Proteasome-independent degradation of HIV-1 in naturally non-permissive human placental trophoblast cells

<p>Abstract</p> <p>Background</p> <p>The human placenta-derived cell line BeWo has been demonstrated to be restrictive to cell-free HIV-1 infection. BeWo cells are however permissive to infection by VSV-G pseudotyped HIV-1, which enters cells by a receptor-independent mechanism, and to infection by HIV-1 via a cell-to-cell route.</p> <p>Results</p> <p>Here we analysed viral entry in wild type BeWo (CCR5⁺, CXCR4⁺) and BeWo-CD4⁺(CD4⁺, CCR5⁺, CXCR4⁺) cells. We report that HIV-1 internalisation is not restricted in either cell line. Levels of internalised p24 antigen between VSV-G HIV-1 pseudotypes and R5 or X4 virions were comparable. We next analysed the fate of internalised virions; X4 and R5 HIV-1 virions were less stable over time in BeWo cells than VSV-G HIV-1 pseudotypes. We then investigated the role of the proteasome in restricting cell-free HIV-1 infection in BeWo cells using proteasome inhibitors. We observed an increase in the levels of VSV-G pseudotyped HIV-1 infection in proteasome-inhibitor treated cells, but the infection by R5-Env or X4-Env pseudotyped virions remains restricted.</p> <p>Conclusion</p> <p>Collectively these results suggest that cell-free HIV-1 infection encounters a surface block leading to a non-productive entry route, which either actively targets incoming virions for non-proteasomal degradation, and impedes their release into the cytoplasm, or causes the inactivation of mechanisms essential for viral replication.</p

Distinct efficacy of HIV-1 entry inhibitors to prevent cell-to-cell transfer of R5 and X4 viruses across a human placental trophoblast barrier in a reconstitution model in vitro

<p>Abstract</p> <p>Background and methods</p> <p>HIV-1 cell-to-cell transmission is more efficient than infection of permissive cells with cell-free particles. The potency of HIV-1 entry inhibitors to inhibit such transmission is not well known. Herein, we evaluated the efficacy of this new class of antiretrovirals to block cell-to-cell transmission of HIV-1 in a model of reconstitution of the human placental trophoblast barrier <it>in vitro</it>.</p> <p>Results</p> <p>Our data show that CCR5 antagonists and T20 inhibit the passage of the virus across the BeWo cell monolayer in contact with PBMCs infected with an R5 (Ba-L) and a dualtropic (A204) HIV-1 with IC50s in the range of 100 – 5,000 nM for TAK779; 90 to 15,000 nM for SCH-350581 and 3,000 to 20,000 nM for T20. The CXCR4 antagonist AMD3100 is also effective against X4 HIV-1 infected PBMCs in our model with IC50 comprised between 4 nM and 640 nM. HIV-1 entry inhibitors are less efficient to block cell-to-cell virus transmission than cell-free HIV-1 infection of PBMCs and CCR5 antagonists do not prevent PBMC infection by dual tropic HIV-1 in contrast to cell-to-cell infection in our model.</p> <p>Surprisingly, T20 (and C34) do not block cell-to-cell transmission of X4 HIV-1 but, rather, increase 80 to 140 fold, compared to control without drug, the passage of the virus across the trophoblast barrier. Additional experiments suggest that the effect of T20 on BeWo/PBMC-X4 HIV-1 is due to an increase of effector-target cells fusion.</p> <p>Conclusion</p> <p>Our results support further evaluation of HIV-1 coreceptor antagonists, alone or combined to other antiretrovirals, in a perspective of prevention but warn on the use of T20 in patients bearing X4 HIV-1 at risk of transmission.</p

Antigen-Presenting Cells Represent Targets for R5 HIV-1 Infection in the First Trimester Pregnancy Uterine Mucosa

BACKGROUND: During the first trimester of pregnancy, HIV-1 mother-to-child transmission is relatively rare despite the permissivity of placental cells to cell-to-cell HIV-1 infection. The placenta interacts directly with maternal uterine cells (decidual cells) but the physiological role of the decidua in the control of HIV-1 transmission and whether decidua could be a source of infected cells is unknown. METHODOLOGY/PRINCIPAL FINDINGS: To answer to this question, decidual mononuclear cells were exposed to HIV-1 in vitro. Decidual cells were shown to be more susceptible to infection by an R5 HIV-1, as compared to an X4 HIV-1. Infected cells were identified by flow cytometry analysis. The results showed that CD14(+) cells were the main targets of HIV-1 infection in the decidua. These infected CD14(+) cells expressed DC-SIGN, CD11b, CD11c, the Fc gamma receptor CD16, CD32 and CD64, classical MHC class-I and class-II and maturation and activation molecules CD83, CD80 and CD86. The permissivity of decidual tissue was also evaluated by histoculture. Decidual tissue was not infected by X4 HIV-1 but was permissive to R5 HIV-1. Different profiles of infection were observed depending on tissue localization. CONCLUSIONS/SIGNIFICANCE: The presence of HIV-1 target cells in the decidua in vitro and the low rate of in utero mother-to-child transmission during the first trimester of pregnancy suggest that a natural control occurs in vivo limiting cell-to-cell infection of the placenta and consequently infection of the fetus

