High proportion of post-migration HIV acquisition in migrant men who have sex with men receiving HIV care in the Paris region, and associations with social disadvantage and sexual behaviours: results of the ANRS-MIE GANYMEDE study, France, 2021 to 2022.

BackgroundSome migrant men who have sex with men (MSM) acquire HIV in France.AimsWe investigated, in migrant MSM receiving HIV care in France, the (i) rate of post-migration-HIV acquisition in France, (ii) delay between arrival and HIV acquisition and (iii) factors affecting HIV acquisition within 1 year after migration.MethodsThis cross-sectional study focused on ≥ 18-year-old MSM born outside France, receiving HIV care in the Paris region. Information on migration history, socioeconomic condition, sexual activity, and health was collected in May 2021-June 2022 through self-administered questionnaires and medical records. Post-migration-HIV-acquisition rate and delay between arrival in France and HIV acquisition were estimated from biographical data and CD4+ T-cell counts. Predictors of HIV acquisition within 1 year after migration were determined using logistic regression.ResultsOverall post-migration HIV-acquisition rate was 61.7% (715/1,159; 95%CI: 61.2-62.2), ranging from 40.5% (95%CI: 39.6-41.6) to 85.4% (95%CI: 83.9-86.0) in participants from Latin America and North Africa. Among post-migration-HIV acquisitions, those within 1 year after migration represented 13.1% overall (95%CI: 11.6-14.6), being highest in participants from sub-Saharan Africa (25%; 95%CI: 21.5-28.3). Participants ≥ 15-years old at migration, with post-migration-acquired HIV, had a 7.5-year median interval from arrival in France to HIV acquisition (interquartile range (IQR): 3.50-14.75). Older age at arrival, region of origin (sub-Saharan Africa and Asia), degree of social disadvantage and numbers of sexual partners were independently associated with acquiring HIV within 1 year in France.ConclusionOur findings may guide HIV prevention policies for most vulnerable migrants to Europe.

Efficacy and safety of baricitinib in hospitalized adults with severe or critical COVID-19 (Bari-SolidAct): a randomised, double-blind, placebo-controlled phase 3 trial.

BACKGROUND: Baricitinib has shown efficacy in hospitalized patients with COVID-19, but no placebo-controlled trials have focused specifically on severe/critical COVID, including vaccinated participants. METHODS: Bari-SolidAct is a phase-3, multicentre, randomised, double-blind, placebo-controlled trial, enrolling participants from June 3, 2021 to March 7, 2022, stopped prematurely for external evidence. Patients with severe/critical COVID-19 were randomised to Baricitinib 4 mg once daily or placebo, added to standard of care. The primary endpoint was all-cause mortality within 60 days. Participants were remotely followed to day 90 for safety and patient related outcome measures. RESULTS: Two hundred ninety-nine patients were screened, 284 randomised, and 275 received study drug or placebo and were included in the modified intent-to-treat analyses (139 receiving baricitinib and 136 placebo). Median age was 60 (IQR 49-69) years, 77% were male and 35% had received at least one dose of SARS-CoV2 vaccine. There were 21 deaths at day 60 in each group, 15.1% in the baricitinib group and 15.4% in the placebo group (adjusted absolute difference and 95% CI - 0.1% [- 8·3 to 8·0]). In sensitivity analysis censoring observations after drug discontinuation or rescue therapy (tocilizumab/increased steroid dose), proportions of death were 5.8% versus 8.8% (- 3.2% [- 9.0 to 2.7]), respectively. There were 148 serious adverse events in 46 participants (33.1%) receiving baricitinib and 155 in 51 participants (37.5%) receiving placebo. In subgroup analyses, there was a potential interaction between vaccination status and treatment allocation on 60-day mortality. In a subsequent post hoc analysis there was a significant interaction between vaccination status and treatment allocation on the occurrence of serious adverse events, with more respiratory complications and severe infections in vaccinated participants treated with baricitinib. Vaccinated participants were on average 11 years older, with more comorbidities. CONCLUSION: This clinical trial was prematurely stopped for external evidence and therefore underpowered to conclude on a potential survival benefit of baricitinib in severe/critical COVID-19. We observed a possible safety signal in vaccinated participants, who were older with more comorbidities. Although based on a post-hoc analysis, these findings warrant further investigation in other trials and real-world studies. Trial registration Bari-SolidAct is registered at NCT04891133 (registered May 18, 2021) and EUClinicalTrials.eu ( 2022-500385-99-00 ).

