Comparison of melanoma antigens in whole tumor vaccine to those from IIB-MEL-J cells

Immunotherapy for melanoma shows promise. Our previous whole tumor (WT) vac cine was noted to have positive clinical effects. We have now developed a n ew, safer melanoma vaccine that is derived from IIB-MEL-J tissue culture (T C) cells. In this study, we compare by Western blot analyses the antigens i n the WT vaccine to antigens in the TC vaccine. Sera from 12 WT vaccine rec ipients, 8 melanoma patients who received no immunotherapy, and 8 controls served as a source of antibodies to investigate potential antigens in the v accines. Three major antigenic peptides with approximate molecular weighs o f 46, 40, and 36 kDA were present in both vaccines, while two other antigen ic peptides with approximate molecular weighs of 68 and 48 kDA were present only in the TC vaccine. The reaction was similar between the patients who received the WT vaccine and those who did not receive the vaccine. Some of the individuals who did not have melanoma showed some reaction, but not to the extent of the melanoma patients. The intensity of immunostaining was gr eater for the TC vaccine when compared to the WT vaccine, indicating that t hese proteins are in a higher concentration in the TC vaccine. This new vac cine from IIB-MEL-J tissue culture cells provides a higher yield and a much more consistent source of potentially clinically relevant antigens without risk of infection or contamination by other irrelevant materials.