Search

Systemic and mucosal humoral immune responses are crucial to fight respiratory viral infections in the current pandemic of COVID-19 caused by the SARS-CoV-2 virus. During SARS-CoV-2 infection, the dynamics of systemic and mucosal antibody infections are affected by patient characteristics, such as age, sex, disease severity, or prior immunity to other human coronaviruses. Patients suffering from severe disease develop higher levels of anti-SARS-CoV-2 antibodies in serum and mucosal tissues than those with mild disease, and these antibodies are detectable for up to a year after symptom onset. In hospitalized patients, the aberrant glycosylation of anti-SARS-CoV-2 antibodies enhances inflammation-associated antibody Fc-dependent effector functions, thereby contributing to COVID-19 pathophysiology. Current vaccines elicit robust humoral immune responses, principally in the blood. However, they are less effective against new viral variants, such as Delta and Omicron. This review provides an overview of current knowledge about the humoral immune response to SARS-CoV-2, with a particular focus on the protective and pathological role of humoral immunity in COVID-19 severity. We also discuss the humoral immune response elicited by COVID-19 vaccination and protection against emerging viral variants.

Reliable immunoassays are essential to early predict and monitor vaccine efficacy against SARS-CoV-2. The performance of an Interferon Gamma Release Assay (IGRA, QuantiFERON® SARS-CoV-2), and a current anti-spike serological test, compared to a plaque reduction neutralization test (PRNT) taken as gold standard were compared. Eighty vaccinated individuals, whose 16% had a previous history of COVID-19, were included in a longitudinal prospective study and sampled before and two to four weeks after each dose of vaccine. In non-infected patients, 2 doses were required for obtaining both positive IGRA and PRNT assays, while serology was positive after one dose. Each dose of vaccine significantly increased the humoral and cellular response. By contrast, convalescent subjects needed a single dose of vaccine to be positive on all 3 tests. Both IGRA and current serology assay were found predictive of a positive titer of neutralizing antibodies that is correlated with vaccine protection. Patients over 65 or 80 years old had a significantly reduced response. The response tended to be better with the heterologous scheme (vs. homologous) and with the mRNA-1273 vaccine (vs. BNT162b2) in the homologous group, in patients under 55 and under 65 years old, respectively. Finally, decrease intensity or absence of IGRA response and to a less extent of anti-spike serology were also correlated to reinfection which has occurred during the follow up. In conclusion, both IGRA and current anti-spike serology assays could be used at defined thresholds to monitor the vaccine response against SARS-CoV-2 and to simply identify non-responding individuals after a complete vaccination scheme. Two available specific tests (IGRA and anti-spike antibodies) could early assess the vaccine-induced immunity against SARS-CoV-2 at the individual scale, to potentially adapt the vaccination scheme in non-responder patients.

BackgroundDried plasma spot specimens may be a viable alternative to traditional liquid plasma in field settings, but the diagnostic accuracy is not well understood.MethodsStandard databases (PubMed and Medline), conferences, and gray literature were searched until January 2019. The quality of evidence was evaluated using the Standards for Reporting Studies of Diagnostic Accuracy and Quality Assessment of Diagnostic Accuracy Studies-2 criteria. We used univariate and bivariate random effects models to determine misclassification, sensitivity, and specificity across multiple thresholds, overall and for each viral load technology, and to account for between-study variation.ResultsWe identified 23 studies for inclusion in the systematic review that compared the diagnostic accuracy of dried plasma spots with that of plasma. Primary data from 16 of the 23 studies were shared and included in the meta-analysis, representing 18 countries, totaling 1847 paired dried plasma spot:plasma data points. The mean bias of dried plasma spot specimens compared with that of plasma was 0.28 log10 copies/mL, whereas the difference in median viral load was 2.25 log10 copies/mL. More dried plasma spot values were undetectable compared with plasma values (43.6% vs. 29.8%). Analyzing all technologies together, the sensitivity and specificity of dried plasma spot specimens were >92% across all treatment failure thresholds compared and total misclassification