Impact on renal function of daily and on-demand HIV pre-exposure prophylaxis in the ANRS-PREVENIR study.

OBJECTIVES: To assess the impact on the estimated glomerular filtration rate (eGFR) of different tenofovir disoproxil/emtricitabine dosing regimens for HIV pre-exposure prophylaxis (PrEP). PATIENTS AND METHODS: We included in the study individuals with baseline eGFR > 50 mL/min/1.73 m2 who initiated PrEP in the ongoing ANRS-PREVENIR PrEP cohort. We retrospectively classified PrEP users in three groups: 'on-demand' (reported at ≥75% of study visits), 'daily' (≥75% of study visits) or 'switches'. We compared the area under curve (AUC) of the eGFR variation from baseline (ΔeGFR) between groups using analysis of covariance, and assessed factors associated with a negative AUC of ΔeGFR. RESULTS: From May 2017 to October 2020, 1253 PrEP-naïve participants (98% of MSM) were included in the study with a median follow-up of 22 months. 499 (40%), 494 (39%) and 260 (21%) users were in the group daily, on-demand and switches, respectively, for a median number of pills taken per week of 6, 1.7 and 4. The mean AUC of the ΔeGFR was -1.09 mL/min/1.73 m2 in the daily PrEP group, -0.69 mL/min/1.73 m2 in the switches group and +0.18 mL/min/1.73 m2 with on-demand PrEP. In a model adjusted on baseline age and eGFR, the AUC of the ΔeGFR was significantly higher with on-demand PrEP compared to daily PrEP (P = 0.037). Independent factors associated with a negative AUC of ΔeGFR were a daily PrEP regimen, a switches regimen, an age > 40 years and a baseline eGFR≥90 mL/min/1.73 m². CONCLUSIONS: On-demand PrEP dosing had a smaller impact on eGFR evolution than daily PrEP, but the difference was not clinically relevant.

Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Among HIV-Negative Participants Using Tenofovir/Emtricitabine-Based Preexposure Prophylaxis in 2020: A Substudy of the French National Agency for Research on AIDS and Viral Hepatitis PREVENIR and Inserm SAPRIS-Sero Cohorts.

The potential preventive efficacy of tenofovir/emtricitabine on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was assessed in human immunodeficiency virus preexposure prophylaxis (PrEP) users. Prevalence of SARS-CoV-2 immunoglobulin G between May and October 2020 was similar in PrEP users and in a matched population-based cohort, suggesting that tenofovir/emtricitabine has no role in reducing the risk of SARS-CoV-2 acquisition.

Daily and on-demand HIV pre-exposure prophylaxis with emtricitabine and tenofovir disoproxil (ANRS PREVENIR): a prospective observational cohort study.

