Expression of T-cell receptor (TCR) gene rearrangements in tumor-infiltrating lymphocytes (TILs) within primary and metastatic melanoma specimens was studied. In order to analyze TCR gene transcription in TILs within these tissues, we analyzed reverse transcribed complementary DNA from mRNA directly from tissues using the polymerase chain reaction. The polymerase chain reaction-amplified products were confirmed by dot or Southern blot hybridization with Cα or Cβ oligoprobes. First, we investigated the diversity of TCR Vα and Vβ gene usage in human malignant melanoma patients with multiple metastasis. We found in one patient, bearing multiple skin lesions, that the pattern of TCR Vα and Vβ repertoires in different sites of the skin (leg and chest wall) were almost the same. However, in another patient with skin and brain melanomas, different TCR repertoires were presented.
Next, we examined the usage of murine TCR Vβ genes in TILs within the primary and metastatic sites (liver, lung, and brain) of C57BL/6 mice bearing B16-F10 murine melanoma. The population of TILs in each primary and metastatic site expressed from one to four TCR Vβ genes. In each metastatic site, the profile of TCR Vβ gene expression was different. A different TCR Vβ usage in TILs distributed within metastases of various organs may reflect differences in tumor antigenicity at these sites or may be due to differential homing patterns to these tumors.