Genetic and Functional Profiling of CD16-Dependent Natural Killer Activation Identifies Patients at Higher Risk of Cardiac Allograft Vasculopathy.

BACKGROUND: Cardiac transplantation is an effective therapy for end-stage heart failure. Because cardiac allograft vasculopathy (CAV) is the major cause of late mortality after heart transplant (HT), there is a need to identify markers that reflect inflammatory or cytotoxic immune mechanisms contributing to its onset. Noninvasive and early stratification of patients at risk remains a challenge for adapting individualized therapy. The CD16 (Fc-gamma receptor 3A [FCGR3A]) receptor was recently identified as a major determinant of antibody-mediated natural killer (NK) cell activation in HT biopsies; however, little is known about the role of CD16 in promoting allograft vasculopathy. This study aimed to investigate whether markers that reflect CD16-dependent circulating NK cell activation may identify patients at higher risk of developing CAV after HT. METHODS: Blood samples were collected from 103 patients undergoing routine coronarography angiography for CAV diagnosis (median 5 years since HT). Genomic and phenotypic analyses of FCGR3A/CD16 Fc-receptor profiles were compared in CAV-positive (n=52) and CAV-free patients (n=51). The levels of CD16 expression and rituximab-dependent cell cytotoxic activity of peripheral NK cells in HT recipients were evaluated using a noninvasive NK-cellular humoral activation test. RESULTS: Enhanced levels of CD16 expression and antibody-dependent NK cell cytotoxic function of HT recipients were associated with the FCGR3A-VV genotype. The frequency of the FCGR3A-VV genotype was significantly higher in the CAV+ group (odds ratio, 3.9; P=0.0317) than in the CAV- group. The FCGR3A-VV genotype was identified as an independent marker correlated with the presence of CAV at the time of coronary angiography by using multivariate logistic regression models. The FCGR3A-VV genotype was also identified as a baseline-independent predictor of CAV risk (odds ratio, 4.7; P=0.023). CONCLUSIONS: This study unravels a prominent role for the CD16-dependent NK cell activation pathway in the complex array of factors that favor the progression of transplant arteriosclerosis. It highlights the clinical potential of a noninvasive evaluation of FCGR3A/CD16 in the early stratification of CAV risk. The recognition of CD16 as a major checkpoint that controls immune surveillance may promote the design of individualized NK cell-targeted therapies to limit vascular damage in highly responsive sensitized patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01569334.

Intradermal injection of a Tat Oyi-based therapeutic HIV vaccine reduces of 1.5 log copies/mL the HIV RNA rebound median and no HIV DNA rebound following cART interruption in a phase I/II randomized controlled clinical trial.

BACKGROUND: A Tat Oyi vaccine preparation was administered with informed consent to 48 long-term HIV-1 infected volunteers whose viral loads had been suppressed by antiretroviral therapy (cART). These volunteers were randomized in double-blind method into four groups (n = 12) that were injected intradermally with 0, 11, 33, or 99 µg of synthetic Tat Oyi proteins in buffer without adjuvant at times designated by month 0 (M0), M1 and M2, respectively. The volunteers then underwent a structured treatment interruption between M5 and M7. RESULTS: The primary outcomes of this phase I/IIa clinical trial were the safety and lowering the extent of HIV RNA rebound after cART interruption. Only one undesirable event possibly due to vaccination was observed. The 33 µg dose was most effective at lowering the extent of HIV RNA and DNA rebound (Mann and Whitney test, p = 0.07 and p = 0.001). Immune responses against Tat were increased at M5 and this correlated with a low HIV RNA rebound at M6 (p = 0.01). CONCLUSION: This study suggests in vivo that extracellular Tat activates and protects HIV infected cells. The Tat Oyi vaccine in association with cART may provide an efficient means of controlling the HIV-infected cell reservoir.

Characterization of the novel Sezary lymphoma cell line BKP1.

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of lymphomas primarily involving the skin. The most common types are mycosis fungoides (MF) and Sezary Syndrome (SS). We report a novel long-term fast-growing SS line termed BKP1 that was characterized by flow cytometry (FC), conventional and molecular cytogenetic [FISH/multi-FISH together with array comparative genomic hybridization (aCGH)]. FC immunophenotype of the BKP1 is CD2+CD5+CD3+CD4+CD8-CD7-CD25-CD26-CD30-CD158k+. The TCRγ characterization of BKP1 by PCR identified a clonal rearrangement. The conventional cytogenetic and Multi-FISH analysis showed complex chromosomal rearrangements. aCGH analysis highlighted the loss of genes involved in cell cycle control, in immune response (HLA, complement complex) and DNA damage repair mechanisms. The BKP1 is another lymphoma cell line thoroughly characterized that can be a valuable tool for both basic and applied research such as identification of deregulated genes and/or pathways and screening for new antilymphoma drugs.

