EFFECT OF SOLUBLE MATERIAL FROM MOLDY HAY DUST ON THE COMPLEMENT-SYSTEM

  • 1 January 1979
    • journal article
    • research article
    • Vol. 37  (1) , 91-101
Abstract
The soluble material derived from the respirable fraction of moldy hay dust had anti-complementary and enzyme activity. The anti-complementary activity resided in a heavy MW fraction (.apprx. 800,000) and acted directly on [human] C1 [complement component 1] without the combination or alteration of Ig[immunoglobulin]G or IgM. The enzyme function had a lower MW (.apprx. 30,000-38,000) and was related to papain in that IgG was split into 2 distinct components of similar MW and with antigenic determinants the same as Fab and Fc pieces, respectively. C1 activation led to C3-9 depletion. On a per sample basis it was calculated that the soluble moldy hay dust material was up to 66 times more active at C3-9 activation than the particulate material in moldy hay dust. The capacity to activate C1 probably resides in other dusts and may be a basis for non-immune histamine release in the lungs when such a dust in inhaled. Non-specific skin reactions are probably related to C1 activation. The finding of an enzyme with papain-like activity is significant since the introduction of papain into the lungs of the experimental animal leads to emphysema. This has been described as a feature of farmer''s lung.