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Abstract Chimeric antigen receptor T (CAR-T) cell therapy has demonstrated promising efficacy in early trials for relapsed/refractory diffuse large B cell lymphoma (DLBCL). However, its efficacy in treating primary refractory DLBCL has not been comprehensively investigated, and the underlying resistance mechanisms remain unclear. Here, we report the outcomes of a phase I, open-label, single-arm clinical trial of relmacabtagene autoleucel (relma-cel), a CD19-targeted CAR-T cell product, with safety and efficacy as primary endpoints. Among the 12 enrolled patients, 8 experienced grade 4 hematologic toxicity of treatment-emergent adverse event. No grade ≥3 cytokine release syndrome or neurotoxicity occurred. Single-cell RNA sequencing revealed an increase proportion of C1QB-expressing macrophages in patients with progressive disease before CAR-T cell therapy. Cholesterol efflux from M2 macrophages was found to inhibit CAR-T cells cytotoxicity by inducing an immunosuppressive state in CD8+ T cells, leading to their exhaustion. Possible interactions between macrophages and CD8+ T cells, mediating lipid metabolism (AFR1-FAS), immune checkpoint activation, and T cell exhaustion (LGALS9-HAVCR2, CD86-CTLA4, and NECTIN2-TIGIT) were enhanced during disease progression. These findings suggest that cholesterol efflux from macrophages may trigger CD8+ T cell exhaustion, providing a rationale for metabolic reprogramming to counteract CAR-T treatment failure. Chinadrugtrials.org.cn identifier: CTR20200376.

Abstract Background Characterizing the unique immune microenvironment of each tumor is of great importance for better predicting prognosis and guiding cancer immunotherapy. However, the unique features of the immune microenvironment of triple negative breast cancer (TNBC) compared with other subtypes of breast cancer remain elusive. Therefore, we aimed to depict and compare the immune landscape among TNBC, human epidermal growth factor receptor 2‐positive (HER2+) breast cancer, and luminal‐like breast cancer. Methods Single‐cell RNA sequencing (scRNA‐seq) was performed on CD45+ immune cells isolated from human normal breast tissues and primary breast tumors of various subtypes. By analyzing the scRNA‐seq data, immune cell clusters were identified and their proportions as well as transcriptome features were compared among TNBC, human HER2+ breast cancer, and luminal‐like breast cancer. Pseudotime and cell‐cell communication analyses were also conducted to characterize the immune microenvironment. Results ScRNA‐seq data of 117,958 immune cells were obtained and 31 immune clusters were identified. A unique immunosuppressive microenvironment in TNBC was decoded as compared to that in HER2+ or luminal‐like breast cancer, which was characterized by higher proportions of regulatory T cells (Tregs) and exhausted CD8+ T cells and accompanied by more abundant plasma cells. Tregs and exhausted CD8+T cells in TNBC exhibited increased immunosuppression signature and dysfunctional scores. Pseudotime analyses showed that B cells tended to differentiate to plasma cells in TNBC. Cell‐cell communication analyses indicated that these unique features are fostered by the diversified T cell‐B cell crosstalk in TNBC. Based on the T cell‐B cell crosstalk, a prognostic signature was established that could effectively predict the prognosis status for patients with TNBC. Additionally, it was found that TNBC had a higher proportion of cytotoxic natural killer (NK) cells, whereas HER2+ or luminal‐like breast cancer lost this feature, suggesting that HER2+ or luminal‐like breast cancer, but not TNBC, may benefit from NK‐based immunotherapy. Conclusions This study identified a distinct immune feature fostered by T cell‐B cell crosstalk in TNBC, which provides better prognostic information and effective therapeutic targets for breast cancer.

Abstract GATA2, a key transcription factor in hematopoiesis, is frequently mutated in hematopoietic malignancies. How the GATA2 mutants contribute to hematopoiesis and malignant transformation remains largely unexplored. Here, we report that Gata2-L359V mutation impeded hematopoietic differentiation in murine embryonic and adult hematopoiesis and blocked murine chronic myeloid leukemia (CML) cell differentiation. We established a Gata2-L359V knockin mouse model in which the homozygous Gata2-L359V mutation caused major defects in primitive erythropoiesis with an accumulation of erythroid precursors and severe anemia, leading to embryonic lethality around E11.5. During adult life, the Gata2-L359V heterozygous mice exhibited a notable decrease in bone marrow (BM) recovery under stress induction with cytotoxic drug 5-fluorouracil. Using RNA sequencing, it was revealed that homozygous Gata2-L359V suppressed genes related to embryonic hematopoiesis in yolk sac, while heterozygous Gata2-L359V dysregulated genes related to cell cycle and proliferation in BM Lin-Sca1+c-kit+ cells. Furthermore, through chromatin immunoprecipitation sequencing and transactivation experiments, we found that this mutation enhanced the DNA-binding capacity and transcriptional activities of Gata2, which was likely associated with the altered expression of some essential genes during embryonic and adult hematopoiesis. In mice model harboring BCR/ABL, single-cell RNA-sequencing demonstrated that Gata2-L359V induced additional gene expression profile abnormalities and partially affected cell differentiation at the early stage of myelomonocytic lineage, evidenced by the increase of granulocyte–monocyte progenitors and monocytosis. Taken together, our study unveiled that Gata2-L359V mutation induces defective hematopoietic development and blocks the differentiation of CML cells.

