Regulatory T cell (Treg) therapy emerges for various indications associated with a breakdown of immune tolerance. Antigen-specific chimeric antigen receptor (CAR) Tregs are frontrunners for transplantation and autoimmune diseases and are currently being clinically evaluated. We aimed to link CAR-antigen engagement with immunosuppressive cargo release into the local microenvironment to boost efficacy and reduce side effects. We used our HLA-A∗02 CAR and immunosuppressive interleukin-10 (IL-10) as model components to generate human CAR Tregs that release IL-10 upon CAR engagement. These were compared to CAR Tregs with constitutive or no IL-10 expression by evaluating phenotypes, antigen-specific IL-10 release, and suppression of effector cell proliferation in vitro and performance in vivo in a humanized xenogeneic graft-versus-host disease (xeno-GvHD) model. We demonstrated successful multi-construct engineering of CAR Tregs, which released upon CAR engagement 2.5-fold more IL-10 than CAR Tregs lacking the corresponding antigen-specific IL-10 secretion module. Neither phenotype nor function was affected by expressing this module. In the xeno-GvHD model, we showed the beneficial effect of IL-10 release, particularly evident when compared to constitutive IL-10 expression that impaired CAR-Treg efficacy. We provide first proof-of-principle for engineering human CAR Tregs to release an immunosuppressive cytokine upon CAR engagement. This approach will both enhance the potency of CAR Tregs at the intended target sites and limit their off-target effects.

Background In the UK, Black women are disproportionately impacted by adverse pregnancy and maternal outcomes whilst also being underrepresented in research. Understanding their experiences of being offered prenatal screening and diagnostic genetic testing (prenatal testing) for a range of genetic and chromosomal conditions is critical for offering equitable prenatal care. Methods This qualitative descriptive study used semi-structured interviews to examine the experiences of prenatal testing amongst 39 women of Black and mixed Black heritage living in England. Discussions were analysed using thematic analysis and examined using a Critical Race Theory lens. Results Four themes were identified: (1) An emotional journey from screening to results, (2) Navigating unequal systems, (3) Anchors and absences, and (4) Envisioning better care. Screening was valued but often accepted because it was viewed as routine. Discussions about potential outcomes were perceived as limited, leaving some women unprepared for high-chance results. Diagnostic testing was pursued to reduce uncertainty and to prepare emotionally and practically-especially in the context of sickle cell. However, some felt pressured in their choices. Invasive procedures were described as frightening, waiting for results was a time of high anxiety and outcomes brought either intense relief or devastation. Care received was inconsistent: experiences of compassion contrasted with paternalism, and racism. Faith and family sometimes provided strength, but the lack of referral to structured support during testing represented a significant gap in care. Conclusions Black women valued prenatal testing for the choice it offered, but their experiences could be undermined by routinisation, paternalism, clinician knowledge gaps, and structural racism. Strengthening pre-test counselling, training, and support pathways is essential to ensure prenatal testing services are equitable and raise standards of care for all families.

Chronic histiocytic intervillositis (CHI) is a rare placental inflammatory disorder associated with adverse pregnancy outcomes, including fetal growth restriction, miscarriage, and stillbirth. Its diagnosis is made retrospectively via histopathology, limiting timely intervention. This review explores the hypothesis that CHI is an alloimmune condition resulting from aberrant maternal immune responses to paternally derived fetal antigens. Key findings from current literature include perivillous fibrin deposition and maternal mononuclear cell accumulation in the placental intervillous space, both of which disrupt maternal-fetal exchange. Additional evidence points to complement activation, particularly C4d and C5b-9 deposition, increased CD8 + T cell infiltration, and inflammasome pathway involvement, all contributing to placental insufficiency. The role of anti-HLA antibodies remains under investigation, with conflicting data on their presence and clinical significance. However, abnormal HLA class II expression on the syncytiotrophoblast in CHI may facilitate maternal alloimmune recognition and antibody production. Current treatments, including anticoagulants and immunosuppressants, show limited efficacy, and no standardised management exists. The findings underscore a critical need for prospective studies, biomarker discovery, and targeted immunomodulatory therapies. Improved understanding of CHI pathogenesis may facilitate earlier diagnosis, personalised treatment, and prevention of recurrence and primary disease in future pregnancies.

