The complement system is an important part of the innate immunity. Complement activation products not only directly help to eliminate invading pathogens, but also participate in many immunological reactions, including clearance of immune complexes, antibody production, and T-cell regulation. Insufficient or excess complement activation has been shown to be important in a wide range of disease states, such as multiple sclerosis, myasthenia gravis, systemic lupus erythematosus, rheumatoid arthritis, and age-related macular degeneration, as well as in allograft rejection.
Using genetically engineered mice as disease models, the Lin laboratory is interested in studying complement activation and regulation in these disease states, thus eventually developing novel therapies. In the group's latest work, for example, they found evidence of a potentially clinically useful connection of complement in mesenchymal stem cell-based therapies, suggesting that complement is a valid target for improving the viability and function of mesenchymal stem cells, which are under extensive evaluation in clinical trials for treating many inflammatory and degenerative diseases.