Immune Cell Response to Stimuli

This study will investigate the response of immune cells (neutrophils, monocytes) to various signals in the test tube to determine how they sense the signals in the body and what substances they produce in response to them. It will determine how the cells may, under certain circumstances, contribute to inflammation, and will measure substances in the blood plasma (the liquid, non-cellular part of the blood) that might stimulate white blood cells, in order to understand how the blood responds to possible disease-related conditions. Healthy normal volunteers 18 years of age and older who weigh at least 110 pounds may be eligible for this study. Participants give about 320 milliliters (mL) of blood (about 1 1/3 cups) or less at each donation. They donate no more than once every 8 weeks and no more than six times a year. On some occasions, less than 320 mL of blood may be drawn. The collected blood is separated into its components and specific cells are exposed to substances to examine their response.