Expression of a splicing isoform of MAIR-V (CD300LF), an inhibitory immunoglobulin-like receptor on myeloid cells.

The myeloid-associated immunoglobulin-like receptor (MAIR) family consists of nine activating or inhibitory cell surface receptors preferentially expressed on myeloid cells, which are encoded by the genes in a small cluster on mouse chromosome 11. MAIR-Va, one of the inhibitory receptors in the family, has a splicing isoform, MAIR-Vb. However, the expression profile of MAIR-Va and MAIR-Vb has remained unclear. Here, we generated three monoclonal antibodies (MAb)-TX70, TX71, and TX73-against MAIR-V. TX70 and TX73 MAbs recognized both MAIR-Va and MAIR-Vb. In contrast, TX71 recognized MAIR-Va, but not MAIR-Vb. Western blot analyses by using these MAbs revealed that MAIR-Va and MAIR-Vb were almost equally expressed in the spleen cells and peritoneal exudate cells. Thus, these MAbs are useful for analyses of molecular and functional characteristics of MAIR-Va and MAIR-Vb.