Search

Problem: Preeclampsia, a pregnancy complication with hypertension and proteinuria, seriously threats the health and lives of the mother and the baby. The pathogenesis of pre‐eclampsia remains incompletely understood. The role of peripheral natural killer cells (NK cells) in the pre‐eclampsia is unclear. Method of study: Flow cytometry was performed to detect the expression of CD158a (KIR2DL1) and CD158b (KIR2DL2/3) in peripheral NK cells of healthy pregnant women (HP) and patients with pre‐eclampsia (PE). Differentially expressed genes (DEGs) in CD158a+ and CD158b+ NK cells were identified by RNA‐sequencing and real‐time PCR. Protein array analysis was used to identify altered protein levels in the serum of study participants. Results: CD158a+ NK cell numbers were increased in the peripheral blood of patients while the number of CD158b+ NK cells was reduced. In addition, the percentage of CD158a+ NK cells within the peripheral NK subset was positively correlated with systolic blood pressure while the percentage of CD158b+ NK cells was negatively correlated with systolic blood pressure. RNA‐seq and real‐time PCR showed that the expression of ERAP2 and GCH1, the genes that regulate blood pressure and angiogenesis, was decreased in CD158a+ compared to CD158b+ NK cells. Consistently, the level of proteins involved in angiogenesis was altered in the serum of pre‐eclampsia patients compared to healthy individuals. Conclusions: CD158a+ NK cells increased while CD158b+ NK cells decreased in the peripheral blood of patients with pre‐eclampsia compared to healthy individuals. The change in the frequency of CD158a+/CD158b+ NK cells is related to the increase in blood pressure. [ABSTRACT FROM AUTHOR]

NK cells are considered an important component of innate immunity, which is the first line of defensing against tumors and viral infections in the absence of prior sensitization. NK cells express an array of germline-encoded receptors, which allow them to eliminate abnormal cells and were previously considered a homogenous population of innate lymphocytes, with limited phenotypic and functional diversity. Although their characteristics are related to their developmental origins, other factors, such as tumors and viral infections, can influence their phenotype. Here, we provide an overview of NK cells in the context of the tumor microenvironment, with a primary focus on their phenotypes, functions, and roles in tumor micro-environment. A comprehensive understanding of NK cells in the tumor microenvironment will provide a theoretical basis for the development of NK cell immunotherapy. [ABSTRACT FROM AUTHOR]

Chronic graft-versus-host disease (cGVHD) is the most common long-term complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The patients with pulmonary cGVHD in particular have a very poor prognosis. NK cells are the first reconstituted lymphocyte subset after allo-HSCT; however, the impact of reconstituted NK cells on cGVHD is unclear. Here, we found allogeneic recipients showed obvious pulmonary cGVHD. Surprisingly, deletion of reconstituted NK cells resulted in maximal relief of pulmonary cGVHD. Mechanistically, reconstituted NK cells with donor profiles modulated the pulmonary inflammatory microenvironment to trigger cGVHD. Reconstituted NK cells secreted IFN-γ and TNF-α to induce CXCL10 production by epithelial cells, which recruited macrophages and CD4+ T cells to the lungs. Then macrophages and CD4+ T cells were activated by the inflammatory microenvironment, thereby mediating lung injury. Through assessment of differences in cellular energy, we found that CD74+ NK cells with high mitochondrial potential and pro-inflammatory activity triggered pulmonary cGVHD. Furthermore, targeted elimination of CD74+ NK cells using the anti-CD74 antibody significantly alleviated pulmonary cGVHD but preserved the CD74− NK cells to exert graft-versus-leukemia (GVL) effects. Data from human samples corroborated our findings in mouse models. Collectively, our results reveal that reconstituted CD74+ NK cells trigger pulmonary cGVHD and suggest that administration of CD74 antibody was a potential therapeutic for patients with cGVHD. • Reconstituted NK cells trigger cGVHD. • Identifying CD74+ NK cells as cGVHD inducers by assessing mitochondrial potential. • Clearance of CD74+ NK cells does not affect the GVL effects. • Identifying CD74 as a potential therapeutic target for cGVHD patients. [ABSTRACT FROM AUTHOR]