Following severe adverse reactions to the AstraZeneca ChAdOx1-S-nCoV-19 vaccine1,2, European health authorities have recommended that patients under the age of 55 who received one dose of ChAdOx1-S-nCoV-19 vaccine receive a second dose of Pfizer BNT162b2 vaccine as a booster. However, the effectiveness and the immunogenicity of this vaccination regimen have not been formally tested. Here, we show that the heterologous ChAdOx1-S-nCoV-19/BNT162b2 combination confers better protection against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection than the homologous BNT162b2/BNT162b2 combination in a real-world observational study of healthcare workers (n=13121). To understand the underlying mechanism, we conducted a longitudinal survey of the anti-spike immunity conferred by each vaccine combination. Both combinations induced strong anti-spike antibody (Ab) responses but sera from heterologous vaccinated individuals displayed a stronger neutralizing activity, regardless of the SARS-CoV-2 variant. This enhanced neutralizing potential was correlated with increased frequencies of switched and activated memory B cells recognizing the SARS-CoV-2 Receptor Binding Domain (RBD). The ChAdOx1-S-nCoV-19 vaccine induced a weaker IgG response but a stronger T cell response than the BNT162b2 vaccine after the priming dose, which could explain the complementarity of both vaccines when used in combination. The heterologous vaccination regimen could therefore be particularly suitable for immune compromised individuals.

International audience; No data concerning antiretroviral drug's (ARV) primary resistance mutation rates in Chad are available. We retrospectively analysed frozen-stored dried blood spot samples that were collected from 48 Chadian human immunodeficiency virus (HIV)-1 seropositive patients naïve of ARV. HIV-1 protease and reverse transcriptase genes were successfully sequenced for 24 (60.0%) of the 40 patients displaying a viral load > 1000 copies/ml. Seven (29.2%) displayed mutations conferring resistance against one or more classes of ARV. We evidenced high levels of primary ARV resistance mutations in Chad, but lower than those observed in patients with failure to first-line ARV.

Objectives This study aimed to evaluate the immunochromatographic coronavirus disease 2019 (COVID-19) speed antigen test (BioSpeedia, France) as an antigen point-of-care test (AgPOCT) to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection at the paediatric emergency department of the University Hospital of Saint-Etienne in France. Methods Between 15 January and 28 May, 2021, children presenting with respiratory symptoms compatible with COVID-19 infection (symptomatic group) or those requiring hospitalization for any reason (asymptomatic group) were included prospectively and received a nasopharyngeal aspiration to carry out both AgPOCT and quantitative reverse transcription (RT) PCR (RT-qPCR) tests, with the latter being used as the reference standard, for the diagnosis of SARS-CoV-2 infection. Results Among the 1009 enrolled children, we obtained a result from both techniques for 990: 33 (3.3%) tested positive with AgPOCT and 46 (4.6%) with RT-qPCR. The overall sensitivity and specificity of the AgPOCT were 69.6% (95% confidence interval (CI), 54.3–82.3) and 99.9% (95% CI, 99.4–100), respectively, compared with the RT-qPCR. Sensitivity increased to 82.9% (95% CI, 66.4–93.4) in symptomatic children. The mean cycle threshold value was significantly lower in positive samples for AgPOCT than in negative samples in the overall population and in both the symptomatic and asymptomatic groups. Discussion The use of the COVID-19 speed antigen test at the bedside in the emergency department has satisfactory performance for diagnosing SARS-CoV-2 infection in symptomatic children.

Background Despite combined antiretroviral therapy (cART), total cure of immunodeficiency virus type 1 (HIV-1) infection remains elusive. Chronic periodontitis (CP) is strongly associated with HIV-1 infection. This condition is characterized by an intense inflammatory infiltrate mainly constituted of immune cells which in turn may be a valuable source of HIV-1 reactivation. This study aimed to determine if gingival tissue could act as a reservoir for HIV-1. Methods Twelve HIV-1-infected patients with CP and 12 controls (no HIV-1-infection and no CP) were evaluated in a cross-sectional study. RNA viral load and interleukin (IL) levels were determined in blood plasma and saliva. Histological sections of gingival tissue were stained with fluorescent antibodies against p24 antigen and different cellular biomarkers. Results In 6 of the 12 patients, HIV RNA load was detected, despite cART; in three of them, expression of viral RNA was also detected in saliva. The levels of IL-2, IL-6 and IL-12 were higher in blood and saliva of HIV-infected patients with CP than controls. HIV-1 p24 antigen was detected by Immunostaining in gingival biopsies of 10 of the 12 patients but in no control. Immune markers for T cells and antigen-presenting cells were also identified in most patients and some controls. Conclusion These preliminary data showing the detection of HIV-1 p24 antigen in the gingival biopsies of a significant part of HIV-1 infected patients with CP under cART together with the presence of immune cells, plead for the existence of a HIV-1 reservoir in the gingival tissue of this population. This article is protected by copyright. All rights reserved.

