In-depth profiling of T-cell responsiveness to commonly recognized CMV antigens in older people reveals important sex differences

The impact of biological sex on T-cell immunity to Cytomegalovirus (CMV) has not been investigated in detail with only one published study comparing CMV-specific T-cell responses in men and women. Many studies, however, have shown an association between CMV infection and immunosenescence, with broad effects on peripheral blood lymphocyte subsets as well as the T and B-cell repertoires. Here, we provide a detailed analysis of CMV-specific T-cell responses in (n=94) CMV+ older people, including 47 women and 47 men aged between 60 and 93 years. We explore sex differences with respect to 16 different CMV proteins arranged in 14 peptide pools (overlapping peptides). Following ex vivo stimulation, CD4 and CD8 T-cells producing IFN-γ, TNF, and IL-2 were enumerated by flow-cytometry (intracellular cytokine staining). T-cell responses were evaluated in terms of each cytokine separately or in terms of cytokines produced simultaneously (polyfunctionality). Surface memory phenotype and CD3 downmodulation were assessed in parallel. The polyfunctionality index and a memory subset differentiation score were used to identify associations between response size, cytokine production, polyfunctionality, and memory subset distribution. While no significant sex differences were found with respect to overall CMV target protein selection, the T-cell response in men appeared more focused and accompanied by a more prominent accumulation of CMV-specific memory CD4 and CD8 T-cells. T-cell polyfunctionality and differentiation were similar in the sexes, however, CMV-specific T-cells in men produced more pro-inflammatory cytokines. Particularly, TNF production by CD4 T-cells was stronger in men than in women. Also, compared with women, men had larger responses to CMV proteins with immediate-early/early kinetics than women, which might have been driven by CMV reactivation. In conclusion, the CMV-specific T-cell response in men was larger and more pro-inflammatory than in women. Our findings may help explain sex differences in CMV-associated pathologies

DSA are associated with more graft injury, more fibrosis and upregulation of rejection associated transcripts in subclinical rejection.

Background: Subclinical T cell-mediated rejection (subTCMR) is commonly found after liver transplantation and has a good short-term prognosis, even when it is left untreated. Donor-specific antibodies (DSA) are putatively associated with a worse prognosis for recipient and graft after liver transplantation. Methods: To assess the immune regulation in subTCMR grafts, gene expression of 93 transcripts for graft injury, tolerance and immune regulation was analyzed in 77 biopsies with “no histological rejection” (NHR; n=25), “clinical TCMR” (cTMCR; n=16) and subTCMR (n=36). In addition, all available subTCMR biopsies (n=71) were tested for DSA with bead assays. Results: SubTCMR showed heterogeneous and intermediate expression profiles of transcripts that were upregulated in cTCMR. Graft gene expression suggested a lower activation of effector lymphocytes and a higher activation of regulatory T cells in grafts with subTCMR compared to cTCMR.DSA positivity in subTCMR was associated with histological evidence of more severe graft inflammation and fibrosis. This more severe DSA+ associated graft injury in subTCMR was converged with an upregulation of cTCMR associated transcripts. In nonsupervised analysis DSA positive subTCMR mostly clustered together with cTCMR, while DSA negative subTCMR clustered together with NHR. Conclusion: T cell-mediated rejection seem to form a continuum of alloimmune activation. Although subTCMR exhibited less expression of TCMR associated transcript, DSA positivity in subTCMR was associated with an upregulation of rejection associated transcripts. The identification of DSA positive subclinical rejection might help to define patients with more inflammation in the graft and development of fibrosis

Phenotyping suicidal ideation and behavior: Comparing clinical characteristics and future suicide attempts between suicidal subtypes in two clinical samples

Abstract Objectives To further validate the concept of suicidal subtypes distinguished by indicators of suicidal thinking and behavior with regard to clinical characteristics and past and future suicide attempts. Methods Psychiatric inpatients were assessed (study 1: ecological momentary assessments in 74 depressed inpatients with suicidal ideation; study 2: clinical assessments in 224 inpatients after a suicide attempt and over a 12‐month follow‐up period). Subtypes were identified using latent profile analysis (based on indicators of real‐time suicide ideation) and latent class analysis (based on features of past suicide ideation and suicide attempt characteristics). Comparisons between subtypes included clinical characteristics (depression, suicidal ideation, trait impulsivity, childhood trauma) as well as past (study 1) and future (study 2) suicide attempts. Results Suicidal subtypes emerged that are characterized by suicidal ideation means and stability and features of past suicidal behavior (four in study 1, three in study 2). The subtypes differed in terms of depression/suicidal ideation, but not in terms of trait impulsivity/childhood trauma. Although not significant, the subtypes “high‐stable” and “low‐moderate stable” reported multiple re‐attempts more frequently during follow‐up than the “low‐stable” subtype in study 2. Conclusion Differences in clinical variables (and by trend in future suicide attempts) clearly point to the clinical relevance of suicidal subtypes (with variability of suicidal thoughts playing a particularly important role)

