Galectin Hco-gal-m from Haemonchus contortus modulates goat monocytes and T cell function in different patterns

Abstract

BackgroundMonocytes and T cells are two major subpopulations of peripheral blood mononuclear cells (PBMC) and play an essential role in the innate and adaptive immune systems. Different members of the galectin family show multiple and distinct regulatory effects on different cell types. Previous studies have demonstrated that the galectin from Haemonchus contortus (Hco-gal-m) performed immunomodulatory effects on goat PBMC, however, which subpopulation of PBMC is the primary target of Hco-gal-m and whether the immune modulations share the same mechanism remain unclear.MethodsIn this study, the developmental expression of Hco-gal-m was analyzed by RT-PCR and Western blot analysis. The distribution of Hco-gal-m in adult worm was detected by an immunohistochemical test. The binding activity of the recombinant Hco-gal-m (rHco-gal-m) on goat monocytes and T cells were assessed by flow cytometry. The immunomodulatory effects of Hco-gal-m on cytokine secretion, cell activation and apoptosis were observed by co-incubation of rHco-gal-m with goat monocytes and T cells.ResultsHco-gal-m was expressed in L4 as well as adult worms and predominantly localized at the internal surface of the worm guts. rHco-gal-m could bind to both monocytes and T cells. The engagement of rHco-gal-m decreased the production of IL-6, IL-10 and TNF-α in T cells, however, it significantly increased the secretion of IL-10 in monocytes. After rHco-gal-m exposure, the expression of MHC-II on monocytes and that of CD25 on T cells were restricted. Consequently, T cell proliferations were potently inhibited by rHco-gal-m. In addition, rHco-gal-m induced apoptosis in T cells, but not significantly in monocytes.ConclusionsOur results indicated that rHco-gal-m modulated goat monocytes and T cell function in different patterns.Electronic supplementary materialThe online version of this article (doi:10.1186/1756-3305-7-342) contains supplementary material, which is available to authorized users.

Haemonchus contortusexcretory and secretory proteins (HcESPs) suppress functions of goat PBMCsin vitro

“…In our previous studies, we found that recombinant galectin of male and female adult H. contortus displayed different effects on the T cells and monocytes [10, 41]. Thus, it was suspected that the ESPs from males and females also had different functions However, in the natural infection of this worm the ESPs from males and females were secreted and functioned simultaneously.…”

“…Cell proliferation assay was performed as described previously [10]. Briefly, PBMCs (1 × 10 6 cells/ml) were activated with ConA (10 μg/ml) and incubated at the same time with a serial concentrations of HcESPs (5, 10, 20, and 40μg/ml) and an equal volume of PBS as control at 37°C in 5% CO 2 incubator for 72 h. CCK-8 solutions (Beyotime Biotechnology, China) were added to each well of the plates 4 h before harvesting the cells and the absorbance values at 450 nm (OD 450 ) were measured using a microplate reader (Thermo Scientific, USA).…”

“…The purified 66-kDa adult H. contortus excretory/secretory (E/S) antigen was confirmed to suppress monocyte function in vitro by decreasing the production of hydrogen peroxide and nitric oxide in the culture medium of the cells [3]. Recently, it was reported that recombinant H. contortus galectin (rHco-gal-m) inhibited the expression of MHC II molecules, decreased the T cell activation and proliferation, induced apoptosis of T cells and effected several signaling cascades in vitro [10]. In vitro studies also showed that ESPs had direct effects on cultured cells or tissues, such as inhibiting acid secretion [19] and inducing the vacuolation and detachment of HeLa cells [20, 21].…”

How do the macrocyclic lactones kill filarial nematode larvae?

“…El-Sadr et al (1983) showed that canine neutrophils and PBMCs would adhere to, and the neutrophils could kill, D. immitis Mf with the help of IgM from occultly infected animal serum. Parasitic nematodes, including the filaria, secrete a cocktail of immunomodulatory proteins, metabolites and microRNAs which have significant effects on the host immune system (Ashour 2013; Harnett 2014; Harnett and Harnett 2006; Hoerauf et al 2005; McSorley et al 2013; Pineda et al 2014; Wang et al 2014; Buck et al 2014), so it is an obvious speculation that they act to inhibit granulocyte and PBMC binding and antibody-dependent killing of Mf in the infected animal. Another important drug used in the LF elimination programme, diethylcarbamizine (DEC), is believed to exert its anthelmintic effects via activation of the host immune system (Maizels and Denham 1992; Vickery et al 1985), which is consistent with its limited direct effects on nematodes in vitro (Alves et al 2005; Court et al 1986; Gunawardena et al 2005).…”

Y75B8A.8 (HC8) protein of Haemonchus contortus: A functional inhibitor of host IL‐2

“…The H contortus strain was maintained in the Laboratory of Veterinary Parasitology, Nanjing Agricultural University. H contortus adults were collected as previously described …”