T cell receptor repertoire of gamma delta cells generated from the 14-day embryonic mouse thymus.

Whole, undisrupted 14 day mouse fetal thymus lobes cultured in the presence of 10 U/ml IL-2 generate a heterogeneous population of gamma delta-expressing T cells. Phenotypic analysis has shown that the majority of gamma delta T cells in such cultures stain with the anti-V gamma 3-specific mAb 536. To investigate the V gamma T-cell receptor diversity of cultured fetal thymocytes, cDNA was prepared and amplified using the polymerase chain reaction. The DNA fragments obtained were subsequently cloned and sequenced and compared with those obtained from fresh and organ-cultured 14 day fetal thymus lobes. Results obtained tend to support a positive selection model of gamma delta T cell differentiation.