Fig. 2.

Activated neutrophils, which mediate the acute phase of innate immune responses, use the myeloperoxidase, hydrogen peroxide, chloride pathway to convert l-tyrosine to p-hydroxyphenylacetaldehyde which partitions to plasma membranes to forms Schiff bases with ɛ-amino groups. In separate studies the latter process has been shown to costimulate T-cells and amplify Th1 responses in the same way as the immunopotentiatory drug tucaresol.