Surface expression of TCR dimers by cells synthetizing three or four distinct types of receptor chains was analyzed. Cells containing intact γ, α, and β chains had only γδ dimers on the cell surface. In human PEER cells, addition of a functional α chain led to the loss of γδ dimer expression and expression of only αβ dimers. This result was not due to transcriptional down-regulation of the γ or δ loci. In murine cells expressing all four chains, both γδ and αβ dimers could be demonstrated on a single cell. No other chain combinations (αγ, αδ, βγ, βδ) were detected. Thus, there is stringent control of assembly and/or transport of TCR heterodimers, such that functional receptors consist only of αβ and γδ pairs, and no additional repertoire diversity is generated by cross pairing.
ASJC Scopus subject areas
- Immunology and Allergy