Avian coccidiosis is a major parasitic disease that poses a significant threat to the poultry industry. Elucidating the regulatory mechanisms of key molecules involved in the interplay between Eimeria and the host immune system is of great importance for the development of novel control strategies. Toll-like receptor 5 (TLR5) is a critical pattern recognition receptor in host innate immunity; however, research on its ligands has primarily focused on bacterial-derived molecules, and Eimeria-derived ligands along with their regulatory mechanisms remain largely uncharacterized. Using immunoprecipitation coupled with proteomics analysis, we identified a novel TLR5 ligand, E. maxima dihydrolipoyl dehydrogenase (EmDLD). In an in vitro macrophage model, recombinant EmDLD (rEmDLD) polarized chicken primary bone marrow-derived macrophages toward an M2-like phenotype. This polarization was characterized by the upregulation of TGFB1 and CD206, alongside the downregulation of TNFA, IL1B, and IL6, without affecting the production of nitric oxide (NO) or reactive oxygen species (ROS). Unexpectedly, in the chicken macrophage cell line HD11, rEmDLD activated the canonical NF-κB and MAPK signaling pathways. Furthermore, rEmDLD promoted maturation of primary bone marrow-derived dendritic cells in vitro, which enhanced T-cell proliferation and increased the proportion of CD4+CD25+ regulatory T cell‑like cells (Treg‑like cells). In vivo experiments demonstrated that immunization with rEmDLD induced the production of specific IgY antibodies in chickens. It moderately alleviated body weight loss following E. maxima infection and reduced oocyst shedding in the jejunum. Our results identify EmDLD as a novel ligand of chTLR5 that induces M2-like macrophage polarization and the generation of Treg-like cells. This study reveals for the first time that Eimeria may modulate host immune responses toward an immunoregulatory state through the EmDLD-TLR5 axis, offering important insights into the mechanisms of immune evasion by Eimeria and the development of novel anti-coccidial intervention strategies.

Trichinellosis is a globally important zoonotic parasitic disease that poses a significant threat to public health and causes substantial economic losses. Trichinella spiralis heat shock protein 70 (Ts-HSP70) has been identified as a potential vaccine candidate with immunomodulatory properties. However, the underlying mechanisms by which Ts-HSP70 regulates host immune responses remain incompletely understood. In this study, we investigated the role of Ts-HSP70 in modulating macrophage functions and explored its involvement in Toll-like receptor 2 (TLR2)-mediated signaling. The interaction between Ts-HSP70 and mouse TLR2 was examined using co-immunoprecipitation (Co-IP) and fluorescence colocalization assays. Recombinant Ts-HSP70 (rTs-HSP70) was used to stimulate RAW264.7 macrophages in vitro, and its effects on cell proliferation, phagocytosis, nitric oxide (NO) production, reactive oxygen species (ROS) generation, and cytokine mRNA expression were evaluated. rTs-HSP70 significantly enhanced macrophage proliferation and phagocytic activity, increased NO and ROS production, and upregulated the mRNA expression of IL-1β, IL-6, TNF-α, and IL-10. In addition, rTs-HSP70-induced activation of NF-κB and MAPK signaling pathways. Functional inhibition assays further suggested that ERK activation was partially dependent on the TLR2/MyD88 pathway. Furthermore, rTs-HSP70 encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles elicited specific antibody responses and conferred partial protection in mice, as evidenced by a 28.0% reduction in muscle larval burden. Collectively, these findings indicate that Ts-HSP70 modulates macrophage immune functions and may contribute to host defense through TLR2-associated signaling, providing insights into its potential application in vaccine development against trichinellosis.

