In this study, we comprehensively charted the cellular landscape of colorectal cancer (CRC) and well-matched liver metastatic CRC using single-cell and spatial transcriptome RNA sequencing. We generated 41,892 CD45 ⁻ nonimmune cells and 196,473 CD45 ⁺ immune cells from 27 samples of six CRC patients, and found that CD8_CXCL13 and CD4_CXCL13 subsets increased significantly in liver metastatic samples that exhibited high proliferation ability and tumor-activating characterization, contributing to better prognosis of patients. Distinct fibroblast profiles were observed in primary and liver metastatic tumors. F3 ⁺ fibroblasts enriched in primary tumors contributed to worse overall survival by expressing protumor factors. However, MCAM ⁺ fibroblasts enriched in liver metastatic tumors might promote generation of CD8_CXCL13 cells through Notch signaling. In summary, we extensively analyzed the transcriptional differences of cell atlas between primary and liver metastatic tumors of CRC by single-cell and spatial transcriptome RNA sequencing, providing different dimensions of the development of liver metastasis in CRC.

Primary Sjögren’s syndrome (pSS) is a systemic autoimmune inflammatory disease mainly defined by T cell–dominated destruction of exocrine glands. Currently, CD8 ⁺ T cells are thought to be involved in the pathogenesis of pSS. However, the single-cell immune profiling of pSS and molecular signatures of pathogenic CD8 ⁺ T cells have not been well elucidated. Our multiomics investigation showed that both T cells and B cells, especially CD8 ⁺ T cells, were undergoing significant clonal expansion in pSS patients. TCR clonality analysis revealed that peripheral blood granzyme K ⁺ (GZMK ⁺ ) CXCR6 ⁺ CD8 ⁺ T cells had higher a proportion of clones shared with CD69 ⁺ CD103 ^– CD8 ⁺ tissue-resident memory T (Trm) cells in labial glands in pSS. CD69 ⁺ CD103 ^– CD8 ⁺ Trm cells featured by high expression of GZMK were more active and cytotoxic in pSS compared with their CD103 ⁺ counterparts. Peripheral blood GZMK ⁺ CXCR6 ⁺ CD8 ⁺ T cells with higher CD122 expression were increased and harbored a gene signature similar to Trm cells in pSS. Consistently, IL-15 was significantly elevated in pSS plasma and showed the capacity to promote differentiation of CD8 ⁺ T cells into GZMK ⁺ CXCR6 ⁺ CD8 ⁺ T cells in a STAT5-dependent manner. In summary, we depicted the immune profile of pSS and further conducted comprehensive bioinformatics analysis and in vitro experimental investigations to characterize the pathogenic role and differentiation trajectory of CD8 ⁺ Trm cells in pSS.

Our laboratory has reported that mice that express a dominant negative form of transforming growth factor β receptor restricted to T cells (dnTGFβRII) develop an inflammatory biliary ductular disease with elevated serum levels of interleukin (IL)-12p40 and other proinflammatory cytokines and antimitochondrial autoantibodies (AMAs) closely resembling human primary biliary cirrhosis (PBC). We have used this mouse model to address the potential mechanisms of immunomodulation of liver disease by creating two unique genetic strains: IL-12p40 knockout (KO)-dnTGFβRII mice and IFN-γ KO-dnTGFβRII mice. The two colonies of genetically modified mice—and, for purposes of controls, the dnTGFβRII mice—were monitored for liver immunopathology, AMAs, and intrahepatic cytokine production. Disease expression in the IFN-γ KO-dnTGFβRII mice, including liver immunopathology, were similar to those of dnTGFβRII mice, whereas the IL-12p40 KO-dnTGFβRII mice had a dramatic reduction in histological autoimmune cholangitis and significant decreases in levels of intrahepatic proinflammatory cytokines, but similar levels of AMAs compared with dnTGFβRII controls. Conclusion: These data indicate that in this mouse model of PBC, signaling by way of IL-12p40 is an essential requirement for the development of autoimmune cholangitis. The results of these studies will play an important role in identifying pathways and reagents that will selectively inhibit IL-12 signaling for the outlining of future therapeutic strategies for human PBC. (Hepatology 2009.)