Average number of CD4+ and CD8+ T cells exported from thymus each day (equivalent to 1% of all thymocytes)

Range 1,000,000 - 4,000,000 T cells/day
Organism Mouse Mus musculus
Reference Krueger A, Ziętara N, Łyszkiewicz M. T Cell Development by the Numbers. Trends Immunol. 2017 Feb38(2):128-139. doi: 10.1016/j.it.2016.10.007 p.135 2nd paragraphPubMed ID27842955
Primary Source [67] Scollay RG, Butcher EC, Weissman IL. Thymus cell migration. Quantitative aspects of cellular traffic from the thymus to the periphery in mice. Eur J Immunol. 1980 Mar10(3):210-8 DOI: 10.1002/eji.1830100310 [68] Scollay, R. and Shortman, K. (1985) Identification of early stages of T lymphocyte development in the thymus cortex and medulla. J. Immunol. 134, 3632–3642PubMed ID7379836, 3886788
Method Primary source [67] abstract: "[Investigators] have used intrathymic injection of fluorescein isothiocyanate to label thymocytes in situ. The method gives random labeling of the thymocyte population and so can be used to quantitate the extent of migration of cells from the thymus to the periphery." Primary source [68] abstract: "Thymocyte subpopulations with a phenotype suggesting they are early stages of T cell development in the adult mouse thymus were characterized and isolated by using multiparameter flow cytometry and sorting, in conjunction with selective killing with antibody and complement (C). The intrathymic localization of these subpopulations was assessed by dipping the thymus in fluorescent dyes to selectively label outer-cortical cells. The main phenotypic markers used were sensitivity to C-mediated lysis by the monoclonal antibody B2A2 (which spares most prothymocytes but kills most thymocytes), the expression of the T cell lineage specific markers Ly-2 and L3T4, and the levels of the common T cell antigens Ly-1 and Thy-1."
Comments P.135 2nd paragraph: "The murine thymus on average exports 1–4×10^6 CD4+ and CD8+ T cells per day, which is equivalent to 1% of all thymocytes [BNID 111618 primary sources]. Before newly selected SP [single positive] thymocytes enter the long-lived T cell pool, they undergo a final step of maturation that starts in the thymus and continues for approximately 3 weeks in the periphery [refs 69–72]."
Entered by Uri M
ID 113829