Hepatitis E virus infection in patients infected with the human immunodeficiency virus.

Hepatitis E virus (HEV) is a newly-identified causative agent of acute and chronic hepatitis in severely immunocompromized patients. The present study sought to assess the prevalences of past, recent, on-going, and chronic HEV infections in patients infected with human immunodeficiency virus (HIV) in Marseille, South-eastern France, and to determine if they were correlated with the patients' immunological status or with cirrhosis. Anti-HEV IgG and IgM and HEV RNA testing were concurrently performed on the plasma from 184 patients infected with HIV, including 81 with a CD4+ T-lymphocyte count (CD4 count) <50 cells/mm(3) and 32 with a cirrhosis. Prevalence of anti-HEV IgG and IgM was 4.4% (8/184) and 1.6% (3/184), respectively. Past, recent, and on-going infections were observed in 3.3% (6/184), 1.6% (3/184), and 0.5% (1/184) of the patients, respectively. Anti-HEV antibodies prevalence did not differ significantly according to CD4 count, cirrhosis, sex, age, mode of HIV transmission, and infection with hepatitis B or C virus. Anti-HEV IgG seroreversion was observed in two patients. The patient whose plasma tested positive for HEV RNA had a CD4 count <50 cells/mm(3) ; HEV genotype was 3f. In this patient, longitudinal testing showed HEV RNA positivity during a 10-month period, indicating chronic HEV infection; in contrast, anti-HEV IgG never tested positive. Further studies are needed to evaluate the performance of commercial HEV serological assays in patients infected with HIV and to assess the actual incidence, prevalence, and outcome of HEV infection in this special group of patients. HEV RNA testing is necessary for such purposes.

Multicentric MFI30 study: Standardization of flow cytometry analysis of CD30 expression in non-Hodgkin lymphoma.

CD30 transmembrane receptor, a member of the tumor necrosis factor receptor family, is expressed in different lymphomas. Brentuximab vedotin (BV), a CD30 monoclonal antibody (Ab)-drug conjugate, is effective in CD30-positive lymphomas. However, the response to BV is not always correlated to CD30 expression detected by immunohistochemistry (IHC). The objectives of this study were to standardize and evaluate CD30 intensity by flow cytometry (FCM) in non-Hodgkin's lymphomas. Twelve centers analyzed 161 cases on standardized cytometers using normalized median fluorescence intensity (nMFI30) of three different Abs, of which one clone can recognize the same epitope as BV. FCM distinguished four groups of cases: negative group (n = 110) which showed no expression with the three clones; high positive group (n = 13) which gave nMFI30 > 5% with all tested clones; dim positive group (n = 17) which showed nMFI30 > 1% with all tested clones and <5% for at least one; discordant group (n = 21) with positive and negative expression of the different clones. In consistency with the literature, CD30 was positive in all anaplastic large cell lymphomas, in some diffuse large B-cell lymphomas (DLBCL), and in other rare lymphomas. FCM results were concordant with those of IHC in 77% of cases. Discrepancies could be explained by clones-related differences, microenvironment, or intracytoplasmic staining. Interestingly, FCM was more sensitive than IHC in 11% of cases, especially in DLBCL. Multicenter standardized FCM of specific CD30 could improve case detection and extend the treatment of BV to various CD30-positive lymphomas.

Mathematical modeling of peripheral blood neutrophil kinetics to predict CLAD after lung transplantation.

