Cutting edge: Rapid cloning of tumor-specific CTL suitable for adoptive immunotherapy of melanoma

Adoptive immunotherapy using CTL has provided some clinical benefit to pati ents with metastatic melanoma, Use of cloned CTL of known specificity might improve clinical effect, but technical difficulties have limited explorati on of this possibility. We have used fluorescence-driven cell sorting to cl one tumor-specific CTL after staining with tetrameric MHC class I/peptide c omplexes. CTL specific for the melanoma Ags melan-A, tyrosinase, and MAGE3 were cloned from the peripheral blood, tumor-infiltrated lymph nodes, and s kin metastases of five patients. Clones were isolated and characterized in as little as 6 weeks, much faster than is possible with previous techniques , We show that these CTL clones express markers compatible with immunothera peutic use in melanoma, including the cutaneous lymphocyte Ag, which is ass ociated with homing to skin.