title: Ligation of MHC class I induces apoptosis in human pre-B cell lines, in promyelocytic cell lines and in CD40-stimulated mature B cells.
abstract: A murine mAb (BAL-1) was previously shown to induce apoptosis when cross-linked on the cell surface of different B acute lymphocytic leukemia (ALL) and pro-myelocytic cell lines. The present study shows that BAL-1 specifically recognizes the MHC class I (MHC-I). The apoptotic response was not dependent on the epitope specificity, since other anti-MHC-I antibodies, reacting with different monomorphic determinants of the alpha chain or beta 2-microglobulin, also induced apoptosis in these cells. However, external cross-linking of antibodies was strictly required for the apoptotic effect. Among cells originating from mature peripheral blood B cells, anti-CD40-stimulated cells were susceptible to anti-MHC-I-induced apoptosis, whereas B cells activated with Staphylococcus aureus Cowan I (SAC) or with the superantigen staphylococcal enterotoxin A (SEA) were non-responsive. Mature SEA-activated T cells were also resistant to MHC-I-induced apoptosis. In situ terminal deoxynucleotidyl transferase staining of apoptotic cells at various stages during MHC-I-induced cell death revealed that apoptosis occurred predominantly in the G2/M phase of the cell cycle, with the first apoptotic cells appearing after approximately 12 h of incubation. These results suggest a role for MHC-I-mediated apoptosis during differentiation and activation of certain hematopoietic cells.
authors.affiliation: Department of Immunotechnology, Lund University, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Wallén-Ohman
authors.forename: J W
authors.initials: JW
authors.lastname: Larrick
authors.forename: R
authors.initials: R
authors.lastname: Carlsson
authors.forename: C A
authors.initials: CA
authors.lastname: Borrebaeck
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000494:pharmacology; D017209:Apoptosis / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D019013:CD40 Antigens / Q000502:physiology*; D002455:Cell Division / Q000276:immunology; D002460:Cell Line; D053938:DNA Fragmentation / Q000276:immunology; D018922:HL-60 Cells; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007399:Interphase / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008938:Mitosis / Q000276:immunology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D019013:CD40 Antigens; D015395:Histocompatibility Antigens Class I