This study aimed to investigate the clinical significance of HOX transcript antisense RNA (HOTAIR) expression as a biomarker for the detection of cervical cancer and cervical premalignant lesions. 41 cervical cancer biopsies, 50 precancerous lesions, and 40 normal adjacent tissues were collected. A Series of qPCR analysis was performed on cervical cancer cells, and biopsy specimens to measure the expression of HOTAIR. We assessed the diagnostic value of HOTAIR expression levels and its correlation with clinical and pathological criteria. The expression levels of HOTAIR in tumor tissues, premalignant lesions, and adjacent normal tissues showed a significant difference (P < 0.0001). HOTAIR levels were higher in tumors compared to controls, and to premalignant lesions. Simultaneously, HOTAIR levels were significantly elevated in premalignant lesions versus controls. HOTAIR overexpression was also associated with progressed FIGO stages (P < 0.0001), tumor size (P < 0.0001), lymph node metastasis (P < 0.0001), and distant metastasis (P < 0.0001). For the diagnostic value, our results showed that HOTAIR could discriminate patients with cervical cancer from controls with 85,37% sensitivity and 85,00% specificity (AUC = 0,9305). In addition, HOTAIR expression levels could also discriminate cervical intraepithelial neoplasia from controls with 96% sensitivity and 65% specificity (AUC = 0,7835). Our findings suggest that HOTAIR might constitute a potential biomarker for detecting cervical cancer at premalignant and malignant stages as well as distinguishing key clinicopathological features.

Background The risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission through corneal graft is an ongoing debate and leads to strict restrictions in corneas procurement, leading to a major decrease in eye banking activity. The aims of this study are to specifically assess the capacity of human cornea to be infected by SARS-CoV-2 and promote its replication ex vivo, and to evaluate the real-life risk of corneal contamination by detecting SARS-CoV-2 RNA in corneas retrieved in donors diagnosed with Coronavirus Disease 2019 (COVID-19) and nonaffected donors. Methods and findings To assess the capacity of human cornea to be infected by SARS-CoV-2, the expression pattern of SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE-2) and activators TMPRSS2 and Cathepsins B and L in ocular surface tissues from nonaffected donors was explored by immunohistochemistry (n = 10 corneas, 78 ± 11 years, 40% female) and qPCR (n = 5 corneas, 80 ± 12 years, 40% female). Additionally, 5 freshly excised corneas (80 ± 12 years, 40% female) were infected ex vivo with highly concentrated SARS-CoV-2 solution (106 median tissue culture infectious dose (TCID50)/mL). Viral RNA was extracted from tissues and culture media and quantified by reverse transcription quantitative PCR (RT-qPCR) (viral RNA copies) 30 minutes (H0) and 24 hours (H24) after infection. To assess the risk of corneal contamination by SARS-CoV-2, viral RNA was tested by RT-qPCR (Ct value) in both corneas and organ culture media from 14 donors diagnosed with COVID-19 (74 ± 10 years, 29% female) and 26 healthy donors (79 ± 13 years, 57% female), and in organ culture media only from 133 consecutive nonaffected donors from 2 eye banks (73 ± 13 years, 29% female). The expression of receptor and activators was variable among samples at both protein and mRNA level. Based on immunohistochemistry findings, ACE-2 was localized mainly in the most superficial epithelial cells of peripheral cornea, limbus, and conjunctiva, whereas TMPRSS2 was mostly expressed in all layers of bulbar conjunctiva. A significant increase in total and positive strands of IP4 RNA sequence (RdRp viral gene) was observed from 30 minutes to 24 hours postinfection in central cornea (1.1 × 108 [95% CI: 6.4 × 107 to 2.4 × 108] to 3.0 × 109 [1.4 × 109 to 5.3 × 109], p = 0.0039 and 2.2 × 107 [1.4 × 107 to 3.6 × 107] to 5.1 × 107 [2.9 × 107 to 7.5 × 107], p = 0.0117, respectively) and in corneoscleral rim (4.5 × 109 [2.7 × 109 to 9.6 × 109] to 3.9 × 1010 [2.6 × 1010 to 4.4 × 1010], p = 0.0039 and 3.1 × 108 [1.2 × 108 to 5.3 × 108] to 7.8 × 108 [3.9 × 108 to 9.9 × 108], p = 0.0391, respectively). Viral RNA copies in ex vivo corneas were highly variable from one donor to another. Finally, viral RNA was detected in 3 out of 28 corneas (11%) from donors diagnosed with COVID-19. All samples from the 159 nonaffected donors were negative for SARS-CoV-2 RNA. The main limitation of this study relates to the limited sample size, due to limited access to donors diagnosed with COVID-19 and concomitant decrease in the procurement corneas from nonaffected donors. Conclusions In this study, we observed the expression of SARS-CoV-2 receptors and activators at the human ocular surface and a variable increase in viral RNA copies 24 hours after experimental infection of freshly excised human corneas. We also found viral RNA only in a very limited percentage of donors with positive nasopharyngeal PCR. The low rate of positivity in donors diagnosed with COVID-19 calls into question the utility of donor selection algorithms. Trial registration Agence de la Biomédecine, PFS-20-011 https://www.agence-biomedecine.fr/.