Toxoplasmosis, a globally prevalent zoonosis caused by Toxoplasma gondii (T. gondii), poses major threats to both human and animal health, leading to reproductive losses in livestock and severe disease in immunocompromised individuals. Although enzyme-linked immunosorbent assay (ELISA) and PCR are widely used for diagnosis and surveillance, they may be limited by turnaround time, laboratory instrumentation, and, in the case of serological assays, the need for species-specific reagents. To enable rapid, equipment-minimal detection applicable to multiple host species, we developed a point-of-care (POC) double-antigen sandwich colloidal gold immunochromatographic assay (GICA) based on recombinant surface antigen 2 (rSAG2) of T. gondii. In this assay, rSAG2 served both as the capture antigen immobilized on the test line and as the colloidal gold-conjugated detection probe. Key parameters, including conjugation pH, antigen loading, and buffer composition, were systematically optimized. The resulting strip showed a detection limit of a 1:40 serum dilution, and no cross-reactivity was observed with sera positive for 23 common pathogens from different host species. Good repeatability and storage stability for 4 months at 4°C were also observed. For field evaluation, 409 clinical serum samples from six animal groups (100 chickens, 68 dogs, 30 cats, 81 pigs, 80 yaks, and 50 sheep) were tested, and seropositivity rates ranged from 2.9% to 31.3% across the sampled groups. In a subset of chicken (n = 46) and dog (n = 44) sera tested in parallel with the corresponding commercial ELISA kits, the rSAG2-GICA showed good preliminary agreement, with overall agreement rates of 91.3% and 97.7%, respectively. Collectively, this rSAG2-based GICA shows potential as a rapid and practical tool for on-site serological screening of T. gondii antibodies across multiple host species and may support epidemiological surveillance in diverse animal populations.

Toxoplasma gondii establishes infection in hosts by deploying effector proteins that reprogram cytokine-driven immunity. While protozoan parasite-encoded macrophage migration inhibitory factor (MIF) homologs exemplify cytokine mimicry, whether T. gondii targets additional host cytokine axes remains unclear. Here, we identify a T. gondii 3-ketoacyl-CoA reductase (KCR) as a noncanonical cytokine modulator that engages the granulocyte-macrophage colony-stimulating factor (CSF2) receptor alpha chain (CSF2Rα). In HEK293T cells, forward and reverse co-immunoprecipitation (Co-IP) assays demonstrated a specific interaction between KCR and murine CSF2Rα. The recombinant KCR triggered rapid activation of canonical CSF2 signaling in RAW264.7 macrophages, inducing phosphorylation of JAK2 and STAT5 to levels comparable to murine CSF2. Functionally, KCR enhanced NADPH oxidase-dependent oxidative responses, increasing intracellular reactive oxygen species (ROS) and upregulating transcripts encoding core oxidase subunits, including CYBB, CYBA, NCF1, and NCF2. KCR also promoted phagocytic capacity, elevating FITC-dextran uptake and inducing expression of complement, Fc, and scavenger receptor genes, including CR3, CD16, CD64, MSR1, and MARCO. Notably, KCR pretreatment attenuated CSF2-induced JAK2/STAT5 phosphorylation, ROS production, and phagocytosis, consistent with competitive interference with endogenous CSF2-CSF2R signaling. Together, these findings reveal KCR as a previously unrecognized T. gondii factor that targets the CSF2/CSF2R axis to recalibrate macrophage effector functions, expanding the repertoire of parasite strategies for cytokine pathway modulation and highlighting CSF2-CSF2R signaling as a potential interface for mechanistic and therapeutic investigation in toxoplasmosis.

Background:Cystic echinococcosis (CE), a zoonosis caused by Echinococcus granulosus, severely endangers human and animal health in western pastoral China. Conventional surgery and chemotherapy suffer from high recurrence and toxic side effects, so immunization is urgently needed for CE prevention. Methods:We constructed a PLGA nanovaccine loading EgG1Y162 antigen (PLGA-EgG1Y162) via double emulsion-solvent evaporation. Its physicochemical features, DC activation, in vivo lymph node retention, immune response, anti-infection protection and CD4⁺ T cell transcriptome were comprehensively detected. Results:The nanovaccine showed uniform spherical morphology with an average particle size of 394 nm and 79% encapsulation efficiency, presenting favorable sustained-release performance and excellent biocompatibility. In vitro experiments verified that PLGA-EgG1Y162 was efficiently taken up by dendritic cells and effectively facilitated DC maturation. In vivo tracking demonstrated that the nanovaccine achieved prolonged retention within lymph nodes. Compared with the free antigen group and Freund's adjuvant-adjuvanted group, PLGA-EgG1Y162 induced significantly higher and longer-lasting antigen-specific IgG antibodies, markedly upregulated splenic IFN-γ, IL-4, IL-10 and TNF-α expression, and maintained elevated proportions of splenic CD4⁺ and CD8⁺ T cells. At 16 and 24 weeks post infection, vaccinated mice had remarkably fewer hepatic cysts, reduced liver-to-body weight ratios and lower serum transaminase levels, with relatively intact hepatic tissue architecture. Transcriptomic data illustrated that the vaccine reshaped CD4⁺ T cell transcriptional profiles, alleviated infection-triggered chronic inflammation, and suppressed aberrant activation of hepatic autophagy-related genes. Conclusion:PLGA-EgG1Y162 realizes lymph node-targeted sustained antigen delivery to elicit balanced long-lasting humoral and cellular immunity, producing prominent protection against E. granulosus. This work offers a promising immunoprophylactic candidate for cystic echinococcosis.

