Persistence of the irradiated host component in thymocyte populations from bone marrow radiation chimeras infected with lymphocytic choriomeningitis virus.
The thymus of chimeras made using T cell-depleted donor bone marrow from Thy1.1+ mice and 950 rad Thy 1.2+ recipients is dominated initially by cells expressing the Thy 1.2+ phenotype of the irradiated host. The thymocyte population recovered at 2 weeks after reconstitution comprises 80% Thy 1.2+ cells (host), the remainder being Thy 1.1+ (donor). This situation is normally reversed within a further week, with the host Ty 1.2+ (donor). This situation is normally reversed within a further week, with the host Thy 1.2+ thymocytes being present at a frequency of less than 5% from Week 4. Infection with lymphocytic choriomeningitis virus (LCMV) at 1 week after reconstitution with bone marrow causes a profound and persistent drop in the total number of thymocytes. The decline is equivalent for all categories of donor-derived thymocytes defined by two-color flow microfluorometric analysis for CD4 and CD8. However, there is a partial compensation by the retention of cells originating from the Thy 1.2+ host, which constitute 30-40% of the total thymocyte pool as late as 8 weeks after administration of bone marrow in the LCMV-infected chimeras. These radiation-resistant precursors give rise to CD4-8-, CD4-8+, CD4+8-, and CD4+8+ thymocytes, with the latter category being present at increased frequency. The potential skewing of the mature T cell repertoire as a consequence of persistent virus infection is discussed.
Lynch
F
F
Department of Experimental Pathology, John Curtin School of Medical Research, Canberra, Australia.
Ceredig
R
R
Hartley
D
D
Doherty
P C
PC
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology*; D015496:CD4-Positive T-Lymphocytes / Q000145:classification / Q000276:immunology; D016827:CD8 Antigens; D007108:Immune Tolerance; D008216:Lymphocytic Choriomeningitis / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D011828:Radiation Chimera; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology*
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D016827:CD8 Antigens; D018800:Thy-1 Antigens