[Expression patterns of the human and mouse IFGP family genes]

The IFGP family is a recently identified group of human and mouse genes structurally related to the genes of leukocyte Fc-receptors. In this study we compared expression patterns of six human and four mouse IFGP genes. With the exception of mouse IFGP2, the genes of the family were found to be predominantly expressed in haemopoietic cells. Expression of human IFGP1-IFGP5 and mouse IFGP3 was B cell-specific. Mouse IFGP1 transcripts were mainly found in B cells, but this gene may be either expressed by nonlymphoid cells. Expression of the human IFGP6 was detected in CD8+ T cells and NK cells. We further demonstrated that alternative splicing of human IFGP1 and IFGP6 mRNA may generate transcripts coding for the previously unknown isoforms. The novel IFGP1 isoform lacks transmembrane domain, whereas the IFGP6 isoform has altered cytoplasmic tail. The data obtained indicate that the receptors of family may contribute to the regulation of development and/or functions of three effector types of lymphocytes, namely B cells, CD8 T cells and NK cells.