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Clinical and Developmental Immunology
Volume 11, Issue 1, Pages 29-34
http://dx.doi.org/10.1080/10446670410001670463

Development of T Lymphocytes in the Nasal-associated Lymphoid Tissue (NALT) from Growing Wistar Rats

Laboratory of Cellular Immunology, CONICET, Faculty of Pharmacy and Biochemistry, Department of Biological Sciences, University of Buenos Aires. Junín 956 5th floor, Buenos Aires C1113AAD, Argentina

Copyright © 2004 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 aim of the present report was to study the development of several T-lymphocyte subsets in the nasal-associated lymphoid tissue (NALT) of growing Wistar rats. CD5+ and CD4+ lymphocytes gradually increased with age. A predominance of CD8α+ over CD4+ T cells was found from 7 to 45 days but from 45 to 60 days of age T helper cells outnumbered the cytotoxic subpopulation. The majority of CD8+ T lymphocytes expressed the heterodimeric isoform. The most relevant findings by immunohistochemistry are: (1) the predominance of TCRγδ+ and CD8α+ cells at 7 days postpartum over all the other T-cell subpopulations; and (2) that TCRγβ+ outnumbered TCRαβ+ T cells from 7 to 45 days postpartum whereas αβ T cells predominated in 45- and 60-day-old rats. Besides, cytometric studies have shown that the percentages of TCRγ+, CD8+, as well as the population coexpressing both phenotypes (TCRγδ+CD8α+), were significantly higher in rats at 7 days postpartum when compared to 60 day-old rats. In the present study, the finding of a high number of γδ+ and CD8+ T cells early in NALT development may indicate the importance of these subpopulations in the protection of the nasal mucosa in suckling and weaning Wistar rats.