Among tumour infiltrating lymphocytes (TIL) of a melanoma patient, A CD8+, WT31+ CTL clone (8B3) had been previously isolated which exhibited specific and MHC-restricted lytic activity against the autologous tumour. To molecularly characterize T cell receptor (TCR) α and β transcripts of clone 8B3, sequence analysis of several cDNA isolates was carried out. Such analysis indicated that the functional α and β chain of 8B3 are composed of Vα2.1/Jα/Cα and Vβ8.2/Dβ/Jβ1.2/Cβ1 gene segments. Eleven additional melanoma-reactive T cell clones from the same patient (one MHC-restricted and 10 MHC-unrestricted) were analysed for usage of the 8B3 Vα2 and Vβ8 gene segments by Northern blot hybridization. Neither the Vα2 nor the Vβ8 segments were used by 8D9, the second MHC-restricted melanoma-specific TIL clone that displayed intra-tumour reactivity identical to that of 8B3 recognizing only 4 out of 25 melanoma clones isolated from the same metastases. No Vβ8 expression was found among the MHC-unrestricted T cell clones and all but two (found in duplicate as 4C4 and 4A6) were also negative for Vα2 expression. Southern blot analysis revealed different TCR β chain rearrangements in most MHC-unrestricted T cell clones providing evidence of their independent derivation. Taken together these findings show that TCR of clone 8B3 is unique in composition and not shared by MHC-unrestricted melanoma-reactive T cell clones. The different set of Vα and Vβ families used by clone 8D9 further indicates that the TCR usage in the specific and MHC-restricted response to melanoma can be polyclonal.
|Number of pages||11|
|Publication status||Published - 1991|
- Cytotoxic T cell clones
- T cell receptor
- Tumour-infiltrating lymphocytes
ASJC Scopus subject areas
- Cancer Research