Vector-Encoded Helicobacter pylori Neutrophil-Activating Protein Promotes Maturation of Dendritic Cells with Th1 Polarization and Improved Migration

Abstract

Helicobacter pylori neutrophil-activating protein (HP-NAP) is a major virulence factor involved in H. pylori infection. Both HP-NAP protein and oncolytic viruses encoding HP-NAP have been suggested as immunotherapeutic anticancer agents and adjuvants for vaccination but with little known about its mode of action to activate adaptive immunity. Dendritic cells (DCs) are key players in bridging innate and adaptive immune responses, and in this study we aim to evaluate the effect of HP-NAP on DC maturation, migration, and induction of adaptive immune response. Maturation markers CD83, CD80, CD86, HLA-DR, CD40, and CCR7 were upregulated on human DCs after treatment with supernatants from HP-NAP adenovirus–infected cells. HP-NAP–activated DCs had a Th1 cytokine secretion profile, with high IL-12 and relatively low IL-10 secretion, and migrated toward CCL19. Ag-specific T cells were efficiently expanded by Ag-presenting HP-NAP–activated DCs, which is an important property of functionally mature DCs. Furthermore, intradermal injections of HP-NAP–encoding adenovirus in C57BL/6 mice enhanced resident DC migration to draining lymph nodes, which was verified by imaging lymph nodes by two-photon microscopy and by phenotyping migrating cells by flow cytometry. In conclusion, therapeutic effects of HP-NAP are mediated by maturation of DCs and subsequent activation of Ag-specific T cells in addition to provoking innate immunity.

Immunization with HSV-2 gB-CCL19 Fusion Constructs Protects Mice against Lethal Vaginal Challenge

“…CCL19, through interactions with its cognate receptor CCR7, plays a pivotal role in recruiting immunocytes, including T cells (16), B cells (19,20), and mature dendritic cells (DCs) (21)(22)(23)(24)(25)(26), to secondary lymphoid organs, such as endothelial venules of lymph nodes and Peyer's patches, as well as the T cell zones of spleen and lymph nodes (18,19,21,(26)(27)(28)(29)(30). The CCL19-CCR7 pathway is also important in mediating lymphocyte colocalization and Ag-specific T cell activation (26), as well as in directing the differentiation of DCassisted B cells into Ab-secreting cells (ASCs) (16,31). CCL19 as a molecular adjuvant was proved to be useful in several immunization models and is capable of promoting Ag-specific humoral and cellular immune responses in combination with vaccine candidates, including HSV-1 gB (14), HIV-1 Env (16), pseudorabies virus gB (32), and HCV core DNA (30).…”

Characterization of the Murine Myeloid Precursor Cell Line MuMac-E8

“…Therefore, different culture conditions should be prepared and the phenotype of the arising cells with focus on markers that are able to discriminate between type 1 versus type 2 macrophages [51] , dendritic cells [52] , monocytic [53] versus granulocytic myeloid derived suppressor cells [54] should be determined. If distinct cell populations are obtained, it would be worthwhile to compare the functionality of these cells after stimulation and with regard to the inhibition of T cells.…”

Oral administration of recombinant Bacillus subtilis spores expressing Helicobacter pylori neutrophil‐activating protein suppresses peanut allergy via up‐regulation of Tregs

“…Neutrophil-activating protein (NAP) is a major virulence factor of Helicobacter pylori and has been identified as a potent toll-like receptor 2 (TLR2) agonist; TLR2 can promote the secretion of IL-12, IL-23, IFN-γ and tumour necrosis factor-α (TNF-α) from human neutrophils and monocytes. 4 In addition, NAP can suppress T helper 2 (Th2) responses by activating regulatory T cells (Tregs). 5 The Th2 cell-mediated immune response is critically important in the development of peanut allergies.…”