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Background: Allergic dermatitis (AD) is an inflammatory skin disease that arises from abnormal T lymphocyte activation. A recombinant fusion protein comprising Helicobacter pylori neutrophil-activating protein and maltose binding protein, rMBP-NAP, has been documented as a novel immunomodulatory TLR agonist.Objective: To explore the effect of the rMBP-NAP on the OXA-induced AD in a mouse model and clarify the possible action mechanism.Methods: The AD animal model was induced by repeated administration of oxazolone (OXA) in BALB/c mice. H&E staining was used to analyze the ear epidermis thickness and the number of infiltrating inflammatory cells. TB staining was used to detect mast cell infiltration in the ear tissue. ELISA was used to analyze the secretion of cytokines IL-4 and IFN-γ in peripheral blood. qRT-PCR was used to determine the expression levels of IL-4, IFN-γ, and IL-13 in ear tissue.Results: OXA induced the establishment of an AD model. After the rMBP-NAP treatment, the thickness of the ear tissue and the number of mast cells infiltrated in AD mice reduced, and the serum and ear tissue levels of IL-4 and IFN-γ increased, but the ratio of IFN-γ (rMBP-NAP group)/IL-4 (rMBP-NAP group) was greater than the ratio of IFN-γ (sensitized group)/IL-4 (sensitized group).Conclusion: The rMBP-NAP improved the disease symptoms including skin lesions in AD, alleviated the inflammation in ear tissue, and restored the Th1/2 balance by inducing a shift from the Th2 to the Th1 response. The results of our work support the use of rMBP-NAP as an immunomodulator for AD treatment in future investigations.

Background: Melanoma is a common and malignant cutaneous tumor, which is responsible for a large proportion of skin cancer deaths. Dendritic cell (DC)-based vaccines have achieved positive results in the treatment of melanoma because of their ability to induce cytotoxic response to facilitate tumor elimination. Objective: To improve the efficacy of dendritic cell-based vaccines by the adjuvant activity of Helicobacter pylori neutrophil activating protein (HP-NAP), which is a virulence factor of Helicobacter pylori, has been proved as a TLR agonist with effective immunomodulatory activity. Methods: The recombinant HP-NAP (rHP-NAP) was expressed by using prokaryotic expression system. Dendritic cells (DCs) were cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4. After treating with rHP-NAP, the maturation of DCs and dendritic cell-based vaccine were assayed by using flow cytometry and qRT-PCR. The activation and proliferation of T cells were measured by FCM, ELISA and MTT methods. The tumor specific cytotoxic response to resistant B16F10 was detected by using lactate dehydrogenase-release assay and qRT-PCR. Results: The recombinant HP-NAP (rHP-NAP), prepared from E. coli prokaryotic expression system, was able to significantly promote the maturation of dendritic cell-based vaccine loaded with tumor cell lysate (TCL) of B16F10 (DC-B16F10-TCL). Furthermore, it effectively induced the activation and proliferation of T cells and tumor specific cytotoxic response to resistant B16F10 melanoma tumor cells. Conclusion: These results suggested that rHP-NAP possesses the potential for use as an adjuvant of dendritic cell-based vaccine in anti-melanoma treatment.