, Volume 49, Issue 1, pp 1–6 | Cite as

Differential MHC expression requirements for positive selection of separate TCR Vb families

  • N. Brenden
  • Jan Böhme


 Positive selection has been proposed to be involved in protection from diabetes. We examined positive selection by fluorescence-activated cell sorter analyses in thymocytes of protected and susceptible E-transgenic and non-transgenic NOD mice. Three Vb families showed positive selection in E-transgenic mice. Vb6+CD4+ and Vb10+CD4+ thymocytes were found at higher frequencies in both protected NOD-Ea and susceptible NOD-DY mice. The increased frequencies of Vb13+CD8+ thymocytes were found in protected NOD-Ea mice only, and not in susceptible NOD-DY transgenic mice. These three Vb families were further examined in bone-marrow chimeras between NOD-Ea and non-transgenic NOD mice, where we could examine the contribution of E-expressing bone-marrow-derived cells in positive selection. We find that NOD-Ea→NOD-Ea chimeras have an increased positive selection of Vb13+CD8+ cells and that positive selection is more efficient when both thymic epithelium and bone-marrow-derived cells express the E molecule. This was also seen for Vb6+CD4+ cells. However, for Vb6, bone-marrow-derived cells alone were also capable of positive selection. Positive selection of Vb10+CD4+ cells was restricted to E-expressing thymic epithelium only. For Vb13+CD8+ cells, we found that positive selection is most efficient with E-expression on both thymic epithelium and bone-marrow-derived cells, although positive selection also occurs with E-positive epithelium only. For Vb6+ CD4+ cells, the dominating selecting cells are bone-marrow-derived cells, and Vb10+CD4+ cells seem to be selected exclusively by the thymic epithelium. Thus, the conditions for positive selection seem to vary considerably between different Vb families.

Key words Postive selection Vb-NOD Thymic epithelium Bone marrow 


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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • N. Brenden
    • 1
  • Jan Böhme
    • 2
  1. 1.Department of Immunology, Wenner-Gren Institute, Arrhenius Laboratories for Natural Sciences, Stockholm University, S-106 91 Stockholm, SwedenSE
  2. 2.Department of Biosciences, Södertörns Högskola, Karolinska Institute, NOVUM, S-141 57 Huddinge, SwedenSE

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