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After I have read this statement in my textbook : "Both bone-marrow and thymus provide micro-environments for the development and maturation of T-lymphocytes."

I have been searching for some detail on internet but I had found that only thymus is involved in maturation of T-cells while bone marrow in involved in maturation of B-lymphocyte.

So I'm bit of confused what exactly is the case .

MattDMo
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Jaydeep Kalal
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1 Answers1

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T cells arise in the bone marrow, as that's where the common lymphoid progenitor cells are (they also give rise to B cells). However, their development and maturation - TCR gene rearrangement, positive selection, and negative selection - occurs in the thymus1.

I suppose that one could say there is a micro-environment for developing T cells in the bone marrow, as that's where they originate, but pretty much all development takes place in the thymus. Your textbook's statement is misleading at best, although I would say it's just wrong.

It's worthwhile to note that some mature T cells do take up residence in the bone marrow as part of immune surveillance, and micro-environments do form with other cells as part of that, so perhaps that may be what your book is referring to.

Reference

  1. Kumar BV, Connors TJ, Farber DL. Human T Cell Development, Localization, and Function throughout Life. Immunity. 2018;48(2):202-213. doi:10.1016/j.immuni.2018.01.007
MattDMo
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