EVIDENCE THAT MURINE V-GAMMA-5 AND V-GAMMA-6 GAMMA-DELTA-TCR+ LYMPHOCYTES ARE DERIVED FROM A COMMON DISTINCT LINEAGE

Murine Vgamma5 and Vgamma6+ T lymphocytes develop sequentially in the thymus during fetal and newborn life, giving rise to intraepithelial l ymphocytes of the epidermis and female reproductive tract. In analyzin g a panel of gammdelta T cell hybridomas derived from various tissues, we found that all Vgamma6+ cells tested (n = 25) expressed Vgamma5-Cg amma1 mRNA, whereas none of a panel of Vgamma6- cells analyzed (n = 33 ) expressed this mRNA. Vgamma6 mRNA was rare in Vgamma5+ cells (1 of 9 ), and absent in all other gammadelta T cells (n = 10). These findings suggest that most, if not all, Vgamma6-TCR+ lymphocytes arise from pr ecursor cells that have previously rearranged the Vgamma5 gene, and in dicate that Vgamma5 and Vgamma6+ lymphocytes belong to a common, disti nct lineage that does not give rise to other gammadelta T cells.