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Developmental Immunology
Volume 8 (2000), Issue 1, Pages 47-60
http://dx.doi.org/10.1155/2000/56106

Maturation of Lymphocyte Immunophenotypes and Memory T Helper Cell Differentiation During Development in Mice

1lmmunology Center, Department of Pathology, Loma Linda University School of Medicine and Medical Center, 11234 Anderson St. Room 2578, Loma Linda, CA 92354-2870, USA
2Immunology Center, Department of Physiology, Loma Linda University School of Medicine and Medical Center, Loma Linda, CA 92354-2870, USA

Received 7 September 1999; Revised 16 September 1999

Copyright © 2000 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The goal of this study was to systematically investigate the ontogeny of lymphoid populations throughout postnatal development. In CD-1 mice, peak lymphocyte numbers occurred in blood on postnatal day 10 (dl0) including those for natural killers (NK1.1), B cells (CD19), T helper (CD3CD4), naïve T helper (CD4CD62LposCD44low), memory T helper (CD4CD62LnegCD44high), and T cytotoxic (CD3CD8) cells. As percent of total lymphocytes, peaks were achieved by d10 for all T helper subtypes but not B cells which declined to a nadir. In spleen, lymphocyte numbers increased exponentially after d10. Proportionately, NK and T cells peaked on d10, declined by d20, and increased 2–3-fold by d45. Naive T cells constituted the majority of lymphocytes during development while memory cells gained to 2.2% (blood) and 12 % (spleen) by d20. C57BL/6 mice had similar profiles except that the B cell nadir and T cell subset peaks were at d5. Peripheralization of critical numbers of lymphocytes by d10, and importantly, development of a repertoire of memory cells by d20, may define immune response capabilities that close the period of immaturity for the neonate.