Immunotherapy of pulmonary metastases using monoclonal antibody to T-cell suppressor factor and interleukin 2
B. Kim, P. Warnaka, M. Iverson and A. L. Imbembo
Department of Surgery, Cleveland Metropolitan General Hospital, OH 44109.
Tumor-induced immune suppression of the host may pose a barrier to
successful immunotherapy. A monoclonal antibody (MAb 14-12) able to bind
and inhibit murine soluble T-cell suppressor factor was tested for in vivo
antitumor activity by treatment of mice bearing three-day established
pulmonary metastases of a weakly immunogenic methylcholanthrene-induced
fibrosarcoma (MCA 106). Administration intraperitoneally in combination
with interleukin 2 (IL-2), a growth factor for activated T lymphocytes,
resulted in a significant reduction (60% to 90%) of metastases. Neither
IL-2 nor monoclonal antibody alone had significant antitumor effects. This
study demonstrates in vivo potentiation of IL-2 antitumor activity with an
anti-T-cell suppressor factor and points to possible strategies for
clinical application.