Long-term thymic reconstitution by peripheral CD4 and CD8 single-positive lymphocytes.
Significant immigration of peripheral T cells into SCID thymus was observed following reconstitution with normal Peyer's patch, mesenteric lymph node or peripheral lymph node cells. Immunohistologic and flow cytometric analyses reveal that T cells from these tissues are found in the thymus for as long as 177 days and can account for up to 67% of intrathymic cells. The returning cells express the CD3/T cell receptor alpha/beta complex, indicative of mature cells, and are equally divided among helper (CD4+CD8-) and cytotoxic (CD4-/CD8+) phenotypes. The immigration of peripheral T cells is not accompanied by the appearance of immature, double-positive (CD4+CD8+) thymocytes as seen in similar reconstitutions using bone marrow. Taken together, these results suggest that peripheral T cells from a variety of lymphoid organs may regularly re-enter the thymus and, thus, possibly play a role in normal thymic development.
Hilbert
D M
DM
Laboratory of Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Holmes
K L
KL
Anderson
A O
AO
Rudikoff
S
S
D000818:Animals; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D002454:Cell Differentiation; D002465:Cell Movement / Q000276:immunology; D005260:Female; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D016513:Mice, SCID; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology; D010641:Phenotype; D016511:Severe Combined Immunodeficiency / Q000276:immunology* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000637:transplantation; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
D015704:CD4 Antigens; D016827:CD8 Antigens