CD16-expressing CD8 alpha alpha super(+) lymphocytes in the intestinal epithelium. Possible precursors of Fc gamma R super(-) CD8 alpha alpha super(+) T cells

• Published in: The Journal of immunology (1950) Vol. 158; no. 10; pp. 4678 - 4687
• Main Authors: She, Jian, Simpson, S J, Gupta, A, Hollaender, G, Levelt, C, Liu, Chih-Pin, Allen, D, Van Houten, N, Wang, Baoping, Terhorst, C
• Format: Journal Article
• Language: English
• Published: 01.05.1997
• ISSN: 0022-1767

T lymphocytes normally express their Ag receptors in association with the CD3 proteins, which include CD3 zeta . In CD3 zeta eta super(null) mice thymic and peripheral T lymphocytes do not express the TCR/CD3 complex on their surface due to retention in the endoplasmic reticulum of the remaining polypeptide chains. However, intestinal intraepithelial lymphocytes (iIEL) of CD3 zeta eta super(null) mice do express surface TCR, because the Fc epsilon RI gamma chain replaced the CD3 zeta chain in the TCR/CD3 complex. Here we report that in a subset of CD8 alpha alpha super(+) iIEL the presence of the Fc epsilon RI gamma chain could be accounted for by the surface expression of the Fc gamma RIII(CD16) complex. Because in wild-type (wt) mice only CD16 super(+) iIEL coexpressed Fc epsilon RI gamma and CD3 zeta , we concluded that the presence of Fc epsilon RI gamma was dictated by its required participation of CD16 complex. CD8 alpha alpha super(+) iIEL bearing CD16 and B220 were also detected in the intestinal mucosa of RAG-2 super(null) mice from 12 days after birth onward. Two independent experimental settings were used in an attempt to demonstrate that CD16 super(+) iIEL matured into CD16 super(-) T cells. First, in the RAG-2 super(null) mice, iIEL responded to in vivo administration of an anti-CD3 epsilon mAb by progression to a more mature stage of development, characterized by a loss of CD16 and B220. Secondly, a conversion to CD16 super(-) iIEL occurred upon transfer of wt CD16 super(+) iIEL into RAG-2 super(null) mice. We conclude from these experiments that in both RAG-2 super(null) and wt mice, a precursor /progeny relationship may exists between CD16 super(+)B220 super(+)CD8 alpha alpha super(+) and CD16 super(-)B220 super(-)CD8 alpha alpha super(+) iIEL.