We have studied the expression and sequences of T cell receptor γ and δ chain gene messages in intrathymic T cell precursors of mice irradiated with 600 rads. On day 7 after irradiation a high level of expression of γ and δ chain messages was detected in thymocytes which were composed of a relatively high proportion of CD3+CD4−CD8‐thymocytes. During further development of the precursors from day 7 to day 14 after irradiation, γ and δ chain messages fell to low levels and α and β mRNA levels increased. Nucleotide sequence analysis of 14 γ and 10 δ chain complementary DNA (cDNA) in the thymocytes on day 7 revealed that there were 7 functional γ chain transcripts composed of Vγ2‐Jγ2‐Cγ2 or Vγ1‐Jγ4‐gene segments, and only 1 functional δ chain transcript composed of the VδM23‐Dδ1‐Dδ2‐Jδl‐Cδ gene segments. The repertoire of γ chain and δ chain genes used in “radioresistant” intrathymic T cell precursors of adult mice appears to be limited.
All Science Journal Classification (ASJC) codes
- Immunology and Allergy