Melanoma specific Th1 cytotoxic T lymphocyte lines in Vogt-Koyanagi-Harada disease.

AIMS/BACKGROUND: To determine the functional properties and cytokine production profiles of melanoma specific cytotoxic T lymphocytes (CTLs) induced from peripheral blood leucocytes of two patients with Vogt-Koyanagi-Harada disease (VKH).

METHODS

Melanoma specific CTL lines were established by long term coculture with a human melanoma cell line (P-36). Cytotoxic activity against P-36 was measured by 51Cr release. The involvement of human leucocyte antigen (HLA) class I or class II molecules in the cytotoxicity of the CTL lines against P-36 was analysed using anti-HLA class I or anti-HLA class II monoclonal antibody (MAb). Surface molecules of CTL lines were analysed by flow cytometry using MAbs specific for CD4, CD8, CD16, CD25, CD56, HLA-DR, T cell antigen receptor (TCR) alpha beta and TCR gamma delta. Cytokine production and soluble interleukin 2 receptor (sIL-2R) secretion were determined by enzyme linked immunosorbent assays. mRNAs of cytokines were analysed using reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

CTLs showed strong cytotoxic activity against P-36. The CTL activity of the cell lines against P-36 was inhibited by the anti-HLA-DR MAb, whereas the MAb specific for monomorphic determinants of HLA-A, B, and C failed to block lytic activity. Flow cytometry identified the following surface molecules: CD4+, CD8-, CD16-, CD25+, CD56-, HLA-DR+, TCR alpha beta +, and TCR gamma delta-. CTLs constitutively produced a high level of IL-6. IL-6 production and sIL-2R secretion of CTLs were enhanced when CTLs were stimulated with P-36. CTLs also produced high levels of interferon gamma (IFN-gamma) and IL-2, but not IL-4. mRNAs of IL-2 and IFN-gamma were detected by RT-PCR in the CTLs.

CONCLUSIONS

Melanoma specific HLADR restricted T helper 1 (Th1) CTLs may play a role in the immunopathogenesis of VKH.