Histamine-releasing factors.
Histamine-releasing factors (HRF) are cell-derived products which cause histamine release from basophils and/or mast cells. We have isolated HRF from human mononuclear cells and platelets and have purified 3 molecular species having molecular weights of 8-10, 15-17 and 35-41 kilodaltons (kDa). We prepared monoclonal antibodies to the 8- to 10-kDa form and have isolated it by affinity chromatography. A broad band was seen upon sodium dodecyl sulfate gel electrophoresis in 15% gels as well as immunoblotting, and the band was divided into an upper and a lower half. Amino acid sequence analysis of the upper half indicated that it is closely homologous to connective-tissue activating peptide III (CTAP III). The lower half also aligned with CTAP III beginning with amino acid 16; thus, proteolysis and occurred removing the N-terminal 15 amino acids. This corresponds to neutrophil-activating peptide 2. Both appear to be active on basophils with a dose-response between 250 ng up to 10 micrograms. Although interleukin-3 and granulocyte/macrophage-colony-stimulating factor have similar histamine-releasing capability at lower effective concentrations, they do not account for HRF activity in mononuclear cell/platelet supernatants, and the 15- to 17 and 40- to 41-kDa moieties appear to be unique gene products unrelated to previously described cytokines.
Kaplan
A P
AP
Department of Medicine, SUNY, Stony Brook.
Baeza
M
M
Reddigari
S
S
Kuna
P
P
D000595:Amino Acid Sequence; D001491:Basophils / Q000187:drug effects / Q000378:metabolism; D014408:Biomarkers, Tumor; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D008222:Lymphokines / Q000494:pharmacology*; D008969:Molecular Sequence Data; D000090324:Tumor Protein, Translationally-Controlled 1
D014408:Biomarkers, Tumor; D008222:Lymphokines; D000090324:Tumor Protein, Translationally-Controlled 1