Immunotherapy with IL-10- and IFN-γ-producing CD4 effector cells modulate "Natural" and "Inducible" CD4 TReg cell subpopulation levels: observations in four cases of patients with ovarian cancer.

Adoptive T cell therapy for cancer patients optimally requires participation of CD4 T cells. In this phase I/II study, we assessed the therapeutic effects of adoptively transferred IL-10- and IFN-γ-producing CD4 effector cells in patients with recurrent ovarian cancer. Using MUC1 peptide and IL-2 for ex vivo CD4 effector cell generation, we show that three monthly treatment cycles of autologous T cell restimulation and local intraperitoneal re-infusion-modulated T cell-mediated immune responses that were associated with enhanced patient survival. One patient remains disease-free, another patient experienced prolonged survival for nearly 16 months with recurrent disease, and two patients expired within 3-5 months following final infusion. Prolonged survivors showed elevated levels of systemic CD3(+)CD4(+)CD25(+) and CD3(+)CD4(+)CD25(-) T cells when compared to that of pre-treatment levels and similarly treated short-term survivors. Such cell populations among these patients contained variable levels of "Inducible" Tr1 (CD4(+)CD25(-)FoxP3(-)IL-10(+)) and "Natural" (CD4(+)CD25(+)CD45RO(+)FoxP3(+)) TReg cell numbers and ratios that were associated with prolonged and/or disease-free survival. Moreover, peptide-restimulated T cells from these patients showed an elevation in both IFN-γ production, memory cell phenotype, and select TNF family ligands associated with enhanced T cell survival and apoptosis-inducing activities. This suggests that intraperitoneally administered Th1-like cells, producing elevated levels of IL-10, may require and/or induce differential levels of distinct systemic TReg subpopulations that influence, in part, long-term tumor immunity and enhanced memory/effector CD4-mediated therapeutic potentials. Furthermore, treatment efficacy and enhanced memory cell phenotype did not appear to be dependent on TReg cell numbers but upon ratios of "Inducible" and "Natural" TReg subpopulations.

Autologous MUC1-specific Th1 effector cell immunotherapy induces differential levels of systemic TReg cell subpopulations that result in increased ovarian cancer patient survival.

Adoptive T cell immunotherapy using autologous lymphocytes is a viable treatment for patients with cancer and requires participation of Ag-specific CD4 and CD8 T cells. Here, we assessed the immunotherapeutic effects of autologous MUC1 peptide-stimulated CD4(+) effector cells following adoptive transfer in patients with ovarian cancer. Using MUC1 peptide and IL-2 for ex vivo CD4(+)/Th1 effector cell generation, we show that three monthly treatment cycles of peripheral blood T cell restimulation and intraperitoneal re-infusion selectively modulated endogenous T cell-mediated immune responses that correlated with diminished serum CA125 tumor marker levels and enhanced patient survival. One patient remains disease-free, another patient survived long-term for nearly 16 months with recurrent disease and two patients expired within 3-5 months following final infusion. Although PBL from all patients showed elevated MUC1 cytolytic activity following therapy, such responses did not correlate with therapeutic efficacy. Long-term survivors showed elevated levels of systemic memory (CD45RO) and naïve (CD45RA) CD3/CD4/CD25(+) T cells when compared to that of pre-treatment levels and similarly treated short-term survivors. Such cells co-expressed different levels of Foxp3 and CTLA-4 that resulted in progressively lower systemic Foxp3/CTLA-4 memory T cell ratios that further correlated with disease-free survival. Lastly, these patients showed elevated levels of MUC1-specific T cells expressing the CCR5 and CCR1 chemokine receptors and the chemokine CCL4 associated with Th1 cell differentiation/memory. We suggest that effective immunotherapy with autologous MUC1-stimulated CD4(+) effector cells induces differential levels of systemic "Ag-experienced" and "Ag-inexperienced" CD4/CD25(+) TReg cell subpopulations that influence long-term tumor immunity in ovarian cancer patients.