Immunotherapy screening, prognosis, and treatment methods and compositions

The invention describes an immunogen or immunogenic preparation derived from cells, cell membranes or proteins therefrom, that have been modified by treatment with a 2',3'-nucleoside or nucleotide dialdehyde crosslinking agent and by exposure to hydrostatic pressure. The pressure and crosslinker treatment of cells performed in accordance with the invention is termed "PCL-modification". Improved immunogenicity is obtained if the cells are treated with pressure at the same time that they are subjected to the protein crosslinking compounds. The cells suitable for PCL-modification in accordance with the invention and for use as immunogens may be tumor or cancer cells, transformed cells, virus-infected or microorganism-infected cells, e.g., bacteria, parasites, yeast, and the like. The PCL-modified tumor or infected cells are especially capable of inducing and eliciting a specific and potent immune response against the respective tumor cells, infected cells, or otherwise altered cells in both animals and human patients. Human peripheral blood mononuclear cells (PBMC) are sensitized and specifically stimulated to immunoreact against PCL-modified tumor or infected cells as determined by in vitro sensitization assays. Such assays, alone and in combination with PBMC cytokine analyses, serve as prognostic means to determine or identify those patients who will either respond or will not respond to PCL-immunotherapies and treatments, both in vitro and in vivo.