The purpose of this study is to evaluate 4-dose levels of CCRE Lot 94332B1 (0.6, 1.0, 2.0, and 4.0 ng/kg). This study is known as, an "endotoxin challenge." Thousands of healthy subjects worldwide over the last 20 years have participated in endotoxin challenge studies as part of clinical research and clinical drug development programs. This study will only test the safety and tolerability of CCRE Lot 94332B1.