Tumor-specific, major histocompatibility complex (MHC) class I– restricted T-cell cytokine response induced in an HLA-matched donor (SG) vaccinated with myeloma idiotype (Id).

Peripheral blood mononuclear cells (PBMC) (2.5 × 10⁶) obtained before and after vaccination from a healthy HLA-matched sibling donor who was vaccinated with the recipient's Id protein were cocultured with (A) 5 × 10⁴ fresh plasmacytoma cells from the recipient, normal B cells from the recipient, or medium; and (B) the recipient's myeloma Id protein, isotype-matched control Id protein (50 μg/mL each), or medium. Anti-MHC class I or II or control monoclonal antibodies (MoAbs) were added as indicated. Five days later, supernatants were harvested and measured for cytokine production by enzyme-linked immunosorbent assay (ELISA). In an additional control preparation in which plasmacytoma cells from the recipient were cultured alone, none of the 3 cytokines tested (interferon γ [IFN-γ]), granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor α [TNF-α]) were detected in the culture supernatant (data not shown). The results are representative of 2 experiments.