An Improved Protocol for Targeted Differentiation of Primed Human Induced Pluripotent Stem Cells into HLA-G-Expressing Trophoblasts to Enable the Modeling of Placenta-Related Disorders

Abnormalities at any stage of trophoblast development may result in pregnancy-related complications. Many of these adverse outcomes are discovered later in pregnancy, but the underlying pathomechanisms are constituted during the first trimester. Acquiring developmentally relevant material to elucidate the disease mechanisms is difficult. Human pluripotent stem cell (hPSC) technology can provide a renewable source of relevant cells. BMP4, A83-01, and PD173074 (BAP) treatment drives trophoblast commitment of hPSCs toward syncytiotrophoblast (STB), but lacks extravillous trophoblast (EVT) cells. EVTs mediate key functions during placentation, remodeling of uterine spiral arteries, and maintenance of immunological tolerance. We optimized the protocol for a more efficient generation of HLA-Gpos EVT-like trophoblasts from primed hiPSCs. Increasing the concentrations of A83-01 and PD173074, while decreasing bulk cell density resulted in an increase in HLA-G of up to 71%. Gene expression profiling supports the advancements of our treatment regarding the generation of trophoblast cells. The reported differentiation protocol will allow for an on-demand access to human trophoblast cells enriched for HLA-Gpos EVT-like cells, allowing for the elucidation of placenta-related disorders and investigating the immunological tolerance toward the fetus, overcoming the difficulties in obtaining primary EVTs without the need for a complex differentiation pathway via naïve pluripotent or trophoblast stem cells

B cell depletion impairs vaccination-induced CD8 T cell responses in a type I interferon-dependent manner.

Objectives: The monoclonal anti-CD20 antibody rituximab is frequently applied in the treatment of lymphoma as well as autoimmune diseases and confers efficient depletion of recirculating B cells. Correspondingly, B cell-depleted patients barely mount de novo antibody responses during infections or vaccinations. Therefore, efficient immune responses of B cell-depleted patients largely depend on protective T cell responses. Methods: CD8+ T cell expansion was studied in rituximab-treated rheumatoid arthritis (RA) patients and B cell-deficient mice on vaccination/infection with different vaccines/pathogens. Results: Rituximab-treated RA patients vaccinated with Influvac showed reduced expansion of influenza-specific CD8+ T cells when compared with healthy controls. Moreover, B cell-deficient JHT mice infected with mouse-adapted Influenza or modified vaccinia virus Ankara showed less vigorous expansion of virus-specific CD8+ T cells than wild type mice. Of note, JHT mice do not have an intrinsic impairment of CD8+ T cell expansion, since infection with vaccinia virus induced similar T cell expansion in JHT and wild type mice. Direct type I interferon receptor signalling of B cells was necessary to induce several chemokines in B cells and to support T cell help by enhancing the expression of MHC-I. Conclusions: Depending on the stimulus, B cells can modulate CD8+ T cell responses. Thus, B cell depletion causes a deficiency of de novo antibody responses and affects the efficacy of cellular response including cytotoxic T cells. The choice of the appropriate vaccine to vaccinate B cell-depleted patients has to be re-evaluated in order to efficiently induce protective CD8+ T cell responses

Preformed donor-specific HLA antibodies in living and deceased donor transplantation: a multicenter study

Background and objectivesThe prognostic value of preformed donor-specific HLA antibodies (DSA), which are only detectable by sensitive methods, remains controversial for kidney transplantation.Design, setting, participants, & measurementsThe outcome of 4233 consecutive kidney transplants performed between 2012 and 2015 in 18 German transplant centers was evaluated. Most centers used a stepwise pretransplant antibody screening with bead array tests and differentiation of positive samples by single antigen assays. Using these screening results, DSA against HLA-A, -B, -C, -DRB1 and -DQB1 were determined. Data on clinical outcome and possible covariates were collected retrospectively.ResultsPretransplant DSA were associated with lower overall graft survival, with a hazard ratio of 2.53 for living donation (95% confidence interval [95% CI], 1.49 to 4.29; P= 3000 MFI resulted in overlapping survival curves. Therefore, separate analyses were performed for 3-month and long-term graft survival. Although DSA = 3000 MFI were only associated with worse long-term transplant survival in deceased donation. In living donation, only strong DSA were associated with reduced graft survival in the first 3 months, but both weak and strong DSA were associated with reduced long-term graft survival. A higher incidence of antibody-mediated rejection within 6 months was only associated with DSA >= 3000 MFI.ConclusionsPreformed DSA were associated with an increased risk for graft loss in kidney transplantation, which was greater in living than in deceased donation. Even weak DSA <3000 MFI were associated with worse graft survival. This association was stronger in living than deceased donation