Scandinavian Journal of Immunology最新文献

This is a report from a one-week workshop held in Athens, Greece in July of 2022. The workshop aimed to identify emerging concepts relevant to the fundamentals of immune regulation and areas for future research. Theories of immune regulation emphasize the role of T cell help or co-stimulation (signal 2). The workshop participants considered how new data on the characteristics of agonist antigens, the role of the antigen receptor signals (signal 1) in driving fate decisions, the effect of energetics on immunity and a better understanding of class-control in the immune response, may impact theories of immune regulation. These ideas were discussed in the context of tumour immunology, autoimmunity, pregnancy and transplantation. Here we present the discussions as a narrative of different viewpoints to allow the reader to join the conversation. These discussions highlight the evolving understanding of the nature of specific antigen recognition and how both antigen-specific and non-specific mechanisms impact immune responses.

Malnourished children are susceptible to an increased risk of mortality owing to impaired immune functions. However, the underlying mechanism of altered immune functions and its interaction with malnutrition is poorly understood. This study investigates the immune function and evaluates the effect of a particular nutritional intervention on the immune cells of undernourished children. Stunted (LAZ <-2) and at-risk of being stunted (length-for-age Z-scores, LAZ <-1 to -2) children aged between 12 and 18 months were enrolled and were provided with the daily nutritional intervention of one egg and 150 mL cow's milk for 90 days. Peripheral blood mononuclear cells (PBMCs) were isolated at enrolment and upon completion of the intervention. Phenotypic profiles for CD3+ cells, CD4+ cells, CD8+ cells, NKT cells, and B cells were similar in both cohorts, both before and after the intervention. However, activated B cells (CD25+) were increased after nutritional intervention in the at-risk of being stunted cohort. Several pro-inflammatory cytokines, IL-6, IFN-γ, and TNF-α, were elevated in the stunted children following the nutritional intervention. The results of the study indicate that nutritional intervention may have a role on activated B cells (CD25+) s in children who are at-risk of being stunted and may alter the capacity of PBMC to produce inflammatory cytokines in stunted children.

Mucosal-associated invariant T (MAIT) cells are important in antibacterial immune responses; however, during sepsis, they are few in number and exhibit highly activated phenotypes. The relationship between MAIT cells in peripheral blood and the prognosis of sepsis is not well understood. Thus, this study aimed to examine the levels and phenotypes of MAIT cells in early sepsis, evaluate their clinical relevance, and investigate their association with patient prognosis. This prospective observational study enrolled 72 septic patients defined according to the Sepsis 3.0 criteria and 21 healthy controls matched for age and sex. Their peripheral blood samples were used to assay the expression of immune activation (CD69 and HLA-DR) and immune checkpoint (PD-1 and PD-L1) markers on MAIT cells. The systemic inflammatory response syndrome, acute physiology and chronic health evaluation (APACHE) II, and sequential organ failure assessment scores were recorded. Subsequently, the association between MAIT cell characteristics and clinical indicators was assessed using Spearman's rank correlation analysis, and binary logistic regression analysis with a forward stepwise approach assessed independent risk factors for 28-day mortality. We noted a decrease in the percentage of MAIT cells in the patients' peripheral blood, which exhibited an activated phenotype. Besides, HLA-DR⁺ MAIT cell percentage and the APACHE II score were independently associated with the 28-day mortality and, in combination, were the best indicators of mortality. Thus, the percentage of HLA-DR⁺ MAIT cells in early sepsis serves as a novel prognostic biomarker for predicting mortality and improves the predictive capacity of the APACHE II score.

