Vaginal microbiome dysbiosis and sexually transmitted infections correlate with concentrations of immunoglobulin isotypes in human cervicovaginal mucus: insights into HIV-1 transmission.

Introduction: Little is known about the relationship between antibody isotype in cervicovaginal mucus (CVM) and the local microenvironment and how this impacts HIV-1 transmission at the female genital mucosa.

Methods: In a cohort of 139 adult women in Kenya, we measured antibody isotypes in CVM and describe their associations with local pH, serum concentrations of estrogen and progesterone, and sexually transmitted infections (STIs), including HIV-1.

Results: We found that immunoglobulin G2 (IgG2) was the most abundant and IgG4 was the least abundant in the CVM.

Blockade of dNTP biosynthesis pathway delays HIV-1 early life cycle kinetics and dynamics.

Unlabelled: The early events of the HIV-1 life cycle, such as reverse transcription, and capsid shedding commonly known as uncoating, are interdependent and tightly regulated, enabling HIV-1 to adapt to diverse host cells. Here, we explored how host cell dNTP pool size modulates the kinetics and dynamics of HIV-1 reverse transcription and uncoating. We optimized an easy-to-use tool to inhibit the ribonucleotide reductase (RNR) catalyzed pathway of dNTP biosynthesis in CHOpgsA-745, HeLa (TZMbl), and owl monkey kidney (OMK) cells.

Live imaging of airway epithelium reveals that mucociliary clearance modulates SARS-CoV-2 spread.

SARS-CoV-2 initiates infection in the conducting airways, where mucociliary clearance inhibits pathogen penetration. However, it is unclear how mucociliary clearance impacts SARS-CoV-2 spread after infection is established. To investigate viral spread at this site, we perform live imaging of SARS-CoV-2 infected differentiated primary human bronchial epithelium cultures for up to 12 days.

PET/CT Targeted Tissue Sampling Reveals Intravenously Administered HGN194 IgG1 Affects HIV Distribution after Rectal Exposure.

Neutralizing monoclonal antibodies hold great potential for prevention of human immunodeficiency virus (HIV) acquisition. IgG is the most abundant antibody in human serum, has a long half-life, and potent effector functions, making it a prime candidate for an HIV prevention therapeutic. We combined Positron Emission Tomography imaging and fluorescent microscopy of Cu-labeled, photoactivatable-green fluorescent protein HIV (PA-GFP-BaL) and fluorescently labeled HGN194 IgG1 to determine whether intravenously instilled IgG influences viral interaction with mucosal barriers and viral penetration in colorectal tissue 2 h after rectal viral challenge.

Temporal and spatial characterization of HIV/SIV infection at anorectal mucosa using rhesus macaque rectal challenge model.

The study described herein is a continuation of our work in which we developed a methodology to identify small foci of transduced cells following rectal challenge of rhesus macaques with a non-replicative luciferase reporter virus. In the current study, the wild-type virus was added to the inoculation mix and twelve rhesus macaques were necropsied 2-4 days after the rectal challenge to study the changes in infected cell phenotype as the infection progressed. Relying on luciferase reporter we noted that both anus and rectum tissues are susceptible to the virus as early as 48h after the challenge.

Blockade of TGF-β signaling reactivates HIV-1/SIV reservoirs and immune responses in vivo.

TGF-β plays a critical role in maintaining immune cells in a resting state by inhibiting cell activation and proliferation. Resting HIV-1 target cells represent the main cellular reservoir after long-term antiretroviral therapy (ART). We hypothesized that releasing cells from TGF-β-driven signaling would promote latency reversal.

An immunoPET probe to SARS-CoV-2 reveals early infection of the male genital tract in rhesus macaques.

The systemic nature of SARS-CoV-2 infection is highly recognized, but poorly characterized. A non-invasive and unbiased method is needed to clarify whole body spatiotemporal dynamics of SARS-CoV-2 infection after transmission. We recently developed a probe based on the anti-SARS-CoV-2 spike antibody CR3022 to study SARS-CoV-2 pathogenesis .

Development of an Probe to Track SARS-CoV-2 Infection in Rhesus Macaques.

Infection with the novel coronavirus, SARS-CoV-2, results in pneumonia and other respiratory symptoms as well as pathologies at diverse anatomical sites. An outstanding question is whether these diverse pathologies are due to replication of the virus in these anatomical compartments and how and when the virus reaches those sites. To answer these outstanding questions and study the spatiotemporal dynamics of SARS-CoV-2 infection a method for tracking viral spread is needed.

Localization of infection in neonatal rhesus macaques after oral viral challenge.

