Peritumoral TIGITCD20 B cell infiltration indicates poor prognosis but favorable adjuvant chemotherapeutic response in gastric cancer.

OBJECTIVE

T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT) is a novel immunosuppressive molecule. This study aimed to investigate the expression of TIGIT on B cells and the function of TIGITCD20 B cells in gastric cancer (GC).

METHODS

Tumor tissue paraffin-embedded sections and clinicopathological data from 194 patients with GC were collected. Dual immunohistochemistry was performed to detect the expression of TIGIT on B cells. Multiplex immunofluorescence was used to initially explore the relationship between TIGITCD20 B cells and the exhaustion of CD8 T cells.

RESULTS

In GC, TIGITCD20 B cells were observed in intratumor, peritumor, and tertiary lymphoid structures (TLS). Patients with GC having high peritumoral TIGITCD20 B cells infiltration had inferior clinical outcomes and could benefit from adjuvant chemotherapy (ACT). In GC tissues, PD-1CD8 T cells were more closer to TIGITCD20 B cells than to TIGITCD20 B cells.

CONCLUSIONS

Peritumoral TIGITCD20 B cells infiltration was an independent prognostic predictor for patients with GC and a potential biomarker for ACT selection. TIGITCD20 B cells might affect the exhaustion of CD8 T cells in GC.