CD CD 93 is a cell surface lectin receptor involved in the control of the inflammatory response stimulated by exogenous DNA DNA

摘要

Summary Bacterial DNA contains CpG oligonucleotide ( ODN ) motifs to trigger innate immune responses through the endosomal receptor Toll‐like receptor 9 ( TLR 9). One of the cell surface receptors to capture and deliver microbial DNA to intracellular TLR 9 is the C‐type lectin molecule DEC ‐205 through its N‐terminal C‐type lectin‐like domain ( CTLD ). CD 93 is a cell surface protein and member of the lectin group XIV with a CTLD . We hypothesized that CD 93 could interact with CpG motifs, and possibly serve as a novel receptor to deliver bacterial DNA to endosomal TLR 9. Using ELISA and tryptophan fluorescence binding studies we observed that the soluble histidine‐tagged CD 93‐ CTLD was specifically binding to CpG ODN and bacterial DNA . Moreover, we found that CpG ODN could bind to CD 93‐expressing IMR 32 neuroblastoma cells and induced more robust interleukin‐6 secretion when compared with mock‐transfected IMR 32 control cells. Our data argue for a possible contribution of CD 93 to control cell responsiveness to bacterial DNA in a manner reminiscent of DEC ‐205. We postulate that CD 93 may act as a receptor at plasma membrane for DNA or CpG ODN and to grant delivery to endosomal TLR 9.