Background Knowledge of immune cell phenotypes, function, and developmental trajectory in acute myeloid leukemia (AML) microenvironment is essential for understanding mechanisms of evading immune surveillance and immunotherapy response of targeting special microenvironment components. Methods Using a single-cell RNA sequencing (scRNA-seq) dataset, we analyzed the immune cell phenotypes, function, and developmental trajectory of bone marrow (BM) samples from 16 AML patients and 4 healthy donors, but not AML blasts. Results We observed a significant difference between normal and AML BM immune cells. Here, we defined the diversity of dendritic cells (DC) and macrophages in different AML patients. We also identified several unique immune cell types including T helper cell 17 (TH17)-like intermediate population, cytotoxic CD4+ T subset, T cell: erythrocyte complexes, activated regulatory T cells (Treg), and CD8+ memory-like subset. Emerging AML cells remodels the BM immune microenvironment powerfully, leads to immunosuppression by accumulating exhausted/dysfunctional immune effectors, expending immune-activated types, and promoting the formation of suppressive subsets. Conclusion Our results provide a comprehensive AML BM immune cell census, which can help to select pinpoint targeted drug and predict efficacy of immunotherapy.

Heterogeneous nuclear ribonucleoparticule A1/A2 (hnRNP A1/A2) and splicing factor 2/alternative splicing factor (SF2/ASF) are pivotal for precursor messenger RNA (pre-mRNA) splicing. Interferon regulatory factor-3 (IRF-3) plays critical roles in host defense against viral and microbial infection. Truncated IRF-3 proteins resulting from alternative splicing have been identified and characterized as functional antagonists to full-length IRF-3. In this study, we examined the molecular mechanism for splicing regulation of IRF-3 pre-mRNA and first reported the regulatory effect of hnRNP A1/A2 and SF2/ASF on IRF-3 splicing and activation. RNA interference-mediated depletion of hnRNP A1/A2 or SF2/ASF in human non-small cell lung cancer (NSCLC) cells increased exclusion of exons 2 and 3 of IRF-3 gene and reduced expression levels of IRF-3 protein and IRF-3 downstream effector molecules interferon-beta and CXCL10/IP-10. In addition, direct binding of hnRNP A1 and SF2/ASF to specific binding motifs in IRF-3 intron 1 was confirmed by RNA electrophoretic mobility shift assay. Subsequent minigene splicing assay showed that IRF-3 minigenes with mutated hnRNPA 1/A2 or SF2/ASF binding motifs increased exclusion of exons 2 and 3. Moreover, knockdown of hnRNP A1/A2 or SF2/ASF in NSCLC cells reinforced phytohemagglutinin-induced tumor necrosis factor-alpha release by peripheral blood mononuclear cells (PBMC) but suppressed that of interleukin-10 in NSCLC/PBMC co-cultures. Taken together, our results suggest that specific knockdown for hnRNP A1/A2 or SF2/ASF increase exclusion of exons 2 and 3 of IRF-3 pre-mRNA and influence immunomodulatory functions of human NSCLC cells.

Highlights The value of swab types on the detection of SARS-CoV-2 from patients during infection late stage is studied. The effect of specimen collection time on the detection rate of novel coronavirus was explored. Nasopharyngeal /nasal swabs collected before washing in the morning are more suitable for screening of large-scale specimens.

Ginseng has beneficial effects on the cardiovascular system, but its underlying mechanism is unclear. This study investigated the effects of ginsenoside Rb1, a major constituent of ginseng, on the changes of lactate dehydrogenase (LDH) activity, nitric oxide (NO), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) in oxidized low-density lipoprotein (oxLDL)-injuring endothelial cells. Human umbilical vein endothelial cells were cultured and divided into 6 groups (n = 6): control group, oxLDL alone group (100 mg/L), ginsenoside Rb1 alone group (10 microg/mL), oxLDL plus ginsenoside Rb1 groups (0.1, 1.0, and 10 microg/mL, respectively.). Twenty-four hours after treatment, LDH activity and concentrations of NO, t-PA, and PAI-1 in culture medium were measured while the expressions of endothelial nitric oxide synthase (eNOS), t-PA, and PAI-1 mRNA in endothelial cells were detected by reverse-transcriptase polymerase chain reaction. Compared with control group, oxLDL (100 mg/L) caused LDH activity, the expressions of eNOS and t-PA mRNA, and concentrations of NO and t-PA to significantly decrease (P < 0.05, respectively), and it also led to dramatic increase of PAI-1 mRNA and concentration (P < 0.05, respectively). Ginsenoside Rb1 alone did not demonstrate this ability. High-dose Rb1 (10 microg/mL) could block the effects of oxLDL on LDH activity, mRNA of eNOS, t-PA, and PAI-1, and concentrations of NO, t-PA, and PAI-1 (P < 0.05, respectively), and neither low-dose Rb1 (0.1 microg/mL) nor medium-dose Rb1 (1.0 microg/mL) demonstrated this ability. We conclude that ginsenoside Rb1 has protective effects on oxLDL-injuring human vascular endothelial cells and can reverse the effects of oxLDL on NO, t-PA, and PAI-1.