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关键词： Artificial neural networks   CD107a   HLA-I alleles   IFN-γ   Peptides  

摘要： Toxoplasma gondii infects approximately 30% of the population, and there is currently no approved vaccine. Identifying immunogenic peptides with high affinity to different HLA molecules is a promising vaccine strategy. This study used an in silico approach using artificial neural networks to identify T. gondii peptides restricted to HLA-A*02, HLA-A*24, and HLA-B*35 alleles. Proteomes from seven T. gondii strains and transcriptomic data of overexpressed genes from T. gondii-RH in human PBMC were also used. Parasite protein sequences were analyzed with R 'Epitope Prediction' library. Peptide candidates were evaluated in the artificial neural networks based on the probabilities of output neurons (p > 0.5). The IFN-γ responses in PBMC from T. gondii seronegative and seropositive individuals were evaluated by ELISpot. Peptides with higher IFN-γ induction were evaluated to identify cytotoxic response in CD8 T cells (CD107a). In silico analysis identified 36 peptides from T. gondii proteins with predicted affinity to HLA-A*02, A*24, and B*35 alleles. Experiments with PBMCs revealed that a peptide restricted to HLA-A02 (P1: FLFAWITYV) induced a significant increase in IFN-γ-producing cells (p = 0.004). For HLA-A24, a peptide (P8: VFAFAFAFFLI) also induced a significant IFN-γ response (p = 0.004), while for the HLA-B*35 allele, the P6 peptide (YPIAPSFAM) induced a response that differed significantly from the control (p = 0.05). These peptides induced also a significant percentage of central memory CD8 + T cells expressing the degranulation marker CD107a (p < 0.05). Finally, we identified three T. gondii peptides that induced IFN-γ response, and a cytotoxic response measured by CD107a expression on CD45RAneg-CD8 cells. These peptides could be considered part of a multi-epitope vaccine against toxoplasmosis in humans.

关键词： SARS-CoV-2 infection   adaptive NK cells   HLAE   NKG2A   NKG2C  

摘要： HLA-E expression plays a central role for modulation of NK cell function by interaction with inhibitory NKG2A and stimulatory NKG2C receptors on canonical and adaptive NK cells, respectively. Here, we demonstrate that infection of human primary lung tissue with SARS-CoV-2 leads to increased HLA-E expression and show that processing of the peptide YLQPRTFLL from the spike protein is primarily responsible for the strong, dose-dependent increase of HLA-E. Targeting the peptide site within the spike protein revealed that a single point mutation was sufficient to abrogate the increase in HLA-E expression. Spike-mediated induction of HLA-E differentially affected NK cell function: whereas degranulation, IFN-gamma production, and target cell cytotoxicity were enhanced in NKG2C+ adaptive NK cells, effector functions were inhibited in NKG2A+ canonical NK cells. Analysis of a cohort of COVID-19 patients in the acute phase of infection revealed that adaptive NK cells were induced irrespective of the HCMV status, challenging the paradigm that adaptive NK cells are only generated during HCMV infection. During the first week of hospitalization, patients exhibited a selective increase of early NKG2C+CD57- adaptive NK cells whereas mature NKG2C+CD57+ cells remained unchanged. Further analysis of recovered patients suggested that the adaptive NK cell response is primarily driven by a wave of early adaptive NK cells during acute infection that wanes once the infection is cleared. Together, this study suggests that NK cell responses to SARS-CoV-2 infection are majorly influenced by the balance between canonical and adaptive NK cells via the HLA-E/NKG2A/C axis.

关键词： Gastric cancer   PD-L1   IL-10   microbiome   butyrate   avatar model   Faecalibacterium prausnitzii  

