HLA-G, -E, -F preworkshop: Tools and protocols for analysis of non-classical class I genes transcription and protein expression

Non-classical MHC class I HLA-E, -F, and -G molecules differ from classical class I histocompatibility antigens by specific patterns of transcription, protein expression, and immunological functions. Restriction of the expres sion pattern of these non-classical antigens may play a key role in modulat ion of immune responses during pregnancy and diseases but remains to be add itionally defined. A specific component of the second International Confere nce on HLA-G and the 13th HLA-G Histocompatibility Workshop will be dedicat ed to the analysis of transcription and expression of non-classical class I genes in normal and pathological tissues. In a first step, referred to as the preworkshop, we here report the analysis and conclusions of a working g roup which was constituted to gather and validate optimal reagents and prot ocols allowing RT-PCR analysis of HLA-E, -F, -G transcript levels and flow cytometry and immunochemistry analysis of HLA-G expression in cells and tis sues. As a result of this work, use of specific primers and probes detectin g alternative transcripts of HLA-E, -F, and G have been validated in transf ected cells expressing differential pattern of HLA class I antigens, Analys is of the specificity and affinity of collected antibodies has allowed defi nition of reagents to be proposed for immunochemistry and flow cytometry an alysis of HLA-G expression in normal and pathological tissues during the wo rkshop. This work has allowed constitution of an extended workshop group wh ich is now initiating analysis of non-classical class I transcription and e xpression in various cells and tissues, a collective contribution that will additionally refine our view of the expression of these antigens in normal and pathological situations. (C) American Society for Histocompatibility a nd Immunogenetics, 2000. Published by Elsevier Science Inc.