Multiantigenic carbohydrate vaccines stimulate strong humoral response in mice.

2003 JAN 1 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - Cancer vaccines containing multiple tumor-associated antigens elicited immune responses on several fronts in mice, according to a report in the Proceedings of the National Academy of Sciences USA.

"Synthetic carbohydrate cancer vaccines have been shown to stimulate antibody-based immune responses in both preclinical and clinical settings," said Govindaswami Ragupathi and colleagues at the Memorial Sloan-Kettering Cancer Center in New York. "Until recently, only monovalent antigen constructs had been prepared and evaluated. Advances in total synthesis have now enabled the preparation of multivalent vaccine constructs, which contain several different tumor-associated carbohydrate antigens. Such constructs could, in principle, serve as superior mimics of cell surface antigens and, hence, as potent cancer vaccines."

The researchers prepared a TF-Le[superscript]y-Tn antigenic construct (compound 3) with a native mucin glycopeptide structure, and a Globo-H-Le[superscript]y-Tn construct (compound 4) with nonnative architecture. Vaccines containing one of the compounds as a free glycopeptide or a conjugate with keyhole limpet hemocyanin, and an adjuvant, either QS-21 or GPI-0100, were formulated and administered to mice.

Although the vaccines containing the keyhole limpet hemocyanin conjugates elicited antigen-specific IgG and IgM antibody responses, compound 4, with its nonnative structure, was more highly antigenic than was compound 3. The responses generated by the adjuvants were also disparate, with GPI-0100 stimulating a stronger antibody response compared with QS-21.

"The presence of multiple glycans in these constructs did not appear to suppress the response against any of the ...