Human Hyaluronidase PH20 Potentiates the Antitumor Activities of Mesothelin-Specific CAR-T Cells Against Gastric Cancer.

Ruocong Zhao,Suna Wang,Jiang Lv,Zhenfeng Zhang,Yuanbin Cui,Youguo Long,Wei Wei,Qiting Wu,Hui Zeng,Shanglin Li,Bin-Chao Wang,Peng Li,Yao Yao,Yangqiu Li,Yongfang Zheng,Jie Yang

doi:10.3389/fimmu.2021.660488

Abstract

T cell infiltration into tumors is essential for successful immunotherapy against solid tumors. Herein, we found that the expression of hyaluronic acid synthases (HAS) was negatively correlated with patient survival in multiple types of solid tumors including gastric cancer. HA impeded in vitro anti-tumor activities of anti-mesothelin (MSLN) chimeric antigen receptor T cells (CAR-T cells) against gastric cancer cells by restricting CAR-T cell mobility in vitro. We then constructed a secreted form of the human hyaluronidase PH20 (termed sPH20-IgG2) by replacing the PH20 signal peptide with a tPA signal peptide and attached with IgG2 Fc fragments. We found that overexpression of sPH20-IgG2 promoted CAR-T cell transmigration through an HA-containing matrix but did not affect the cytotoxicity or cytokine secretion of the CAR-T cells. In BGC823 and MKN28 gastric cancer cell xenografts, sPH20-IgG2 promoted anti-mesothelin CAR-T cell infiltration into tumors. Furthermore, mice infused with sPH20-IgG2 overexpressing anti-MSLN CAR-T cells had smaller tumors than mice injected with anti-MSLN CAR-T cells. Thus, we demonstrated that sPH20-IgG2 can enhance the antitumor activity of CAR-T cells against solid tumors by promoting CAR-T cell infiltration.

Highlights

Adoptive T cell therapies, including chimeric antigen receptor T cells, have produced substantial responses in patients with hematological malignancies [1, 2]
The results showed that the expression of all three hyaluronic acid synthases (HAS) family members (HAS1, HAS2, and HAS3) was negatively correlated with patient survival in stomach adenocarcinoma (Figure 1A), and high HAS2 expression was negatively correlated with patient survival in multiple types of solid cancers, including hepatocellular carcinoma (LIHC), lung squamous cell carcinoma (LUSC), colon adenocarcinoma (COAD), sarcoma (SARC), and cholangiocarcinoma (CHOL) (Figure 1B), suggesting that a high level of HA in tumor tissues negatively impacts the prognosis of patients with solid cancers
We seeded BGC823GL and KATOIIIGL gastric cancer cells that expressed mesothelin [17] as target cells in the lower chamber, while HA was added to the upper chamber at different concentrations, and CAR-T cells were seeded in the upper chamber in the HA matrix

Summary

Introduction

Adoptive T cell therapies, including chimeric antigen receptor T cells, have produced substantial responses in patients with hematological malignancies [1, 2]. The efficacy of CAR-T cells in solid tumor patients remains uncertain, and the microenvironment of solid tumors is accepted to be a major impediment which causes the lack of efficacy. Overproduction of ECM components including hyaluronic acid, an extracellular glycosaminoglycan, can result in increased interstitial fluid pressure and enhanced formation of physical barrier that protects tumor cells from being attacked by immune effector cells [8,9,10,11,12,13]. Hyaluronidases are natural enzymes able to degrade polymeric high-molecularweight hyaluronic acid into low-molecular-weight soluble hyaluronic acid molecules. A recombinant PH20 protein has been shown to be able to enhance the penetration of chemotherapeutic drugs and infiltration of immune cells [13,14,15,16]. Since low infiltration efficiency is a limitation of T cell therapy against solid cancers, and PH20 may enhance the infiltrating capacity of CAR-T cells, the combination of PH20 with CAR-T cell therapy is of translational potential and remains to be explored

Methods

Results

Conclusion