scholarly journals Immediate Interferon Gamma Induction Determines Murine Host Compatibility Differences between Toxoplasma gondii and Neospora caninum

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Rachel S. Coombs ◽  
Matthew L. Blank ◽  
Elizabeth D. English ◽  
Yaw Adomako-Ankomah ◽  
Ifeanyi-Chukwu Samuel Urama ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Interferon Gamma ◽  
Neospora Caninum ◽  
Ectopic Expression ◽  
Parasite Burden ◽  
Interleukin 12 ◽  
Content Type ◽  
Ifn Γ ◽  
And Control

ABSTRACT Rodents are critical for the transmission of Toxoplasma gondii to the definitive feline host via predation, and this relationship has been extensively studied as a model for immune responses to parasites. Neospora caninum is a closely related coccidian parasite of ruminants and canines but is not naturally transmitted by rodents. We compared mouse innate immune responses to N. caninum and T. gondii and found marked differences in cytokine levels and parasite growth kinetics during the first 24 h postinfection (hpi). N. caninum-infected mice produced significantly higher levels of interleukin-12 (IL-12) and interferon gamma (IFN-γ) by as early as 4 hpi, but the level of IFN-γ was significantly lower or undetectable in T. gondii-infected mice during the first 24 hpi. “Immediate” IFN-γ and IL-12p40 production was not detected in MyD88−/− mice. However, unlike IL-12p40−/− and IFN-γ−/− mice, MyD88−/− mice survived N. caninum infections at the dose used in this study. Serial measures of parasite burden showed that MyD88−/− mice were more susceptible to N. caninum infections than wild-type (WT) mice, and control of parasite burdens correlated with a pulse of serum IFN-γ at 3 to 4 days postinfection in the absence of detectable IL-12. Immediate IFN-γ was partially dependent on the T. gondii mouse profilin receptor Toll-like receptor 11 (TLR11), but the ectopic expression of N. caninum profilin in T. gondii had no impact on early IFN-γ production or parasite proliferation. Our data indicate that T. gondii is capable of evading host detection during the first hours after infection, while N. caninum is not, and this is likely due to the early MyD88-dependent recognition of ligands other than profilin.

scholarly journals CCR7-Dependent Immunity during Acute Toxoplasma gondii Infection

2010 ◽  
Vol 78 (5) ◽  
pp. 2257-2263 ◽  
Author(s):  
Shahani Noor ◽  
Andrew S. Habashy ◽  
J. Philip Nance ◽  
Robin T. Clark ◽  
Kiav Nemati ◽  
...  
Keyword(s):  
T Cell ◽  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Parasite Burden ◽  
Serum Levels ◽  
Interleukin 12 ◽  
Necrosis Factor Alpha ◽  
Monocyte Chemoattractant Protein 1 ◽  
Absolute Requirement ◽  
Ifn Γ

ABSTRACT The chemokine receptor CCR7 is a well-established homing receptor for dendritic cells and T cells. Interactions with its ligands, CCL19 and CCL21, facilitate priming of immune responses in lymphoid tissue, yet CCR7-independent immune responses can be generated in the presence of sufficient antigen. In these studies, we investigated the role of CCR7 signaling in the generation of protective immune responses to the intracellular protozoan parasite Toxoplasma gondii. The results demonstrated a significant increase in the expression of CCL19, CCL21, and CCR7 in peripheral and central nervous system (CNS) tissues over the course of infection. Unexpectedly, despite the presence of abundant antigen, CCR7 was an absolute requirement for protective immunity to T. gondii, as CCR7−/− mice succumbed to the parasite early in the acute phase of infection. Although serum levels of interleukin 12 (IL-12), IL-6, tumor necrosis factor alpha (TNF-α), and IL-10 remained unchanged, there was a significant decrease in CCL2/monocyte chemoattractant protein 1 (MCP-1) and inflammatory monocyte recruitment to the site of infection. In addition, CCR7−/− mice failed to produce sufficient gamma interferon (IFN-γ), a critical Th1-associated effector cytokine required to control parasite replication. As a result, there was increased parasite dissemination and a significant increase in parasite burden in the lungs, livers, and brains of infected mice. Adoptive-transfer experiments revealed that expression of CCR7 on the T-cell compartment alone is sufficient to enable T-cell priming, increase IFN-γ production, and allow the survival of CCR7−/− mice. These data demonstrate an absolute requirement for T-cell expression of CCR7 for the generation of protective immune responses to Toxoplasma infection.