Abstract The pathophysiology of coronavirus disease 19 (COVID-19) involves a multitude of host responses, yet how they unfold during the course of disease progression remains unclear. Here, through integrative analysis of clinical laboratory tests, targeted proteomes, and transcriptomes of 963 patients in Shanghai, we delineate the dynamics of multiple circulatory factors within the first 30 days post-illness onset and during convalescence. We show that hypercortisolemia represents one of the probable causes of acute lymphocytopenia at the onset of severe/critical conditions. Comparison of the transcriptomes of the bronchoalveolar microenvironment and peripheral blood indicates alveolar macrophages, alveolar epithelial cells, and monocytes in lungs as the potential main sources of elevated cytokines mediating systemic immune responses and organ damages. In addition, the transcriptomes of patient blood cells are characterized by distinct gene regulatory networks and alternative splicing events. Our study provides a panorama of the host responses in COVID-19, which may serve as the basis for developing further diagnostics and therapy.

Abstract Background Little is known about the phylogeography of norovirus (NoV) in China. In norovirus, a clear understanding for the characteristics of tree topology, migration patterns and its demographic dynamics in viral circulation are needed to identify its prevalence trends, which can help us better prepare for its epidemics as well as develop useful control strategies. The aim of this study was to explore the genetic diversity, temporal distribution, demographic dynamics and migration patterns of NoV that circulated in China. Results Our analysis showed that two major genogroups, GI and GII, were identified in China, in which GII.3, GII.4 and GII.17 accounted for the majority with a total proportion around 70%. Our demography inference suggested that during the long-term migration process, NoV evolved into multiple lineages and then experienced a selective sweep, which reduced its genetic diversity. The phylogeography results suggested that the norovirus may have originated form the South China (Hong Kong and Guangdong), followed by multicenter direction outbreaks across the country. Conclusions From these analyses, we indicate that domestic poultry trade and frequent communications of people from different regions have all contributed to the spread of the NoV in China. Together with recent advances in phylogeographic inference, our researches also provide powerful illustrations of how coalescent-based methods can extract adequate information in molecular epidemiology.

BACKGROUND:Noroviruses are one of the major causes of acute human nonbacterial gastroenteritis, and genotype II.4 (GII.4) has accounted for the majority of adult outbreaks. In addition, novel epidemic strain emerges every 2 to 3 years and spreads globally in months. There are little data reporting the evolutionary dynamics of GII.4 variants along a specific period in China. METHODS:All norovirus GII.4 sequences in China were downloaded from GenBank Database. Phylogenetic tree was constructed by MEGA and Bayesian evolutionary inference techniques were applied by BEAST software to study the genetic relationships, evolution rate, evolutionary time scale and the demographic history of GII.4 variants. Homology models were predicted by SWISS-MODEL to analyze the spatial structure changes. RESULTS:During the 12-year period, 624 GII.4 sequences were subtyped into six GII.4 variants (clusters). A rate of 4.74×10-3, 6.99×10-3 and 7.68×10-3 nucleotide substitutions/site/year for the strict, uncorrelated log-normal and uncorrelated exponential derivation clocks were estimated, respectively. Three amino acid mutations (G255S, S393G and H414P) in both Den Haag_2006b sub-clusters and six mutations (I244T, N309S, A377T, T244I, T377A and S393G) in three Sydney_2012 sub-clusters were observed. CONCLUSIONS:The temporal distribution pattern of noroviruses GII.4 lineages in China was similar to the worldwide observation. The evolutionary rate of GII.4 was consistent with the global studies. Amino acid changes in the vicinity of norovirus epitope may have profound influences on carbohydrate binding affinity between different sub-clusters of norovirus variants. Hence understanding the evolutionary dynamics of norovirus is of great value for developing effective prevention and control strategies.

Objective To investigate the mechanism of IGF2/JAK2/STAT3 on learning and memory impairment induced by aluminum maltol in rats. Methods A total of 32 SD rats were divided into normal saline control group and low, medium and high maltol aluminum exposure groups (10, 20 and 40 µmol/kg) by random number table, respectively, and intraperitoneally injected every other day for three months. After exposure, Morris water maze was applied to examine the learning and memory ability of rats, and HE staining was used to check the arrangement of hippocampal neurons. Real-time fluorescence quantitative PCR was applied to detect the relative expression level of IGF2 mRNA in hippocampus of rats. Western Blotting was used for detecting the relative protein expression levels of Cleaved Caspase3, IGF2, p-JAK2 (Tyrl007/1008), and p-STAT3 (Ser727) in the hippocampus of rats. Results With the increase of aluminum dose, the escape latency of rats in the same day was prolonged, and the residence time in the target quadrant and the times of crossing the platform were gradually reduced (F = 7. 900, P = 0.001; F = 6.693, P = 0.002) . HE staining results showed that the number of neurons in CA1 region of hippocampus gradually decreased and the arrangement of neurons was obviously loose with the increase of aluminum dose (F = 25. 947, P < 0.001) . With increasing aluminum dose, apoptosis-associated protein Bel-2 levels decreased gradually (F = 83. 235, P < 0.001), Bax (F = 153. 189, P < 0.001) and Cleaved Caspase3 (F = 11.636, P < 0.01) levels was gradually increased, and the relative expression levels of IGF2 mRNA and IGF2, p-JAK2 (Tyr1007/1008), p-STAT3 (Ser727) proteins decreased gradually with the increase of aluminum dose (F = 18. 423, P < 0.001; F = 11.072, P = 0.001; F = 55. 161, P < 0.001; F = 10.481, P = 0.001). Conclusion Aluminum maltol can induce cell apoptosis by inhibiting IGF2/JAK2/STAT3 pathway, which could damage the learning and memory ability of rats. [ABSTRACT FROM AUTHOR]