Chicken coccidia can suppress the host immune response through CD4+CD25+ T cells, compromising the effectiveness of immune prophylaxis and potentially leading to immune failure. However, the role of chicken CD4+CD25+ T cells in chicken coccidia infection is not well understood. This study aimed to elucidate the immunomodulatory function of CD4+CD25+ T cells during Eimeria maxima infection and assess the impact of CD25+ cell depletion on immune response and infection outcomes. The study comprised three trials: (1) examining CD4+CD25+ T cells and cytokine changes post-E. maxima infection, (2) assessing the impact of in vitro CD25+ cell depletion on the immunomodulatory function of peripheral blood mononuclear cells (PBMCs) and (3) evaluating the effects of in vivo CD25+ cell depletion on PBMC function and E. maxima infection. The results revealed that E. maxima infection significantly increased CD4+CD25+ T cell proportions in PBMCs and spleen, along with upregulated mRNA levels of IL-10, TGF-β and IL-4. In vitro CD25+ cell depletion enhanced PBMC proliferation as well as Th1, Th2 and Th17 response. In vivo CD25+ cell depletion partially disrupted E. maxima infection, as evidenced by reduced weight loss, alleviated intestinal lesions, lower oocyst shedding, and an anticoccidial index (ACI) exceeding 120. In conclusion, E. maxima infection upregulates CD4+CD25+ T cells along with their associated cytokines (IL-10 and TGF-β) and the surface molecule CTLA-4; and the depletion of CD25+ cells restores protective Th responses (Th1, Th2 and Th17), while blockade of CD25 in vivo mitigates the E. maxima infection process. This study demonstrates the immunomodulatory role of CD4+CD25+ T cells during E. maxima infection, providing key insights for elucidating the immune evasion mechanisms of this parasite.

Avian coccidiosis caused by Eimeria species threatens the global poultry industry. Current control measures rely mainly on anticoccidial drugs and live vaccines, but drug resistance and safety concerns drive the need for novel vaccines such as subunit vaccines. Among Eimeria species, Eimeria necatrix is one of the most pathogenic. Its life cycle involves sporozoites invading the jejunum and undergoing two generations of schizogony; the released second-generation merozoites then migrate specifically to the cecum for further development—a step essential for completing the life cycle. Previously, we identified EnMIC as the key molecule mediating this cecum-specific invasion, and its essential adhesive domain EnMAR2. In the present study, we evaluated the immunoprotective potential of EnMIC and EnMAR2. Recombinant subunit vaccines of EnMIC and EnMAR2 were administered to chickens. Humoral and cellular immune responses were assessed by measuring serum IgY, intestinal IgA, T-cell subsets (CD4⁺/CD8⁺), and cytokine transcripts (IL-2, IFN-γ, IL-4) in the spleen and cecal tonsils. After challenge with E. necatrix, protective effects were evaluated by survival rate, weight gain, lesion index, oocyst output, and the anticoccidial index (ACI). Both vaccines significantly elevated serum IgY and intestinal IgA levels. They also increased splenic IL‑2, IFN‑γ, and IL‑4 mRNA levels, while downregulating these cytokines in cecal tonsils. Furthermore, the rEnMIC group showed an increased proportion of CD4⁺ T cells in both the spleen and cecal tonsils. In the challenge trial, both the rEnMIC and rEnMAR2 groups exhibited significantly better weight gain, lower lesion index, and greater oocyst reduction than the non‑immunized infected group. Their ACI values were 168.92 and 166.60, respectively. These results demonstrate that EnMIC and EnMAR2, as key mediators of E. necatrix site-specific cecal invasion, can induce both humoral and cellular immune responses when delivered as recombinant protein vaccines. The vaccines effectively alleviated pathological damage, reduced oocyst output, and improved growth performance. Therefore, EnMIC and EnMAR2 represent promising novel vaccine candidates against E. necatrix infection in chickens.

