Protection studies of an excretory-secretory protein HcABHD against Haemonchus contortus infection

Unlike the successful immunization of native H. contortus antigens that contributed to the realization of the first commercial vaccine Barbervax, not many studies revealed the encouraging protective efficacies of recombinant H. contortus antigens in laboratory trials or under field conditions. In our preliminary study, H. contortus α/β-hydrolase domain protein (HcABHD) was demonstrated to be an immunomodulatory excretory-secretory (ES) protein that interacts with goat T cells. We herein evaluated the protective capacities of two HcABHD preparations, recombinant HcABHD (rHcABHD) antigen and anti-rHcABHD IgG, against H. contortus challenge via active and passive immunization trials, respectively. Parasitological parameter, antibody responses, hematological pathology and cytokine profiling in unchallenged and challenged goats were monitored and determined throughout both trials. Subcutaneous administration of rHcABHD with Freund adjuvants elicited protective immune responses in challenged goats, diminishing cumulative fecal egg counts (FEC) and total worm burden by 54.0% and 74.2%, respectively, whereas passive immunization with anti-rHcABHD IgG conferred substantial protection to challenged goats by generating a 51.5% reduction of cumulative FEC and a 73.8% reduction of total worm burden. Additionally, comparable changes of mucosal IgA levels, circulating IgG levels, hemoglobin levels, and serum interleukin (IL)-4 and IL-17A levels were observed in rHcABHD protein/anti-rHcABHD IgG immunized goats in both trials. Taken together, the recombinant version of HcABHD might have further application under field conditions in protecting goats against H. contortus infection, and the integrated immunological pipeline of ES antigen identification, screening and characterization may provide new clues for further development of recombinant subunit vaccines to control H. contortus.

Hollow Carbon-Based Nanoarchitectures Based on ZIF: Inward/Outward Contraction Mechanism and Beyond

Hollow carbon-based nanoarchitectures (HCAs) derived from zeolitic imidazolate frameworks (ZIFs), by virtue of their controllable morphology and dimension, high specific surface area and nitrogen content, richness of metal/metal compounds active sites, and hierarchical pore structure and easy exposure of active sites, have attracted great interests in many fields of applications, especially in heterogeneous catalysis, and electrochemical energy storage and conversion. Despite various approaches that have been developed to prepare ZIF-derived HCAs, the hollowing mechanism has not been clearly disclosed. Herein, a specialized overview of the recent progress of ZIF-derived HCAs is introduced to provide an insight into their preparation strategy and the corresponding hollowing mechanisms. Based on the fundamental understanding of the structural evolution of ZIF nanocrystals during the high-temperature pyrolysis process, the hollowing mechanisms of ZIF-derived HCAs are classified into four categories: i) inward contraction of core-shell template@ZIF composites or hollow ZIFs, ii) outward contraction of ZIF@shell composites, iii) special outward contraction of ZIF arrays, and iv) mechanism beyond inward/outward contraction of pure ZIF nanocrystals. Finally, an outlook on the development prospects and challenges of HCAs based on ZIF precursors, especially in terms of controlled synthesis and future electrochemical application, is further discussed.

Modulation Effects of Toxoplasma gondii Histone H2A1 on Murine Macrophages and Encapsulation with Polymer as a Vaccine Candidate

Toxoplasma gondii (T. gondii) is the most common zoonotic protozoa and has infected about one-third of the population worldwide. Recombinant epitopes encapsulated in nanospheres have advantages over traditional T. gondii vaccines. For an efficient delivery system, poly (DL-lactide-co-glycolide) (PLGA) and chitosan are the most frequently used biodegradable polymeric nanospheres with strong safety profiles. In the present study, we first expressed and purified histone H2A1 of T. gondii using the prokaryotic expression system. The effects of recombinant TgH2A1 on the functions of murine macrophages were then studied. Purified recombinant TgH2A1 was then encapsulated in nanospheres with PLGA and chitosan. After subcutaneous vaccination in mice, the immune response was evaluated by double antibody sandwich ELISA kits. The results from this study showed that PLGA and chitosan loaded with rTgH2A1 could trigger a stronger Th1 oriented immune response and prolong the survival time of mice effectively. In conclusion, PLGA and chitosan nanospheres loaded with histone H2A1 are an effective method for the development of vaccines against T. gondii. Further studies should focus on evaluating the regulatory mechanism of TgH2A1, vaccine potency, and cellular response in chronic T. gondii infections.

