Proteomic profiling reveals that Th2-inducing dendritic cells stimulated with helminth antigens have a 'limited maturation' phenotype.

Dendritic cells (DCs) are important in the initiation of primary immune responses against pathogens. To aid understanding of how DCs guide T helper (Th)2-type responses, we employed 2-DE in association with MS/MS to identify proteins which characterise pro-Th2 DCs (matured with zero-to-three hours released proteins (0-3hRP), released by Schistosoma mansoni cercariae) versus pro-Th1 DCs (matured with lipopolysaccharide, LPS) and immature DCs. Software analysis of average 2-DE gels (three replicates per DC type) showed many similarities in the pattern of spots between the three groups of DCs but also marked changes. The major and significant changes in protein expression mainly affected cytoskeletal proteins. Other differences included chaperone proteins and enzymes involved in protein folding, S100 calcium-binding proteins, peroxiredoxin 1, superoxide dismutase 1, several annexins and arginase 1. Our study demonstrates that pro-Th2 DCs matured with 0-3hRP exhibit a proteome that is intermediate between that of immature DCs and pro-Th1 DCs. Finally, the differential regulation of protein spots identified by MALDI-MS/MS as having cytoskeletal and morphological functions was confirmed by contrast, confocal and scanning electron microscopy examination of DCs. Together, our results support the view that Th2 differentiation results from a 'limited maturation' of DCs.