Expansion of a novel population of NK cells with low ribosome expression in juvenile dermatomyositis

Decreased Peripheral Blood Natural Killer Cell Count in Untreated Juvenile Dermatomyositis Is Associated with Muscle Weakness

Juvenile Dermatomyositis (JDM) is the most common inflammatory myopathy in pediatrics. This study evaluates the role of Natural Killer (NK) cells in Juvenile Dermatomyositis (JDM) pathophysiology. The study included 133 untreated JDM children with an NK cell count evaluation before treatment. NK cell subsets (CD56low/dim vs. CD 56bright) were examined in 9 untreated children. CD56 and perforin were evaluated in situ in six untreated JDM and three orthopedic, pediatric controls. 56% of treatment-naive JDM had reduced circulating NK cell counts, designated "low NK cell". This low NK group had more active muscle disease compared to the normal NK cell group. The percentage of circulating CD56low/dim NK cells was significantly lower in the NK low group than in controls (0.55% vs. 4.6% p < 0.001). Examination of the untreated JDM diagnostic muscle biopsy documented an increased infiltration of CD56 and perforin-positive cells (p = 0.023, p = 0.038, respectively). Treatment-naive JDM with reduced circulating NK cell counts exhibited more muscle weakness and higher levels of serum muscle enzymes. Muscle biopsies from treatment-naive JDM displayed increased NK cell infiltration, with increased CD56 and perforin-positive cells.

Coordinated immune dysregulation in juvenile dermatomyositis revealed by single-cell genomics

Juvenile dermatomyositis (JDM) is one of several childhood-onset autoimmune disorders characterized by a type I IFN response and autoantibodies. Treatment options are limited due to an incomplete understanding of how the disease emerges from dysregulated cell states across the immune system. We therefore investigated the blood of patients with JDM at different stages of disease activity using single-cell transcriptomics paired with surface protein expression. By immunophenotyping peripheral blood mononuclear cells, we observed skewing of the B cell compartment toward an immature naive state as a hallmark of JDM at diagnosis. Furthermore, we find that these changes in B cells are paralleled by T cell signatures suggestive of Th2-mediated inflammation that persist despite disease quiescence. We applied network analysis to reveal that hyperactivation of the type I IFN response in all immune populations is coordinated with previously masked cell states including dysfunctional protein processing in CD4+ T cells and regulation of cell death programming in NK cells, CD8+ T cells, and γδ T cells. Together, these findings unveil the coordinated immune dysregulation underpinning JDM and provide insight into strategies for restoring balance in immune function.

Characterizing influence of rCHOP treatment on diffuse large B-cell lymphoma microenvironment through in vitro microfluidic spheroid model

For over two decades, Rituximab and CHOP combination treatment (rCHOP) has remained the standard treatment approach for diffuse large B-cell lymphoma (DLBCL). Despite numerous clinical trials exploring treatment alternatives, few options have shown any promise at further improving patient survival and recovery rates. A wave of new therapeutic approaches have recently been in development with the rise of immunotherapy for cancer, however, the cost of clinical trials is prohibitive of testing all promising approaches. Improved methods of early drug screening are essential for expediting the development of the therapeutic approaches most likely to help patients. Microfluidic devices provide a powerful tool for drug testing with enhanced biological relevance, along with multi-parameter data outputs. Here, we describe a hydrogel spheroid-based microfluidic model for screening lymphoma treatments. We utilized primary patient DLBCL cells in combination with NK cells and rCHOP treatment to determine the biological relevance of this approach. We observed cellular viability in response to treatment, rheological properties, and cell surface marker expression levels correlated well with expected in vivo characteristics. In addition, we explored secretory and transcriptomic changes in response to treatment. Our results showed complex changes in phenotype and transcriptomic response to treatment stimuli, including numerous metabolic and immunogenic changes. These findings support this model as an optimal platform for the comparative screening of novel treatments.

Coordinated immune dysregulation in Juvenile Dermatomyositis revealed by single-cell genomics

Juvenile Dermatomyositis (JDM) is one of several childhood-onset autoimmune disorders characterized by a type I interferon response and autoantibodies. Treatment options are limited due to incomplete understanding of how the disease emerges from dysregulated cell states across the immune system. We therefore investigated the blood of JDM patients at different stages of disease activity using single-cell transcriptomics paired with surface protein expression. By immunophenotyping peripheral blood mononuclear cells, we observed skewing of the B cell compartment towards an immature naive state as a hallmark of JDM. Furthermore, we find that these changes in B cells are paralleled by signatures of Th2-mediated inflammation. Additionally, our work identified SIGLEC-1 expression in monocytes as a composite measure of heterogeneous type I interferon activity in disease. We applied network analysis to reveal that hyperactivation of the type I interferon response in all immune populations is coordinated with dysfunctional protein processing and regulation of cell death programming. This analysis separated the ubiquitously expressed type I interferon response into a central hub and revealed previously masked cell states. Together, these findings reveal the coordinated immune dysregulation underpinning JDM and provide novel insight into strategies for restoring balance in immune function.

Single-cell profiling reveals immune disturbances landscape and HLA-F-mediated immune tolerance at the maternal-fetal interface in preeclampsia

Background

Preeclampsia is a pregnancy-specific disorder that always causes maternal and fetal serious adverse outcome. Disturbances in maternal immune tolerance to embryo at the maternal-fetal interface (MFI) may be associated with preeclampsia onset. Recent studies have revealed the reduced expression pattern of HLA-F at the MFI in preeclampsia, while the mechanism of it mediating maternal fetal immune tolerance has not been revealed.

Methods

Single-cell RNA sequencing on placental decidua was performed to reveal the immune disturbances landscape at the MFI in preeclampsia. Human Jar cells and NK-92MI cells were employed to study the role of HLA-F in trophoblasts and lymphocyte.

Results

A total of 101,250 cells were classified into 22 cell clusters. Disease-related IGFBP1+SPP1+ extracellular villus trophoblast (EVT) was identified in the preeclamptic placental decidua, accompanied by newly discovered immune cellular dysfunction such as reduced ribosomal functions of NK populations and abnormal expression of antigen-presenting molecules in most cell clusters. Certain genes that are characteristic of the intermediate stage of myeloid or EVT cell differentiation were found to have unexplored but important functions in the pathogenesis of preeclampsia; specifically, we detected enhanced cell cross-talk between IGFBP1+SPP1+ EVT2 or SPP1+M1 cells and their receptor cell populations at the MFI of PE patients compared to controls. With respect to HLA-F, mIF staining confirmed its reduced expression in PE samples compared to controls. Over-expression of HLA-F in Jar cells promoted cell proliferation, invasion, and migration while under-expression had the opposite effect. In NK-92MI cells, over-expression of HLA-F increased the secretion of immunoregulation cytokines such as CSF1 and CCL22, and promoted adaptive NKG2C+NK cell transformation.

Conclusions

We revealed the immune disturbance landscape at the MFI in preeclampsia. Our findings regarding cellular heterogeneity and immune cellular dysfunction, as revealed by scRNA-seq, and the function of HLA-F in cells provide new perspectives for further investigation of their roles in the pathogenesis of preeclampsia, and then provide potential new therapeutic target.