BackgroundSARS-CoV-2 mutations appeared recently and can lead to conformational changes in the spike protein and probably induce modifications in antigenicity. In this study, we wanted to assess the neutralizing capacity of antibodies to prevent cell infection, using a live virus neutralisation test.MethodsSera samples were collected from different populations: two-dose vaccinated COVID-19-naïve healthcare workers (HCWs; Pfizer-BioNTech BNT161b2), 6-months post mild COVID-19 HCWs, and critical COVID-19 patients. We tested various clades such as 19A (initial one), 20B (B.1.1.241 lineage), 20I/501Y.V1 (B.1.1.7 lineage), and 20H/501Y.V2 (B.1.351 lineage).ResultsNo significant difference was observed between the 20B and 19A isolates for HCWs with mild COVID-19 and critical patients. However, a significant decrease in neutralisation ability was found for 20I/501Y.V1 in comparison with 19A isolate for critical patients and HCWs 6-months post infection. Concerning 20H/501Y.V2, all populations had a significant reduction in neutralising antibody titres in comparison with the 19A isolate. Interestingly, a significant difference in neutralisation capacity was observed for vaccinated HCWs between the two variants whereas it was not significant for the convalescent groups.ConclusionNeutralisation capacity was slightly reduced for critical patients and HCWs 6-months post infection. No neutralisation escape could be feared concerning the two variants of concern in both populations. The reduced neutralising response observed towards the 20H/501Y.V2 in comparison with the 19A and 20I/501Y.V1 isolates in fully immunized subjects with the BNT162b2 vaccine is a striking finding of the study.

This study assessed the diagnostic performance of the new coronavirus disease 2019 (COVID-19) SEROSpeed IgM/IgG Rapid Test (BioSpeedia, a spinoff of the Pasteur Institute of Paris) for the detection of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in comparison to other commercial antibody assays through a large cross-European investigation. The clinical specificity was assessed on 215 prepandemic sera (including some from patients with viral infections or autoimmune disorders)., This study assessed the diagnostic performance of the new COVID19SEROSpeed IgM/IgG rapid test (BioSpeedia, a spinoff of the Pasteur Institute of Paris) for the detection of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in comparison to other commercial antibody assays through a large cross-European investigation. The clinical specificity was assessed on 215 prepandemic sera (including some from patients with viral infections or autoimmune disorders). The clinical sensitivity was evaluated on 710 sera from 564 patients whose SARS-CoV-2 infection was confirmed by quantitative reverse transcription-PCR (qRT-PCR) and whose antibody response was compared to that measured by five other commercial tests. The kinetics of the antibody response were also analyzed in seven symptomatic patients. The specificity of the test (BioS) on prepandemic specimens was 98.1% (95% confidence interval [CI], 96.2% to 99.4%). When tested on the 710 pandemic specimens, BioS showed an overall clinical sensitivity of 86.0% (95% CI, 0.83 to 0.89), with good concordance with the Euroimmun assay (overall concordance of 0.91; Cohen’s kappa coefficient of 0.62). Due in part to simultaneous detection of IgM and IgG for both S1 and N proteins, BioS exhibited the highest positive percent agreement at ≥11 days post-symptom onset (PSO). In conclusion, the BioS IgM/IgG rapid test was highly specific and demonstrated a higher positive percentage of agreement than all the enzyme-linked immunosorbent assay/chemiluminescence immunoassay (ELISA/CLIA) commercial tests considered in this study. Moreover, by detecting the presence of antibodies prior to 11 days PSO in 78.2% of the patients, the BioS test increased the efficiency of the diagnosis of SARS-CoV-2 infection in the early stages of the disease.