BACKGROUND: There are few data available regarding the use of on-demand pre-exposure prophylaxis (PrEP) for HIV prevention. We aimed to assess PrEP effectiveness, adherence, and safety in adults using daily or on-demand PrEP. METHODS: We conducted a prospective observational cohort study (ANRS PREVENIR) at 26 sites in the Paris region, France. We enrolled HIV-negative adults (aged ≥18 years) at high risk of HIV infection who were starting or continuing PrEP. PrEP was prescribed as a fixed-dose combination of tenofovir disoproxil and emtricitabine (245 mg and 200 mg, respectively, per pill). PrEP could be prescribed as a daily regimen with one pill per day or, in men who have sex with men (MSM) or in transgender women who have sex with men, as an on-demand regimen following the IPERGAY dosing recommendation. At enrolment and every 3 months thereafter, participants were tested for HIV and provided information regarding the PrEP dosing regimen used. Adherence to PrEP was assessed by self-report and by tenofovir diphosphate concentrations in dried blood spots. The primary outcome of HIV-1 incidence was assessed using Poisson regression among participants who started PrEP. This study is registered with ClinicalTrials.gov, NCT03113123, and EudraCT, 2016A0157744. FINDINGS: Between May 3, 2017, and May 2, 2019, 3082 people were assessed for eligibility and 3065 participants were enrolled. 3056 (99·7%) of 3065 participants reported using PrEP and were included in the analyses. The median age was 36 years (IQR 29-43), 1344 (44·0%) of 3056 participants were PrEP-naive, and 3016 (98·7%) were MSM. At enrolment, 1540 (50·5%) of 3049 participants opted for daily PrEP dosing and 1509 (49·5%) opted for on-demand PrEP dosing; these proportions remained stable during follow-up. Median follow-up was 22·1 months (IQR 15·9-29·7) and incidence of study discontinuation was 17·6 participants (95% CI 16·5-18·7) per 100 person-years. At the data cutoff on Sept 30, 2020, there had been six HIV-1 seroconversions (three participants using daily PrEP and three using on-demand PrEP; all were MSM) over 5623 person-years. Overall HIV-1 incidence was 1·1 cases (95% CI 0·4-2·3) per 1000 person-years, and did not differ between participants using daily PrEP and those using on-demand PrEP (incidence rate ratio 1·00, 95% CI 0·13-7·49; p=0·99). Four participants (two using daily PrEP and two using on-demand PrEP) discontinued PrEP due to treatment-related adverse events (nausea [n=2], vomiting and diarrhoea [n=1], and lumbar pain [n=1]). INTERPRETATION: In this study, which enrolled mainly MSM, HIV-1 incidence on PrEP was low and did not differ between participants using daily PrEP and those using on-demand PrEP. On-demand PrEP therefore represents a valid alternative to daily PrEP for MSM, providing greater choice in HIV prevention. FUNDING: ANRS/Maladies Infectieuses Emergentes, Gilead Sciences, SIDACTION, and Région Ile de France. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Fat gain differs by sex and hormonal status in persons living with suppressed HIV switched to raltegravir/etravirine.

: Fat gain is reported in integrase strand transfer inhibitors exposed persons living with HIV. We investigated in 165 persons living with HIV (117 men/48 women), included in the 96-week ANRS-163-ETRAL trial and switched to raltegravir/etravirine, the impact of sex, menopausal status and ovarian reserve (detectable anti-Müllerian hormone). From baseline to 48/96 weeks, women with ovarian reserve were protected from raltegravir/etravirine-induced weight/fat gain and associated insulin-resistance while peri/postmenopausal women increased weight, fat and insulin resistance as did men. The functional ovarian status could protect against raltegravir/etravirine-induced weight gain.

Characterization of viral rebounds on dual etravirine/raltegravir maintenance therapy (ANRS-163 ETRAL trial).

