Xingbin Hu

This study investigated the impact of Caspase-3 gene deletion on bone marrow-derived dendritic cells (BMDCs) and their anti-tumor functions. BMDCs were generated in vitro using GM-CSF and IL-4 from Caspase-3 knockout (Casp3-KO) and heterozygous (Heter) mouse progenitors. Caspase-3 ablation reduced dendritic cell numbers in vivo and hindered BMDC generation in vitro. Casp3-KO BMDCs exhibited impaired maturation, characterized by diminished dendritic arborization and reduced expression of surface markers (CD80, CD86, CXCR4, MHCI, MHCII). Migration assays revealed Caspase-3 deficiency impaired BMDC motility both in vitro and in vivo. Critically, Casp3-KO BMDCs showed compromised capabilities in phagocytosing tumor antigens and activating naïve T cells. In vivo tumorigenicity assays demonstrated that Caspase-3 deletion undermined the ability of BMDCs to suppress tumor growth. This attenuation correlated with reduced infiltration of CD4 + and CD8 + T lymphocytes at primary tumor sites and draining lymph nodes. These findings provide novel insights into the essential role of Caspase-3 in BMDC development, maturation, migration, antigen presentation, and anti-tumor efficacy. The data suggests Caspase-3 is crucial for the optimal function of dendritic cells in initiating anti-tumor immune responses, potentially informing the development of more effective cancer immunotherapies.

Objective To investigate the common molecular features of immunothrombosis, thus enhancing the comprehension of thrombosis triggered by immune and inflammatory responses and offering crucial insights for identifying potential diagnostic and therapeutic targets. Methods Differential gene expression analysis and functional enrichment analysis were conducted on datasets of systemic lupus erythematosus (SLE) and venous thromboembolism (VTE). The intersection of differentially expressed genes in SLE and VTE with those of neutrophil extracellular traps (NET) yielded cross-talk genes (CG) for SLE-NET and VTE-NET interaction. Further analysis included functional enrichment and protein-protein interaction (PPI) network assessments of these CG to identify hub genes. Venn diagrams and receiver operating characteristic (ROC) curve analysis were employed to pinpoint the most effective shared diagnostic CG, which were validated using a graft-versus-host disease (GVHD) dataset. Results Differential expression genes in SLE and VTE were associated with distinct biological processes, whereas SLE-NET-CG and VTE-NET-CG were implicated in pathways related to leukocyte migration, inflammatory response, and immune response. Through PPI network analysis, several hub genes were identified, with matrix metalloproteinase 9 (MMP9) and S100 calcium-binding protein A12 (S100A12) emerging as the best shared diagnostic CG for SLE (AUC: 0.936 and 0.832) and VTE (AUC: 0.719 and 0.759). Notably, MMP9 exhibited good diagnostic performance in the GVHD dataset (AUC: 0.696). Conclusion This study unveils the common molecular features of SLE, VTE, and NET, emphasizing MMP9 and S100A12 as the optimal shared diagnostic CG, thus providing valuable evidence for the diagnosis and therapeutic strategies related to immunothrombosis. Additionally, the expression of MMP9 in GVHD highlights its critical role in the risk of VTE associated with immune system disorders.

Multidrug-resistant Klebsiella pneumoniae strains, especially carbapenem-resistant K. pneumoniae , have become a rapidly emerging crisis worldwide, greatly limiting current therapeutic options and posing new challenges to infection management. Therefore, it is imperative to develop novel and effective biological agents for the treatment of multidrug-resistant K. pneumoniae infections. Platelets play an important role in the development of inflammation and immune responses. The main component responsible for platelet antibacterial activity lies in the supernatant stimulated by gram-positive bacteria. However, little research has been conducted on the interaction of gram-negative bacteria with platelets. Therefore, we aimed to explore the bacteriostatic effect of the supernatant derived from platelet- K. pneumoniae coculture and the mechanism underlying this effect to further assess the potential of platelet-bacterial coculture supernatant. We conducted this study on the gram-negative bacteria K. pneumoniae and CRKP and detected turbidity changes in K. pneumoniae and CRKP cultures when grown with platelet- K. pneumoniae coculture supernatant added to the culture medium. We found that platelet- K. pneumoniae coculture supernatant significantly inhibited the growth of K. pneumoniae and CRKP in vitro . Furthermore, transfusion of platelet- K. pneumoniae coculture supernatant alleviated the symptoms of K. pneumoniae and CRKP infection in a murine model. Additionally, we observed apoptosis-like changes, such as phosphatidylserine exposure, chromosome condensation, DNA fragmentation, and overproduction of reactive oxygen species in K. pneumoniae following treatment with the supernatant. Our study demonstrates that the platelet- K. pneumoniae coculture supernatant can inhibit K. pneumoniae growth by inducing an apoptosis-like death, which is important for the antibacterial strategies development in the future. IMPORTANCE: With the widespread use of antibiotics, bacterial resistance is increasing, and a variety of multi-drug resistant Gram-negative bacteria have emerged, which brings great challenges to the treatment of infections caused by Gram-negative bacteria. Therefore, finding new strategies to inhibit Gram-negative bacteria and even multi-drug- resistant Gram-negative bacteria is crucial for treating infections caused by Gram-negative bacteria, improving the abuse of antibiotics, and maintaining the balance between bacteria and antibiotics. K. pneumoniae is a common clinical pathogen, and drug-resistant CRKP is increasingly difficult to cure, which brings great clinical challenges. In this study, we found that the platelet- K. pneumoniae coculture supernatant can inhibit K. pneumoniae growth by inducing an apoptosis-like death. This finding has inspired the development of future antimicrobial strategies, which are expected to improve the clinical treatment of Gram-negative bacteria and control the development of multidrug-resistant strains.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become the most common coronavirus that causes large-scale infections worldwide. Currently, several studies have shown that the ABO blood group is associated with coronavirus disease 2019 (COVID-19) infection and some studies have also suggested that the infection of COVID-19 may be closely related to the interaction between angiotensin-converting enzyme 2 (ACE2) and blood group antigens. However, the relationship between blood type to clinical outcome in critically ill patients and the mechanism of action is still unclear. The current study aimed to examine the correlation between blood type distribution and SARS-CoV-2 infection, progression, and prognosis in patients with COVID-19 and the potential mediating role of ACE2. With 234 patients from 5 medical centers and two established cohorts, 137 for the mild cohort and 97 for the critically ill cohort, we found that the blood type A population was more sensitive to SARS-CoV-2, while the blood type distribution was not relevant to acute respiratory distress syndrome (ARDS), acute kidney injury (AKI), and mortality in COVID-19 patients. Further study showed that the serum ACE2 protein level of healthy people with type A was significantly higher than that of other blood groups, and type O was the lowest. The experimental results of spike protein binding to red blood cells also showed that the binding rate of people with type A was the highest, and that of people with type O was the lowest. Our finding indicated that blood type A may be the biological marker for susceptibility to SARS-CoV-2 infection and may be associated with potential mediating of ACE2, but irrelevant to the clinical outcomes including ARDS, AKI, and death. These findings can provide new ideas for clinical diagnosis, treatment, and prevention of COVID-19.