DEVELOPMENT OF MAST-CELLS INVITRO .2. BIOLOGIC FUNCTION OF CULTURED MAST-CELLS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 118  (1) , 211-217
Abstract
Mast cells were obtained by long term culture of rat thymus cells on rat embryonic fibroblast monolayers. Pure mast cell preparations obtained by culture were incubated with 125I-labeled rat E myeloma protein to study receptors for IgE [immunoglobulin E] on their surface. When the cells were obtained after 35-45 days culture, the average number of receptors per mast cell was 100,000-400,000. An equilibrium constant of the binding reaction between their receptor and rat IgE was .simeq. 108 M-1. The histamine content of the cultured mast cells was 0.2 to 5 .mu.g/106 cells. The measurement of histamine content in mast cells recovered after different periods of culture suggested that the histamine content increased with maturation. Even after 45-50 days culture, the histamine content of cultured mast cells was significantly lower than that in rat peritoneal mast cells. The cultured mast cells were passively sensitized in vitro with rat IgE antibody against Nippostrongylus brasiliensis. The sensitized cells released histamine upon incubation with the antigen. Cultured mast cells released histamine upon exposure to compound 48/80 [p-methoxyphenethyl methylamine formaldehyde product]. Cultured mast cells apparently have physiologic functions similar to those of normal rat mast cells, but they have not reached full maturation.