Degranulation of human basophils: quantitative analysis of histamine release and desensitization, due to a bivalent penicilloyl hapten
Dembo, M.; Goldstein, B.; Sobotka, A.K.; Lichtenstein, L.M.
Journal of Immunology 123(4): 1864-1872
1979
ISSN/ISBN: 0022-1767 PMID: 90102 Document Number: 141917
A quantitative model of histamine release from human basophils due to the symmetric bivalent hapten, bis-benzylpenicilloyl 1,6-diaminohexane, (BPO)2 is presented. The major elements of the model are given. The histamine content of basophils is divided into a large number of discrete and quasi-independent quanta. A certain fraction of the quanta in a population of basophils are non-releasable. Release of the contents of a quanta is a stochastic event. The binding and cross-linking reaction between (BPO)2 and cell surface Igex .fwdarw. 0 for all values of Xpoly. Antigen-specific IgE molecules and/or their associated Fc receptors are inactivated at a rate that is a saturable function of Xpoly. This process of inactivation is not dependent on the extracellular Ca concentration. The model is tested by carrying out a detailed fitting to histamine release data obtained by using cells from a single donor. Good agreement between theory and experiment is obtained, and all the parameters of the model are determined. The ways in which the model can be extended to include systems more complex than the (BPO)2 system are briefly discussed.