title: In vivo phenotypic characteristics of AKR T-cell lymphomas with different leukemic potential: possible role of alpha 4 beta 7 integrin in the progression towards the leukemic phenotype.
abstract: The present study was undertaken in order to determine whether the expression of specific surface molecules which mediate immune recognition as well as cell-cell and cell-matrix interactions is associated with the leukemic evolution of T-cell lymphomas. To this end, we have investigated the in vivo phenotypic characteristics and the in vitro natural-killer(NK)-cell susceptibility of a group of MCF-247-induced AKR/J T-cell lymphomas with different leukemic potential. We found that in the AKR/J model, the biological aggressiveness of leukemic cells is not dependent upon an escape from host immune surveillance as a consequence of an in vivo down-regulation of H2-Kk determinants or a resistance to NK lysis. Moreover, NK susceptibility of AKR/J lymphomas does not seem to correlate with the level of H2-antigen expression. No obvious correlation was found between the leukemic phenotype and the amount of MEL-14, LFA-1, ICAM-1, Pgp-1/CD44 and THAM/CD26 antigen expression. An in vivo coordinated up-regulation of alpha 4 and beta 7 integrin chains, with the highest levels of expression detected in secondary sites of leukemic infiltration, was observed in the highly leukemic lymphoma NQ22 and, albeit to a lesser extent, in lymphomas with moderate leukemic potential. Conversely, non-leukemic lymphomas were repeatedly alpha 4- and beta 7-negative. These findings suggest that in the AKR/J system the expression of alpha 4 beta 7 integrin may contribute to leukemic spreading of T-cell lymphomas.
authors.affiliation: Department of Experimental Oncology 1, Centro di Riferimento Oncologico, Aviano (PN), Italy.
authors.forename: R
authors.initials: R
authors.lastname: Dolcetti
authors.forename: T
authors.initials: T
authors.lastname: Frisan
authors.forename: G
authors.initials: G
authors.lastname: Palmieri
authors.forename: S
authors.initials: S
authors.lastname: Rizzo
authors.forename: R
authors.initials: R
authors.lastname: Maestro
authors.forename: A
authors.initials: A
authors.lastname: Santoni
authors.forename: M
authors.initials: M
authors.lastname: Boiocchi
mesh_terms: D000818:Animals; D005260:Female; D006183:H-2 Antigens / Q000032:analysis; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D016023:Integrins / Q000276:immunology / Q000502:physiology*; D007694:Killer Cells, Natural / Q000276:immunology / Q000473:pathology; D007938:Leukemia / Q000276:immunology*; D016399:Lymphoma, T-Cell / Q000276:immunology*; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D010641:Phenotype
chemical_list: D006183:H-2 Antigens; C024755:H-2K(K) antigen; D015395:Histocompatibility Antigens Class I; D016023:Integrins; C071777:integrin alpha4beta7