BACKGROUND: The presence of neutrophils in the lung was identified as a factor associated with CLAD but requires invasive samples. The aim of this study was to assess the kinetics of peripheral blood neutrophils after lung transplantation as early predictor of CLAD. METHODS: We retrospectively included all recipients transplanted in our center between 2009 and 2014. Kinetics of blood neutrophils were evaluated to predict early CLAD by mathematical modeling using unadjusted and adjusted analyses. RESULTS: 103 patients were included, 80 in the stable group and 23 in the CLAD group. Bacterial infections at 1 year were associated with CLAD occurrence. Neutrophils demonstrated a high increase postoperatively and then a progressive decrease until normal range. Recipients with CLAD had higher neutrophil counts (mixed effect coefficient beta over 3 years = +1.36 G/L, 95% Confidence Interval [0.99-1.92], p < .001). A coefficient of celerity (S for speed) was calculated to model the kinetics of return to the norm before CLAD occurrence. After adjustment, lower values of S (slower decrease of neutrophils) were associated with CLAD (Odds Ratio = 0.26, 95% Confidence Interval [0.08-0.66], p = .01). CONCLUSION: A slower return to the normal range of blood neutrophils was early associated with CLAD occurrence.

Antibody-Dependent NK Cell Activation Is Associated with Late Kidney Allograft Dysfunction and the Complement-Independent Alloreactive Potential of Donor-Specific Antibodies.

Although kidney transplantation remains the best treatment for end-stage renal failure, it is limited by chronic humoral aggression of the graft vasculature by donor-specific antibodies (DSAs). The complement-independent mechanisms that lead to the antibody-mediated rejection (ABMR) of kidney allografts remain poorly understood. Increasing lines of evidence have revealed the relevance of natural killer (NK) cells as innate immune effectors of antibody-dependent cellular cytotoxicity (ADCC), but few studies have investigated their alloreactive potential in the context of solid organ transplantation. Our study aimed to investigate the potential contribution of the antibody-dependent alloreactive function of NK cells to kidney graft dysfunction. We first conducted an observational study to investigate whether the cytotoxic function of NK cells is associated with chronic allograft dysfunction. The NK-Cellular Humoral Activation Test (NK-CHAT) was designed to evaluate the recipient and antibody-dependent reactivity of NK cells against allogeneic target cells. The release of CD107a/Lamp1(+) cytotoxic granules, resulting from the recognition of rituximab-coated B cells by NK cells, was analyzed in 148 kidney transplant recipients (KTRs, mean graft duration: 6.2 years). Enhanced ADCC responsiveness was associated with reduced graft function and identified as an independent risk factor predicting a decline in the estimated glomerular filtration rate over a 1-year period (hazard ratio: 2.83). In a second approach, we used the NK-CHAT to reveal the cytotoxic potential of circulating alloantibodies in vitro. The level of CD16 engagement resulting from the in vitro recognition of serum-coated allogeneic B cells or splenic cells was further identified as a specific marker of DSA-induced ADCC. The NK-CHAT scoring of sera obtained from 40 patients at the time of transplant biopsy was associated with ABMR diagnosis. Our findings indicate that despite the administration of immunosuppressive treatments, robust ADCC responsiveness can be maintained in some KTRs. Because it evaluates both the Fab recognition of alloantigens and Fc-driven NK cell activation, the NK-CHAT represents a potentially valuable tool for the non-invasive and individualized evaluation of humoral risk during transplantation.

Impact of hepatitis C virus coinfection on T-cell dynamics in long-term HIV-suppressors under combined antiretroviral therapy.

OBJECTIVE: The objective of this study is to evaluate the impact of hepatitis C virus (HCV) serostatus on the evolution of CD8 cells and CD4 : CD8 ratio in HIV-infected patients on combined antiretroviral therapy (cART) who achieve sustained undetectable viral load (HIV-pVL). DESIGN AND METHODS: A longitudinal study performed in an outpatient HIV-unit following 1495 HIV-infected patients. Data of patients on cART achieving undetectable HIV-pVL for at least 3 years were collected retrospectively from our medical e-database NADIS from January 1997 to April 2005, a period defined in order to select patients who were naive of hepatitis treatment. T-cell counts were assessed every 6 months from HIV-suppression over the study period. RESULTS: Two hundred and twenty-six HIV mono-infected (group 1) and 130 HCV-coinfected patients (group 2; genotype prevalence: 42% HCV-G1, 26% HCV-G3, 11% HCV-G4 and 21% HCV-G2) fulfilled the selection criteria. cART regimens were comparable between the groups, as were CD4 and CD8 cell counts at the first undetectable HIV-pVL. After 3 years, both groups displayed similar CD4 cell reconstitution, although CD4 percentage was higher in group 1 (30.3 ±â€Š1.1 vs. 27 ±â€Š1.1%; P < 0.001). HIV suppression led to a significant drop of median CD8 cell counts in group 1 (P = 0.027), but not in group 2, which displayed higher CD8 cell counts all through the follow-up (mean diff. = 135.71 ±â€Š26.89 cells/µl, P < 0.001). Moreover, the fraction of patients reaching CD4 : CD8 ratio ≥ 1 was lower in group 2 (14 vs. 27.7%; P < 0.05). CONCLUSION: Despite sustained HIV suppression under cART, HCV coinfection was found to hamper CD8 downregulation. Further studies will determine the impact of treatment with direct-acting antiviral agents on the CD8 pool, and the advantage of systematic HCV-targeted therapy for HIV/HCV-coinfected patients.