Nanoparticles (PLGA and Chitosan)-Entrapped ADP-Ribosylation Factor 1 of Haemonchus contortus Enhances the Immune Responses in ICR Mice

ADP-ribosylation factor 1 (HcARF1) is one of the Haemonchus contortus (H. contortus) excretory/secretory proteins involved in modulating the immune response of goat peripheral blood mononuclear cells (PBMC). Here, we evaluated the immunogenic potential of recombinant HcARF1 (rHcARF1) against H. contortus infection in Institute of Cancer Research (ICR) mice. Briefly, rHcARF1 was entrapped in poly (D, L-lactide-co-glycolide) (PLGA) and chitosan (CS) nanoparticles (NP) and injected into mice as a vaccine. Fifty-six ICR mice were assigned randomly into seven groups, with eight animals in each group, and they were vaccinated subcutaneously. At the end of the experiment (14th day), the blood and the spleen were collected from euthanized mice to detect lymphocyte proliferation, cytokine analysis, and the production of antigen-specific antibodies. Scanning electron microscope was used to determine the size, morphology, and zeta potential of nanoparticles. Flow cytometry was performed, which presented the increase percentages of CD4+ T cells (CD3e+CD4+), CD8+ T cells (CD3e+CD8+) and dendritic cells (CD11c+CD83+, CD11c+CD86+) in mice vaccinated with rHcARF1+PLGA NP. Immunoassay analysis show raised humoral (Immunoglobulin (Ig)G1, IgG2a, IgM) and cell-mediated immune response (Interleukin (IL)-4, IL-12, and IL-17, and Interferon (IFN)-γ) induced by rHcARF1+PLGA NP. Experimental groups that were treated with the antigen-loaded NP yield higher lymphocyte proliferation than the control groups. Based on these results, we could propose that the rHcARF1 encapsulated in NP could stimulate a strong immune response in mice rather than administering alone against the infection of H. contortus.

Unveiling the Immunomodulatory Characteristics of Haemonchus contortus Ephrin Domain Containing Protein in the Parasite-Host Interactions

Simple Summary

Haemonchus contortus excretory/secretory products (HcESPs) contain many proteins that can perform various functions including modulating the host immune response. Recent studies indicate that IL-9 can be secreted by a specialized population of T cells called Th9 cells, which mediate anti-parasite immunity. Furthermore, HcESPs could enhance goat peripheral blood mononuclear cells (PBMCs) derived Th9 cells production. Ephrin domain containing protein (EPH) was identified as one of the HcESPs that can be isolated from different stages of this helminth. Nonetheless, the understanding of immunomodulatory roles of EPH on Th9 and other immune cells remains limited. In this study, the correlation between recombinant H. contortus Ephrin domain containing protein(rHcEPH)and goat PBMCs significantly enhanced Th9 cells differentiation, IL-9 expression, cell apoptosis efficiency, and cell migration, whereas cell proliferation was suppressed significantly depending on the concentration. Our findings illustrated that rHcEPH protein is linked to modulate the host immune cells and could enhance protective immunity by inducing Th9 cells secreted IL-9 in vitro.