Previous studies indicated that infection with Haemonchus contortus is host-specific (goat: susceptible host; gerbil: paratenic host; mouse: resistant host). Neutrophils play an essential role in host defense against parasitic infection through phagocytic engulfment, reactive oxygen species (ROS) generation, and neutrophil extracellular traps (NETs) formation. NETs are large web-like complexes consisting of a DNA scaffold decorated with various proteins components, including histones, myeloperoxidase, and elastase. They are released through both ROS-dependent and ROS-independent pathways. Previous studies have demonstrated both constraints and effectiveness of NETs in helminths. However, the roles of NETs in anti-infection of H. contortus in different hosts are still unclear. To assess host-specific variations in NETs release, neutrophils isolated from goats, gerbils, and mice were co-cultured with Haemonchus contortus third-stage larvae (HcL3), followed by quantitative analysis of NETs formation using the PicoGreen® fluorescence assay. Subsequently, H. contortus excretory–secretory proteins (HcESPs) were co-cultured with neutrophils isolated from each host species. NETs release and ROS production were then quantitatively assessed using PicoGreen® fluorescence intensity and oxidation-sensitive dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence. In addition, the neutrophil’s phagocytic ability for FITC-dextran was evaluated by flow cytometric analysis. Finally, to elucidate the signaling pathways involved in HcESP-induced NETs release in goat neutrophils, four specific inhibitors were employed for pretreatment prior to stimulation. Our results demonstrate that in vitro stimulation with HcL3 triggers NETs formation. The release of NETs exhibits significant host-specific variation, specifically, neutrophils from mice showed the highest NETs release, followed by gerbils, and a minimal response in goats. Moreover, HcESP treatment markedly inhibited ROS generation and phagocytic capacity in neutrophils from all three host species. Intriguingly, HcESPs exerted host-specific modulation of NETs release, with inhibition observed in goats, enhancement in mice, and context-dependent modulation in gerbils. Mechanistic investigations revealed that the NETs suppression in goats neutrophils involved both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase- and neutrophil elastase-dependent pathways. Our results demonstrate that HcESPs significantly inhibit NETs formation in goat neutrophils through dual modulation of NADPH oxidase and neutrophil elastase activity. This finding highlights these two enzymes as promising molecular targets for anti-helminthic vaccine development.

Trehalase can hydrolyze trehalose and is the first key enzyme in the chitin synthesis pathway of arthropods. However, little is known about the function of trehalase in Haemonchus contortus (HcTre). In this study, the purified recombinant HcTre protein (rHcTre) was obtained by prokaryotic expression technology, and it was proved that rHcTre protein has trehalase activity. Western blot results verified that HcTre protein belongs to the excretory/secretory proteins of H. contortus, and rHcTre protein can be recognized by goat serum infected with H. contortus. Moreover, Western blot results demonstrated the expression of the HcTre gene in various developmental stages of H. contortus, with the highest level observed during the egg stage. Meanwhile, the immunofluorescence results revealed a widespread distribution of HcTre protein in adult worms. Interestingly, we found that rat serum against rHcTre protein inhibited the development of larvae by blocking the activity of trehalase. Furthermore, the results showed that rHcTre protein significantly inhibited the proliferation and promoted the apoptosis of goat PBMCs in a dose-dependent manner. This study is expected to further understand the immune escape mechanism of H. contortus and provide new drug targets and vaccine candidate molecules for the prevention and control of the disease.

