RESUMEN
Antigen-presenting cells (APCs) are multifunctional components of the immune defense system. In this study, murine APCs were used as biosensors to detect immunologically active components of bovine milk and colostrum. By measuring changes in cell surface protein markers [major histocompatibility complex II, cluster designation (CD)40, CD86] and cytokines (tumor necrosis factor-alpha and interleukin-10) associated with APC activation, we identified a number of compounds that are immunoactive. The mouse macrophage cell line MH-S offered a simple and robust target for identification of immunoactives. The assay was shown to be adaptable for measuring immunoenhancing or immunosuppressive substances. Large-scale screening of milk extracts using this bioassay has the potential to identify substances that could be developed into nutraceuticals or pharmaceutical-grade immunotherapeutics.