BACKGROUND: The ANRS-163 ETRAL trial, a switch study to an etravirine 200 mg/raltegravir 400 mg twice-daily regimen in 165 patients with HIV-1 infection, showed durable efficacy until Week 96. The aim of this work was to investigate in detail the virological rebounds (VRs), defined as at least one plasma HIV viral load (VL) >50 copies/mL. METHODS: Quantification of HIV-DNA level was assessed at baseline, Week 48 and Week 96 (n = 157). VLs were measured in seminal plasma at Week 48 (n = 26). Genotypic resistance testing by ultra-deep sequencing (UDS) for reverse transcriptase (RT) and integrase regions was performed at baseline and at the time of VR. RESULTS: In this study, 19 patients experienced VR, with 2 patients having virological failure (VF; two consecutive VLs >50 copies/mL). For the first patient with VF, UDS detected minority resistant variants only in RT (K103N, 9.6%; Y181C, 4.9%) at baseline. Some RT variants became dominant at VF (K101E, 86.3%; Y181C, 100.0%; G190A, 100.0%) and others emerged in integrase (Y143C, 2.4%; Q148R, 6.2%; N155H, 18.8%). For the second patient with VF, neither RT nor integrase mutations were detected at baseline and VF. Median HIV-DNA level was similar at baseline, Week 48 and Week 96 (2.17, 2.06 and 2.11 log10 copies/106 cells, respectively). Only one patient had a detectable seminal HIV VL (505 copies/mL). CONCLUSIONS: The dual etravirine/raltegravir regimen as maintenance therapy was effective and the emergence of mutations in cases of VF was similar to that seen in other dual-regimen studies. No HIV-DNA level modification was evidenced by Week 96.

Addition of Maraviroc Versus Placebo to Standard Antiretroviral Therapy for Initial Treatment of Advanced HIV Infection: A Randomized Trial.

Background: Patients diagnosed with advanced HIV infection have a poor prognosis despite initiation of combined antiretroviral therapy (c-ART). Objective: To assess the benefit of adding maraviroc, an antiretroviral drug with immunologic effects, to standard c-ART for patients with advanced disease at HIV diagnosis. Design: Randomized controlled trial. (ClinicalTrials.gov: NCT01348308). Setting: Clinical sites in France (n = 25), Italy (n = 5), and Spain (n = 20). Participants: 416 HIV-positive, antiretroviral-naive adults with CD4 counts less than 0.200 × 109 cells/L and/or a previous AIDS-defining event (ADE). Intervention: C-ART plus placebo or maraviroc (300 mg twice daily with dose modification) for 72 weeks. Measurements: The primary end point was first occurrence of severe morbidity (new ADE, selected serious infections, serious non-ADE, immune reconstitution inflammatory syndrome, or death). Prespecified secondary outcomes included primary outcome components, biological and pharmacokinetic measures, and adverse events graded 2 or higher. Results: 409 randomly assigned participants (207 in the placebo group and 202 in the maraviroc group) who received more than 1 dose were included in the analysis. During 72 weeks of follow-up, incidence of severe morbidity was 11.1 per 100 person-years in the maraviroc group and 11.2 per 100 person-years in the placebo group (hazard ratio, 0.97 [95% CI, 0.57 to 1.67]). Incidence of adverse events graded 2 or higher was 36.1 versus 41.5 per 100 person-years (incidence rate ratio, 0.87 [CI, 0.65 to 1.15]). Limitations: Sixty-four participants discontinued therapy during follow-up. The study was not designed to evaluate time-dependent outcomes or effect modification. Conclusion: Addition of maraviroc to standard c-ART does not improve clinical outcomes of patients initiating therapy for advanced HIV infection. Primary Funding Source: INSERM-ANRS (French National Agency for Research on AIDS).

Dual therapy combining raltegravir with etravirine maintains a high level of viral suppression over 96 weeks in long-term experienced HIV-infected individuals over 45 years on a PI-based regimen: results from the Phase II ANRS 163 ETRAL study.

