A new line of research suggests that mammals form autoantibodies against chemokines such as IL8 in humans and KC in mice, and immune complexes derived from these autoantibodies can induce inflammation by binding to Fcγ receptors on leukocytes, endothelial cells and other cells. Measurement of anti-KC:KC complexes in the BALF revealed an increase in B6 mice treated with MV + LPS, which was not seen in the lpr mice (Figure 7) We also used immunofluorescence staining and confocal microscopy to investigate if there were differences in the deposition of anti-KC:KC complexes in ventilated B6 and lpr mice. The alveolar walls of the ventilated B6 mice contained abundant leukocytes, identified based on Gr-1 positivity ( Figure 8 ). The leukocytes expressed the receptor FcγRIII on their membrane surface. KC co-localized with the FcγRIII receptors. In contrast, there were, in general, Caspase-3 activity was significantly higher in the lpr mice exposed to MV + LPS. n = at least 6/group. Double-labeling for TUNEL (green) and cytokeratin (red) reveals that the TUNEL positive cells are located in the alveolar wall, but most of them are cytokeratin negative.