Yin et al. BMC Genomics 2010, 11:612 http://www.biomedcentral.com/1471-2164/11/612 the residence of LCs in the epidermis [24]. Such antigen encounter can result in down-regulation of E-cadherin that allows LC migration out of the skin [25]. The release of collagenase by DCs can facilitate their migra- tion through the basement membranes [26]. Our data show that the gene expressing E-cadherin was down- regulated in DCs at both 4 h and 12 h after treatment with [BF/S+L/Ep]. Genes encoding for the cell adhesion protein integrin alpha 6 (Itga6) and the cell signaling protein gap junction membrane channel protein a1 (Gja1) were down-regulated at 4 h and 12 h post treat- ment, respectively. Moreover, expression of specific col- lagenases and proteases, such as Mmp-8 (Table 2), Mmp-2, and Mmp-14, and the macrophage elastase Mmp-12 (data not shown in Table 2 and 3, due to rela- tively low level slightly lower than 2 fold in fold change) were appearently up-regulated after 12 h of treatment. Taking these results together, and in conjunction with the in vivo trafficking assay data (Figure 5), we suggest that [BF/S+L/Ep] phytoextract can confer a modulatory effect on cell mobility of mouse BMDCs. In future stu- dies it will be important and interesting to determine whether such an in vivo effect is also observed for human DCs, and thus for potential clinical application. In general, various major inflammatory and immuno- modulatory cytokines such as IL-1, TNF-a, IFNg, IL-4, IL-5, IL-6, IL-13, and IL-17, which are readily induced by injury or infection, are known to stimulate the produc- tion of a spectrum of different chemokines though med- iation via their respective receptors [27-29]. For instance, it is known that mice deficient in CCR2, the only known CCL2 receptor, have impaired Th1 responses [30], owing to a reduction of monocyte trafficking to the sites of inflammation [31]. In this study we show that a number of immune-related genes were up-regulated after 4 h and 12 h treatment of [BF/S+L/Ep]. These include genes encoding angiomotin (Amot), which is involved in cell movement and embryogenesis [32], chemokine (C-X-C motif) ligand 2 (Cxcl5), pro-platelet basic protein (Cxcl7), involved in chemokine activity and leukocyte transen- dothelial migration [33], immunoresponsive gene 1 (Irg1) and cytotoxic T-lymphocyte-associated protein 4 (Ctla4). These results suggest that [BF/S+L/Ep] may modify the chemotactic behavior of mouse DCs. Since some respon- sive chemokines such as CXCL5 and CXCL7, which we detected here in test DCs, are currently not well defined in terms of cellular function and biochemistry, further studies are needed to examine how [BF/S+L/Ep] can exert an effect on the secretion of these chemokines and to find out whether these chemokines do play a role in the chemoattraction and trafficking of treated DCs in the mouse system. On the other hand, our in vitro study did allow us to show that phenotypic expression of chemo- taxis-related receptor proteins, including CCR5 and Page 14 of 18 CCR7, can be significantly regulated in test mouse DCs treated with [BF/S+L/Ep] (Figure 6). Whether or not spe- cific chemotaxis-related receptors, such as CCR5, can mechanistically modulate the [BF/S+L/Ep]-enhanced DC mobility will also require further investigations. Unlike our previous findings on human DCs [9], [BF/S+L/Ep] treatment had a readily distinguishable and a slower level effect on the expression of immune-related genes in mouse BMDCs. These results again suggest, like the effects observed for cell surface marker proteins, the immunomodulatory effects of phytocompounds from Echinacea extracts apparently could also differ substan- tially between humans and mice. It is well known that DCs are the principal antigen presenting cells (APCs) for T-cell priming [34]. It is important to note, however, that DCs are also involved in the induction of central and peripheral tolerance [35]. One protein, called cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), is known as an immunomodulatory membrane molecule. By decreasing T-cell responsive- ness and raising the threshold for T-cell activation, CTLA-4 plays a critical role in the maintenance of per- ipheral T-cell tolerance [36,37]. Here, we found that the expression of Ctla4 was drastically up-regulated in DCs after 12 h of treatment with [BF/S+L/Ep]. Whether the CTLA-4 signaling system for DCs were also affected by our test phyto-compound and could in turn further affect T cell or other DC associated immunities would need to be further analyzed in future studies. In human DCs, we showed that [BF/S+L/Ep] can effect the expression of specific cytoskeleton proteins, including macrophage-capping protein, cofilin, profilin, F-actin capping protein b subunit, and laminin A/C [10]. In the present study using mouse DC cells, our 2D gel electro- phoretic analyses on DC proteins revealed that expression of several cytoskeleton-related proteins, such as alpha- actin-2 and F-actin capping protein alpha and macrophage capping protein, were also altered by [BF/S+L/Ep]. These results together suggest that Ep phytocompound extract modulates specific cytoskeleton functions, which are known to play a role in testing DCs to specific immune processes. A group of specific proteins, such as annexin A4, which can reversibly modify various membrane prop- erties (e.g., fluidity and permeability), anchoring of cytos- keletal elements, aggregation of vesicles, and the regulation of ion conductance [38], and peroxiredoxin 4, which exhibits thioredoxin-dependent peroxidase activity and regulates the activation of the transcription factor NF- B [39], were up-regulated in mouse DCs after treatment with [BF/S+L/Ep] (Figure 4B). These results suggest again that [BF/S+L/Ep] may affect the cell mobility and NF- B signaling of BMDCs. Moreover, expression of several cel- lular metabolism-related proteins, including vimentin, pro- liferin-1 precursor-1, -2, -3, phenylalanyl-tRNA synthetase,