Lymphocyte activation gene-3 (LAG-3; CD223) is structurally similar to CD4 and binds to MHC class II with a 100-fold higher affinity than that of CD4. Soluble LAG-3 (sLAG-3Ig) might be useful for immunotherapy by inducing MHC class II-mediated cell activation. A new form of sLAG-3Ig was constructed containing a critical binding site (D1 and D2 region) to MHC class II, combined with a Fc portion of an immunoglobulin γ1. After treatment of sLAG-3Ig in fetal thymic organ culture from DO11.10 transgenic mouse, CD4+ T cell precursors were increased in the positive selection but not affected in the negative selection. Further analysis by treating sLAG-3Ig on thymic epithelial cells revealed that CD40 and MHC class II were up-regulated. These results may demonstrate that the treatment of sLAG-3Ig increases the precursor frequency of CD4+ T cells by activation of thymic epithelial cells.
|Number of pages||7|
|Publication status||Published - 2004 Sept|
Bibliographical noteFunding Information:
The authors thank Hae-Ja Lee for technical assistance. This work was supported by Korea Research Foundation Grant (KRF-2002-003-E00057).
- Fetal thymic organ culture
- Fusion protein
- Lymphocyte activation gene-3
- T cell precursor
- Thymic selection
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology