Biomaterial Database

Complement activation by cell wall fractions of Micropolyspora faeni. 1978

S M Smith, and R Burrell, and I S Snyder

The ability of several cell wall fractions of Micropolyspora faeni, a thermophilic actinomycete associated with farmer's lung disease, to activate complement is reported. Cell walls, obtained by mechanical disruption, were purified by enzyme treatment and chemical extractions. Fractions containing the most purified cell walls were most active in consuming complement, as measured by reduction of hemolytic complement levels of normal human serum. Cell wall fractions activated the alternative complement pathway, as shown by monitoring the conversion of C3 proactivator (factor B) to C3 activator (activated factor B) in the presence of specific cation chelators. Selective degradation of cell walls by lysozyme resulted in a decreased ability to consume complement and implicated peptidoglycan as the major complement-reactive component. The role of this nonspecific complement activation in relation to farmer's lung disease is discussed.

UI	MeSH Term	Description	Entries
D008848	Micromonosporaceae	A family of gram-positive, saprophytic bacteria occurring in soil and aquatic environments.
D009113	Muramidase	A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.	Lysozyme,Leftose,N-Acetylmuramide Glycanhydrolase,Glycanhydrolase, N-Acetylmuramide,N Acetylmuramide Glycanhydrolase
D010457	Peptidoglycan	A structural polymer of the bacterial cell envelope consisting of sugars and amino acids which is responsible for both shape determination and cellular integrity under osmotic stress in virtually all bacteria.	Murein,Pseudomurein
D002473	Cell Wall	The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.	Cell Walls,Wall, Cell,Walls, Cell
D003167	Complement Activation	The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.	Activation, Complement,Activations, Complement,Complement Activations
D003170	Complement Pathway, Alternative	Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.	Alternative Complement Pathway,Properdin Pathway,Alternative Complement Activation Pathway,Complement Activation Pathway, Alternative
D005203	Farmer's Lung	A form of alveolitis or pneumonitis due to an acquired hypersensitivity to inhaled antigens associated with farm environment. Antigens in the farm dust are commonly from bacteria actinomycetes (SACCHAROPOLYSPORA and THERMOACTINOMYCES), fungi, and animal proteins in the soil, straw, crops, pelts, serum, and excreta.	Mushroom Worker's Lung,Farmer Lung,Farmer's Lungs,Farmers Lung,Mushroom Worker Lung,Mushroom Worker's Lungs,Mushroom Workers Lung