BACKGROUND: Dual therapy combining integrase inhibitors and NNRTIs represents a promising regimen in ageing HIV-infected individuals with long exposure to nucleoside analogues and PIs. METHODS: The ANRS 163 ETRAL trial (NCT02212379) was a 96 week, multicentre, single-arm study evaluating the efficacy and safety of raltegravir (400 mg twice daily)/etravirine (200 mg twice daily) in individuals >45 years, on a PI-containing regimen who were integrase inhibitor and etravirine naive. The primary endpoint was the proportion of participants with virological success, defined by the absence of virological failure up to week 48. Main secondary outcomes included evolution of metabolic parameters, CD4/CD8 count, bone mineral density and inflammatory markers. The study was designed to show an efficacy >90%, assuming a success rate ≥95%, with a power of 80% and a 5% type-1 error. RESULTS: One hundred and sixty-five participants (median age 52 years, duration of ART 16.9 years, viral suppression 6.9 years and CD4 count 700 cells/mm3) were enrolled. By ITT analysis, viral suppression was maintained in 99.4% of participants (95% CI = 95.6%-99.9%) at week 48 and 98.7% (95% CI = 95.0%-99.7%) at week 96. Two virological failures occurred (week 24 and week 64) without emergence of integrase inhibitor resistance. Eight participants discontinued raltegravir/etravirine for adverse events, leading to a strategy success rate of 95.1% (95% CI = 90.5%-97.5%) at week 48 and 92.7% (95% CI = 87.5%-95.8%) at week 96. Over 96 weeks, lipid fractions improved (P < 0.001), CD4/CD8 ratio increased, IFNγ-induced protein 10 (IP-10) decreased (-8.1%), soluble CD14 decreased (-27%, P < 0.001) bone mineral density improved and BMI increased. CONCLUSIONS: Raltegravir plus etravirine dual therapy demonstrated durable efficacy in virologically suppressed ageing patients.

Accurate quantification of CXCR4-using HIV-1 variants by Illumina deep-sequencing.

: Next-generation sequencing is a sensitive method for determining HIV-1 tropism but there is a lack of data on the quantification of X4 variants. We evaluated MiSeq and 454 GS-Junior platforms for determining HIV-1 tropism and for quantifying X4 variants. Both platforms were 93% concordant for determining HIV-1 tropism and correlated well for determining the proportion of X4 variants (Spearman correlation, ρ = 0.748; P < 0.0001). MiSeq Illumina sequencing seems to be well adapted for characterizing X4-containing samples.

Decreased mutation frequencies among immunoglobulin G variable region genes during viremic HIV-1 infection.

BACKGROUND/OBJECTIVE: HIV-1 infection is complicated by high rates of opportunistic infections against which specific antibodies contribute to immune defense. Antibody function depends on somatic hypermutation (SHM) of variable regions of immunoglobulin heavy chain genes (VH-D-J). We characterized the frequency of SHM in expressed IgG mRNA immunoglobulin transcripts from control and HIV-1-infected patients. DESIGN: We compared utilization of genes in the most prominent VH family (VH3) and mutation frequencies and patterns of cDNA from VH3-IgG genes from 10 seronegative control subjects and 21 patients with HIV-1 infection (6 without and 15 patients with detectable plasma viremia). METHODS: Unique IgG VH3 family cDNA sequences (n = 1,565) were PCR amplified, cloned, and sequenced from blood. Sequences were analyzed using online (Vbase) and in-house immunoglobulin alignment resources. RESULTS: Mutation frequencies in the antigen-binding hypervariable complementarity determining regions (CDR1/2) of IgG class-switched B cells were lower among viremic HIV-1-infected patients vs. controls for nucleotides (CDR1/2: 10±5% vs. 13.5±6%, p = 0.03) and amino acids (CDR: 20%±10 vs. 25%±12, p = 0.02) and in structural framework regions. Mutation patterns were similar among groups. The most common VH3 gene, VH3-23, was utilized less frequently among viremic HIV-1-infected patients (p = 0.03), and overall, mutation frequencies were decreased in nearly all VH3 genes compared with controls. CONCLUSIONS: B cells from HIV-1-infected patients show decreased mutation frequencies, especially in antigen-binding VH3 CDR genes, and selective defects in gene utilization. Similar mutation patterns suggest defects in the quantity, but not quality, of mutator activity. Lower levels of SHM in IgG class-switched B cells from HIV-1-infected patients may contribute to the increased risk of opportunistic infections and impaired humoral responses to preventative vaccines.

Clinical and virological study of dengue cases and the members of their households: the multinational DENFRAME Project.

