Collectins: pattern recognition molecules involved in first line host defense.

A group of chimeric molecules comprising globular heads, which contain the carbohydrate recognition domain, and collagen tails are defined as collectins. The mannose-binding proteins, pulmonary surfactant apoproteins A and D and conglutinin all qualify as members of this family, whose function appears to be as pattern recognition molecules involved in the first line of defense in the pre-immune host.