Plasmodium falciparum Infection Significantly Impairs Placental Cytokine Profile in HIV Infected Cameroonian Women

BACKGROUND:Placental cytokines play crucial roles in the establishment and maintenance of pregnancy as well as protecting the foetus from infections. Previous studies have suggested the implication of infections such as P. falciparum and HIV in the stimulation of placental cytokines. This study assessed the impact of P. falciparum on placental cytokine profiles between HIV-1 positive and negative women. MATERIALS AND METHODS:P. falciparum infection was checked in peripheral and placental blood of HIV-1 negative and positive women by the thick blood smear test. Cytokines proteins and messenger RNAs were quantified by ELISA and real time PCR, respectively. Non-parametric tests were used for statistical analyses. RESULTS:Placental and peripheral P. falciparum infections were not significantly associated with HIV-1 infection (OR: 1.4; 95% confidence interval (95%CI): 0.5-4.2; p = 0.50 and OR: 0.6; 95%CI: 0.3-1.4; p = 0.26, respectively). Conversely, placental P. falciparum parasitemia was significantly higher in the HIV-1 positive group (p = 0.04). We observed an increase of TNF-alpha mRNA median levels (p = 0.02) and a trend towards a decrease of IL-10 mRNA (p = 0.07) in placenta from HIV-1 positive women compared to the HIV negative ones leading to a median TNF-alpha/IL-10 mRNA ratio significantly higher among HIV-1 positive than among HIV-1 negative placenta (p = 0.004; 1.5 and 0.8, respectively). Significant decrease in median secreted cytokine levels were observed in placenta from HIV-1 positive women as compared to the HIV negative however these results are somewhat indicative since it appears that differences in cytokine levels (protein or mRNA) between HIV-1 positive and negative women depend greatly on P.falciparum infection. Within the HIV-1 positive group, TNF-alpha was the only cytokine significantly associated with clinical parameters linked with HIV-1 MTCT such as premature rupture of membranes, CD4 T-cell number, plasma viral load and delay of NVP intake before delivery. CONCLUSIONS:These results show that P. falciparum infection profoundly modifies the placenta cytokine environment and acts as a confounding factor, masking the impact of HIV-1 in co-infected women. This interplay between the two infections might have implications in the in utero MTCT of HIV-1 in areas where HIV-1 and P. falciparum co-circulate

Seminal Plasma Exposures Strengthen Vaccine Responses in the Female Reproductive Tract Mucosae

HIV-1 sexual transmission occurs mainly via mucosal semen exposures. In the female reproductive tract (FRT), seminal plasma (SP) induces physiological modifications, including inflammation. An effective HIV-1 vaccine should elicit mucosal immunity, however, modifications of vaccine responses by the local environment remain to be characterized. Using a modified vaccinia virus Ankara (MVA) as a vaccine model, we characterized the impact of HIV-1+ SP intravaginal exposure on the local immune responses of non-human primates. Multiple HIV-1+ SP exposures did not impact the anti-MVA antibody responses. However, SP exposures revealed an anti-MVA responses mediated by CD4+ T cells, which was not observed in the control group. Furthermore, the frequency and the quality of specific anti-MVA CD8+ T cell responses increased in the FRT exposed to SP. Multi-parameter approaches clearly identified the cervix as the most impacted compartment in the FRT. SP exposures induced a local cell recruitment of antigen presenting cells, especially CD11c+ cells, and CD8+ T cell recruitment in the FRT draining lymph nodes. CD11c+ cell recruitment was associated with upregulation of inflammation-related gene expression after SP exposures in the cervix. We thus highlight the fact that physiological conditions, such as SP exposures, should be taken into consideration to test and to improve vaccine efficacy against HIV-1 and other sexually transmitted infections

Women for science and science for women: Gaps, challenges and opportunities towards optimizing pre-exposure prophylaxis for HIV-1 prevention

Preventing new HIV infections remains a global challenge. Young women continue to bear a disproportionate burden of infection. Oral pre-exposure prophylaxis (PrEP), offers a novel women-initiated prevention technology and PrEP trials completed to date underscore the importance of their inclusion early in trials evaluating new HIV PrEP technologies. Data from completed topical and systemic PrEP trials highlight the role of gender specific physiological and social factors that impact PrEP uptake, adherence and efficacy. Here we review the past and current developments of HIV-1 prevention options for women with special focus on PrEP considering the diverse factors that can impact PrEP efficacy. Furthermore, we highlight the importance of inclusion of female scientists, clinicians, and community advocates in scientific efforts to further improve HIV prevention strategies

Higher placental anti-inflammatory IL-10 cytokine expression in HIV-1 infected women receiving longer zidovudine prophylaxis associated with nevirapine

