Backgrwund:The immune system of advanced stage head and neck cancer patients is frequently suppressed. Poor immune function has been correlated with poor clinical outcome. Immunotherapeutic strategies have been previously attempted in an effort to enhance immune function and improve survival. Previous studies have shown surgical suture can be transformed into an immune stimulant capable of activating the T lymphocytes of cancer patients. The development of a process for covalently linking proteins and cytokines to suture could have enormous potential for the in vivo manipulation of the immune system. Hypothesis: We hypothesize proteins and cytokines can be covalently linked to surgical suture while preserving their functional properties. Study Design: Prospective study testing normal donor and head and neck squamous cell carcinoma (HNSCC) patient lymphocytes. Method. Polyester suture was acid hydrolyzed followed by reacting with l-ethyl-3(-3-dimethylamino propyl carbodiimide) (EDAC) to create a suture-EDAC intermediate. activity. The optimal conditions for linking 1C2 or m-7 were defined. The covalently linked cytokines retained their immune enhancing properties for stimulating PBL and lymph node lymphocytes (LNL) from HNSCC patients to proliferate, generate a TH1 immunologic profile of cytokines (IG2, IL-12, IFN-y), and stimulate T lymphocytes. Conclusion: This is the first report to demonstrate that cytokines can be covalently linked to surgical sutures and retain their immune-stimulating properties. Proteins linked to suture also retained their enzymatic activity. The clinical implications of functionally active cytokines or proteins linked to surgical suture may be very significant in the future for manipulating the immune system in vivo o r enhancing wound healing.