Decoding the transcriptional heterogeneity, differentiation lineage, clinical significance in tissue-resident memory CD8 T cell of the small intestine by single-cell analysis

Resident memory T (Trm) cells which are specifically located in non-lymphoid tissues showed distinct phenotypes and functions compared to circulating memory T cells and were vital for the initiation of robust immune response within tissues. However, the heterogeneity in the transcriptional features, development pathways, and cancer response of Trm cells in the small intestine was not demonstrated. Here, we integrated scRNA-seq and scTCR-seq data pan-tissue T cells to explore the heterogeneity of Trm cells and their development pathways. Trm were enriched in tissue-specific immune response and those in the DUO specially interacted with B cells via TNF and MHC-I signatures. T cell lineage analyses demonstrated that Trm might be derived from the T_CD4/CD8 subset within the same organ or migrated from spleen and mesenteric lymph nodes. We compared the immune repertoire of Trm among organs and implied that clonotypes in both DUO and ILE were less expanded and hydrophilic TRB CDR3s were enriched in the DUO. We further demonstrated that Trm in the intestine infiltrated the colorectal cancer and several effector molecules were highly expressed. Finally, the TCGA dataset of colorectal cancer implied that the infiltration of Trm from the DUO and the ILE was beneficial for overall survival and the response to immune checkpoint blockade.

A Comparison of Clinicopathologic Outcomes and Patterns of Lymphatic Spread Across Neoadjuvant Chemotherapy, Neoadjuvant Chemoradiotherapy, and Neoadjuvant Immunochemotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma

BACKGROUND

Neoadjuvant chemoradiotherapy (NCRT) is recommended as the treatment standard for locally advanced esophageal squamous cell carcinoma (ESCC). The use of immunotherapy in the neoadjuvant setting has gained attention. Multiple, clinical trials have explored the efficacy and safety of neoadjuvant immunochemotherapy (NICT). We evaluated the differences in clinicopathologic outcomes and the patterns of lymphatic spread among patients receiving neoadjuvant chemotherapy (NCT), NCRT, and NICT before esophagectomy for locally advanced ESCC.

METHODS

A total of 702 patients with ESCC who completed transthoracic esophagectomy followed neoadjuvant therapy were included. Pathological characteristics, including pathologic complete response (pCR), tumor regression grade (TRG) score and patterns of lymphatic spread, were evaluated.

RESULTS

Compared with the NCT group, the NCRT group and NICT group had an advantage in pathological response (P < 0.05). The pCR rate was 8.1% in the NCT group, 29.9% in the NCRT group, and 23.6% in the NICT group. The TRG score (P < 0.05) and pathologic T stage (P < 0.05) in the NCT group were significantly higher. Compared with NICT, NCRT can significantly reduce the rate of lymph node metastasis rate in station 1R (0 vs. 3.4%, P < 0.05) and 2R (1.1% vs. 6.8%, P < 0.05). Subgroup analysis according to the tumor location distribution showed that NICT group had higher lymph node metastasis rate in station 2R (9.1%) in middle thoracic cases (P < 0.05) and in station 18 (7.5%) (P < 0.05) in lower thoracic cases.

CONCLUSIONS

NCRT or NICT followed by surgery may result in a promising pCR rate and show a better performance in therapeutic response of primary lesion. For patients with lymph node metastasis in station 1R and 2R, NCRT should be the optimal preoperative treatment strategy.