Systemic and intravesical adoptive cell therapy of tumor-reactive T cells can decrease bladder tumor growth in vivo

Abstract

BackgroundThe therapeutic armamentarium of bladder cancer has been recently enriched with the introduction of new therapies including immune checkpoint inhibitors, receptor tyrosine kinase inhibitors and antibody drug conjugates, however treatment responses and duration of responses are still less than expected. Adoptive cellular therapy (ACT) using tumor-infiltrating lymphocytes (TILs) has potential to treat bladder cancer, as previously demonstrated by successful expansion of tumor reactive T cells from human bladder tumors.MethodsA model system using OT-I T cells and an ovalbumin expressing MB49 tumor cell line (MB49OVA) was developed to study ACT in bladder cancer. Systemic ACT-treated mice were given T cells intravenously after lymphodepleting chemotherapy and followed by interleukin (IL)-2 administration. Intravesical ACT treated mice were given T cells directly into the bladder, without chemotherapy or IL-2. TILs were isolated from MB49 orthotopic tumors and expanded ex vivo in IL-2. Immune cell infiltrates were analyzed by flow cytometry. T cell infiltration was studied using a CXCR3 blocking antibody.ResultsSystemic ACT-treated mice had a decrease in tumor growth, increase in T cell infiltration and long-term immune protection compared with control-treated mice. OT-I T cells delivered intravesically were able to control tumor growth without lymphodepleting chemotherapy or IL-2 in MB49OVA orthotopic tumors. Intravesical delivery of TIL expanded from MB49 tumors was also able to decrease tumor growth in mice with MB49 orthotopic tumors. Blocking CXCR3 on OT-I T cells prior to intravesical delivery decreased T cell infiltration into the tumor and prevented the control of tumor growth.ConclusionsThis study demonstrates how TIL therapy can be used in treating different stages of bladder cancer.

Targeting myeloid-derived suppressor cells with gemcitabine to enhance efficacy of adoptive cell therapy in bladder cancer

“…We received MB49 bladder tumor cell line as a kind gift from Dr. Jeffery Schlom (National Cancer Institute, Bethesda, MA) ( 22 ). An ovalbumin (OVA) expressing fluorescent MB49 cell line (MB49OVA) was generated as described ( 15 ). Cells were cultured in complete media (CM), as previously described ( 15 ).…”

“…An ovalbumin (OVA) expressing fluorescent MB49 cell line (MB49OVA) was generated as described ( 15 ). Cells were cultured in complete media (CM), as previously described ( 15 ). Cells were passaged at 80% confluency, tested routinely for mycoplasma, and passaged no more than 10 times for experiments.…”

“…After harvest, tumors were processed as previously described ( 15 ). Spleens were mechanically digested through a 100 µm filter using a syringe plunger and treated with RBC lysis buffer, described previously.…”

“…Feasibility studies of growing TIL from bladder tumors support that TIL can be expanded from bladder cancer patient samples ( 13 , 14 ). Additionally, previous work in murine models show that intravesical ACT with TIL is an effective method of treating smaller bladder tumors ( 15 ). However, preconditioning the tumor microenvironment prior to ACT has yet to be investigated.…”

Cell Therapies in Bladder Cancer Management

“…The first step in autologous TIL therapy was performed by TIL expansion using IL-2 from primary bladder tumors and then functionally selected by co-culture with autologous tumor and INF-γ measurement [ 42 ]. Furthermore, intravesical therapy with tumor-reactive T cells decreased bladder tumor growth in mice and increased T cell infiltration without lymphodepleting chemotherapy in orthotopic tumors [ 43 ]. However, ex vivo TIL expansion and reinfusion into patients required large surgical samples with enough TILs and appropriate technological facilities; therefore, T cell engineering for immunotherapy is being developed.…”