13 research outputs found

    Tumor-Derived Chaperone-Rich Cell Lysate (CRCL) Can Be Effectively Combined with Syngeneic Bone Marrow Transplantation to Treat Bcr-abl+ Leukemia in a Murine Model.

    Full text link
    Abstract We have previously reported that purified tumor derived chaperone-rich cell lysate (CRCL) containing multiple heat shock proteins (HSPs) is a promising cancer vaccine, capable of generating tumor-specific T cell responses and protective immunity in different animal tumor models. In this study, we have explored the therapeutic applicability of CRCL in the context of syngeneic bone marrow transplantation (BMT) to treat preexisting leukemia. BALB/c mice received a 10-fold LD100 dose of bcr-abl+ leukemia cells (12B1) subcutaneously (s.c.) on day -7. On day -1, 900cGy of total body irradiation (TBI) was given followed by syngeneic bone marrow transplantation (BMT) on day 0. Transplanted mice received 20X106 bone marrow cells along with 50X106 splenocytes (SPC) intravenously (i.v.). We have demonstrated that BMT/SPC prolonged survival of mice by a median time of 7 days (median survival time [MST] from tumor inoculation of no BMT versus BMT/SPC =19 vs 26 days), however, all mice eventually died of disseminated leukemia. When recipients received BMT and SPC from syngeneic donors that had been previously immunized with 12B1-derived CRCL (immune BMT/SPC) the MST was increased to 29 days with 26.1% of transplanted mice surviving without tumor (p&amp;lt;0.01 immune BMT/SPC vs naive BMT/SPC). Vaccination of immune BMT/SPC recipients with 20 mg 12B1-derived CRCL in the early post-transplant period (day +1 and day +6) increased MST to 32 days (p&amp;lt;0.01 vs naïve BMT/SPC control) but did not significantly improve overall survival (26.3%) when compared to immune BMT/SPC mice not receiving post transplant 12B1-CRCL vaccine. Eleven to 17 weeks later, mice with no evidence of disease were re-challenged with 12B1 cells in one groin and A20 B cell leukemia cells in the opposite groin. Eighty percent of the mice demonstrated long term tumor specific immunity by rejecting the 12B1 rechallenge while 100% of the mice developed A20 tumors. Our results indicate that CRCL is a promising vaccine that can be used to generate specific anti-tumor immunity that can be effectively transferred to a host via BMT.</jats:p

    Tumor-derived CD4+CD25+ regulatory T cell suppression of dendritic cell function involves TGF-β and IL-10

    No full text
    CD4+CD25+ regulatory T cells have been characterized as a critical population of immunosuppressive cells. They play a crucial role in cancer progression by inhibiting the effector function of CD4+ or CD8+ T lymphocytes. However, whether regulatory T lymphocytes that expand during tumor progression can modulate dendritic cell function is unclear. To address this issue, we have evaluated the inhibitory potential of CD4+CD25+ regulatory T cells from mice bearing a BCR–ABL+ leukemia on bone marrow-derived dendritic cells. We present data demonstrating that CD4+CD25+FoxP3+ regulatory T cells from tumor-bearing animals impede dendritic cell function by down-regulating the activation of the transcription factor NF-κB. The expression of the co-stimulatory molecules CD80, CD86 and CD40, the production of TNF-α, IL-12, and CCL5/RANTES by the suppressed DC is strongly down-regulated. The suppression mechanism requires TGF-β and IL-10 and is associated with induction of the Smad signaling pathway and activation of the STAT3 transcription factor

    A chaperone protein-enriched tumor cell lysate vaccine generates protective humoral immunity in a mouse breast cancer model

    No full text
    We have documented previously that a multiple chaperone protein vaccine termed chaperone-rich cell lysate (CRCL) promotes tumor-specific T-cell responses leading to cancer regression in several mouse tumor models. We report here that CRCL vaccine generated from a mouse breast cancer (TUBO, HER2/neu positive) is also capable of eliciting humoral immunity. Administration of TUBO CRCL triggered anti-HER2/neu antibody production and delayed the progression of established tumors. This antitumor activity can be transferred through the serum isolated from TUBO CRCL-immunized animals and involved both B cells and CD4(+) T lymphocytes. Further evaluation of the mechanisms underlying TUBO CRCL-mediated humoral immunity highlighted the role of antibody-dependent cell-mediated cytotoxicity. These results suggest that tumor-derived CRCL vaccine has a wider applicability as a cancer vaccine because it can target both T-cell- and B-cell-specific responses and may represent a promising approach for the immunotherapy of cancer
    corecore