Transformation of undifferentiated Thy-1lo B220+ thymic lymphoid cells by the Abelson murine leukemia virus.
Intrathymic injection of the Abelson murine leukemia virus (A-MuLV) results in transformation of immature T and B lymphoid cells. In this report we demonstrate that the concentration of A-MuLV injected into murine thymi influences the selection of the transformation target. Thus, concentrated A-MuLV gives rise to Thy-1+ B220- thymomas. In contrast, dilute virus induces B220+ thymomas that also express low levels of Thy-1 (Thy-1lo), a phenotype that is similar to marrow-derived progenitor B-lymphoid cells (pro-B cells) that are highly susceptible to A-MuLV transformation in vitro. However, rare B220+ lymphoid cells isolated from normal adult thymi were not transformed by A-MuLV in vitro, while B220+ cells isolated from bone marrow were highly susceptible to transformation by A-MuLV. The Thy-1lo B220+ population in the primary thymomas had not rearranged TCRgamma, TCRbeta, or Igkappa genes, but contained subpopulations that assembled Ig DJ(H) or VDJ(H) genes and were therefore similar to transformed pro- and pre-B cells obtained from A-MuLV infected fetal liver and adult bone marrow, respectively. However, unlike A-MuLV-transformed pro- and pre-B cells, many (40-70%) of the Thy-1lo B220+ transformed thymoma cells had not rearranged Igh genes, and therefore appear to represent undifferentiated lymphoid cells. We conclude that A-MuLV may transform an undifferentiated lymphoid target in the thymus.
Chen
E Y
EY
Department of Human Oncology, University of Wisconsin, Madison 53792, USA.
Swanson
B J
BJ
Clark
S S
SS
D000011:Abelson murine leukemia virus; D000818:Animals; D002472:Cell Transformation, Viral; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte; D005803:Genes, Immunoglobulin; D006412:Hematopoietic Stem Cells; D017493:Leukocyte Common Antigens / Q000302:isolation & purification*; D008214:Lymphocytes / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D018800:Thy-1 Antigens / Q000302:isolation & purification*; D013945:Thymoma / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D013950:Thymus Gland / Q000166:cytology* / Q000821:virology
D018800:Thy-1 Antigens; D017493:Leukocyte Common Antigens