BACKGROUND: Dengue has emerged as the most important vector-borne viral disease in tropical areas. Evaluations of the burden and severity of dengue disease have been hindered by the frequent lack of laboratory confirmation and strong selection bias toward more severe cases. METHODOLOGY: A multinational, prospective clinical study was carried out in South-East Asia (SEA) and Latin America (LA), to ascertain the proportion of inapparent dengue infections in households of febrile dengue cases, and to compare clinical data and biological markers from subjects with various dengue disease patterns. Dengue infection was laboratory-confirmed during the acute phase, by virus isolation and detection of the genome. The four participating reference laboratories used standardized methods. PRINCIPAL FINDINGS: Among 215 febrile dengue subjects-114 in SEA and 101 in LA-28 (13.0%) were diagnosed with severe dengue (from SEA only) using the WHO definition. Household investigations were carried out for 177 febrile subjects. Among household members at the time of the first home visit, 39 acute dengue infections were detected of which 29 were inapparent. A further 62 dengue cases were classified at early convalescent phase. Therefore, 101 dengue infections were found among the 408 household members. Adding these together with the 177 Dengue Index Cases, the overall proportion of dengue infections among the study participants was estimated at 47.5% (278/585; 95% CI 43.5-51.6). Lymphocyte counts and detection of the NS1 antigen differed significantly between inapparent and symptomatic dengue subjects; among inapparent cases lymphocyte counts were normal and only 20% were positive for NS1 antigen. Primary dengue infection and a specific dengue virus serotype were not associated with symptomatic dengue infection. CONCLUSION: Household investigation demonstrated a high proportion of household members positive for dengue infection, including a number of inapparent cases, the frequency of which was higher in SEA than in LA.

Whole-cell pertussis vaccine induces low antibody levels in human immunodeficiency virus-infected children living in sub-Saharan Africa.

The WHO recommendations for the immunization of children infected with human immunodeficiency virus (HIV) differ slightly from the guidelines for uninfected children. The introduction of antiretroviral therapy for HIV-infected infants should considerably prolong their life expectancy. The question of the response to the whole-cell pertussis (wP) vaccine should now be addressed, particularly in countries in which pertussis remains endemic. To evaluate the persistence of antibodies to the wP vaccine in HIV-infected and uninfected children who had previously received this vaccine in routine clinical practice, we conducted a cross-sectional study of children aged 18 to 36 months, born to HIV-infected mothers and living in Cameroon or the Central African Republic. We tested blood samples for antibodies to the wP vaccine and for antibodies to diphtheria and tetanus toxoids (D and T, respectively) in the context of the use of a combined DTwP vaccine. We enrolled 50 HIV-infected children and 78 uninfected, HIV-exposed children in the study. A lower proportion of HIV-infected children than uninfected children had antibodies against the antigens tested for all valences of the DTwP vaccine. Agglutinin levels were substantially lower in HIV-infected than in HIV-exposed but uninfected children (30.0% versus 55.1%, respectively; P = 0.005). We also observed a high risk of low antibody levels in response to the DTwP vaccine in HIV-infected children with severe immunodeficiency (CD4 T-cell level, <25%). The concentrations of antibodies induced by the DTwP vaccine were lower in HIV-infected children than in uninfected children. This study supports the need for a booster dose of the DTwP vaccine in order to maintain high antibody levels in HIV-infected children.

HIV-infected children living in Central Africa have low persistence of antibodies to vaccines used in the Expanded Program on Immunization.

