Abstract: The invention provides uses and methods for alleviating respiratory tract symptoms of allergy, asthma, and of viral, bacterial, fungal and parasitic infections by shifting inappropriate TH2 responses to TH1 responses by administering IL-13 receptor-targeted immunotoxins to the respiratory tract.

Abstract: The present invention is a recombinant vector encoding and expressing at least three or more costimulatory molecules. The recombinant vector may additionally contain a gene encoding one or more target antigens or immunological epitope thereof. The synergistic effect of them costimulatory molecules on the enhanced activation of T cells is demonstrated. The degree of T-cell activation using recombinant vectors containing genes encoding three costimulatory molecules was far greater than the sum of recombinant vector constructs containing one costimulatory molecule and greater that the use of two costimulatory molecules. Results employing the triple costimulatory vectors were most dramatic under conditions of either low levels of first signal or low stimulator to T-cell ratios. This phenomenon was observed with both isolated CD4+and CD8+T cells.