PURPOSE OF REVIEW:To review advances from the past 18 months in allogeneic hematopoietic stem cell transplantation (HSCT) and autologous gene-modified stem cell transplantation for sickle cell disease (SCD), and to relate these developments to stem cell biology, conditioning and emerging prenatal strategies. RECENT FINDINGS:Matched sibling HSCT remains the clinical benchmark, but recent studies show age- and regimen-dependent trade-offs between durable engraftment, graft-versus-host disease and toxicity. Haploidentical platforms using posttransplant cyclophosphamide, thiotepa or intensified low-dose irradiation have widened donor access, although infection, graft failure and chronic graft-versus-host disease remain important. Autologous CRISPR-edited and lentiviral grafts can nearly eliminate severe vaso-occlusive events, but still require stem cell collection, individualized manufacture and myeloablative conditioning. New work identifies inflammation, lineage skewing, reduced GATA1 and premature senescence as determinants of sickle stem cell fitness, while culture-sparing editing and antibody-directed conditioning offer routes to safer transplantation. SUMMARY:Curative SCD therapies are converging on the same challenge: establishing durable healthy hematopoiesis with acceptable toxicity. Progress will depend on graft quality, safer niche creation, patient-centred outcomes and equitable delivery. In vivo and prenatal approaches remain preclinical and require a substantially higher maternal-foetal safety threshold.

BACKGROUND:Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with hyperglycaemia, chronic inflammation and adverse health outcomes. Regulatory T cells (Tregs) are thought to contribute to GDM due to their role in suppressing inflammation. However, whether specific Treg subsets are transcriptionally dysregulated in patients with GDM remains unclear. METHODS:To investigate Treg transcriptional variation in GDM, we applied single-cell RNA sequencing to Tregs and CD4 + T cells isolated from the blood of 13 healthy pregnant women and 10 female patients with GDM. RESULTS:We observed no significant differences in Treg cluster proportions with disease status, however, Memory CD4 + T cells were more abundant in patients diagnosed with GDM, substantiated by mass cytometry. We report Treg subsets altered in GDM, including naive Tregs with reduced expression of AP-1 transcription factor subunits and effector Tregs with increased signalling of genes associated with angiogenesis. Expression levels of genes dysregulated in GDM Tregs were informative of GDM status in pseudobulk, placental and whole blood mRNA from independent cohorts. TXNIP, which regulates glucose levels, emerged as the most significant discriminator of GDM status from bulk mRNA. CONCLUSIONS:This study uncovers transcriptional differences of Treg cell subsets from GDM patients and transcriptional markers informative of GDM status.

Regulatory T cells (Tregs) play a crucial role in moderating immune responses offering promising therapeutic options for autoimmune diseases and allograft rejection. Genetically engineering Tregs with chimeric antigen receptors (CARs) enhances their targeting specificity and efficacy. With non-viral transfection methods suffering from low efficiency and reduced cell viability, viral transduction is currently the only viable approach for GMP-compliant CAR-Treg production. However, viral transduction raises concerns over immunogenicity, insertional mutagenesis risk, and high costs, which limit clinical scalability. This study introduces a scalable nanoneedle electroporation (nN-EP) platform for GMP-compatible transfection of HLA-A2-specific CAR plasmids into primary human Tregs. The nN-EP system achieves 43% transfection efficiency, outperforming viral transduction at multiplicity of infection 1 by twofold. Importantly, nN-EP preserves Treg viability, phenotype and proliferative capacity. HLA-A2-specific CAR-Tregs generated using nN-EP show specific activation and superior suppressive function compared to polyclonal or virally transduced Tregs in the presence of HLA-A2 expressing antigen presenting cells. These findings underscore the potential of nN-EP as a GMP-suitable method for CAR-Treg production, enabling broader clinical application in immune therapies.