BACKGROUND: The Expanded Program on Immunization (EPI) is the most cost-effective measures to control vaccine-preventable diseases. Currently, the EPI schedule is similar for HIV-infected children; the introduction of antiretroviral therapy (ART) should considerably prolong their life expectancy. METHODS AND PRINCIPAL FINDINGS: To evaluate the persistence of antibodies to the EPI vaccines in HIV-infected and HIV-exposed uninfected children who previously received these vaccines in routine clinical practice, we conducted a cross-sectional study of children, aged 18 to 36 months, born to HIV-infected mothers and living in Central Africa. We tested blood samples for antibodies to the combined diphtheria, tetanus, and whole-cell pertussis (DTwP), the measles and the oral polio (OPV) vaccines. We enrolled 51 HIV-infected children of whom 33 were receiving ART, and 78 HIV-uninfected children born to HIV-infected women. A lower proportion of HIV-infected children than uninfected children had antibodies to the tested antigens with the exception of the OPV types 1 and 2. This difference was substantial for the measles vaccine (20% of the HIV-infected children and 56% of the HIV-exposed uninfected children, p<0.0001). We observed a high risk of low antibody levels for all EPI vaccines, except OPV types 1 and 2, in HIV-infected children with severe immunodeficiency (CD4(+) T cells <25%). CONCLUSIONS AND SIGNIFICANCE: Children were examined at a time when their antibody concentrations to EPI vaccines would have still not undergone significant decay. However, we showed that the antibody concentrations were lowered in HIV-infected children. Moreover, antibody concentration after a single dose of the measles vaccine was substantially lower than expected, particularly low in HIV-infected children with low CD4(+) T cell counts. This study supports the need for a second dose of the measles vaccine and for a booster dose of the DTwP and OPV vaccines to maintain the antibody concentrations in HIV-infected and HIV-exposed uninfected children.

Differential production of immunoglobulin classes and subclasses by mucosal-type human B-lymphocytes exposed in vitro to CpG oligodeoxynucleotides.

As B-lymphocytes play an important role in innate and adaptive immunity, we aimed to examine the effects of CpG oligodeoxynucleotides (ODNs) on purified tonsil-originating CD19+ B-cells, representing mucosal B-cells. We screened various K-type ODNs, reactive with human B-cells, and tested for the production of immunoglobulins in vitro. Using one CpG-ODN, DSP30, we observed that it could upregulate not only Toll-like receptor 9 (TLR9) mRNA expression in activated B-cells, but also the early expression of CD69 followed by the sequential expression of CD80, CD86 and the nuclear factor (NF)-kappaB pathway. Furthermore, mRNA expression of certain B-cell-derived cytokines was influenced by exposure to DSP30, with a strong upregulation of interleukin 6 (IL-6) and downregulation of IL1-beta. Stimulation of B-cells, co-stimulated with IL-2, IL-10 and soluble CD40 ligand (sCD40L) with different CpG-ODNs, had differing effects on the terminal differentiation in vitro of B-cells into immunoglobulin-secreting cells. TLR9 is involved in innate immunity and the recognition of bound CpG DNA from invading bacterial pathogens. As tonsillar B-cells are mucosal-type B-lymphocytes, this study suggests that CpG-ODNs show promise as mucosal adjuvants in modulating the local production of immunoglobulins of certain classes and subclasses, a crucial issue in vaccine perspectives.

Specific antibody production by blood B cells is retained in late stage drug-naïve HIV-infected Africans.

Unseparated peripheral blood mononuclear cells (PBMCs) obtained from drug-naïve African individuals living in a context of multi-infections and presenting with high viral load (VL), were cultured in vitro and tested for their ability to produce antibodies (Abs) reacting with HIV-1 antigens. Within these PBMCs, circulating B cells were differentiated in vitro and produced IgG Abs against not only ENV, but also GAG and POL proteins. Under similar experimental conditions, HAART treated patients produced Abs to ENV proteins only. The in vitro antibody production by drug-naïve individuals' PBMCs depended on exogenous cytokines (IL-2 and IL-10) but neither on the re-stimulation of reactive cells in cultures by purified HIV-1-gp160 antigen nor on the re-engagement of CD40 surface molecules. Further, it was not abrogated by the addition of various monoclonal Abs (mAbs) to co-stimulatory molecules. This suggests that the in vitro antibody production by drug-naïve individuals' PBMCs resulted from the maturation of already envelope and core antigen-primed, differentiated B cells, presumably pre-plasma cells, which are not known to circulate at homeostasy. As in vitro produced Abs retained the capacity of binding antigen and forming complexes, this study provides pre-clinical support for functional humoral responses despite major HIV- and other tropical pathogen-induced B cell perturbations.

