Terminal deoxynucleotidyl transferase (TdT) enzyme in thymus and bone marrow. I. Age-associated decline of TdT in humans and mice

Rajendra Pahwa, Mukund J. Modak, Teresa McMorrow, Savita G Pahwa, Gabriel Fernandes, Robert A. Good

Research output: Contribution to journalArticle

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Abstract

This study was aimed at characterizing terminal deoxynucleotidyl transferase (TdT) levels in populations of normal human and murine lymphocytes and toward correlating TdT enzyme levels with the biological process of aging. A newly developed method that utilizes a small number of cells was employed to determine TdT levels in bone marrow and thymus cells following cell fractionation at unit gravity sedimentation. By these methods, cell fractions with high TdT activity were found to comprise only 5-10% of the parent cell pools. In the human bone marrow, we show here that TdT-positive cell fractions are largely depleted of HTLA, E-rosette forming, and mitogen-responsive cells, whereas TdT-positive human thymocyte fractions contain a high percentage of HTLA and E-rosette-positive cells. Our observations in the murine model confirm the earlier observations that TdT activity decreases with age. We further show here that the age-associated decline of TdT in the bone marrow preceded that in the thymus. As is true for the mouse, TdT activity in human bone marrow and thymus was also found to decrease with advancing age. The decline in TdT was not associated with a change in cell distribution profiles after unit gravity sedimentation of bone marrow or thymus cells. From these data, the age-associated loss of TdT cannot be attributed to a loss of a particular subpopulation of cells.

Original languageEnglish
Pages (from-to)39-48
Number of pages10
JournalCellular Immunology
Volume58
Issue number1
DOIs
StatePublished - Jan 1 1981
Externally publishedYes

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DNA Nucleotidylexotransferase
Thymus Gland
Bone Marrow
Enzymes
Gravitation
Cell Fractionation
Biological Phenomena
Thymocytes
Mitogens
Human Activities
Bone Marrow Cells
Cell Count
Lymphocytes

ASJC Scopus subject areas

  • Cell Biology
  • Immunology

Cite this

Terminal deoxynucleotidyl transferase (TdT) enzyme in thymus and bone marrow. I. Age-associated decline of TdT in humans and mice. / Pahwa, Rajendra; Modak, Mukund J.; McMorrow, Teresa; Pahwa, Savita G; Fernandes, Gabriel; Good, Robert A.

In: Cellular Immunology, Vol. 58, No. 1, 01.01.1981, p. 39-48.

Research output: Contribution to journalArticle

Pahwa, Rajendra ; Modak, Mukund J. ; McMorrow, Teresa ; Pahwa, Savita G ; Fernandes, Gabriel ; Good, Robert A. / Terminal deoxynucleotidyl transferase (TdT) enzyme in thymus and bone marrow. I. Age-associated decline of TdT in humans and mice. In: Cellular Immunology. 1981 ; Vol. 58, No. 1. pp. 39-48.
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