Graphical abstract, Context Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that emerged late in 2019 is the etiologic agent of coronavirus disease 2019 (Covid-19). There is an urgent need to develop curative and preventive therapeutics to limit the current pandemic and to prevent the re-emergence of Covid-19. This study aimed to assess the in vitro activity of copper gluconate against SARS-CoV-2. Methods Vero E6 cells were cultured with or without copper gluconate 18−24 hours before infection. Cells were infected with a recombinant GFP expressing SARS-CoV-2. Cells were infected with a recombinant GFP expressing SARS-CoV-2. Infected cells were incubated in fresh medium containing varying concentration of copper gluconate (supplemented with bovine serum albumin or not) for an additional 48 -h period. The infection level was measured by the confocal microscopy-based high content screening method. The cell viability in presence of copper gluconate was assessed by XTT and propidium iodide assays. Results The viability of Vero E6 cells exposed to copper gluconate up to 200 μM was found to be similar to that of unexposed cells, but it dropped below 70 % with 400 μM of this agent after 72 h of continuous exposure. The infection rate was 23.8 %, 18.9 %, 20.6 %, 6.9 %, 5.3 % and 5.2 % in cells treated prior infection with 0, 2, 10, 25, 50 and 100 μM of copper gluconate respectively. As compared to untreated cells, the number of infected cells was reduced by 71 %, 77 %, and 78 % with 25, 50, and 100 μM of copper gluconate respectively (p < 0.05). In cells treated only post-infection, the rate of infection dropped by 73 % with 100 μM of copper gluconate (p < 0.05). However, the antiviral activity of copper gluconate was abolished by the addition of bovine serum albumin. Conclusion Copper gluconate was found to mitigate SARS-CoV-2 infection in Vero E6 cells but this effect was abolished by albumin, which suggests that copper will not retain its activity in serum. Furthers studies are needed to investigate whether copper gluconate could be of benefit in mucosal administration such as mouthwash, nasal spray or aerosols.

Highlights • In case of virus emergence, laboratory-developed assays (LDA) should be urgently assessed. • Recommended open one-step RT-qPCR reagents are rapidly on tension in case of pandemic. • Five other reagents were shown to be used for SARS-CoV-2 RNA detection by LDA. • This study can help laboratories to assess LDA for detecting emerging RNA viruses., Background Facing the emergence of a new RNA virus, clinical laboratories are often helpless in the face of a shortage of reagents recommended by Reference Centres. Objectives To compare five open one step RT-qPCR reagents to the SuperScript™ III Platinum™ One-Step qRT-PCR kit (Invitrogen) considered as the reference one in France at the beginning of the pandemic for detection of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in respiratory specimens by using laboratory-developed assay targeting the viral RNA dependant RNA polymerase (RdRp) gene. Study design A total of 51 NUCLISENS easyMAG extracts from respiratory specimens was tested on ABI 7500 thermocycler with TaqMan Fast Virus 1-Step Master Mix (Applied Biosystems), Luna® Universal Probe One-Step RT-qPCR Kit (New England Biolabs), GoTaq® Probe 1- Step RT-qPCR System (Promega), LightCycler® Multiplex RNA Virus Master (Roche) and One-step PrimeScript RT-PCR kit (Takara). The CT values obtained using the 5 challenged reagents were compared to those obtained using the reference assay. Results The percentages of concordance were all above 95 %. When comparing the CT values of the 48 extracts exhibiting CT values < 35 obtained with the reference reagent, the results were similar between the reagents although the differences of CT values were quite dispersed. Conclusions All five reagents can be considered as alternative reagents to the reference for detecting SARS−COV-2 RNA.

Understanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection from re-infection and, thus, for public health policy and for vaccine development against the COVID-19. Here, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum specimens from a cohort of 140 SARS-CoV-2 qPCR-confirmed patients, including patient with mild symptoms but also more severe form including those that require intensive care. We show that nAb titers were strongly correlated with disease severity and with anti-Spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers, whereas patients with milder disease symptoms displayed heterogenous nAb titers and asymptomatic or exclusive outpatient care patients had no or poor nAb levels. We found that the nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery, as compared to individuals infected with alternative coronaviruses. We show the absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAb against SARS-CoV-2 infection. Finally, we found that the D614G mutation in the Spike protein, which has recently been identified as the major variant now found in Europe, does not allow neutralization escape. Altogether, our results contribute to the understanding of the immune correlate of SARS-CoV-2 induced disease and claim for a rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2.

International audience; Cytomegalovirus (CMV) infects approximately 40% of adults in France and persists lifelong as a latent agent in different organs, including gut. A close relationship is observed between inflammation that favors viral expression and viral replication that exacerbates inflammation. In this context, CMV colitis may impact the prognosis of patients suffering from inflammatory bowel diseases (IBDs), and notably those with ulcerative colitis (UC). In UC, the mucosal inflammation and T helper cell (TH) 2 cytokines, together with immunomodulatory drugs used for controlling flare-ups, favor viral reactivation within the gut, which, in turn, increases mucosal inflammation, impairs corticoid and immunosuppressor efficacy (the probability of steroid resistance is multiplied by more than 20 in the case of CMV colitis), and enhances the risk for colectomy. This review emphasizes the virological tools that are recommended for exploring CMV colitis during inflammatory bowel diseases (IBD) and underlines the interest of using ganciclovir for treating flare-ups associated to CMV colitis in UC patients.

BackgroundHerpetic keratitis (HK) models using whole human corneas are essential for studying virus-host relationships, because of high species specificity and the role of interactions between corneal cell populations that cell culture cannot reproduce. Nevertheless, the two current corneal storage methods (hypothermia and organ culture (OC)) do not preserve corneas in good physiological condition, as they are characterized by epithelial abrasion, stromal oedema, and excessive endothelial mortality.MethodsTo rehabilitate human corneas intended for scientific use, we used an active storage machine (ASM) that restores two physiological parameters that are essential for corneal homeostasis: intraocular pressure and storage medium renewal (21mmHg and 2.6 μL/min, respectively). ASM storage regenerates a normal multilayer epithelium in 2 weeks. We infected six pairs of corneas unsuitable for graft by inoculating the epithelium with herpes simplex virus type 1 (HSV-1), and compared each ASM-stored cornea with the other cornea stored in the same medium using the conventional OC method.ResultsOnly corneas in the ASM developed a dendritic (n = 3) or geographic (n = 2) epithelial ulcer reproducing typical HSV-1-induced clinical lesions. Corneas in OC showed only extensive desquamations. None of the uninfected controls showed epithelial damage. Histology, immunohistochemistry, transmission electron microscopy and polymerase chain reaction on corneal tissue confirmed infection in all cases (excluding negative controls).ConclusionsThe ASM provides an innovative ex vivo model of HK in whole human cornea that reproduces typical epithelial lesions.

L’assistance médicale à la procréation (AMP) répond à un double objectif : remédier à une infertilité médicalement constatée et éviter la transmission d’une pathologie grave à l’enfant ou à un membre du couple. Une réglementation stricte encadre la maîtrise du risque infectieux afin d’éviter la contamination de la partenaire, des gamètes et des embryons de l’enfant à naître ainsi que du personnel médicotechnique réalisant les actes d’AMP. Ainsi, un dépistage de plusieurs infections sexuellement transmissibles ou potentiellement chroniques est réalisé chez les deux membres du couple, préalablement à l’AMP. En ce qui concerne les pathologies liées aux virus HIV et les hépatites B et C, l’AMP a été utilisée après 2001 pour contrôler le risque de transmission, notamment en éliminant le virus à l’aide des techniques de préparation/séparation des fractions séminales par gradient de densité et lavage. La prise en charge médicale de ces couples dont au moins l’un des deux membres est infecté est réalisée par une équipe pluridisciplinaire composée de spécialistes de l’AMP, de biologistes de la reproduction, de virologues, d’infectiologues et/ou d’hépatologues. L’efficacité des traitements antiviraux actuels permet de contrôler ou de guérir certaines de ces pathologies et, de ce fait, d’éliminer la présence de virus au niveau des sécrétions génitales, permettant dans la majorité des cas un retour vers une conception naturelle. La prise en charge dans un circuit dit « à risque viral » s’adresse actuellement essentiellement à des couples infectés et infertiles. Ce circuit reste toutefois indispensable dans le contexte de l’émergence de nouveaux agents infectieux, dont le virus Zika est un exemple récent.

