Lymphocyte blastogenic response to autologous tumor cells pretreated with neuraminidase in patients with gastric carcinoma.

The effect of Vibrio cholerae neuraminidase (VCN) treatment of tumor cells on lymphoblastic response was studied using the assay of mixed lymphocyte-tumor cell reaction in 24 patients with gastric carcinoma. Lymphoblastic responses as indicated by stimulation index were significantly augmented in cultures with autologous tumor cells pretreated with mitomycin (MMC) and VCN as compared to those pretreated with MMC alone when cultured in the presence of normal plasma (p < 0.05). In autologous plasma cultures, however, the mean stimulation index in MMC-VCN-treated cell cultures was only slightly higher than that in MMC-treated cell cultures. Accentuation of the response was not observed in any type of cultures using MMC-VCN-treated normal tissue cells. In 20 of these patients, the blastic response to nonviable frozen stored tumor cells was measured simultaneously and significant increase in blastic transformation by pretreatment of the cells with VCN was also observed in normal plasma cultures (p < 0.05). There was significant correlation between the response to nonviable frozen VCN-treated cells and to these, not frozen, viable cells (p < 0.001). These results indicate that lymphoblastic response to autologous tumor cells could be enhanced by pretreating the cells with VCN in patients with gastric carcinoma and the freezing could render the cells nonviable without interfering with the augmented immunogenicity of VCN-treated tumor cells.