摘要： Early detection and surgical treatment are essential to achieve a good outcome in gastric cancer (GC). Stage IV and recurrent GC have a poor prognosis. Therefore, new treatments for GC are needed. We investigated the intestinal microbiome of GC patients and attempted to reverse the immunosuppression of the immune and cancer cells of GC patients through the modulation of microbiome metabolites. We evaluated the levels of programmed death-ligand 1 (PD-L1) and interleukin (IL)-10 in the peripheral blood immunocytes of GC patients. Cancer tissues were obtained from patients who underwent surgical resection of GC, and stained sections of cancer tissues were visualized via confocal microscopy. The intestinal microbiome was analyzed using stool samples of healthy individuals and GC patients. Patient-derived avatar model was developed by injecting peripheral blood mononuclear cells (PBMCs) from advanced GC (AGC) patients into NSG mice, followed by injection of AGS cells. PD-L1 and IL-10 had higher expression levels in immune cells of GC patients than in those of healthy controls. The levels of immunosuppressive factors were increased in the immune and tumor cells of tumor tissues of GC patients. The abundances of Faecalibacterium and Bifidobacterium in the intestinal flora were lower in GC patients than in healthy individuals. Butyrate, a representative microbiome metabolite, suppressed the expression levels of PD-L1 and IL-10 in immune cells. In addition, the PBMCs of AGC patients showed increased levels of immunosuppressive factors in the avatar mouse model. Butyrate inhibited tumor growth in mice. Restoration of the intestinal microbiome and its metabolic functions inhibit tumor growth and reverse the immunosuppression due to increased PD-L1 and IL-10 levels in PBMCs and tumor cells of GC patients.

关键词： covid-19   acute kidney injury   IL-8   IP-10   biomarker  

摘要： Objectives: Persistent severe acute kidney injury (PS-AKI) is associated with poor clinical outcomes. Our study attempted to evaluate the diagnostic value of chemokines for early-stage PS-AKI prediction. Methods: According to the KDIGO criteria, 115 COVID-19 patients diagnosed with stage 2/3 AKI were recruited from the intensive care unit between December 2022 and February 2023. Primary clinical outcomes included detecting PS-AKI in the first week (>= KDIGO stage 2 >= 72 h). Cytometric Bead Array was used to detect patient plasma levels (interleukin-8 (IL-8), C-C chemokine ligand 5 (CCL5), chemokine (C-X-C Motif) ligand 9 (CXCL9), and interferon-inducible protein 10 (IP-10)) of chemokines within 24 h of enrollment. Results: Of the 115 COVID-19 patients with stage 2/3 AKI, 27 were diagnosed with PS-AKI. Among the four measured chemokines, only the IL-8 level was significantly elevated in the PS-AKI group than in the Non-PS-AKI group. IL-8 was more effective as a biomarker while predicting PS-AKI with an area under the curve of 0.769 (0.675-0.863). This was superior to other biomarkers related to AKI, including serum creatinine. Moreover, plasma IL-8 levels of >32.2 pg/ml on admission could predict PS-AKI risk (sensitivity = 92.6%, specificity = 51.1%). Additionally, the IL-8 level was associated with total protein and IL-6 levels. Conclusion: Plasma IL-8 is a promising marker for the early identification of PS-AKI among COVID-19 patients. These findings should be validated in further studies with a larger sample size.

关键词： Macrophage   human immunodeficiency virus   Mycobacterium tuberculosis   multiplex staining   spatial transcriptomics   IL-6R/STAT3 pathway   SOCS3  

摘要： Tuberculosis (TB) remains a leading cause of mortality among individuals coinfected with HIV, characterized by progressive pulmonary inflammation. Despite TB's hallmark being focal granulomatous lung lesions, our understanding of the histopathological features and regulation of inflammation in HIV & TB coinfection remains incomplete. In this study, we aimed to elucidate these histopathological features through an immunohistochemistry analysis of HIV & TB co-infected and TB patients, revealing marked differences. Notably, HIV & TB granulomas exhibited aggregation of CD68 + macrophage (M phi), while TB lesions predominantly featured aggregation of CD20+ B cells, highlighting distinct immune responses in coinfection. Spatial transcriptome profiling further elucidated CD68+ M phi aggregation in HIV & TB, accompanied by activation of IL6 pathway, potentially exacerbating inflammation. Through multiplex immunostaining, we validated two granuloma types in HIV & TB versus three in TB, distinguished by cell architecture. Remarkably, in the two types of HIV & TB granulomas, CD68 + M phi highly co-expressed IL6R/pSTAT3, contrasting TB granulomas' high IFNGRA/SOCS3 expression, indicating different signaling pathways at play. Thus, activation of IL6 pathway may intensify inflammation in HIV & TB-lungs, while SOCS3-enriched immune microenvironment suppresses IL6-induced over-inflammation in TB. These findings provide crucial insights into HIV & TB granuloma formation, shedding light on potential therapeutic targets, particularly for granulomatous pulmonary under HIV & TB co-infection. Our study emphasizes the importance of a comprehensive understanding of the immunopathogenesis of HIV & TB coinfection and suggests potential avenues for targeting IL6 signaling with SOCS3 activators or anti-IL6R agents to mitigate lung inflammation in HIV & TB coinfected individuals.

关键词： MUC1   lung adenocarcinoma   cancer cell stemness   paclitaxel resistance   NF-kappa B   MAPK  

摘要： Background: The chemotherapy resistance often leads to chemotherapy failure. This study aims to explore the molecular mechanism by which MUC1 regulates paclitaxel resistance in lung adenocarcinoma (LUAD), providing scientific basis for future target selection. Methods: The bioinformatics method was used to analyse the mRNA and protein expression characteristics of MUC1 in LUAD. RT-qPCR and ELISA were used to detect the mRNA and protein expression, flow cytometry was used to detect CD133(+) cells, and cell viability was detected by CCK-8 assay. The mRNA-seq was performed to analyse the changes in expression profile, GO and KEGG analysis were used to explore the potential biological functions. Results: MUC1 is highly expressed in LUAD patients and is associated with a higher tumour infiltration. In paclitaxel resistance LUAD cells (A549/TAX cells), the expression of MUC1, EGFR/p-EGFR and IL-6 were higher than that of A549 cells, the proportion of CD133(+) cells was significantly increased, and the expression of cancer stem cell (CSCs) transcription factors (NANOG, OCT4 and SOX2) were significantly up-regulated. After knocking down MUC1 in A549/Tax cells, the activity of A549/Tax cells was significantly decreased. Correspondingly, the expression of EGFR, IL-6, OCT4, NANOG, and SOX2 were significantly down-regulated. The mRNA-seq showed that knocking down MUC1 affected the gene expression, DEGs mainly enriched in NF-kappa B and MAPK signalling pathway. Conclusion: MUC1 was highly expressed in A549/TAX cells, and MUC1-EGFR crosstalk with IL-6 may be due to the activation of NF-kappa B and MAPK pathways, which promote the enrichment of CSCs and lead to paclitaxel resistance.

关键词： Lupus nephritis   HAR1A   SMARCD1   iNOS   CD8(+)CD103(+) iTreg cells  

摘要： Lupus nephritis (LN) is a highly prevalent complication of systemic lupus erythematosus (SLE). Long non-coding RNAs (lncRNAs) are essential modulators in multiple types of human diseases, including LN. In the current study, we searched on online GEO database to select out lncRNAs that were differentially expressed in blood samples of LN patients. Through further RT-qPCR analysis, we found that lncRNA Highly Accelerated Region 1 A (HAR1A) is most significantly upregulated in blood samples of LN patients. Functionally, we detected that overexpression of HAR1A could aggravate LPS-induced injury and inflammation. According to the results of bioinformatics analysis and mechanism experiments, we determined that HAR1A binds with miR-149-3p to upregulate SMARCD1 through competing endogenous RNA (ceRNA) mechanism. It has been proven that iNOS is an inflammation inducer. Here, we found that HAR1A/miR-149-3p/SMARCD1 upregulates iNOS expression through enhancing H3K27ac level in iNOS promoter. Previously, we proved that CD8(+)CD103(+) iTreg cells could alleviate glomerular endothelial cell injury. Moreover, we demonstrated that CD8 (+) CD103(+) iTreg cells-secreted IL-10 downregulated HAR1A expression by impeding NF-kappa B pathway activation. In conclusion, this study provides evidences revealing a novel molecular pathway blocked by CD8(+)CD103(+) iTreg cells in LN.

关键词： Carnitine palmitoyltransferase 1C   cancer-associated fibroblast   M2-like macrophage   interleukin 6   immunosuppression   gastric cancer  

