Role of lymphocyte activation products (LAP) in cell-mediated immunity. I. Preparation and partial purification of guinea-pig LAP.

  • 1 January 1972
    • journal article
    • Vol. 10  (1) , 25-47
Abstract
Partial purification of soluble products of guinea-pig lymphocyte activation (LAP) was undertaken by fractional precipitation with ammonium sulphate, ion-exchange and Sephadex chromatography, and by immune precipitation of inducing antigen and of contaminating serum protein. During these purification steps the activity of macrophage migration-inhibition factor (MIF) was concentrated up to 1300-fold and separated from inducing antigen and serum protein. An endpoint assay was devised for expressing antigen-induced MIF activity of LAP fractions as weights of material giving 30% inhibition of migration (MI30 doses).