Tolerogenic properties of human IgG subclasses in mice

The tolerogenic properties of the purified myelomatous human IgG subclasses IgG1, IgG2, IgG3 and IgG4 were investigated in mice, when given at a dose of 1 or 5 mg either, chemically nonmodified or trinitrophenylated. A complete tolerance at the helper T cell level was obtained with IgG1, IgG2 and IgG3, and a partial tolerance with IgG4 at the dose of 5 mg. At a dose of 1 mg, tolerance was observed only with IgG3. The ability of these human IgG subclasses to induce tolerance at the helper T cell level was modified after trinitrophenylation. Each subclass induced a complete tolerance when given at a dose of 1 mg. At higher doses (5 mg), a complete tolerance was obtained at the B cell level, using trinitophenyl (TNP) IgG1, TNP IgG2, TNP IgG3 or TNP IgG4 as carriers.