Abstract

Ephrin domain containing protein (EPH), a significant excreted and secreted product (ESPs) of Haemonchus contortus, has been identified to have antigenic functions. Over the past years, a new subset of CD4 + T named as T helper 9 cells that secrete interleukin-9 (IL-9) as a signature cytokine is associated with tumor immunity and allergy. Nonetheless, the understanding of immunomodulatory roles of EPH on goat Th9 and other immune cells remains limited. Herein, EPH from H. contortus (HcEPH) was cloned and expressed in pET-28a. Immunofluorescence assay (IFA) was carried-out to localize rHcEPH within H. contortus adult worms and to bind with goat peripheral blood mononuclear cells (PBMCs). Besides, the impact of rHcEPH on signature cytokine IL-9 expression in goat PBMCs was evaluated. Flow cytometry was employed to examine Th9 cells production and cell apoptosis. The results revealed success in the expression and localization of rHcEPH in surface of adult H. contortus gut sections. According to IFA analysis, the rHcEPH protein was capable to react precisely with anti-H. contortus antibodies. Further functional analysis showed that correlation between rHcEPH and host PBMCs significantly enhanced Th9 cell differentiation, IL-9 expression, cell apoptosis efficiency, and cell migration, whereas cell proliferation was suppressed significantly depending on the concentration. Our observations indicated that rHcEPH protein is linked to modulate the host immune cells and could enhance protective immunity by inducing Th9 responses.

In vitro effects of 5 recombinant antigens of Eimeria maxima on maturation, differentiation, and immunogenic functions of dendritic cells derived from chicken spleen

Eimeria maxima possesses integral families of immunogenic constituents that promote differentiation of immune cells during host-parasite interactions. Dendritic cells (DCs) have an irreplaceable role in the modulation of the host immunity. However, the selection of superlative antigen with immune stimulatory efficacies on host DCs is lacking. In this study, 5 recombinant proteins of E. maxima (Em), including Em14-3-3, rhomboid family domain containing proteins (ROM) EmROM1 and EmROM2, microneme protein 2 (EmMIC2), and Em8 were identified to stimulate chicken splenic derived DCs in vitro. The cultured populations were incubated with recombinant proteins, and typical morphologies of stimulated DCs were obtained. DC-associated markers major histocompatibility complex class II, CD86, CD11c, and CD1.1, showed upregulatory expressions by flow cytometry assay. Immunofluorescence assay revealed that recombinant proteins could bind with the surface of chicken splenic derived DCs. Moreover, quantitative real-time PCR results showed that distinct gene expressions of Toll-like receptors and Wnt signaling pathway were upregulated after the coincubation of recombinant proteins with DCs. The ELISA results indicated that the DCs produced a significant higher level of interleukin (IL)-12 and interferon-γ secretions after incubation with recombinant proteins. While transforming growth factor-β was significantly increased with rEmROM1, rEmROM2, and rEmMIC2 as compared to control groups, and IL-10 did not show significant alteration. Taken together, these results concluded that among 5 potential recombinant antigens, rEm14-3-3 could promote immunogenic functions of chicken splenic derived DCs more efficiently, which might represent an effective molecule for inducing the host Th1-mediated immune response against Eimeria infection.

Advances in the Development of Anti-Haemonchus contortus Vaccines: Challenges, Opportunities, and Perspectives

The gastrointestinal nematode parasite Haemonchus contortus (H. contortus) is a resident of tropical and subtropical regions worldwide that imposes significant production losses, economic losses, and animal health issues in the small ruminant industry, particularly sheep and goats. Considerable efforts have been made to understand how immunity is elicited against H. contortus infection. Various potential vaccine antigens have been tested by different methods and strategies applied in animal models, and significant progress has been made in the development of vaccines against H. contortus. This review highlighted and shared the knowledge about the current understanding of host immune responses to H. contortus and ongoing challenges in the development of a protective, effective, and long-lasting vaccine against H. contortus infection. We have also pinpointed some achievements and failures in the development and testing of vaccines, which will establish a road map for future research directions to explore new effective vaccine candidates for controlling and preventing H. contortus infection.

Lycopene protects myocardial ischemia injury through anti-apoptosis and anti-oxidative stress

OBJECTIVE

The aim of this research was to explore the protective effect of lycopene (Lyc) on myocardial ischemia injury through anti-apoptosis and anti-oxidative stress.

MATERIALS AND METHODS

75 rats were divided into 5 groups: sham operation group (control group), model group, low-dose group (Lyc+2 mg/kg), medium-dose group (Lyc+4 mg/kg) and high-dose group (Lyc+6 mg/kg). The rat model of myocardial ischemia was established by a subcutaneous injection of isoproterenol (85 mg/kg) for two consecutive days. Conventional HE staining and Masson staining were performed for pathological changes. Biochemical indicators were measured by the enzyme-linked immuno sorbent assay (ELISA). Western blotting was used to measure the levels of related proteins in JNK/STAT signaling pathway.

