. A large number of studies conducted during the past 20 years have shown that HIV persists in a small pool of cells harboring integrated and replication-competent viral genomes.

Post-exposure prophylaxis completion and condom use in the context of potential sexual exposure to HIV.

Objectives: Post-exposure prophylaxis (PEP) care remains a challenge for individuals with potential sexual exposure to HIV in terms of PEP completion and ongoing risk behaviours.

Methods: A retrospective analysis was carried out on data from the French Dat'AIDS prevention cohort (NCT03795376) for individuals evaluated for PEP between 2004 and 2017. A multivariable analysis was performed of predictors of both PEP completion and condom use [odds ratios (ORs)] and their associated probabilities (P, with P > 95% being clinically relevant).

Elvitegravir-Cobicistat-Emtricitabine-Tenofovir Alafenamide Single-tablet Regimen for Human Immunodeficiency Virus Postexposure Prophylaxis.

Unlabelled: We evaluated an elvitegravir-cobicistat-emtricitabine-tenofovir alafenamide single-tablet regimen for human immunodeficiency virus postexposure prophylaxis. The completion rate and adherence were good, and the tolerance was acceptable; no seroconversion was observed. We confirm that this regimen could be appropriate for postexposure prophylaxis.

Tick-borne encephalitis virus: molecular determinants of neuropathogenesis of an emerging pathogen.

tick vector, and a vertebrate reservoir, such as small mammals (rodents, or shrews). Humans are accidentally involved in this transmission cycle. Tick-borne encephalitis (TBE) has been a growing public health problem in Europe and Asia over the past 30 years.