Background

Hyper-IL-11 (H11) is a fusion protein comprising IL-11 and soluble IL-11 receptor directly targeting gp130. We evaluated efficacy of H11 as a molecular adjuvant in therapeutic whole tumor cell vaccine formulation.

Methods

H11 was tested in ectopic and orthotopic murine renal cell carcinoma (RENCA) models. H11 cDNA was transduced into RENCA cells (RENCA-H11). Mice were immunized with RENCA-H11 or control vaccine (RENCA-IRR) in prophylactic, adjuvant and therapeutic settings. Tumor formation, survival and immune mechanisms activated by H11 were studied.

Results

Biologically active H11 was secreted by RENCA-H11 cells. Immunization with RENCA-H11 resulted in mounting specific anti-RENCA response. Treatment of tumor bearing mice in adjuvant setting prevented disease recurrence in therapeutic setting eradicated tumors. In induction phase H11 inhibited T-regulatory cell formation and activated recruitment and maturation of dendritic cells. Downstream of immunization tumors were densely infiltrated by CD8(+), CD4(+), NK cells, cells expressing CD8(+)CD69(+) and CD4(+)CD62L(low).

Conclusions

H11 is a good candidate for adjuvant of whole tumor cell vaccines. Direct targeting of gp130 leads to induction of specific and long lasting anticancer immune response. Enhancement of tumor antigen presentation, abrogation of immune tolerance, and activation of NK cells and generation of memory cells lead to eradication of existing tumors.