RESULTS

Compared to control group, the levels of CK-MB, TC, and TGs were significantly increased in model group. The levels of CK-MB, TC, and TGs in each Lyc-administered group were decreased. After Lyc was administered, the SOD, CAT, GSH-Px activities and MDA content were all restored. The serum levels of IL-1β, TNF-α and IL-6 in control group were significantly lower than in model group. When the Lyc was administered, the serum IL-1β, TNF-α and IL-6 levels in medium-dose group and high-dose group were significantly decreased. The levels of Bax/Bcl-2, Cyt-c, and Caspase-3 in model group were significantly higher than control group. Changes of Bax/Bcl-2, Cyt-c, and Caspase-3 in medium-dose and high-dose groups after the administration of Lyc were restored significantly. The levels of p-JNK/JNK, p-STAT1 (Tyr701)/STAT1, p-STAT1 (Ser727)/STAT1, p-STAT3 (Tyr705)/STAT3 were significantly increased, while p-STAT3 (Ser727)/STAT3 was significantly decreased. When Lyc was administered, the expression levels of p-JAK/JAK, p-STAT1 (Tyr701)/STAT1, p-STAT1 (Ser727)/STAT1, p-STAT3 (Tyr705)/STAT3 protein in medium-dose group and high-dose group were significantly decreased, and the expression level of p-STAT3 (Ser727)/STAT3 protein was significantly increased.

CONCLUSIONS

Lyc could show a protective effect on oxidative stress injury and anti-cardiomyocyte apoptosis of myocardial ischemia, and its possible mechanism was to attenuate the activation of JNK/ERK signaling pathway induced by myocardial injury.

HcFAR, a functional inhibitor of goat TGF-β1 identified from excretory and secretory products of Haemonchus contortus

Haemonchus contortus has developed complexed and multifaceted mechanisms of immune evasion to enable the survival in the host. Generating excretion and secretion products (ESPs) to subvert or suppress the functions of host cytokines is a newly immune regulatory pattern found during recent years. Transforming growth factor-β (TGF-β) has critical immune regulatory functions in nematode infections. In this study, co-immunoprecipitation (co-IP) assay was used to identify the goat TGF-β1 binding proteins from HcESPs. The interaction between TGF-β1 and nematode fatty acid retinoid binding domain containing protein of H. contortus (HcFAR) was analyzed by glutathione S-transferase (GST)-pull down assay. The suppressive effect of rHcFAR on TGF-β1-induced immunoglobulin A (IgA) secretion was observed by co-incubation of rHcFAR and TGF-β1 with goat peripheral blood mononuclear cells (PBMCs). The IgA concentrations were determined using enzyme linked immunosorbent assay (ELISA) kit. Meanwhile, the suppressive effect of rHcFAR on TGF-β1-induced T helper (Th) 9 differentiation was investigated by co-incubation of rHcFAR, TGF-β1 and interleukin (IL)-4 with goats PBMCs. In parallel, IL-4 was replaced by IL-6 to determine the effects on the Th17 differentiation. The transcriptions of IL-9 and IL-17 in PBMCs were then evaluated by real-time PCR. Finally, we found that HcFAR from HcESPs could bind to goat TGF-β1 in vitro. The ELISA results of IgA showed that 40 μg/mL rHcFAR could suppress the IgA secretion of PBMCs induced by TGF-β1. Additionally, rHcFAR (at 10 μg/mL and 20 μg/mL) could inhibit the mRNA transcription of IL-9 induced by TGF-β1 and IL-4. Meanwhile, rHcFAR could also downregulate the transcription of IL-17 induced by TGF-β1 and IL-6 in a dose-dependent manner. These results indicated that HcFAR was a functional inhibitor of goat TGF-β1 and this information may help contribute to understanding of the relationship between the ESPs and host cytokines.

