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Inhibition of Neutrophil Chemotaxis by Elastase‐Generated IgG Fragments
Author(s) -
ECKLE I.,
KOLB G.,
HAVEMANN K.
Publication year - 1991
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1991.tb01557.x
Subject(s) - chemotaxis , chemokinesis , elastase , granulocyte , pancreatic elastase , chemistry , n formylmethionine leucyl phenylalanine , in vitro , receptor , microbiology and biotechnology , casein , immunoglobulin g , in vivo , biochemistry , antibody , enzyme , biology , immunology
IgG 1 is cleaved in vitro by granulocyte elastase into Fc and Fab fragments. The elastase‐specific Fe fragment has been previously detected in vivo. Biological activity of the fragments has been described in modulating neutrophil oxidative metabolism and enzyme release. To investigate further effects granulocyte chemotaxis(CT) was tested. The CT was assayed in Boyden chambers and the chemotactic index (CI) was calculated which represents the mean distance travelled by the activated cells. Stimulation of leucocyte CT by casein, activated scrum and FMLP gives maximal values of Δ CI = 46.7, 26.4 and 7.1 μm, respectively. Native IgG 1 and the elastase‐produced IgG fragments do not stimulate leucocyte CT. FMLP‐stimulated CT is specifically inhibited by the elastase‐produced Fc fragments. Addition of 7 nmol Fc to stimulus concentrations of 16 to 125 nM FMLP results in total inhibition of chemotaxis demonstrated by CI values which are lower than those for unstitmulated cells. The inhibition of CT is concentration dependent in the range of 2 to 7 nmol Fc/10 6 PMN. Number and affinity of FMLP receptors are not incipience by Fc fragments, so Fc binds neither to FMLP nor the FMLP receptor. CT stimulated by casein shows a large portion of chemokinesis. Only at suboptimal casein concentrations do Fc and IgG have an Inhibitory effect on CT (0.63 mg casein /ml. 10 nmol peptide/10 6 PMN). C5a‐stimulaicd CT is not influenced by IgG or IgG fragments which indicates that the samples are not cytotoxic. So the FMLP and casein‐stimulated CT is specifically inhibited by the elastase‐produced Fc fragments in a low concentration range.