Targeting of the hNC16A collagen domain to dendritic cells induces tolerance to human type XVII collagen

Abstract

as palmitic acid, palmitoleic acid and stearic acid, and unsaturated fatty acids, such as oleic acid induced HMel differentiation in vitro and a-MSH increases SZ95 sebocytes intra-Ca 2+ level, which could be an additional indirect mechanism of action on HMel (22,23). In contrast to proliferation studies, high Ca 2+ SZ95 sebocytes resulted in a significant decrease in melanin when compared with low Ca 2+ SZ95 sebocytes, possibly because of pigment dilution and or excessive consumption of melanin precursors by proliferating cells. As previously mentioned, HK extracellular matrix proteins induced HMel proliferation without effect on melanisation; and so could be SZ95 sebocytes in high Ca 2+ level cultures (21). It is also possible that the absence of serum and other supplements may be responsible for these results. Although further studies are needed to clearly define sebocytederived HMel growth factor(s) and their effects on melanin synthesis, the present study denotes that sebocytes exert major paracrine effects on epidermal HMel, which may contribute to constitutive and facultative skin colour. AcknowledgementsPlease refer to Data S1 Acknowledgements. Conflicts of InterestsThe authors have declared no conflicting interests. Supporting informationAdditional Supporting Information may be found in the online version of this article: Data S1. Methods. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. Abstract: Antibodies, specific to murine DEC205, can be used to target antigens to dendritic cells. The immunodominant domain of human type XVII collagen, hNC16A, was fused to this antibody (DEC-hNC16A) and was administered as expression plasmid by gene gun transfection with the aim of inducing tolerance to human type XVII collagen in a skin transplantation model. Mice transfected with DEC-hNC16A were challenged with skin grafts from transgenic mice engineered to express human type XVII collagen. Graft survival was either prolonged or grafts were accepted infinitely (33% and 16%, respectively) upon treatment with DEC-hNC16A while 100% of grafts were rejected in untreated controls. Graft acceptance was associated 395with the absence of a CD4+ infiltrate and a dense CD8+ T-cell infiltrate and was not strictly dependent on antibody production. Our results show that DEC-hNC16A targets dendritic cells in vivo leading to prolonged survival of transgenic skin grafts. This indicates that DEC205-targeting may be used for the induction of tolerance to skin antigens, which would increase the chances of successful skin gene therapy of epidermolysis bullosa patients.

DNA vaccines encoding DEC205‐targeted antigens: immunity or tolerance?

“…Although Ettinger et al did not include a control scFV in their study, their results support our hypothesis, because gene gun immunizations with DNA encoding DEC-hNC16A could induce peripheral tolerance and improved the graft-acceptance after transplantation. 40 Hence, the effect of DC-targeting has to be carefully evaluated for each antigen and in the appropriate disease model.…”

“…Despite the application of similar protocols including in vivo electroporation, two groups showed an enhanced efficacy of the vaccine whereas Ettinger et al . reported on the induction of antigen‐specific tolerance in mice . In our previous experiment, in rhesus macaques, DEC205‐targeting of the encoded antigen also had a negative effect on the immunogenicity of simian immunodeficiency virus‐specific DNA vaccines …”

Anatomical distribution analysis reveals lack of Langerin+ dermal dendritic cells in footpads and tail of C57BL/6 mice

“…This may shed light on the frequencies of site-specific dermatitis or tumor formation in diverse genetic backgrounds. Finally, our results suggest new means to target specific DC subsets to manipulate the outcome of immunisation (27,28). Asterisks (*) indicate a significant difference between a given strain and C57BL/6 mice.…”

Dendritic Cells As Inducers of Peripheral Tolerance

“…Finally, targeted delivery of proteoglycan (PG) to DEC205 + DCs prevented the subsequent induction of a PG-induced arthritis [114]. In addition to the models of autoimmunity, targeting DEC205 + DCs with the immunodominant domain of human type XVII collagen prolonged the survival of skin grafts in a skin transplantation model [115]. …”