Aim: To clone and express the leukocyte-associated immunoglobulin-like receptor (LAIR) and to identify the immune reactivity of LAIR-2 to anti-LAIR-1 specific monoclonal antibodies(mAb).
Methods: Genes encoding LAIR-1 and LAIR-2 were cloned by RT-PCR from human peripheral blood mononuclear cells(PBMC) and two leukemia cell lines Jurkat and HL-60. The extracellular region gene of LAIR1 and LAIR-2 were inserted into vector pGEX-4T-3 expressing GST fusion protein, expressed on IPTG induction and purified through glutathione-sepharose 4B column. The immunological reactivity of expressed LAIR-2 to anti-LAIR-1 mAb was identified by indirect ELISA.
Results: LAIR-1 and LAIR-2 cDNAs had been cloned and expressed. Five new LAIR-1 cDNA isoforms were cloned. Among them, two isoforms from HL-60 included LAIR-1 open reading frames (ORF) and three isoforms from Jurkat were LAIR-1 cDNA segments. The LAIR-1 and LAIR-2 showed different immunological reactivities.
Conclusion: The transcription, processing after transcription and expression of LAIRs may be related to disparities in individuals and disease status. The difference in immunological reactivity may be involved in their structure.