Vertical transmission of human immunodeficiency virus (HIV) can occur in utero, during delivery, and through breastfeeding. We utilized Positron Emission Tomography (PET) imaging coupled with fluorescent microscopy of 64Cu-labeled photoactivatable-GFP-HIV (PA-GFP-BaL) to determine how HIV virions distribute and localize in neonatal rhesus macaques two and four hours after oral viral challenge. Our results show that by four hours after oral viral exposure, HIV virions localize to and penetrate the rectal mucosa.

Th17 T Cells and Immature Dendritic Cells Are the Preferential Initial Targets after Rectal Challenge with a Simian Immunodeficiency Virus-Based Replication-Defective Dual-Reporter Vector.

Understanding the earliest events of human immunodeficiency virus (HIV) sexual transmission is critical to developing and optimizing HIV prevention strategies. To gain insights into the earliest steps of HIV rectal transmission, including cellular targets, rhesus macaques were intrarectally challenged with a single-round simian immunodeficiency virus (SIV)-based dual reporter that expresses luciferase and near-infrared fluorescent protein 670 (iRFP670) upon productive transduction. The vector was pseudotyped with the HIV-1 envelope JRFL.

PET/CT targeted tissue sampling reveals virus specific dIgA can alter the distribution and localization of HIV after rectal exposure.

Human immunodeficiency virus (HIV) vaccines have not been successful in clinical trials. Dimeric IgA (dIgA) in the form of secretory IgA is the most abundant antibody class in mucosal tissues, making dIgA a prime candidate for potential HIV vaccines. We coupled Positron Emission Tomography (PET) imaging and fluorescent microscopy of 64Cu-labeled, photoactivatable-GFP HIV (PA-GFP-BaL) and fluorescently labeled dIgA to determine how dIgA antibodies influence virus interaction with mucosal barriers and viral penetration in colorectal tissue.

Rare Detection of Antiviral Functions of Polyclonal IgA Isolated from Plasma and Breast Milk Compartments in Women Chronically Infected with HIV-1.

The humoral response to invading mucosal pathogens comprises multiple antibody isotypes derived from systemic and mucosal compartments. To understand the contribution of each antibody isotype/source to the mucosal humoral response, parallel investigation of the specificities and functions of antibodies within and across isotypes and compartments is required. The role of IgA against HIV-1 is complex, with studies supporting a protective role as well as a role for serum IgA in blocking effector functions.

Increases in Endogenous or Exogenous Progestins Promote Virus-Target Cell Interactions within the Non-human Primate Female Reproductive Tract.

Currently, there are mounting data suggesting that HIV-1 acquisition in women can be affected by the use of certain hormonal contraceptives. However, in non-human primate models, endogenous or exogenous progestin-dominant states are shown to increase acquisition. To gain mechanistic insights into this increased acquisition, we studied how mucosal barrier function and CD4+ T-cell and CD68+ macrophage density and localization changed in the presence of natural progestins or after injection with high-dose DMPA.

Visualization of HIV-1 interactions with penile and foreskin epithelia: clues for female-to-male HIV transmission.

To gain insight into female-to-male HIV sexual transmission and how male circumcision protects against this mode of transmission, we visualized HIV-1 interactions with foreskin and penile tissues in ex vivo tissue culture and in vivo rhesus macaque models utilizing epifluorescent microscopy. 12 foreskin and 14 cadaveric penile specimens were cultured with R5-tropic photoactivatable (PA)-GFP HIV-1 for 4 or 24 hours. Tissue cryosections were immunofluorescently imaged for epithelial and immune cell markers.

Characterization of the Influence of Semen-Derived Enhancer of Virus Infection on the Interaction of HIV-1 with Female Reproductive Tract Tissues.

Unlabelled: The majority of human immunodeficiency virus type 1 (HIV-1) transmission events occur in women when semen harboring infectious virus is deposited onto the mucosal barriers of the vaginal, ectocervical, and endocervical epithelia. Seminal factors such as semen-derived enhancer of virus infection (SEVI) fibrils were previously shown to greatly enhance the infectivity of HIV-1 in cell culture systems. However, when SEVI is intravaginally applied to living animals, there is no effect on vaginal transmission.

Keratinization of the adult male foreskin and implications for male circumcision.

Objective: The theory that a more thinly keratinized inner foreskin leads to increased HIV-1 susceptibility has been based on relatively little published data. We sought to quantify the keratin thicknesses of the inner and outer foreskin to determine the plausibility of this hypothesis.

Design: We took repeated measurements of the keratin layer of 16 adult male foreskins to determine whether differences existed between the inner and outer foreskin.