摘要： Cancer-associated fibroblasts (CAFs) exhibit remarkable phenotypic heterogeneity, with specific subsets implicated in immunosuppression in various malignancies. However, whether and how they attenuate anti-tumor immunity in gastric cancer (GC) remains elusive. CPT1C, a unique isoform of carnitine palmitoyltransferase pivotal in regulating fatty acid oxidation, is briefly indicated as a protumoral metabolic mediator in the tumor microenvironment (TME) of GC. In the present study, we initially identified specific subsets of fibroblasts exclusively overexpressing CPT1C, hereby termed them as CPT1C+CAFs. Subsequent findings indicated that CPT1C+CAFs fostered a stroma-enriched and immunosuppressive TME as they correlated with extracellular matrix-related molecular features and enrichment of both immunosuppressive subsets, especially M2-like macrophages, and multiple immune-related pathways. Next, we identified that CPT1C+CAFs promoted the M2-like phenotype of macrophage in vitro. Bioinformatic analyses unveiled the robust IL-6 signaling between CPT1C+CAFs and M2-like phenotype of macrophage and identified CPT1C+CAFs as the primary source of IL-6. Meanwhile, suppressing CPT1C expression in CAFs significantly decreased IL-6 secretion in vitro. Lastly, we demonstrated the association of CPT1C+CAFs with therapeutic resistance. Notably, GC patients with high CPT1C+CAFs infiltration responded poorly to immunotherapy in clinical cohort. Collectively, our data not only present the novel identification of CPT1C+CAFs as immunosuppressive subsets in TME of GC, but also reveal the underlying mechanism that CPT1C+CAFs impair tumor immunity by secreting IL-6 to induce the immunosuppressive M2-like phenotype of macrophage in GC.

关键词： Clostridioides difficile   infection   progranulin   immunity   interleukin-22  

摘要： Enhanced mortality, relapse rates, and increased prevalence of Clostridioides difficile infection (CDI) emphasize the need for better therapies and management approaches. Modulating host immune response to ameliorate CDI-associated immunopathology may provide new advantages to currently inadequate antibiotic therapies. Here, we identified progranulin (PGRN) as an important immune target upregulated in response to CDI. PGRN-deficient mice displayed dramatically higher mortality and aggravated epithelial barrier disruption compared with wild type (WT) mice after CDI despite equivalent levels of bacterial burden or toxin in the large intestine. Mechanistically, PGRN protection was mediated by IL-22 production from CD4(+) T helper cells, as demonstrated by a decrease in colonic IL-22-producing CD4(+) T helper cells in the intestine of PGRN-deficient mice upon CDI and a boost of IL-22-producing CD4(+) T helper cells activated by PGRN ex vivo. Clinical evidence suggests that CDI patients had significantly higher serum levels of PGRN compared with healthy controls, which was significantly and positively correlated with IL-22. Our findings thus indicate a critical role for PGRN-promoted CD4(+) T cell IL-22 production in shaping gut immunity and reestablishing the intestinal barrier during CDI. As an alternative to pathogen-targeted therapy, this study may provide a new host-directed therapeutic strategy to attenuate severe, refractory CDI.

关键词： Dedifferentiation   Interferon-γ   JAK/STAT pathway   Melanoma   PD-L1  

摘要： BACKGROUND:Melanoma cells frequently dedifferentiate in response to inflammation which can increase responses to certain cytokines. Interferon-γ (IFNγ) is an integral part of the anti-tumor immune response and can directly induce both differentiational changes and expression of immunosuppressive proteins in melanoma cells. How the differentiation status of melanoma cells affects IFNγ responses remains unclear. METHODS:Dedifferentiation of melanoma cells was induced via either siRNA or shRNA mediated MITF knockdown and the cells were subsequently treated with IFNγ. Effects of MITF knockdown and IFNγ treatment on gene expression were evaluated via qPCR and RNA sequencing. A Luminex assay was used to analyze the effects of dedifferentiation and IFNγ treatment on cytokine secretion. Effects on PD-L1 protein expression were analyzed via flow cytometry and western blotting. Inhibition of the JAK kinases, NF-κB and STAT3 with small molecule inhibitors, and siRNA mediated knockdown of STAT1 and IRF1 was applied to investigate the molecular mechanism behind IFNγ induced PD-L1 expression in dedifferentiated melanoma cells. The effects of inhibitor treatments and siRNA mediated knockdowns were evaluated via qPCR and western blotting. Bioinformatic analysis of publicly available RNA sequencing data, consisting of 45 patient derived melanoma cell lines, with or without IFNγ treatment, was conducted to assess the generalizability of the in vitro results. RESULTS:Dedifferentiation renders 624Mel melanoma cells hypersensitive to IFNγ stimulation in a context-dependent manner, resulting in non-additive upregulation of IFNγ-induced genes, increased PD-L1 protein expression and amplified secretion of CCL2, CXCL10 and IL-10. Furthermore, the intensified PD-L1 protein expression occurs through the JAK-STAT1-IRF1 axis. Lastly, dedifferentiated patient derived melanoma cell lines showed enhanced inflammatory signaling in response to IFNγ compared to differentiated cells, and tended to hav