The mediation of macrophage reaction in inflammation, with special reference to IgG-derived chemotactic factor.

Three different macrophage chemotactic factors were separated from hypersensitivity skin lesions induced by DNP-ascaris extract or PPD. The amount of each factor seemed to be changeable according to the nature of inflammatory stimuli. The chemotactic activity of the factor a was completely absorbed by anti-IgG and anti-light chain antibodies, while that of the factors b and c was not absorbed by the antibodies. The factor a was produced from IgG by neutrophil neutral serine protease resembling elastase but failing to digest elastin-orcein; its chemotactic generation was accompanied by release of dialysable peptide(s) from the IgG molecule, suggesting a minor structural change of the IgG molecule. Production of leucoegresin or lymphocyte chemotactic factor by neutrophil neutral thiol protease from IgG molecule was discussed.