Fig. 7.
The activity of human recombinant lactoferrin in the secondary immune response in vitro is abolished by addition of sialic acid. Splenocytes isolated from sheep red blood cell (SRBC) primed mice were incubated with SRBC, alone in the presence of methotrexate (MTX). Antibody forming cells (AFC) were evaluated after 4 days. Cells were cultured in the presence of sialylated LF (LF B). Free sialic acid was added alone, or in combination with LF (a). Alternatively, anti-sialoadhesin monoclonal antibody CD169 (sialoadhesin) was added before LF (1:250) (b). a Control vs. LF B p=0.0001; control vs MTX p=0.0001; control vs. Sia NS; control vs. LF B+Sia NS; control vs. LF B+MTX NS; control vs LF B+Sia+MTX p=0.0001; MTX vs. LF B+MTX p=0.0001; MTX vs LF B+Sia+MTX NS; LF B+MTX vs. LF B+Sia+MTX p=0.0023 (ANOVA). b Control vs.LF B p=0.0291; control vs. MTX p=0.0001; control vs. Ab NS; control vs. LF B+Ab+MTX p=0.0001; LF B vs. LF B+Ab p=0.0001; MTX vs. LF B+MTX p=0.0001; MTX vs. LF B+Ab+MTX NS; LF B+MTX vs. LF B+Ab+MTX p=0.0001 (ANOVA)