Little is known about the dynamic of HIV-1 shedding and resistance profiles in the female genital reservoir after antiretroviral therapy (ART) initiation in resource-limited countries (RLCs), which is critical for evaluating the residual sexual HIV-1 transmission risk. The present study aimed to evaluate the efficacy of 1 year duration ART at blood and genital levels in females newly diagnosed for HIV-1 from three centers in Bamako, Mali. Seventy-eight consenting females were enrolled at the time of their HIV-1 infection diagnosis. HIV-1 RNA loads (Abbott Real-Time HIV-1 assay) were tested in blood and cervicovaginal fluids (CVF) before and 12 months after ART initiation. Primary and acquired resistances to ART were evaluated by ViroseqTM HIV-1 genotyping assay. The vaginal microbiota was analyzed using IonTorrentTM NGS technology (Thermo Fisher Scientific). Proportions of primary drug resistance mutations in blood and CVF were 13.4% and 25%, respectively. Discrepant profiles were observed in 25% of paired blood/CVF samples. The acquired resistance rate was 3.1% in blood. At month 12, undetectable HIV-1 RNA load was reached in 84.6% and 75% of blood and CVF samples, respectively. A vaginal dysbiosis was associated with HIV RNA shedding. Our findings emphasize the need of reinforcing education to improve retention in care system, as well as the necessity of regular virological monitoring before and during ART and of implementing vaginal dysbiosis diagnosis and treatment in RLCs.

Background Transfusion-related acute lung injury (TRALI) is a severe pulmonary reaction due to blood transfusions. The pathophysiology of this complication is still not widely elucidated by the scientific community, especially regarding the direct role of blood platelets within the cellular mechanism responsible for the development of TRALI. Study design and methods In this study, a mouse model was used to induce the development of antibody-mediated acute lung injury through injections of lipopolysaccharide and an anti-major histocompatibility complex Class I antibody. BALB/c mice were pretreated with an anti-GPIbα antibody, which induces platelet depletion, or ML354, a protease receptor 4 pathway inhibitor, 30 minutes before TRALI induction. Results Depletion of platelets before TRALI induction appeared to reduce the severity of TRALI without completely inhibiting its development. Also, inhibition of platelet activation by ML354 did not prevent the onset of TRALI. Finally, the stimuli used for TRALI induction also triggered specific platelet activation upon ex vivo stimulation. Conclusions This study suggests that blood platelets are not critically required for TRALI induction, although they are to some extent involved in its pathophysiology.

Platelet transfusions can cause adverse reactions in their recipients, including transfusion-related acute lung injury (TRALI). The pathophysiology of TRALI depends on a number of signaling pathways and the inflammatory role played by blood platelets remains controversial. Platelets are important in inflammation, particularly via the immunomodulator complex CD40/CD40L. We studied the specific function of the CD40/CD40L interaction in regulating an experimental TRALI Two-hit model. A mouse model of immune TRALI was triggered by injection of LPS and an anti-MHC I antibody, and the effect of injection of a neutralizing anti-CD40L antibody before induction of TRALI investigated. The characteristics of TRALI were decreased body temperature, pulmonary lesions, and immune cell infiltration into the alveolar space. Pulmonary infiltration was evaluated by blood counts of specific immune cells and their detection in lung sections. Inhibition of the CD40/CD40L immunomodulator interaction significantly reduced communication between immune and/or endothelial cells and the development of pulmonary edema. Hence, our results indicate that targeting of the CD40/CD40L interaction could be an important method to prevent TRALI. While considering that our work concerned a mouse model, we postulate that improvement of the conditions under which platelet concentrates are prepared/stored would assist in alleviating the risk of TRALI.

