Induction of tolerogenic properties by Anisakis larval antigens on murine dendritic cells

Abstract

Summary Aims The objective of this work is to investigate whether Anisakis simplex larval antigens present immunomodulatory properties by the induction of tolerogenic dendritic cells (DCs) from two strains of mice (BALB/c and C57BL/6J). Methods and Results We used mouse bone marrow‐derived DCs. We determined their antigen‐presenting ability by expression of membrane markers (MHC I and MHC II, CD80, CD86) and intracellular expression levels of IL‐10 and IL‐12 cytokines. We also analysed whether stimulation with A simplex larval antigens is enhanced by the co‐administration of the TLR4 and TLR9 agonists [LPS E coli 026B6 and CpG (ODN1826), respectively]. Two differential types of responses were found in the two mouse strains studied: the BALB/c strain showed an acute and inflammatory response, whereas the C57BL/6J mice developed a more discrete and resistant response. This suggests the coexistence of two opposing responses generated by A simplex larval antigens and confirms that the host genetic basis plays a role in the development of a Th2 or Treg response. Conclusion The study of the mechanisms by which Anisakis manipulates the immune response through anti‐inflammatory molecules is of interest not only for the direct application on the development of anthelmintic strategies, but also for the development of new anti‐inflammatory products.

Comparative Transcriptomics Reveals Clues for Differences in Pathogenicity between Hysterothylacium aduncum, Anisakis simplex sensu stricto and Anisakis pegreffii

“…Anisakidosis is an emerging fish-borne zoonosis of major public health concern and despite the increasing concern on the impact of the disease, which is thought to be largely underestimated; our current understanding of the mechanisms of infection and clinical disease in humans is limited. Recently, some attempts have been made to clarify some aspect of infection using in-vivo tests with animal models [19] or to explore human immune responses using in-vitro systems [33], suggesting a general strong induction of immune reaction. However, studies on comparison of pathogenic anisakid species versus phylogenetically related non-pathogenic nematodes were thus far unavailable.…”

“…The draft genome sequence was available for A. simplex [23,32] and we assumed that was related to the species A. simplex sensu stricto. Raw reads generated for the three taxa HA, AS and AP were mapped to the existing genome assembly sequences [23,33]. The highest percentages of mapping were obtained for transcriptomes belonging to the same genus.…”

Expansion of T regulatory lymphocytes by murine bone marrow dendritic cells previously stimulated with Anisakis simplex larval antigens

“…In our previous work, we demonstrated that even though murine DCs stimulated in vitro with A. simplex larval antigens did not reach a complete activated phenotype, they showed ability to present antigens to T cells and cause polarization. (1) Likewise, Napoletano et al observed that Anisakis pegreffii generated human DCs with an impaired phenotype as demonstrated by low expression of HLAII-DR and CD86 costimulatory molecules. (9) In this work, co-cultivation of mouse splenocytes with DCs previously stimulated with A. simplex larval antigens caused the expansion of T regs .…”

“…(8) Different stimuli were employed: ES (0.012 µg/mL) or CE (50 µg/mL) for 24 hours (CO 2 5%, 37ºC). (1) A control of DCs cultured in medium without antigens was included in all the experiments. All experiments were performed in triplicate wells for each condition and repeated at least three times.…”

“…In a previous work, immunomodulatory properties of Anisakis simplex larval antigens were demonstrated by the induction of tolerogenic dendritic cells (DCs) in two strains of mice (C57BL/6J and BALB/c). (1) DC's antigen-presenting ability was determined by measuring the expression of membrane markers (MHC I and MHC II, CD80, CD86) and intracellular expression levels of IL-10 and IL-12 cytokines. It was also analyzed whether stimulation with A. simplex larval antigens was enhanced by the co-administration of TLR4 and TLR9 agonists [LPS Escherichia coli 026B6 and CpG (ODN1826), respectively].…”