BackgroundTrehalose-6-phosphate synthase (HcTPS) and trehalose-6-phosphate phosphatase (HcGOB) are key enzymes for trehalose synthesis in Haemonchus contortus. In addition, previous studies have also demonstrated that HcTPS and HcGOB can regulate the function of host immune cells in vitro, and are important immunosuppressive molecules. Therefore, this study evaluated the potential of HcTPS and HcGOB as vaccine candidates through in vitro and in vivo experiments.MethodsTo evaluate the inhibitory effects of polyclonal antibodies on egg hatching and larval development, anti-rHcTPS and anti-rHcGOB antibodies were incubated separately with eggs and first-stage larvae (L1s) under controlled in vitro conditions. For immunization studies, recombinant proteins (rHcTPS and rHcGOB) were formulated with Quil-A adjuvant, and administered to goats through subcutaneous injection. Vaccine efficacy against Haemonchus contortus infection was determined through comprehensive analysis of multiple parasitological parameters, including: (1) egg abnormality rate, (2) hatching success rate, (3) reduction egg output rates, and (4) reduction in adult worm burden.ResultsThe results of in vitro experiments showed that polyclonal antibodies against HcTPS and HcGOB had no effect on the hatching rate of eggs, but significantly affected the development from L1s to infectious third stage larvae (L3s). After immunization with recombinant HcTPS protein (rHcTPS) and recombinant HcGOB protein (rHcGOB), high levels of antigen-specific immunoglobulin G (IgG) were produced in goats, and remained till the end of the experiment. Compared with the Quil-A adjuvant control group, the number of deformed eggs in the rHcTPS protein- immunized group and the rHcGOB protein- immunized group were significantly increased. In the rHcTPS protein-immunized group and the rHcGOB protein-immunized group, the deformity rate of eggs was 9.59% and 17.30%, respectively, and the hatching rate of eggs was reduced by 11.27% and 13.71%, respectively. Moreover, compared with the Quil-A adjuvant control group, the number of eggs and adults in the HcTPS protein- immunized group decreased by 64.47% and 60.93%, respectively, and the number of eggs and adults in the rHcGOB protein- immunized group decreased by 63.97% and 69.54%, respectively. Furthermore, compared with the control group (Quil-A adjuvant), the trehalose content in the rHcTPS protein- immunized group and the rHcGOB protein- immunized group was also significantly reduced.ConclusionsThese findings indicate that rHcTPS and rHcGOB exhibit superior immune protective effects, rendering them promising candidates for vaccine development.

BackgroundEchinococcus granulosus cyst fluid (EgCF) is a complex mixture of parasite’s containing a variety of antigens. Th9 cells are a newly reported subpopulation of Th cells whose primary function is to secrete IL-9 and exert biological effects. Research on whether antigens in the vesicle fluid can evade the host immune response by increasing IL-9 secretion is limited.MethodsThe effects of EgCF on lymphocyte function in mice were evaluated using CCK-8 and flow cytometry for apoptosis. The effect of EgCF on CD4+IL-9+T cell differentiation was reflected by flow cytometry. The expression of TGF-β, IL-4, PU.1, IRF4 and IL-9 was detected by WB, qRT-PCR and ELISA under the influence of varying concentrations of EgCF. Analysis of differential metabolites and genes in mouse splenic lymphocytes was stimulated by EgCF using metabolomics and transcriptomics.ResultsDifferent concentrations of EgCF stimulated lymphocytes, promoted cell proliferation and apoptosis, facilitated the differentiation of CD3+T cells and CD4+IL-9+T cells in splenic lymphocytes, and inhibited the differentiation of CD4+T cells. It regulated the host immune response by up-regulating Th9 cell-associated cytokines such as IL-4, TGF-β, IL-9 and related transcription factors PU.1 and IRF4. Metabolomic analysis identified 221 differential metabolites, 12 up-regulated and 11 down-regulated. These metabolites were primarily enriched in metabolic pathways such as beta-Alanine metabolism and Pyrimidine metabolism. Transcriptome analysis identified 16,694 differentially expressed genes, highlighting necroptosis and TGF-β signaling as top pathways, where Hgf and Myof were potential diagnostic markers.ConclusionsMetabolomics and transcriptomics analyses help identify potential candidate genes and provide diagnostic tools for future research and the discovery of new therapeutic targets. EgCF may regulates the host immune response by up-regulating Th9 cell-related cytokines such as IL-4, TGF-β and IL-9, along with related transcription factors PU.1 and IRF4. This provides a theoretical basis for understanding how Echinococcus granulosus modulates the host immune response and may offer new research avenues for immunoprophylaxis against Echinococcus granulosus.