Isolation and characterization of endophytic bacteria for controlling root rot disease of Chinese jujube

AIM

Fusarium oxysporum is the primary pathogen causing root rot disease that severely affects cultivation of jujube fruit in the Xinjiang province of China. The aim of this study was to identify endophytic bacteria in healthy jujube organs that could effectively suppress F. oxysporum growth.

METHODS AND RESULTS

Different plant organs (leaves, twigs and roots) were collected from healthy Chinese jujube cultivated in southern Xinjiang province of China. The endophytic bacterium Brevibacterium halotolerans JZ7 was selected for its strong antagonistic activity and growth-promoting characteristics. Gas-chromatography mass-spectrometry analysis showed that acetoin, 2,3-butanediol and fenretinide were the three dominant volatile organic compounds produced by strain JZ7. Fenretinide strongly suppressed spore germination of F. oxysporum in vitro. Pot experiments showed that strain JZ7 colonized both the roots and rhizosphere soil of Chinese jujube and significantly reduced F. oxysporum level in jujube rhizosphere soil.

CONCLUSION

We demonstrated that B. halotolerans JZ7 can be developed into a biological control agent to combat root rot disease of Chinese jujube in the Xinjiang province of China.

SIGNIFICANCE AND IMPACT OF THE STUDY

The suggested strategy for biological control of jujube root rot disease is fully in accordance with the current principles of sustainability.

Unveiling the immunomodulatory properties of Haemonchus contortus adhesion regulating molecule 1 interacting with goat T cells

Background

Gastrointestinal nematodes could release excretory-secretory (ES) proteins into the host environment to ensure their survival. These ES proteins act as immunomodulators to suppress or subvert the host immune response via the impairment of immune cell functions, especially in chronic infections. In our preliminary study, Haemonchus contortus adhesion-regulating molecule 1 (HcADRM1) was identified from H. contortus ES proteins (HcESPs) that interacted with host T cells via liquid chromatography-tandem mass spectrometry analysis. However, little is known about HcADRM1 as an ES protein which may play a pivotal role at the parasite-host interface.

Methods

Based on bioinformatics approaches, multiple amino acid sequence alignment was conducted and the evolutionary relationship of HcADRM1 with ADRM1 orthologues was extrapolated. Employing RT-qPCR and immunohistochemistry assays, temporal transcriptional and spatial expression profiles of HcADRM1 were investigated. Using immunostaining approaches integrated with immunological bioassays, the immunomodulatory potentials of HcADRM1 on goat T cells were assessed.

Results

We hereby demonstrated that HcADRM1 with immunodiagnostic utility was a mammalian ADRM1 orthologue abundantly expressed at all developmental stages of H. contortus. Given the implications of ADRM1 proteins in cell growth, survival and development, we further investigated the immunomodulatory property of HcADRM1 as an individual ES protein acting at the parasite-host interface. The rHcADRM1 stimuli notably suppressed T cell viability, promoted intrinsic and extrinsic T cell apoptosis, inhibited T cell proliferation and induced cell cycle arrest at G1 phase. Simultaneously, rHcADRM1 stimuli exerted critical controls on T cell cytokine secretion profiles, predominantly by restraining the secretions of interleukin (IL)-4, IL-10 and interferon-gamma.

Conclusions

Importantly, HcADRM1 protein may have prophylactic potential for anti-H. contortus vaccine development. Together, these findings may contribute to the clarification of molecular and immunomodulatory traits of ES proteins, as well as improvement of our understanding of parasite immune evasion mechanism in H. contortus-host biology.

Canadian cohort expanded-access program of nivolumab plus ipilimumab in advanced melanoma

Background

The combination of nivolumab and ipilimumab is approved in several jurisdictions (United States, European Union, Canada) for the first-line treatment of patients with advanced melanoma. CheckMate 218 is a North American expanded-access program (eap) of nivolumab plus ipilimumab in patients with advanced melanoma. Here, we report safety and survival outcomes for the Canadian cohort in the eap.

