Characterization of Haemonchus contortus Excretory/Secretory Antigen (ES-15) and Its Modulatory Functions on Goat Immune Cells In Vitro

Abstract

Small size excretory/secretory (ES) antigens of the Haemonchus contortus parasite have intense interest among researchers for understanding the molecular basis of helminths immune regulation in term of control strategies. Immunomodulatory roles of H. contortus ES-15 kDa (HcES-15) on host immune cells during host–parasite interactions are unknown. In this study, the HcES-15 gene was cloned and expression of recombinant protein (rHcES-15) was induced by isopropyl-ß-d-thiogalactopyranoside (IPTG). Binding activity of rHcES-15 to goat peripheral blood mononuclear cells (PBMCs) was confirmed by immunofluorescence assay (IFA) and immunohistochemical analysis showed that H. contortus 15 kDa protein localized in the outer and inner structure of the adult worm, clearly indicated as the parasite’s ES antigen. The immunoregulatory role on cytokines production, cell proliferation, cell migration, nitric oxide (NO) production, apoptosis, and phagocytosis were observed by co-incubation of rHcES-15 with goat PBMCs. The results showed that cytokines IL-4, IL-10, IL-17, the production of nitric oxide (NO), PBMCs apoptosis, and monocytes phagocytosis were all elevated after cells incubated with rHcES-15 at differential protein concentrations. We also found that IFN-γ, TGF-β1, cells proliferation and migration were significantly suppressed with the interaction of rHcES-15 protein. Our findings indicated that low molecular ES antigens of H. contortus possessed discrete immunoregulatory roles, which will help to understand the mechanisms involved in immune evasion by the parasite during host–parasite interactions.

Regulatory effects of a novel cysteine protease inhibitor in Baylisascaris schroederi migratory larvae on mice immune cells

“…NO is considered to be involved in most parasitic infections, mediating the host's non-specific defense by eliminating parasites or delaying parasite growth [ 45 – 48 ]. Consistent with previous studies [ 47 , 49 , 50 ], this study demonstrated that rBsCPI-1 significantly induces PBMCs to produce NO, which might promote the inflammatory response and pathogenesis during B. schroederi infection.…”

In vitro characterization of Haemonchus contortus trehalose-6-phosphate phosphatase and its immunomodulatory effects on peripheral blood mononuclear cells (PBMCs)

“…Previous studies have shown that various HcESP-derived protein molecules, such as rHcMTF-12 [ 54 ], rHCRD [ 37 ], rHc-GDC [ 40 ], rHcEF-1α [ 46 ], rHcES-15 [ 34 ], rMiro-1 [ 55 ], HCcyst-3 [ 56 ] and RHC-AK [ 57 ], can bind to PBMCs in vitro and regulate cellular immune function. Our studies showed that rHcGOB can bind to goat PBMCs and activate the IL-10/TGF-β/STAT3 pathway in PBMCs in vitro.…”

“…Adult H. contortus worms were obtained as previously described [ 33 ]. Total RNA was extracted from adult worms by the TRIzol reagent (Invitrogen, Carlsbad, CA, USA) method [ 34 ]. The complementary DNA (cDNA) was synthesized by HiScript III Kit (Vazyme, Nanjing, China) according to the manufacturer’s instructions.…”

The GT1-TPS Structural Domain Protein From Haemonchus contortus Could Be Suppressive Antigen of Goat PBMCs

“…H. contortus complementary DNA (cDNA) was synthesized as previously described ( 28 ). The 160–702-aa region of the glycosyltransferase domain-containing protein (GenBank: HF965754.1) is the 6-phosphorylase synthase structural domain (Hc-TPS).…”