Mobile phones (MPs) of healthcare workers (HCWs) may represent an important source of transmission of infectious agents. This longitudinal study documents the contamination of these tools. Ten MPs handled by senior pediatricians were sampled once a week during 23 weeks in three pediatric wards of the University Hospital of Saint-Etienne, France. Cultures were performed for bacteria and multiplex PCR assays for a panel of respiratory and enteric viruses. A questionnaire on hygiene habits regarding phoning and care was filled-in by pediatricians before and after the study. From a total of 230 samples, 145 (63%) were contaminated by at least one pathogen. The MPs from emergency departments were the most impacted. Viruses were detected in 179 samples, bacteria were isolated in 59 samples. Contamination increased during the winter epidemic peak. A cross-contamination by Paracoccus yeei between hands and MPs of different HCWs was demonstrated. The communication of the study results influenced the hygiene behaviors. This study highlights the contamination of MPs by pathogens that are resistant in the environment, and its sustainability along the winter season. The role of MPs as vectors of nosocomial infection needs to be better investigated.

Background: The semen of HIV-1 infected men represents the main vector of HIV-1 spread following sexual transmission of cell-free or cell-associated virions. Objective: The present study aimed to assess the impact of HAART on HIV-1 RNA/DNA and on inflammatory environment in the semen of long-term HAART-experienced men. Methods: Forty-five paired samples of semen and blood were obtained from 37 consenting men, 10 untreated and 27 under HAART. Blood and seminal HIV RNA and DNA loads were quantified by the Abbott RealTime m2000rt assay and an inhouse real-time PCR protocol, respectively. Tat/rev/nef intra-cellular mRNA was tested by qualitative PCR. Interleukin (IL)- 1β, IL-2, IL-6, IL-7, IL-8, IL-10, GM-CSF and TNFα were quantified in 20 paired samples by Bio-plex® assay. Results: No semen was found HIV RNA positive in men under HAART. Twenty-six percent of semen samples from HAART-experienced men remained positive for HIV DNA. Seminal HIV DNA was significantly associated with the duration of infection and the HIV DNA load in blood. No seminal mononuclear cells were found positive for intracellular HIV RNA in HAART experienced men. All the tested chemokines exhibited significantly higher concentration in semen than in blood in both treated and untreated men. No effect of HAART on cytokines/chimiokines loads was observed. Conclusion: These results demonstrate the efficacy of HAART on the reduction of seminal RNA HIV-1 loads despite the persistence of local inflammation. Moreover, in our hands the seminal cell-associated virus reservoir was not reactivated in an inflammatory environment was not productive and its reactivation seems unlikely.

Objective: To evaluate the mutational patterns on the pol gene of the main HIV-1 strain archived in cell genome of 10 chronically infected men according to their clinical and therapeutic history. The genotyping resistance profiles were compared between the first blood plasma available at the time of HIV diagnosis and rectal biopsies and PBMC sampled 1-5 years after the initiation of combined antiretroviral therapy (cART). Methods: HIV-1 RNA and cell-associated HIV-1 DNA were quantified by Abbott Real-Time HIV-1 and Generic HIV® DNA cell (Biocentric) assays. The mutations in protease and reverse transcriptase genes were assessed by the Trugene® assay (Siemens). The C2V3 region was amplified to determine the viral tropism. Results: In 9 patients, slight or no differences were observed between the 3 resistance profiles. Those mostly detected were related to the resistance to nucleos(t)ide (D67N, L210W, T215A, T69D) and nonnucleoside (K103N, V106I, V179I) inhibitors. In 1 rilpivirine-treated patient, the M230I mutation was detected in PBMC. No change of viral tropism was observed between samples. Conclusion: These data suggest that resistance mutations harbored by the main HIV strain in plasma at the time of diagnosis are durably archived in DNA cells whatever the delay between infection and initiation of therapy in patients well controlled by cART.

The gut associated lymphoid tissue (GALT) is the site of numerous immunological disturbances during HIV-1 infection. It constitutes the largest reservoir for HIV, not or very poorly susceptible to antiretroviral therapy (ART), making it a major obstacle to HIV cure. Moreover, the GALT is involved in systemic immune activation in HIV-infected individuals: intestinal damage due to viral replication and severe CD4(+) T cell depletion in the GALT leads to microbial translocation, a key driver of immune activation, and in turn, disease progression. In this review, we describe the role of the GALT in HIV infection and we discuss therapeutic options to decrease the intestinal viral reservoir and to preserve immune function in the gut of HIV-infected people. Achieving these goals is necessary for a long-term infection control after the interruption of ART.