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A pTα‐Negative Subpopulation of CD25 + TN Thymocytes Revealed by a Transgenic Marker
Author(s) -
Petersson K.,
Mårtensson A.,
Mertsching E.,
Winkler T.,
Ceredig R.,
Mårtensson I.L.,
Ivars F.
Publication year - 2002
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.2002.01022.x
Subject(s) - il 2 receptor , biology , microbiology and biotechnology , cd44 , cd8 , transgene , population , t cell , gene , cell , genetics , antigen , immune system , demography , sociology
We have recently generated 5′λ5‐huTAC mice, which express the human CD25 (huTAC) gene under the control of the 5′‐flanking region of the mouse λ5‐gene. The huTAC‐transgene was expressed in pre‐B cells but neither in mature B cells nor in T cells of these mice. In this report we demonstrate that the transgene is also transiently expressed by adult CD25 + CD3 − CD4 − CD8 − (triple negative, TN) thymocytes and in fetal thymocytes. The huTAC + , in contrast to the huTAC − subpopulation of the CD44 + CD25 + TN cells, was unexpectedly found not to express the pTα‐gene. Still the huTAC + CD44 + CD25 + TN cells reconstituted the development of both αβ and γδ lineage cells equally efficiently as the pTα‐expressing huTAC − fraction, demonstrating that this pTα‐negative subpopulation contained precursors for both T‐cell lineages. Single cell reverse transcription–polymerase chain reaction (RT–PCR) experiments demonstrated that also in normal mice only a fraction of CD44 + CD25 + and CD44 − CD25 + TN cells expressed this gene. Taken together, these data indicate that huTAC transgene expression revealed a truly pTα‐negative fraction of the CD44 + CD25 + TN cells. The observation that not all precursors in the CD25 + TN population express the pTα‐gene has important implications for the understanding of early T‐cell development and T‐cell lineage commitment.