Costimulatory molecule vaccine effective against B-cell lymphoma in mice.

2003 JUN 4 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - A vaccine containing recombinant fowlpox virus encoding B7-1, intercellular adhesion molecule-1, and leukocyte function-associated antigen-3 elicited an antitumor immune response in mice, according to a report in the Journal of the National Cancer Institute.

"The costimulatory molecules B7-1, intercellular adhesion molecule-1 (ICAM-1), and leukocyte function-associated antigen-3 (LFA-3) play pivotal roles in the activation of T cells," said Javier Briones and colleagues at Stanford University and Therion Biologics Corporation. "We investigated whether in vivo vaccination with lymphoma cells infected with a recombinant, nonreplicating fowlpox (FP) virus encoding this triad of costimulatory molecules (TRICOM) could stimulate lymphoma-specific immunity."

The investigators vaccinated mice with irradiated A20 B lymphoma cells infected with the TRICOM vector (n=10) or the wild-type fowlpox virus (WT-FP) (n=10). Mice with established A20 tumors also received the vaccine. After vaccination, the mice were challenged with live A20 tumor cells.

A significantly higher survival rate at 110 days was noted in mice that received the TRICOM vaccine (80%) compared to mice vaccinated with the WT-FP (20%, p

"In mice with established tumors, tumor growth was slower in those treated with TRICOM-infected tumor cells than in those treated with WT-FP-infected cells, and this treatment provided a survival advantage," stated Briones and collaborators.

T lymphocytes from vaccinated mice possessed cytotoxic activity ...