作者：郭雨刚a,b，李锐a,b，宋小平c，钟永军a,b，王晨光a,b，贾浩a,b，吴黎丹a,b，王栋a,b，方芳a,b，马佳佳a,b，康文遥a,b，孙洁a,b，田志刚a,b，肖卫华a,b
a：Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Biology, School of Life Sciences, University of Science and Technology of China
b：Center of Medical Biotechnology of Anhui Province, University of Science and Technology of China, Hefei, China

c：Department of Pharmacy, Anhui Medical College, Hefei, China

Abstract: CD83 is a highly glycosylated type I transmembrane glycoprotein that belongs to the immunoglobulin superfamily. CD83 is upregulated during dendritic cell (DC) maturation, which is critical for the initiation of adaptive immune responses. The soluble isoform of CD83 (sCD83) is encoded by alternative splicing from full-length CD83 mRNA and inhibits DC maturation, which suggests that sCD83 acts as a potential immune suppressor. In this study, we developed a sound strategy to express functional sCD83 from Pichia pastoris in extremely high-density fermentation. Purified sCD83 was expressed as a monomer at a yield of more than 200 mg/L and contained N-linked glycosylation sites that were characterized by PNGase F digestion. In vitro tests indicated that recombinant sCD83 bound to its putative counterpart on monocytes and specifically blocked the binding of anti-CD83 antibodies to cell surface CD83 on DCs. Moreover, sCD83 from yeast suppressed lymphocyte proliferation in a dose-dependent manner. Therefore, sCD83 that was expressed from the P. pastoris was functionally active and may be used for in vivo and in vitro studies as well as future clinical applications.

URL: http://dx.plos.org/10.1371/journal.pone.0089264