Th17 cells play important roles in anti-infective responses. The 15 kDa excretory/secretory protein of Haemonchus contortus (HcES-15) has been identified as a promising immune-protective antigen against H. contortus infection capable of up-regulating IL-17, IL-4 and IL-10 production. To obtain the peptides that primarily induce the Th17 immune response, we amplified and expressed the peptides ES15-1, ES15-2 and ES15-3 from HcES-15. In vitro studies demonstrated that ES15-1 stimulated transcriptional activation of the STAT3/RORγt signaling pathway and induced IL-17 production in goat peripheral blood mononuclear cells (PBMCs). In vivo studies, flow cytometric analysis revealed that subcutaneous injection of PLGA-encapsulated ES15-1 peptide (PLGA-ES15-1, 50 μg) significantly enhanced Th17 cell differentiation in the spleens of BALB/c mouse. Consistent with these findings, ELISA quantification demonstrated that ES15-1 treatment significantly increased serum levels of pro-inflammatory cytokine (IL-17, IL-1, IL-6, and TNF-α). In goat immune protection studies, goats ( n = 6) were subcutaneously immunized with 500 μg of PLGA-ES15-1 on days 0 and 14, followed by infection with H. contortus infective third-stage larvae (iL3s) 1 week post-second immunization. ES15-1 significantly enhanced serum levels of pro-inflammatory cytokines (IL-17, IL-1, IL-6, TNF-α). At autopsy, vaccinated goats exhibited 69.0% ( p < 0.001) reduction of fecal egg counts (FEC) and 50.54% ( p < 0.05) reduction of worm burdens versus controls. Our findings suggested that peptide ES15-1 enhanced Th17 responses through regulation of the STAT3/RORγt pathway, conferring a certain immune protection against H. contortus infection.

Eimeria maxima (E. maxima) infection inhibits the expression of IFN-γ, a cytokine that is essential for the Th1 immune response and plays a key role in combating this parasite. In our preliminary investigations, we identified the E. maxima surface antigen (EmSAG) as an inhibitory molecule of IFN-γ. EmSAG was screened and characterised from an E. maxima sporozoite cDNA expression library. The present study aimed to evaluate the immunomodulatory effects of EmSAG on chicken peripheral blood mononuclear cells (PBMCs) and various T cell subsets. We analysed cell proliferation, nitric oxide (NO) release, and cytokine transcription. The results revealed that EmSAG boosts PBMC proliferation and promotes differentiation of CD4+/CD8+ T cells. Additionally, stimulation with EmSAG significantly inhibited NO release and IFN-γ transcription while enhancing the transcription of IL-4, IL-10, and TGF-β1 in chicken PBMCs. The sorting purity of T cell subsets was as follows: CD8+ (96.90

Toll-like receptor (TLR)-mediated recognition of specific ligands is critical for initiating innate immunity against Eimeria infections. However, the avian-specific TLR15 has unclear immunological functions, including its specific ligands and role in anti-coccidia immunity. In this study, an aspartyl protease from Eimeria tenella (EteASP) was identified as a potential TLR15 ligand by co-immunoprecipitation. Two distinct TLR15-expressing innate immune cell populations, macrophages and dendritic cells, were employed as models to investigate the immune responses triggered by recombinant EteASP protein (rEteASP). In macrophages, rEteASP induced robust immune activation, associated with the stimulation of both NF-κB and MAPK pathways. This activation correlated with increased production of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), nitric oxide, and reactive oxygen species, alongside enhanced phagocytosis. Furthermore, rEteASP promoted classical dendritic cell activation in chicken bone marrow-derived dendritic cells, marked by stellate morphology and upregulated CD11c and MHC II surface expression. The activation patterns in chBMDCs mirrored those in macrophages, characterized by increased production of immune mediators. A mixed lymphocyte reaction (MLR) further demonstrated that rEteASP-activated dendritic cells efficiently triggered naive T cell activation, driving a shift towards balanced Th1/Th2-type cellular immune response. Collectively, these findings establish EteASP as a potent immunomodulator capable of activating key innate immune effector functions in macrophages and dendritic cells, and bridging to adaptive immunity. Our data implicate TLR15 as a potential receptor contributing to these responses, broadening the investigation of TLR15 ligands in protozoa and offering novel insights into Eimeria-host immune interactions. However, the potential involvement of additional pattern recognition receptors in EteASP recognition and the definitive role of TLR15 requires further investigation.

