Characterization of a rhodanese homologue from Haemonchus contortus and its immune-modulatory effects on goat immune cells in vitro

Abstract

Background Modulation of the host immune response by nematode parasites has been widely reported. Rhodaneses (thiosulfate: cyanide sulfurtransferases) are present in a wide range of organisms, such as archaea, bacteria, fungi, plants and animals. Previously, it was reported that a rhodanese homologue could be bound by goat peripheral blood mononuclear cells (PBMCs) in vivo. Methods In the present study, we cloned and produced a recombinant rhodanese protein originating from Haemonchus contortus (rHCRD), a parasitic nematode of small ruminants. rHCRD was co-incubated with goat PBMCs to assess its immunomodulatory effects on proliferation, apoptosis and cytokine secretion. Results We verified that the natural HCRD protein localized predominantly to the bowel wall and body surface of the parasite. We further demonstrated that serum produced by goats artificially infected with H. contortus successfully recognized rHCRD, which bound to goat PBMCs. rHCRD suppressed proliferation of goat PBMCs stimulated by concanavalin A but did not induce apoptosis in goat PBMCs. The production of TNF-α and IFN-γ decreased significantly, whereas secretion of IL-10 and TGF-β1 increased, in goat PBMCs after exposure to rHCRD. rHCRD also inhibited phagocytosis by goat monocytes. Moreover, rHCRD downregulated the expression of major histocompatibility complex (MHC)-II on goat monocytes in a dose-dependent manner, but did not alter MHC-I expression. Conclusions These results propose a possible immunomodulatory target that may help illuminate the interactions between parasites and their hosts at the molecular level and reveal innovative protein species as candidate drug and vaccine targets.

Protein interactions network of goat innate immune signalling pathway proteins and Haemonchus contortus excretory‐secretory proteins

“…Besides, we also identified 5 H. contortus ESPs that interact with goat prey proteins with the highest frequency, including the chitin‐binding protein domain containing protein HCON_00008300 and rhodanese domain containing protein HCON_00106270. Previous studies found that a rhodanese homologue could be bound by goat PBMCs and suppress cell proliferation 73 . The 15 kDa protein HCON_00154030 also has more interactions with goat prey proteins.…”

“…Previous studies found that a rhodanese homologue could be bound by goat PBMCs and suppress cell proliferation. 73 The 15 kDa protein HCON_00154030 also has more interactions with goat prey proteins. The H. contortus 15 kDa proteins are low molecular weight antigens, which can significantly suppress goat PBMCs proliferation and migration.…”

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.…”

“…The rHcGOB protein was purified and expressed as previously described [ 36 , 37 ]. The recombinant plasmid [pET28a(+) ligated with GOB] was transformed into Escherichia coli BL21(DE3) and cultured into Luria–Bertani medium containing kanamycin at 37 °C.…”

Fasciola gigantica tegumental calcium-binding EF-hand protein 4 exerts immunomodulatory effects on goat monocytes

“…Major histocompatibility complex (MHC) molecule expression analysis was performed as previously described [ 35 ]. Freshly isolated monocytes (1 × 10 5 cells/ml per well) were seeded in 24-well cell culture plates containing complete RPMI 1640 medium.…”