Efficient anti-viral responses of CD8⁺ T cells require signals that promote their effector cell differentiation, that are mainly provided by dendritic cells (DCs). Mast cells (MCs) are key drivers of DC maturation, but also influence their migration and antigen presenting properties and therefore indirectly mediate CD8⁺ T cell activation. MCs initiate innate immune responses at pathogen entry sites, promote the development of adaptive immune responses after infection, and release mediators including chemokines that recruit and activate immune cells including T cells during viral infections. However, whether MCs can directly activate virus-specific CD8⁺ T cells remains largely unknown. Here, we used an in vitro viral infection model with lymphocytic choriomeningitis virus (LCMV)-infected MCs or DCs co-cultured with either LCMV-specific CD8⁺ T cells or with WT (unspecific) CD8⁺ T cells. Similar to LCMV-infected DCs, LCMV-infected MCs clustered with virus-specific CD8⁺ T cells and induced their activation and production of antiviral cytokines. In addition, the co-stimulatory molecules CD86 and OX40L, but not CD80, were upregulated on MCs and an increased production of IL-6 and type I interferons after LCMV infection was shown. Our findings suggest that MCs can promote CD8⁺ T cell activation during viral infections. MC-mediated CD8⁺ T cell activation might be especially important within infected tissues where direct cellular interaction can take place. A better understanding of anti-viral functions of MCs may help developing new strategies to better treat viral infections.

Multiple sclerosis (MS) is an inflammatory autoimmune disorder of the central nervous system and the leading cause of progressive neurological disability in young adults. It decreases the patient's lifespan by about 10 years and affects women more than men. No medication entirely restricts or reverses neurological degradation. However, early diagnosis and treatment increase the possibility of a better outcome. To identify new MS biomarkers, we tested the expression of six potential markers (P2X4, P2X7, CXCR4, RGS1, RGS16 and VAV1) using qPCR in peripheral blood mononuclear cells (PBMC) of MS patients treated with interferon β (IFNβ), with glatiramer acetate (GA) or untreated. We showed that P2X7 and VAV1 are significantly induced in MS patients. In contrast, the expression of P2X4, CXCR4, RGS1 and RGS16 was not significantly modified by MS in PBMC. P2X7 and VAV1 are essentially induced in female patients, suggesting these markers are connected to sex-specific mechanisms. Strikingly, VAV1 expression is higher in healthy women than healthy men and IFNβ treatment of MS reduced VAV1 expression in female MS patients while it up-regulated VAV1 in male MS patients. Our data point to the differential, sex-dependent value of MS markers and treatment effects. Although rgs16 expression in PBMC was not a valid MS marker in patients, the strong upregulation of P2X4 and P2X7 induced in the spinal cord of WT mice by EAE was abrogated in rgs16KO mice suggesting that rgs16 is required for P2X4 and P2X7 induction by neurological diseases.

In recent years, chimeric antigen receptor-T (CAR-T) cell therapy has emerged as a novel immunotherapy method. It has shown significant therapeutic efficacy in the treatment of haematological B cell malignancies. In particular, the CAR-T therapy targeting CD19 has yielded unprecedented efficacy for acute B-lymphocytic leukaemia (B-ALL) and non-Hodgkin's lymphoma (NHL). In haematologic malignancies, tumour stem cells are more prone to stay in the regulatory bone marrow (BM) microenvironment (called niches), which provides a protective environment against immune attack. However, how the BM microenvironment affects the anti-tumour efficacy of CAR-T cells and its underlying mechanism is worthy of attention. In this review, we discuss the role of the BM microenvironment on the efficacy of CAR-T in haematological malignancies and propose corresponding strategies to enhance the anti-tumour activity of CAR-T therapy.

In the last 20 years, discoveries about the autoimmune regulator (AIRE) protein and its critical role in immune tolerance have provided fundamental insights into understanding the molecular basis of autoimmunity. This review provides a comprehensive overview of the effect of AIRE on immunological tolerance and the characteristics of autoimmune diseases in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), which is caused by biallelic AIRE mutations. A better understanding of the immunological mechanisms of AIRE deficiency may enlighten immune tolerance mechanisms and new diagnostic and treatment strategies for autoimmune diseases. Considering that not all clinical features of APECED are present in a given follow-up period, the diagnosis is not easy in a patient at the first visit. Longer follow-up and a multidisciplinary approach are essential for diagnosis. It is challenging to prevent endocrine and other organ damage compared with other diseases associated with multiple autoimmunities, such as FOXP3, LRBA, and CTLA4 deficiencies. Unfortunately, no curative therapy like haematopoietic stem cell transplantation or specific immunomodulation is present that is successful in the treatment.