Placental cytokine balance may be critical for the control of mother-to-child transmission (MTCT) of HIV. We assessed whether the type and duration of antiretrovirals used for prevention of HIV-1-MTCT modified the inflammatory cytokine profile. We investigated the levels of cytokine expression in the placentas of 61 HIV-1-infected women who received zidovudine (ZDV) plus single dose nevirapine (SD-NVP) or ZDV only for prevention of MTCT. Placentas of 38 HIV-1-uninfected women were included as controls. All placentas were obtained after vaginal delivery. Levels of mRNA and cytokine expression were quantified using real-time PCR and ELISA, respectively, in placental explants and 24-hour culture supernatants and analyzed in relation to the women's characteristics and the type and duration of antiretroviral prophylaxis. HIV-1-infected and uninfected women did not show any differences in the expression of placental cytokine secretion except for a trend toward lower TNF-10 mRNA levels in HIV-1-infected women. Within the HIV-1-infected group, women who were exposed to a long duration of ZDV (>72 days) or received SD-NVP less than 5h prior to delivery, more frequently expressed detectable levels of IL-10 in their placentas (32% versus 7% (p = 0.01) and 32% versus 5% (p = 0.02), respectively). No infant was found to be HIV-1-infected. Our results showed a normalization of the placental cytokine balance in HIV-1-infected women receiving antiretroviral prophylaxis. Furthermore, the type and duration of antiretroviral prophylaxis have an impact on the placental anti-inflammatory IL-10 expression level, which may contribute to controlling HIV replication at the placental level, thus reducing MTCT of HIV-1.Fil: Pornprasert, Sakorn. Chiang Mai University; TailandiaFil: Mary, Jean-Yves. Université Paris Diderot - Paris 7; FranciaFil: Faye, Albert. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Leechanachai, Pannee. Chiang Mai University; TailandiaFil: Limtrakul, Aram. Health Promotion Center Region; TailandiaFil: Rugpao, Sungwal. Chiang Mai University; TailandiaFil: Sirivatanapa, Pannee. Chiang Mai University; TailandiaFil: Gomuthbutra, Vorapin. Nakornping Hospital; TailandiaFil: Matanasaravoot, Wanmanee. Lamphun Hospital; TailandiaFil: Le Coer, Sophie. Institut National d’Etudes Démographiques; FranciaFil: Lallemant, Marc. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; FranciaFil: Barré-Sinoussi, Françoise. Instituto Pasteur; FranciaFil: Menu, Elisabeth. Instituto Pasteur; FranciaFil: Ngo Giang Huong, Nicole. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; FranciaFil: Ayouba, Ahidjo. Instituto Pasteur; FranciaFil: Chailert, Sanupong. Chiang Mai University; Tailandia. Instituto Pasteur; FranciaFil: Chaouat, Gérard. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Derrien, Muriel. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Dolcini, Guillermina Laura. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Sanidad Animal y Medicina Preventiva. Laboratorio de Virología; Argentina. Instituto Pasteur; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Eteki, Nicole. Hôpital Central de Yaoundé. Maternité Principale; CamerúnFil: Kfutwah, Anfumbom Jude. Instituto Pasteur; FranciaFil: Kouo, Odette. Instituto Pasteur; FranciaFil: Lemen, Brigitte. Instituto Pasteur; FranciaFil: Abal, Facundo Juan Pablo. Instituto Pasteur; FranciaFil: Nerrienet, Eric. Instituto Pasteur; FranciaFil: Njinku, Bernadette. Instituto Pasteur; FranciaFil: Scarlatti, Gabriella. Suan Dok Hospital; TailandiaFil: Tejiokem, Mathurin. Centre Pasteur du Cameroun; CamerúnFil: Téné, Gilbert. No especifíca

In Vitro and In Vivo Human Herpesvirus 8 Infection of Placenta

Herpesvirus infection of placenta may be harmful in pregnancy leading to disorders in fetal growth, premature delivery, miscarriage, or major congenital abnormalities. Although a correlation between human herpesvirus 8 (HHV-8) infection and abortion or low birth weight in children has been suggested, and rare cases of in utero or perinatal HHV-8 transmission have been documented, no direct evidence of HHV-8 infection of placenta has yet been reported. The aim of this study was to evaluate the in vitro and in vivo susceptibility of placental cells to HHV-8 infection. Short-term infection assays were performed on placental chorionic villi isolated from term placentae. Qualitative and quantitative HHV-8 detection were performed by PCR and real-time PCR, and HHV-8 proteins were analyzed by immunohistochemistry. Term placenta samples from HHV-8-seropositive women were analyzed for the presence of HHV-8 DNA and antigens. In vitro infected histocultures showed increasing amounts of HHV-8 DNA in tissues and supernatants; cyto- and syncitiotrophoblasts, as well as endothelial cells, expressed latent and lytic viral antigens. Increased apoptotic phenomena were visualized by the terminal deoxynucleotidyl transferase-mediated deoxyuridine nick end-labeling method in infected histocultures. Ex vivo, HHV-8 DNA and a latent viral antigen were detected in placenta samples from HHV-8-seropositive women. These findings demonstrate that HHV-8, like other human herpesviruses, may infect placental cells in vitro and in vivo, thus providing evidence that this phenomenon might influence vertical transmission and pregnancy outcome in HHV-8-infected women