Detection of HLA-DP serological allodeterminants by the use of radioiodinated DP molecules

✍ Scribed by Nobuyuki Tanigaki; Roberto Tosi; Barbara Parodi; Rosa Sorrentino; Giovanni B. Ferrara; Jack L. Strominger

• Book ID: 102828306
• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 895 KB
• Volume: 17
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830170602

✦ Synopsis

Detection of HLA-DP serological allodeterminants by the use of radioiodinated DP molecules*

HLA class I1 molecules were partially purified from cells of an HLA deletion mutant cell line, LCL721.82, that lost DR and DQ expression but retained DPw2 specificity and labeled with radioactive 1251. The radioiodinated preparation bound to DPspecific monoclonal antibody B7/21 as well as rabbit anti-HLA class I1 antiserum. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the component involved in these bindings gave, unlike known HLA class I1 molecules, a sharp and dense band of -60 kDa under nonreducing conditions and a single but diffuse band of -30 kDa under reducing conditions. By screening 401 anti-HLA class I1 alloantisera, including those distributed in the 9th International Histocompatibility Workshop and also those locally available, eight were found to possess significant binding activity. Specificity analysis of these eight binding-positive antisera on a panel of DP-pretyped HLA homozygous typing cells revealed the presence of two clusters, one corresponding to an allodeterminant associated with DPwl, 2 and 3 and the other to that associated with DPw2 and 4. These two determinants were shown by the sequential binding test to reside on the B7/21-defined HLA class I1 molecules. Thus, two major conclusions were drawn: (a) two distinct allodeterminants are carried by a single DP molecule; and (b) these serologically detected DP allodeterminants are supertypic to cellularly defined DP allospecificities.