Abstract: CD4+ cells obtained from individuals with defective CD40L gene and transfected with a vector containing CD40-L are described.

Abstract: There is disclosed a method of detecting a mutation in a CD40 ligand gene, comprising isolating nucleic acid from an individual, selectively amplifying nucleic acid derived from the CD40 ligand gene, and analyzing the amplified nucleic acid to determine if there is a mutation (or mutations) in the CD40 ligand gene. The ability of a CD40 ligand protein expressed from the gene may be determined. Methods of treating individuals exhibiting a defective CD40 ligand gene (i.e., X-linked hyper IgM patients and certain individuals afflicted with combined variable immunodeficiency) are also disclosed. Also disclosed are non-human animals that lack functional CD40 ligand as a result of gene targeting technology.

Abstract: Methods of enhancing a mammal's immune response to a vaccine antigen are disclosed. Interleukin-15 can be used as a vaccine adjuvant to enhance or potentiate the immune response to a vaccine. Compositions comprising an immunogenic amount of vaccine antigen and an immunogenicity-augmenting amount of IL-15 are also provided by the invention. IL-15 can be used alone in the invention or in concurrent or sequential combination with additional vaccine adjuvants.