MONOCLONAL-ANTIBODY TO ENDOTOXIN CORE PROTECTS MICE FROM ESCHERICHIA-COLI SEPSIS BY A MECHANISM INDEPENDENT OF TUMOR-NECROSIS-FACTOR AND INTERLEUKIN-6

To study the role of cytokines as mediators of endotoxin-induced shock, the serum levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6) were compared in mice receiving either a monoclonal antibody to endotoxin core (clone 20), an irrelevant monoclonal antibody (A1), or culture media (DMEM/FCS) alone before lethal challenge with live Escherichia coli 0111:B4. Clone 20 given 1.5 h before the bacterial challenge protected mice from death (mortality at 48 h 3% vs. 87%, P <.001). The pattern of IL-6 release was indistinguishable in clone 20 recipients and controls: The area under the curve (AVC) for 5 h was 1.22 ± 0.07 × 106, 1.03 ± 0.17 × 106, and 1.22 ± 0.07 × 106 units/ml for clone 20, Al, and DMEM/FCS, respectively. Similarly, the timing and extent of TNF release in the serum was virtually identical in clone 20 recipients that survived and control animals that died. AVC for 5 h was 30.8 ± 4.0 × 103, 28.1 ± 1.1 × 103, and 30.4 ± 4.7 × 103 ng/ml in clone 20, A1, and DMEM/FCS recipients, respectively. Thus, TNF and IL-6 appear insufficient to cause death in this model ofexperimental gram-negative shock. © 1990, by The University of Chicago.