Lack of correlation between the size of HIV proviral DNA reservoir and the level of immune activation in HIV-infected patients with a sustained undetectable HIV viral load for 10 years.

BACKGROUND: The persistence of HIV residual replication in patients with an undetectable plasma viral load (pVL) may limit immune recovery and facilitate inflammation-induced comorbidities. OBJECTIVE: The objective was to evaluate any correlation between immune restoration and intracellular [IC] HIV-DNA in cART-treated patients with a sustained undetectable pVL. STUDY DESIGN: This retrospective cross sectional study included 62 patients with a median duration of undetectable pVL of 10.3 years. IC HIV DNA in peripheral mononuclear blood cells (PBMCs) and T cell subsets were measured at the last visit. pVL, CD4(+) and CD8(+) T cell counts were retrospectively collected from the onset of long-term inhibition by antiretroviral treatment. The patients were separated into two groups: 27 non-blippers (sustained pVL< threshold value during all the visits) and 35 blippers ( ≥ 1 episodes of pVL> threshold but < 1000 copies/ml). The median pVL in blippers was 115 copies/ml. RESULTS: The median IC HIV DNA rate was 34 copies/10(6) PBMCs (71% ≥ 20 copies/10(6) PBMCs) with no significant difference between the groups. The proportion of CD8(+)CD38(+) and CD8(+)DR(+) T cells was higher in blipper patients, but the difference was only significant for the CD8(+)DR(+) marker (p = 0.036). No correlation was found between markers of immune activation on CD4(+) and CD8(+) T cells and the IC HIV-DNA level. CONCLUSION: No relation was found between the size of HIV reservoirs and immune activation in patients with sustained undetectable pVL. Mechanisms of immune activation have to be better understood in order to define specific therapeutic interventions.

HIV protease inhibitors do not cause the accumulation of prelamin A in PBMCs from patients receiving first line therapy: the ANRS EP45 "aging" study.

BACKGROUND: The ANRS EP45 "Aging" study investigates the cellular mechanisms involved in the accelerated aging of HIV-1 infected and treated patients. The present report focuses on lamin A processing, a pathway known to be altered in systemic genetic progeroid syndromes. METHODS: 35 HIV-1 infected patients being treated with first line antiretroviral therapy (ART, mean duration at inclusion: 2.7±1.3 years) containing boosted protease inhibitors (PI/r) (comprising lopinavir/ritonavir in 65% of patients) were recruited together with 49 seronegative age- and sex-matched control subjects (http://clinicaltrials.gov/, NCT01038999). In more than 88% of patients, the viral load was <40 copies/ml and the CD4+ cell count was >500/mm³. Prelamin A processing in peripheral blood mononuclear cells (PBMCs) from patients and controls was analysed by western blotting at inclusion. PBMCs from patients were also investigated at 12 and 24 months after enrolment in the study. PBMCs from healthy controls were also incubated with boosted lopinavir in culture medium containing various concentrations of proteins (4 to 80 g/L). RESULTS: Lamin A precursor was not observed in cohort patient PBMC regardless of the PI/r used, the dose and the plasma concentration. Prelamin A was detected in PBMC incubated in culture medium containing a low protein concentration (4 g/L) but not in plasma (60-80 g/L) or in medium supplemented with BSA (40 g/L), both of which contain a high protein concentration. CONCLUSIONS: Prelamin A processing abnormalities were not observed in PBMCs from patients under the PI/r first line regimen. Therefore, PI/r do not appear to contribute to lamin A-related aging in PBMCs. In cultured PBMCs from healthy donors, prelamin A processing abnormalities were only observed when the protein concentration in the culture medium was low, thus increasing the amount of PI available to enter cells. ClinicalTrials.gov NCT01038999 http://clinicaltrials.gov/ct2/show/NCT01038999.