title: Serum factor: the inhibition of phytohemagglutinin-induced blastogenesis of chronic lymphocytic leukemia lymphocytes.
abstract: A serum factor (SF), isolated from acidified sera of normal donors, inhibited phytohemagglutinin (PHA) stimulation of lymphocytes isolated from patients with chronic lymphocytic leukemia (CLL),but had no effect on those from healthy donors. An SF isolated by an identical procedure from the sera of patients with CLL had essentially no inhibitory effect on DNA synthesis in normal or leukemic lymphocytes. The SF was isolated from sera or plasma by ammonium sulfate precipitation, acidification to pH  1.5, and chromatography on DEAE-cellulose. The SF was heat labile and sensitive to digestion by trypsin. Maximum inhibition was obtained when the factor was added within 24 hours after the cells were stimulated with PHA.
mesh_terms: D001798:Blood Proteins / Q000276:immunology* / Q000494:pharmacology; D002455:Cell Division; D002478:Cells, Cultured; D006801:Humans; D037102:Lectins / Q000494:pharmacology*; D007945:Leukemia, Lymphoid / Q000097:blood / Q000276:immunology*; D008213:Lymphocyte Activation
chemical_list: D001798:Blood Proteins; D037102:Lectins