MABF2271-100UG Sigma-AldrichAnti-BLAST-2 (CD23) Antibody, clone EBVCS2

Human monocyte-derived dendritic cell (MoDC) have been used in the clinic with moderately encouraging results. Mouse XCR1(+) DC excel at cross-presentation, can be targeted in vivo to induce protective immunity, and share characteristics with XCR1(+) human DC. Assessment of the immunoactivation potential of XCR1(+) human DC is hindered by their paucity in vivo and by their lack of a well-defined in vitro counterpart. We report in this study a protocol generating both XCR1(+) and XCR1(-) human DC in CD34(+) progenitor cultures (CD34-DC). Gene expression profiling, phenotypic characterization, and functional studies demonstrated that XCR1(-) CD34-DC are similar to canonical MoDC, whereas XCR1(+) CD34-DC resemble XCR1(+) blood DC (bDC). XCR1(+) DC were strongly activated by polyinosinic-polycytidylic acid but not LPS, and conversely for MoDC. XCR1(+) DC and MoDC expressed strikingly different patterns of molecules involved in inflammation and in cross-talk with NK or T cells. XCR1(+) CD34-DC but not MoDC efficiently cross-presented a cell-associated Ag upon stimulation by polyinosinic-polycytidylic acid or R848, likewise to what was reported for XCR1(+) bDC. Hence, it is feasible to generate high numbers of bona fide XCR1(+) human DC in vitro as a model to decipher the functions of XCR1(+) bDC and as a potential source of XCR1(+) DC for clinical use.

Metabolically labeled monoclonal antibodies were used to measure the number of determinants per cell for an Epstein-Barr virus (EBV) cell surface antigen (EBVCS) (C. Kintner and B. Sugden, Nature [London] 294:458-460, 1981) which is expressed on the surface of EBV-transformed cells. The antigenic determinants were present approximately 5 X 10(5) times per in vitro-transformed cell. Immunoprecipitation followed by electrophoresis in polyacrylamide gels containing sodium dodecyl sulfate indicated that four independent monoclonal antibodies to EBVCS recognized a protein of 47,000 daltons. The identification of EBVCS isolated from EBV-transformed cells grown in tunicamycin demonstrated that the antigen when isolated from cells grown without this drug was glycosylated. Finally, preclearing experiments with monoclonal antibodies to EBVCS or to HLA (class I products of the human major histocompatibility locus) and to beta 2-microglobulin indicated that EBVCS is not a major histocompatibility type 1 antigen.