A pTalpha-negative subpopulation of CD25+ TN thymocytes revealed by a transgenic marker.

• We have recently generated 5'lambda5-huTAC mice, which express the human CD25 (huTAC) gene under the control of the 5'-flanking region of the mouse lambda5-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 pTalpha-gene. Still the huTAC+CD44+CD25+ TN cells reconstituted the development of both alphabeta and gammadelta lineage cells equally efficiently as the pTalpha-expressing huTAC- fraction, demonstrating that this pTalpha-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 pTalpha-negative fraction of the CD44+CD25+ TN cells. The observation that not all precursors in the CD25+ TN population express the pTalpha-gene has important implications for the understanding of early T-cell development and T-cell lineage commitment.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Immunologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Immunology in the medical area (hsv//eng)

Nyckelord

Antigen

T-Cell

gamma-delta/metabolism

Receptors

Interleukin-2/*genetics/*metabolism

alpha-beta/metabolism

Transgenic

Mice

Membrane Glycoproteins/*genetics

Liver/cytology/immunology

Hematopoietic Stem Cells/immunology

Genetic Markers

Reporter

Genes

Gene Expression

Fetus/cytology/immunology

B-Lymphocytes/immunology

CD44/metabolism

Animal

Antigens

T-Lymphocyte Subsets/*immunology

Thymus Gland/cytology/immunology

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)