Our aims, were to: a) elucidate whether MBT-2 cells, lethally irradiated or nonirradiated, express TGF-β1 mRNA and secrete TGF-β1 protein, and b) to investigate whether the adverse effects from IRMBT-2-secreting TGF-β1 in the tumor vaccine can be abrogated by exogenous addition of monoclonal anti-TGF-β1 antibody and/or IFN-α. Materials and methods: using the Northern hybridization analysis and the two-antibody sandwich ELISA, we demonstrate that both irradiated IRMBT-2 and non-irradiated MBT-2 cells secrete TGF-β1. The effect of anti-TGF-β and/or IFN-α were studied by an in vitro splenocyte proliferation assay and in vivo turner rechallenge study on day 17-TBM. Results: Both IRMBT-2 and splenocytes from day 17-TBM secrete TGF-β1 which can express suppression of the proliferation of the splenocytes from day I7-TBM. This suppression can be partially reversed by the simultaneous addition of both anti-TGF-β and IFN-α, either alone being insufficient. The result of the in vivo tumor rechallenge study on day 17-TBM reveals that a lower tumor outgrowth incidence can be obtained in groups of mice treated with postoperative vaccination with anti-TGF-β modified tumor vaccine with or without an additional administration of IFN-α. Conclusion: Apart from TGF-β MBT-2 cells, both irradiated and nonirradiated, may also secrete other suppressive factors that adversely downregulate the immune response of TBM which can not then be adequately reversed by IFN-α.
|Number of pages||6|
|Issue number||2 A|
|Publication status||Published - 1997 Jan 1|
All Science Journal Classification (ASJC) codes
- Cancer Research