Fenella C. Raymond

Interleukin 21 and its receptor are involved in NK cell expansion and regulation of lymphocyte function.

Cytokines are important in the regulation of haematopoiesis and immune responses, and can influence lymphocyte development. Here we have identified a class I cytokine receptor that is selectively expressed in lymphoid tissues and is capable of signal transduction. The full-length receptor was expressed in BaF3 cells, which created a functional assay for ligand detection and cloning. Conditioned media from activated human CD3+ T cells supported proliferation of the assay cell line. We constructed a complementary DNA expression library from activated human CD3+ T cells, and identified a cytokine with a four-helix-bundle structure using functional cloning. This cytokine is most closely related to IL2 and IL15, and has been designated IL21 with the receptor designated IL21R. In vitro assays suggest that IL21 has a role in the proliferation and maturation of natural killer (NK) cell populations from bone marrow, in the proliferation of mature B-cell populations co-stimulated with anti-CD40, and in the proliferation of T cells co-stimulated with anti-CD3.

Assignment1 of fibroblast growth factor 18 (FGF18) to human chromosome 5q34 by use of radiation hybrid mapping and fluorescence in situ hybridization

FGF18 is a recently discovered member of the fibroblast growth factor family (Deisher et al., 1999). FGF18 has been reported to induce hepatic and intestinal proliferation in vivo (Hu et al., 1998), and to activate neural cell proliferation in vitro (Ohbayashi et al., 1998). Recently, FGF18 was mapped to both human chromosome 14p11 (Hu et al., 1999), and chromosome 5 (Sanger Centre, NCBI GeneMap’99). To help resolve this discrepancy, we carried out radiation hybrid mapping using both the GeneBridge 4 and the Stanford G3 human/hamster radiation hybrid mapping panels and fluorescence in situ hybridization using a human genomic BAC clone containing the FGF18 gene.