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Low‐molecular‐weight Leukocyte Chemotactic Factors in Psoriatic Scales: Contribution of Lipid‐soluble Factors to the Chemotactic Activity
Author(s) -
Takematsu Hideaki,
Kato Taizo,
Tagami Hachiro
Publication year - 1988
Publication title -
the journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 65
eISSN - 1346-8138
pISSN - 0385-2407
DOI - 10.1111/j.1346-8138.1988.tb03695.x
Subject(s) - chemotaxis , chemistry , biochemistry , leukotriene b4 , peptide , protease , sephadex , chemotaxis assay , immunology , biology , enzyme , receptor , inflammation
Psoriatic scales contain polymorphonuclear leukocyte (PMN) chemotactic factors which presumably are responsible for transepidermal PMN chemotaxis in psoriatic lesions. On molecular sieve chromatography, psoriatic scale extracts revealed PMN chemotactic activity in the peptide fractions eluted near 12 kDa in addition to low molecular weight (MW) chemotactic fractions. PMN chemotactic peptides with MW around 12 kDa that contain a C5‐cleavage product have been characterized as a unique major chemotactic factor in the aqueous components. On the other hand, it is uncertain whether or not lipid‐soluble low MW chemotactic factors, i.e. , leukotriene B 4 (LTB 4 ) and its related compound 12‐hydroxy‐5,8,10,14‐eicosatetraenoic acid (12‐HETE), play major roles as PMN chemoattractants. In the present study, we found that the chemotactic activity in the aqueous psoriatic extracts was much higher than that in the organic extracts. Chemotactic activity in the low MW chemotactic fractions of psoriatic scale extracts, about half of which was recovered after extraction with ether at acidic pH, was heat‐stable (100°C) and withstood protease digestion, but was partially inactivated by treatment with trypsin. Immunoreactive LTB 4 was demonstrated in these fractions. The previous findings and the present results suggest that the lipid‐soluble chemotactic factors, LTB 4 and 12‐HETE, which constitute the low MW fraction of the psoriatic scale extracts, do not play as major a role as a PMN chemoattractants as do the chemotactic peptide fractions.