Objective:CAR-T/NK cells have had limited success in the treatment of solid tumors,such as colorectal cancer(CRC),in part because of the heterogeneous nature of tumor-associated antigens that lead to antigen-negative ...Objective:CAR-T/NK cells have had limited success in the treatment of solid tumors,such as colorectal cancer(CRC),in part because of the heterogeneous nature of tumor-associated antigens that lead to antigen-negative relapse after the initial response.This barrier might be overcome by enhancing the recruitment and durability of endogenous immune cells.Methods:Immunohistochemistry and flow cytometry were used to assess the expression of CD133 antigen in tissue microarrays and cell lines,respectively.Retroviral vector transduction was used to generate CBLB502-secreting CAR133-NK92 cells(CAR133-i502-NK92).The tumor killing capacity of CAR133-NK92 cells in vitro and in vivo were quantified via LDH release,the RTCA assay,and the degranulation test,as well as measuring tumor bioluminescence signal intensity in mice xenografts.Results:We engineered CAR133-i502-NK92 cells and demonstrated that those cells displayed enhanced proliferation(9.0×10^(4)cells vs.7.0×10^(4)cells)and specific anti-tumor activities in vitro and in a xenogeneic mouse model,and were well-tolerated.Notably,CBLB502 secreted by CAR133-i502-NK92 cells effectively activated endogenous immune cells.Furthermore,in hCD133+/hCD133−mixed cancer xenograft models,CAR133-i502-NK92 cells suppressed cancer growth better than the counterparts(n=5,P=0.0297).Greater T-cell infiltration was associated with greater anti-tumor potency(P<0.0001).Conclusions:Armed with a CBLB502 TLR5 agonist,CAR133-NK92 cells were shown to be capable of specifically eliminating CD133-positive colon cancer cells in a CAR133-dependent manner and indirectly eradicating CD133-negative colon cancer cells in a CBLB502-specific endogenous immune response manner.This study describes a novel technique for optimizing CAR-T/NK cells for the treatment of antigenically-diverse solid tumors.展开更多
基金supported by the Technology Innovation and Application Developnent Key Program of Chongqing(Grant No.CSTC2021jscx-gksb-N0026)the National Natural Science Foundation of China(Grant No.31540016)+1 种基金the Basic Research and Frontier Exploration Projects of Chongqing(Grant No.cstc2018jcyjAX0075)the Subsidy Fund for the Development of National Silk in Chongqing(Grant No.CQ2018JSCE05).
文摘Objective:CAR-T/NK cells have had limited success in the treatment of solid tumors,such as colorectal cancer(CRC),in part because of the heterogeneous nature of tumor-associated antigens that lead to antigen-negative relapse after the initial response.This barrier might be overcome by enhancing the recruitment and durability of endogenous immune cells.Methods:Immunohistochemistry and flow cytometry were used to assess the expression of CD133 antigen in tissue microarrays and cell lines,respectively.Retroviral vector transduction was used to generate CBLB502-secreting CAR133-NK92 cells(CAR133-i502-NK92).The tumor killing capacity of CAR133-NK92 cells in vitro and in vivo were quantified via LDH release,the RTCA assay,and the degranulation test,as well as measuring tumor bioluminescence signal intensity in mice xenografts.Results:We engineered CAR133-i502-NK92 cells and demonstrated that those cells displayed enhanced proliferation(9.0×10^(4)cells vs.7.0×10^(4)cells)and specific anti-tumor activities in vitro and in a xenogeneic mouse model,and were well-tolerated.Notably,CBLB502 secreted by CAR133-i502-NK92 cells effectively activated endogenous immune cells.Furthermore,in hCD133+/hCD133−mixed cancer xenograft models,CAR133-i502-NK92 cells suppressed cancer growth better than the counterparts(n=5,P=0.0297).Greater T-cell infiltration was associated with greater anti-tumor potency(P<0.0001).Conclusions:Armed with a CBLB502 TLR5 agonist,CAR133-NK92 cells were shown to be capable of specifically eliminating CD133-positive colon cancer cells in a CAR133-dependent manner and indirectly eradicating CD133-negative colon cancer cells in a CBLB502-specific endogenous immune response manner.This study describes a novel technique for optimizing CAR-T/NK cells for the treatment of antigenically-diverse solid tumors.
