Natural killer (NK) cells are prototypic cytotoxic innate lymphocytes that can kill target cells, such as tumor cells, in the absence of antigen-restriction. Peripheral NK cells exhibit a high degree of heterogeneity. Here, we set out to broadly assess intrinsic modulators of NK cell degranulation in an unbiased manner. We stimulated human primary blood-borne NK cells pre-treated with different cytokine regimens with the HCT116 human colon cancer cell line and used detection of lysosome-associated membrane glycoprotein 1 (LAMP1) as an identifier of rapid NK cell degranulation. RNA sequencing of FACS-sorted LAMP1hi NK cells showed CXCR4 and S1PR5 were top down-regulated genes. Using compounds that modulate activity of CXCR4 and S1P receptor family members S1P1 and S1P5, we confirmed they play an important immunosuppressive role in NK cell cytotoxicity. Mechanistically, engagement of CXCR4 and S1P1/5 receptors triggered phosphorylation of p42 and Ca2+ influx. CXCR4 activation promoted S1P5 upregulation and vice versa, and joint activation of both receptors amplified the defect NK cell degranulation. Intriguingly, in tumor samples the expression of both receptors and the synthesis of their ligands themselves appear to be coordinately regulated. Together, these data suggest that specifically and simultaneously targeting CXCR4 and S1P5 activity in the tumor microenvironment (TME) could be a beneficial strategy to unleash full cytotoxic potential of cytotoxic NK effector cells in the tumor.
© 2025. The Author(s).

While CAR-T therapy has successfully treated haematological malignancies, it has proved sub-optimal for solid tumours. The main limitation is the inability of CAR-T cells to infiltrate and then proliferate within tumours.
We co-expressed IL-7 and PH20, a type of hyaluronidase, with CAR targeting GPC3 (G3CAR-7 × 20). We test the anti-tumour ability in vitro and in vivo. Moreover the capacity of infiltration and proliferation of G3CAR-7 × 20 was measured.
We found (G3CAR-7 × 20) exhibited better proliferation in vivo and in vitro than G3CAR, reduced the level of apoptosis after stimulation by tumour cells, and maintained the memory phenotype of CAR-T cells. G3CAR-7 × 20 also increased the ability of CAR-T cells to infiltrate tumour tissue.
co-expressed IL-7 and PH20 may significantly enhance the efficacy of targeted GPC3 CAR-T cells in solid tumours treatment.
© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

While CAR-T therapy has successfully treated hematological malignancies, it has proved sub-optimal for solid tumors. The main limitation is the inability of CAR-T cells to infiltrate and then proliferate within tumors. In this study, we co-expressed IL-7 and PH20, a type of hyaluronidase, with CAR targeting GPC3 (G3CAR-7×20) to address these issues. We found (G3CAR-7×20) exhibited better proliferation in vivo and in vitro than G3CAR, reduced the level of apoptosis after stimulation by tumor cells, and maintained the memory phenotype of CAR-T cells. G3CAR-7×20 also increased the ability of CAR-T cells to infiltrate tumor tissue. G3CAR-7×20 may significantly enhance the efficacy of CAR-T cells in solid tumors.