Human primary fetal stem cell-derived organoids are used to model developing tissues in vitro. However, ethical and legislative constraints restrict fresh fetal tissue collection in several countries. Amniotic fluid (AF) is easily accessible with minimal ethical and regulatory constraints for collection. Our team recently showed that tissue-specific stem/progenitor cells can be isolated from fetal fluids collected during pregnancy through clinically indicated minimally invasive procedures conducted during the second and third trimesters. These samples consistently generate fetal lung, kidney tubule and gastrointestinal epithelial organoids autologous to the developing fetus. AF-derived organoids (AFOs) allow the investigation of fetal epithelia at developmentally relevant stages. Moreover, AFOs allow research to be conducted on late gestational stages, hardly accessible with other methods. Here, we provide a detailed protocol to establish, characterize and cryopreserve AFOs from viable AF cells. This includes the processing of patient-derived AF samples, viable cell sorting, seeding, establishment of clonal AFO lines, tissue phenotyping, expansion and cryopreservation. Additionally, we describe a straightforward immunofluorescence-based approach to pinpoint the tissue identity of the AFOs in a quick and cost-effective manner. In our hands, the protocol enabled the generation of primary fetal AFOs from 85.71 This is a Protocol for the derivation, expansion and cryopreservation of primary organoids from human amniotic fluid cells. These cells generate lung, kidney tubule and gastrointestinal epithelial organoids autologous to the developing fetus.

OBJECTIVES:The aim of this study was to utilise T2* relaxometry (an indirect method of quantifying tissue oxygenation) to assess the fetal thymus in uncomplicated pregnancies throughout gestation and in a cohort of fetuses that subsequently deliver very preterm. METHODS:A control group of participants with low-risk pregnancies were recruited and retrospectively excluded if they developed any pregnancy related complications after scanning. Participants were recruited who were deemed to be at very high risk of delivery prior to 32 weeks' gestation and retrospectively excluded if they did not deliver prior to this gestation. All participants underwent a fetal MRI scan on a 3 T system incorporating the fetal thorax. T2 and T2* data were aligned and the mean T2* of the thymus tissue determined. RESULTS:Mean thymus T2* decreased with gestation in control fetuses (n = 49). In fetuses who went on to deliver prior to 32 weeks' gestation (n = 15), thymus volume was reduced as was mean T2* (p ≤ 0.001) as compared to controls. This finding persisted in a subgroup analysis of participants with PPROM (p = 0.002), although not in those with intact membranes (p = 0.067). CONCLUSION:These data demonstrates both a likely reduction in perfusion of the thymuses prior to extreme preterm birth, and also the potential for advanced MRI techniques to better interrogate the fetal immune changes prior to preterm birth in vivo.

Chronic histiocytic intervillositis (CHI) is a rare placental inflammatory lesion increasingly viewed through maternal–foetal immune rejection. In this invited commentary, we discuss how a recent study bolsters the paradigm that CHI represents maternal immune rejection of the semi‐allogeneic foetus, analogous to antibody‐mediated rejection in organ transplantation. We highlight the shared histological and molecular features between CHI and kidney allograft rejection, including macrophage‐dominated inflammation, complement activation, and interferon‐gamma‐driven gene expression signatures and explore the implications of this common pathogenesis for clinical practice. Recognising CHI as an alloimmune process opens new avenues for early prediction, diagnosis, and intervention. We particularly emphasise the need for early identification of CHI, even in a first pregnancy, where no prior obstetric history exists to raise suspicion. Finally, we outline how transplant immunotherapy principles (e.g. immunosuppression and immune modulation) could transform the management of CHI, and we call for forward‐looking research that bridges immune pathology, maternal–foetal medicine, and translational therapeutics to improve pregnancy outcomes. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.