Strongyloidiasis caused by Strongyloides papillosus is a significant parasitic disease affecting the health and productivity of small ruminants globally. In this study, a novel recombinase-aided amplification (RAA) combined with lateral flow dipstick (LFD) assay was developed and validated for the rapid and specific detection of S. papillosus infection in goats and sheep, targeting the 18S ribosomal RNA (18S rRNA) gene. A total of 815 fecal samples were collected from nine provinces in China, encompassing major goats and sheep production regions. The RAA-LFD assay exhibited high sensitivity, with a minimum detection limit of 15 eggs per gram (EPG) of feces. Clinical fecal examination yielded a positive rate of 62.30% (433/695), while the RAA-LFD assay achieved a positive rate of 58.28% (475/815), indicating that the diagnostic accuracy of the RAA-LFD assay is consistent with that of fecal examination. Compared with conventional fecal examination, the RAA-LFD assay offers superior rapidity, portability, and sensitivity, presenting a valuable diagnostic tool for large scale epidemiological surveillance and point-of-care applications, particularly in resource constrained environments.

AbstractBackgroundFor decades, studies have demonstrated the anti‐inflammatory potential of proteins secreted by helminths in allergies and asthma. Previous studies have demonstrated the immunomodulatory capabilities of Succinate Coenzyme A ligase beta‐like protein (SUCLA‐β) derived from Trichinella spiralis, a crucial excretory product of this parasite.ObjectiveTo explore the therapeutic potential of SUCLA‐β in alleviating and controlling ovalbumin (OVA)‐induced allergic asthma, as well as its influence on host immune modulation.MethodsIn this research, we utilized the rTs‐SUCLA‐β protein derived from T. spiralis to investigate its potential in mitigating airway inflammation in a murine model of asthma induced by OVA sensitization/stimulation, both pre‐ and post‐challenge. The treatment's efficacy was assessed by quantifying the extent of inflammation in the lungs.ResultsTreatment with rTs‐SUCLA‐β demonstrated efficacy in ameliorating OVA‐induced airway inflammation, as evidenced by a reduction in eosinophil infiltration, levels of OVA‐specific Immunoglobulin E, interferon‐γ, interleukin (IL)‐9, and IL‐17A, along with an elevation in IL‐10. The equilibrium between Th17 and Treg cells plays a pivotal role in modulating the abundance of inflammatory cells within the organism, thereby ameliorating inflammation and alleviating symptoms associated with allergic asthma.Conclusions and Clinical RelevanceOur data revealed that T. spiralis‐derived Ts‐SUCLA‐β protein may inhibit the allergic airway inflammation by regulating host immune responses.

Haemonchus contortus poses a global challenge as a parasite affecting small ruminants, yet the problem of absence of an effective vaccine against H. contortus infection still exists. This investigation sought to appraise the immunological reaction induced by recombinant H. contortus excretory/secretory-24 (rHcES-24) in combination with complete Freund’s adjuvant (CFA) and bio-polymeric nanoparticles (NPs) within a murine model. In this study, rHcES-24 was encapsulated in poly(d, l-lactide-co-glycolide) (PLGA) and chitosan (CS) NPs, administered subcutaneously to mice. Researchers analyzed the NPs using scanning electron microscope (SEM) and assessed lymphocyte proliferation, specific antibodies, cytokines, T cell proliferation (CD3e+CD4+, CD3e+CD8a+), and phenotypic alteration in splenocytes (CD11c+CD83+, CD11c+CD86+) through flow cytometry to understand the immune response. The results demonstrated that the administration of nanovaccines (NVs) prompted immune responses towards Th1 pathway. This was indicated by notable enhancements in the production of specific antibodies, heightened cytokine levels, and a robust proliferation of lymphocytes observed in mice that received the NVs compared to control groups. Remarkably, mice vaccinated with the antigen-loaded NPs formulations exhibited considerably higher proportions of splenic dendritic cells (DCs) and T cells in comparison to those receiving the traditional adjuvant or the control groups. Incorporating HcES-24 protein into NPs effectively conferred immunity against H. contortus, paving the way for developing a targeted and commercial vaccine.

