CD4⁺CD8⁺ thymocytes develop into CD4 or CD8 single‐positive cells in athymic nude mice^*

Abstract

A differentiation pathway from CD4+CD8+ cells to CD4+CD8- or CD4-CD8+ cells was investigated in athymic nude mice. Using fluorescence-activated cell sorter, CD4+CD8+ cells were sorted out from AKR thymocytes (H-2k, Thy-1.1) stained with two monoclonal antibodies against CD4 and CD8 (anti-L3T4 and anti-Ly-2). These CD4+CD8+ AKR thymocytes were injected i.v. into CBA or C3H nude mice (H-2k, Thy-1.2) which had received 650 rads and had been reconstituted with syngeneic nude bone marrow cells. The lymph node cells of the nude recipients at 4 wks post-thymocyte transfer were shown to contain 50% AKR-derived Thy-1.1+ cells. The majority of the Thy-1.1+ cells were found to express either CD4 or CD8 alone but not to express both CD4 and CD8. These findings indicate that CD4+CD8+ thymocytes can develop into CD4+CD8- and CD4-CD8+ single-positive cells in extrathymic tissues.

Differential effects of a single dose of cyclophosphamide on T cell subsets of the thymus and spleen in mice: flow cytofluorometry analysis.

“…A possible explanation for the delayed decrease in the CD4+SP cell number after CY treatment is as follows : CY preferentially acts on the DP cells (precursors of the CD4+SP cells (Smith 1987 ;Tamauchi et al 1988)) rather than on the CD4+SP cells themselves and therefore this delayed decrease is a sequel to the profound impairment of the DP cells on Day 2. The behavior of the CD8+SP subset was most intriguing.…”

Changes in the relative abundance of type I and type II lck mRNA transcripts suggest differential promoter usage during T-cell development.

“…These doublepositive T cells undergo extensive selection that results in the death of the majority of these cells. The surviving double-positive T cells differentiate into medullary T cells that express either CD4 or CD8 but not both (29,30,32). Functionally mature T cells within the thymus express little (35) or no (6) HSA.…”

Correction of T cell deficiency in ZAP-70 knock-out mice by simple intraperitoneal adoptive transfer of thymocytes

“…Most T cell reconstitution studies so far have concentrated on analysing the reconstitution of T cells after the transfer of BM HSC into irradiated hosts ; furthermore, adoptive transfer of cells isolated from fetal liver or neonatal spleen , committed T cell progenitors , double‐positive thymocytes , isolated thymocytes and in‐vitro‐ generated T cell precursors (reviewed in ) have also been studied. Here, we have shown that with a single, simple i.p.…”

“…between 3 and 5 weeks of age for best results. Based on technical considerations (accessibility of donor tissue, required cell numbers, route of administration) and the scarcity of studies investigating adoptive transfer of thymocytes , we decided that the i.p. thymocyte transfer was the simplest and most promising method to be tested further.…”