The long term objective of this project is to develop a model of the inflammatory reaction as it can occur in the mouth and to use such a model to survey members of the population in various states of general and oral health. The specific aims of the present application are as follows: A) Explore the nature and mechanism of the reaction of salivary sediment with human complement. B) Generate a picture of the normal range of salivary sediment reactivity with complement. The saliva donors for the survey will be students of dental hygiene and dentistry in good health. This project is related to oral health for the following reasons: A) Complement is a prominent reactant in the inflammatory reaction. B) Salivary sediment has considerable potential and is in direct contact with oral tissues. Salivary sediment is a potent activator of complement. C) Periodontal disease is an inflammatory disease which involves the participation of complement. (Note: It is not being suggested that the sediment-complement reaction is necessarily the direct cause of periodontal disease; rather, that this reaction may be a useful model of some pathological events in the mouth). Methodology: Saliva will be collected from the various donors under standardized conditions. The salivary sediment will be collected by high speed centrifugation. Using the sediment the following questions will be asked experimentally: A) When sediment reacts with complemet in human serum, which components are consumed and which pathway is utilized? B) Does sediment react with purified components? That is, will it interact with a complement protein in the absence of the complement cascade? C) Is it possible to prepare an active sediment-complement complex? D) Does salivary sediment interfere with the regulation of C1 action? With the information generated using the above experimental procedures, a survey of healthy donors will be carried out to see how the complement reactivity varies in a select population (students of dental hygiene and dentistry). It would then be of considerable interest to extend such a survey to individuals in various states of poor oral health; the latter survey will probably not be possible during the duration of a Small Grant.