Methods

Eligible patients were those 18 years of age or older with unresectable stage iii or iv melanoma, an Eastern Cooperative Oncology Group performance status of 0 or 1, and no prior anti-PD-1 or anti-ctla-4 therapy. Patients were treated with nivolumab 1 mg/kg and ipilimumab 3 mg/kg every 3 weeks for 4 cycles (induction phase); they then continued with nivolumab 3 mg/kg every 2 weeks (maintenance phase) until progression, unacceptable toxicity, or a maximum of 48 weeks, whichever occurred first. Safety and overall survival (os) data were collected.

Results

Of 194 patients enrolled, 174 were treated, and 51% continued on nivolumab maintenance. Median follow-up was 12.9 months. All-grade and grades 3-4 treatment-related adverse events were reported in 98% and 60% of patients respectively and led to treatment discontinuation in 40% and 28% of patients. Two treatment-related deaths were reported. The 12- and 18-month os rates were 80% [95% confidence interval (ci): 73% to 86%] and 76% (95% ci: 67% to 82%) respectively.

Conclusions

In this Canadian population, nivolumab plus ipilimumab demonstrated a safety profile and survival outcomes consistent with phase ii and iii clinical trial data.

Small RNA sequencing reveals miRNAs important for hypoxic adaptation in the Tibetan chicken

1. The Tibetan chicken, which is an indigenous breed living on the Tibetan Plateau, exhibits hypoxic adaptations to its high-altitude environment. However, the molecular mechanism behind this hypoxic adaptation is still unclear. This study aimed to investigate differentially expressed miRNAs involved in hypoxic adaptation through high-throughput RNA sequencing. 2. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to verify the differentially expressed miRNAs and their target genes in chicken embryonic heart tissues and fibroblasts. Luciferase reporter assays were performed to confirm the relationship between miRNAs and target genes. 3. The study identified 37 differentially expressed miRNAs in Tibetan chicken embryonic heart tissues, including 20 up- and 17 down-regulated miRNAs, compared to those found in lowland chickens. Differentially expressed miRNAs were mainly involved in biological processes, such as cell cycle arrest, toll-like receptor signalling pathways, and I-kappa B kinase/NF-kappa B signalling. The data showed that gga-miR-34 c-5p was significantly upregulated in Tibetan chicken tissues and hypoxic fibroblasts, while EHHADH, a target gene of gga-miR-34 c-5p, was downregulated. Moreover, gga-miR-34 c-5p dramatically decreased the luciferase activity of the wild EHHADH, whereas no effect on the mutational EHHADH was found. 4. This study identified miRNA expression profiles in the Tibetan chicken and suggested that miR-34 c-5p acts as a novel miRNA associated with hypoxic adaptation. This facilitates the understanding of molecular mechanisms that underlie long-term exposure to hypoxia.

Pathological changes from the originating to the peripheral sites of Sinonasal Inverted Papilloma are the underlying mechanisms of preoperative MRI-tumor origin prediction

BACKGROUND

Our previous study showed that convoluted cerebriform pattern (CCP)-based reverse tracing method in preoperative magnetic resonance imaging (MRI) is a reliable tool in predicting originating site of sinonasal inverted papilloma (SNIP). This study aimed to determine the underlying pathological mechanism of the preoperative MRI-CCP reverse tracing method by assessing the histopathological changes from the origin to the peripheral sites of SNIP.

METHODOLOGY

The originating site of SNIP was predicted by preoperative MRI in 30 consecutive patients suspected to have primary SNIP. Samples of SNIP originating and peripheral sites were processed by pathological staining for evaluation of stroma score, micro-vessel density (MVD), and tight junction proteins (claudin-5, zonula occludens (ZO)-1 and occludin) expression.

RESULTS

The originating site of SNIP was accurately predicted by preoperative MRI in all patients. Stroma scores, and MVD were significantly greater in the periphery of SNIP than in the originating site. In contrast, Claudin-5 expression in micro-vessels was greater at the originating site than the periphery.

CONCLUSIONS

More edematous stroma and intensive micro-vessels with defective tight junction in periphery of SNIP result in more contrast agent diffusing and CCP that can only be observed at the periphery of SNIP on T2 and contrast-enhanced T1 weighted MR images, which may be the mechanisms underlying the CCP reverse tracing method.