Characterization of TNF receptor type 2 isoform in the mouse

In this report a TNF receptor type 2 (TNFR2) isoform in the mouse, termed micp75TNFR, was compared to its human orthologue hicp75TNFR and to the known mouse TNFR2. The micp75TNFR is generated by the use of an alternative transcriptional start site within the mouse TNFR2 gene. This receptor isoform was found to be expressed in different macrophage-like and endothelial tumor cell lines and mouse spleen cells after stimulation. Lacking the leader sequence and part of the amino-terminal end of the mature TNFR2, the micp75TNFR was characterized by mainly intracellular expression. In contrast to its human paralogue, the micp75TNFR lacked the capacity to bind TNF. Therefore, micp75TNFR expression did not mediate protection from TNF-induced cytotoxicity but may interfere with TNFR2 signalling.