A novel sandwich ELISA for α1 domain based detection of soluble HLA-G heavy chains

Beyond the increasing complexity of the immunomodulatory HLA-G molecule

“…Recent crystallography studies 71 have confirmed that the structure of HLA-G1 is class I-like (heterotrimer of heavy chain, ␤ 2 -microglobulin, and peptide, herein referred to as monomers), but have also shown that it differs at the ␣3 domain, which is more hydrophobic and may explain why HLA-G has a higher affinity for ILT2 than classic HLA class I molecules. In addition, HLA-G1 and HLA-G5 can also be found as ␤ 2 -microglobulin-free heavy chains, 72 and more importantly, as disulphide-bonded homodimers. 73,74 The existence of HLA-G dimers was first hypothesized after sequence analysis of HLA-G2 75 but first observed for HLA-G1 73 and then crystallized.…”

HLA-G: from biology to clinical benefits

“…Thanks to these reference antibodies and many others that have now been made available, several enzyme-linked immunosorbent assays (ELISAs) were developed, aimed at measuring sHLA-G in biological fluids (for a list of ELISA formats, see [14,15]). This allowed investigation of the potential benefit of HLA-G as a biomarker for diagnosis or prediction of the clinical outcome in human diseases ( Table 2).…”

The role of HLA-G in immunity and hematopoiesis

“…The multiple structures of HLA-G HLA-G has multiple shapes: (1) it can already be expressed as seven different isoforms due to alternative splicing of its primary transcript, (2) the structure of HLA-G1 and HLA-G5 isoforms is similar to that of classical HLA class I molecules and can be found as heterotrimers (heavy chain, b2M, peptide) or as free heavy chain [11], and (3) membrane-bound isoforms of HLA-G can be shed by proteolytic cleavage, giving rise to soluble HLA-G isoforms that may differ from the secreted ones [12]. Considering the possibility that all isoforms may be shed, as is HLA-G1, this brings the number of HLA-G possible isoforms/structures to 14, of which 12 are already published [11][12][13][14][15][16][17][18].…”

“…Considering the possibility that all isoforms may be shed, as is HLA-G1, this brings the number of HLA-G possible isoforms/structures to 14, of which 12 are already published [11][12][13][14][15][16][17][18]. These are the simplest HLA-G structures and, until recently, they were the basis for HLA-G research.…”