Isotype profiles of anti-gp160 antibodies from HIV-infected patients in plasma and culture supernatants.

We studied isotype profiles of anti-HIV antibodies (Ab) in HIV-1-infected African patients with high viral loads and major B cell dysfunction. We focussed on IgG1, IgG3, and IgA as these classes and subclasses tend to support neutralizing functions against HIV. Total IgG1, IgG3 and IgA were detected in the plasma of both HIV-1-infected and HIV-negative African individuals, but there was significantly more IgG3, a rare subclass, in HIV-1-infected patients (P < 0.05). Anti-HIV-gp160 specific antibodies were detected in sera from nearly all HIV-1-infected individuals tested, but not in HIV- individuals: 10/10, 9/10 and 8/10 individuals displayed specific IgG1, IgG3 and IgA, respectively. In the corresponding PBMC cultures carried out in the presence of IL-10 and IL-2, there was specific IgG1 and IgA in 5/10, and 3/10, respectively, but no IgG3 was detected. When HAART-treated European HIV-infected PBMC cultures were tested using the same protocol, specific IgG3 was detected in 4/10 cultures, and was unaffected by the addition of soluble CD40L molecules. The present study thus shows that, despite lymph node disorganization in HIV-infected drug-naïve Africans, these individuals retain the ability to produce HIV-specific IgG1, IgG3 and IgA. However, the specific mechanisms controlling the selective production of IgG3, probably the most potent subclass and a potential target of immuno-intervention, warrants further investigation.

Identification of germinal center B cells in blood from HIV-infected drug-naive individuals in Central Africa.

To better understand the pathophysiology of B cell populations-the precursors of antibody secreting cells-during chronic human immunodeficiency virus (HIV) infection, we examined the phenotype of circulating B cells in newly diagnosed Africans. We found that all African individuals displayed low levels of naive B cells and of memory-type CD27+ B cells, and high levels of differentiated B cells. On the other hand, HIV-infected African patients had a population of germinal center B cells (i.e. CD20+, sIgM-, sIgD+, CD77+, CD138(+/-)), which are generally restricted to lymph nodes and do not circulate unless the lymph node architecture is altered. The first observations could be linked to the tropical environment whereas the presence of germinal center B cells may be attributable to chronic exposure to HIV as it is not observed in HIV-negative African controls and HAART treated HIV-infected Europeans. It may impact the management of HIV infection in countries with limited access to HIV drugs and urges consideration for implementation of therapeutic vaccines.

A flow cytometry technique to study nuclear factor-kappa B (NFkappaB) translocation during human B cell activation.

We aimed at examining NFkappaB translocation in B lymphocytes during in vitro activation through the specific receptor for antigen using a technique convenient in most laboratories such as flow cytometry. We present here an original, convenient, and reproducible technique to study B cell activation events through NFkappaB translocation by means of a novel, specific flow cytometry assay. Intranuclear translocation of NFkappaB p65 was induced after a 45min stimulation; the highest signal was detected for a 10 ng/ml stimulus compared to the unstimulated condition (P< 0.05). Purified CD19+ B cells--cultured in the presence of optimal concentrations of anti-micro fragment Abs (10ng/ml) for 45min at 37 degrees C--induced a mean 60% (range: 45-67%) MFI-- and thus, nuclear NFkappaB translocation-increase. We observed a one-pike profile of NFkappaB staining in PBMC B cells and a two-pike profile of NFkappaB staining in using tonsil B cells. B cells are susceptible to various dysregulations leading to minor to severe pathology (including immunoproliferative disorders). Studies of signal transduction carried out specifically in human B cells, using a novel technique gave considerable advantages: feasibility, sensitivity, reproducibility, ease.