Induction of Th2-directed immune responses by IL-4-transduced dendritic cells in mice

Dendritic cell (DC)-based vaccines have been used to generate Th1-mediated, protective immunity against cancers and infectious microorganisms. As an a ttempt to develop a new vaccine protocol for the induction of Th2-directed responses, we introduced an IL-4 plasmid vector into the XS106 DC line (der ived from A/J mice). Although relatively small fractions of XS106 cells exh ibited apparent intracellular deposition of IL-4, they secreted biologicall y relevant amounts of the cytokine. IL-4-transduced XS106 DC and control XS 106 DC transfected with vector alone were pulsed with KLH and injected s.c. into A/J mice. The overall magnitude of KLH-specific cellular and humoral responses was comparable between the two animal groups. However, they diffe red in the isotype profile albeit only transiently, with the IL-4-transduce d DC group showing higher IgE and lower IgG2a responses, and in the cytokin e profile, with spleen cells isolated from the IL-4-transduced DC group pro ducing higher IL-13 and lower IL-12. Thus, delivery of IL-4 gene to relativ ely small numbers of DC is sufficient to modify the immunological outcome o f DC-based vaccines. (C) 2000 Elsevier Science Ltd. All rights reserved.