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan that can elicit a robust immune response during infection. Macrophage cells have been shown to play an important role in the immune response against T. gondii. In our previous study, the eukaryotic translation initiation factor 5A (eIF-5A) gene of T. gondii was found to influence the invasion and replication of tachyzoites. In this study, the recombinant protein of T. gondii eIF-5A (rTgeIF-5A) was incubated with murine macrophages, and the regulatory effect of TgeIF-5A on macrophages was characterized. Immunofluorescence assay showed that TgeIF-5A was able to bind to macrophages and partially be internalized. The Toll-like receptor 4 (TLR4) level and chemotaxis of macrophages stimulated with TgeIF-5A were reduced. However, the phagocytosis and apoptosis of macrophages were amplified by TgeIF-5A. Meanwhile, the cell viability experiment indicated that TgeIF-5A can promote the viability of macrophages, and in the secretion assays, TgeIF-5A can induce the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) from macrophages. These findings demonstrate that eIF-5A of T. gondii can modulate the immune response of murine macrophages in vitro, which may provide a reference for further research on developing T. gondii vaccines.

Haemonchus contortus (Barber pole worm) is one of the dominant helminth parasitic infections in small ruminants which is economically important and causes severe losses in the livestock industry, particularly in tropical and subtropical regions. This parasite resides in the abomasum and is responsible for severe blood loss, leading to anemia, emaciation, hypoproteinemia, weight loss, and potentially death. The economic impact of H. contortus on the livestock industry necessitates effective control measures, including early diagnosis and the development of effective vaccines. H. contortus secretes a variety of excretory and secretory proteins (ESPs), which are glycoproteins that play a crucial role in modulating the host's immune response. These ESPs are not only vital for understanding the immunological interactions between the parasite and the host but also serve as potential diagnostic tools and vaccine candidates. Similar ESPs have been identified in other parasitic species such as Cooperia spp, Ostertagia ostertagia, Teladorsagia circumcincta, Ascaris sum, Schistosoma japonicum, and Echinococcus multilocularis, underscoring their importance in both detection and vaccine development. In addition, there is a lack of highly potential specific proteins which having immunogenic properties that can be used for the accurate, early diagnosis serologically and serve as a potential candidate for the vaccine development against H. contortus. Recent research highlights that TH-9 stimulated proteins from H. contortus are emerging as promising candidates for vaccine development due to their immunomodulatory effects. These proteins have been shown to induce a TH-9 immune response, characterized by increased production of interleukin-9 (IL-9), which is critical for enhancing protective immunity against helminth infections. It is suggested to investigate TH-9 stimulated protein as potential candidates for vaccine development and diagnostic antigen.

Background: Haemonchus contortus (H. contortus), a nematode with global prevalence, poses a major threat to the gastrointestinal health of sheep and goats. In an effort to combat this parasite, a nanovaccine was created using a recombinant ADP-ribosylation factor 1 (ARF1) antigen encapsulated within poly lactic-co-glycolic acid (PLGA). This study aimed to assess the effectiveness of this nanovaccine in providing protection against H. contortus infection. Methods: Fifteen goats were randomly divided into three groups. The experimental group received two doses of the PLGA encapsulated rHcARF1 (rHcARF1-PLGA) nanovaccine on days 0 and 14. Fourteen days after the second immunization, both the experimental and positive control groups were challenged with 8000 infective larvae (L3) of H. contortus, while the negative control group remained unvaccinated and unchallenged. At the end of the experiment on the 63rd day, all animals were humanly euthanized. Results: The results showed that the experimental group had significantly higher levels of sera IgG, IgA, and IgE antibodies, as well as increased concentrations of cytokines, such as IL-4, IL-9, IL-17, and TGF-β, compared to the negative control group after immunization. Following the L3 challenge, the experimental group exhibited a 47.5% reduction in mean eggs per gram of feces (EPG) and a 55.7% reduction in worm burden as compared to the positive control group. Conclusions: These findings indicate that the nanovaccine expressing rHcARF1 offers significant protective efficacy against H. contortus infection in goats. The results also suggest the need for more precise optimization of the antigen dose or a reassessment of the vaccination regimen. Additionally, the small sample size limits the statistical rigor and the broader applicability of the findings.