title: In vitro inhibition of normal human hematopoiesis by marrow CD3+, CD8+, HLA-DR+, HNK1+ lymphocytes.
abstract: We previously demonstrated that after allogeneic bone marrow transplantation (BMT) a subset of CD8, HNK1, and DR-positive T lymphocytes are able to inhibit CFU-GM and BFU-E growth with an HLA-DR restriction. In this study we investigated whether these cells, present in normal marrow in low concentration (less than 1%), play the same role. HNK1-positive sorted marrow cells forming rosettes (E+C) were able to inhibit BFU-E and CFU-GM growth when added back to the marrow E-C at a ratio of 1:10 (HNK1+ E+C/E-C) in a range from 40% to 60%. This inhibitory effect was also detected for a cellular ratio of 1:100, which is the normal marrow value for this subset of T cell. HNK1+ DR+-sorted E+C after double-immunofluorescent labeling also showed the same inhibitory activity as the HNK1+ E+C, whereas the negative fraction including all the other E+C had no detectable inhibitory activity. CD3 and CD8 antigens were also present on the membrane of these cells, as demonstrated in two cases by double-immunofluorescent labeling performed with anti-CD3 or anti-CD8 monoclonal antibodies (MoAbs) and HNK1 MoAb, respectively, and subsequent cell sorting. Blocking experiments, performed by adding in culture anti-CD4 and anti-CD8 MoAbs to HNK1+ T cells showed that only the last MoAb was able to prevent inhibition of hematopoietic colony growth. These results confirmed that one subset of CD3+, CD8+, HNK1+, and DR+ T cells was responsible for in vitro inhibition of normal hematopoiesis. In addition, this inhibition was genetically restricted to HLA-class II antigens, since in three co-culture experiments with unrelated bone marrow cells inhibition occurred only when cells with one haplo-identical HLA-DR antigen was added back to the culture. Indeed, this effect was really HLA-DR restricted, since in blocking experiments with different anti-HLA class II MoAbs (anti-DR, anti-DP, and anti-DQ MoAbs) only an anti-HLA-DR MoAb was able to prevent the colony growth inhibition by CD3+ HNK1+, or CD8+ HNK1+ E+C. In conclusion, the CD3+, HNK1+, CD8+, DR+ cells may be the T-cell subset able to inhibit normal hematopoiesis with an HLA-DR restriction.
authors.affiliation: INSERM U.91, Service d'Hématologie Hôpital Henri Mondor, Créteil, France.
authors.forename: G
authors.initials: G
authors.lastname: Vinci
authors.forename: J P
authors.initials: JP
authors.lastname: Vernant
authors.forename: M
authors.initials: M
authors.lastname: Nakazawa
authors.forename: M
authors.initials: M
authors.lastname: Zohair
authors.forename: A
authors.initials: A
authors.lastname: Katz
authors.forename: A
authors.initials: A
authors.lastname: Henri
authors.forename: H
authors.initials: H
authors.lastname: Rochant
authors.forename: J
authors.initials: J
authors.lastname: Breton-Gorius
authors.forename: W
authors.initials: W
authors.lastname: Vainchenker
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001854:Bone Marrow Cells; D017252:CD3 Complex; D016827:CD8 Antigens; D002455:Cell Division; D003114:Colony-Forming Units Assay; D003602:Cytotoxicity, Immunologic; D006684:HLA-DR Antigens / Q000032:analysis; D006410:Hematopoiesis; D006801:Humans; D007111:Immunity, Cellular; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000145:classification / Q000502:physiology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D016827:CD8 Antigens; D006684:HLA-DR Antigens; D011948:Receptors, Antigen, T-Cell