scholarly journals Induction of Protective Immune Responses by a Multiantigenic DNA Vaccine Encoding GRA7 and ROP1 of Toxoplasma gondii

2012 ◽  
Vol 19 (5) ◽  
pp. 666-674 ◽  
Author(s):  
Juan-Hua Quan ◽  
Jia-Qi Chu ◽  
Hassan Ahmed Hassan Ahmed Ismail ◽  
Wei Zhou ◽  
Eun-Kyeong Jo ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Dna Vaccine ◽  
Protective Efficacy ◽  
Single Gene ◽  
Reduction Rate ◽  
Interleukin 12 ◽  
Content Type ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACTToxoplasma gondiiis distributed worldwide and infects most species of warm-blooded animals, including humans. The heavy incidence and severe or lethal damage caused byT. gondiiinfection clearly indicates the need for the development of a vaccine. To evaluate the protective efficacy of a multiantigenic DNA vaccine expressing GRA7 and ROP1 ofT. gondiiwith or without a plasmid encoding murine interleukin-12 (pIL12), we constructed DNA vaccines using the eukaryotic plasmids pGRA7, pROP1, and pGRA7-ROP1. Mice immunized with pGRA7, pROP1, or pGRA7-ROP1 showed significantly increased serum IgG2a titers; production of gamma interferon (IFN-γ), IL-10, and tumor necrosis factor alpha (TNF-α);in vitroT cell proliferation; and survival, as well as decreased cyst burdens in the brain, compared to mice immunized with either the empty plasmid, pIL12, or vector with pIL12 (vector+pIL12). Moreover, mice immunized with the multiantigenic DNA vaccine pGRA7-ROP1 had higher IgG2a titers, production of IFN-γ and TNF-α, survival time, and cyst reduction rate compared to those of mice vaccinated with either pGRA7 or pROP1 alone. Furthermore, mice immunized with either a pGRA7-ROP1+pIL12 or a single-gene vaccine combined with pIL12 showed greater Th1 immune response and protective efficacy than the single-gene-vaccinated groups. Our data suggest that the multiantigenic DNA antigen pGRA7-ROP1 was more effective in stimulating host protective immune responses than separately injected single antigens, and that IL-12 serves as a good DNA adjuvant.

scholarly journals Interleukin-18 (IL-18) Enhances Innate IL-12-Mediated Resistance to Toxoplasma gondii

2000 ◽  
Vol 68 (12) ◽  
pp. 6932-6938 ◽  
Author(s):  
Guifang Cai ◽  
Robert Kastelein ◽  
Christopher A. Hunter
Keyword(s):  
Toxoplasma Gondii ◽  
Nk Cells ◽  
Nk Cell ◽  
Parasite Burden ◽  
Scid Mice ◽  
Interleukin 12 ◽  
Cell Mediated Immunity ◽  
Protective Effects ◽  
Innate Resistance ◽  
Ifn Γ

ABSTRACT Innate resistance to Toxoplasma gondii is dependent on the ability of interleukin-12 (IL-12) to stimulate natural killer (NK) cell production of gamma interferon (IFN-γ). Since IL-18 is a potent enhancer of IL-12-induced production of IFN-γ by NK cells, SCID mice (which lack an adaptive immune response) were used to assess the role of IL-18 in innate resistance to T. gondii. Administration of anti-IL-18 to SCID mice infected with T. gondii resulted in an early reduction in serum levels of IFN-γ but did not significantly decrease resistance to this infection. In contrast, administration of exogenous IL-18 to infected SCID mice resulted in increased production of IFN-γ, reduced parasite burden, and a delay in time to death. The protective effects of IL-18 treatment correlated with increased NK cell numbers and cytotoxic activity at the local site of administration and with elevated levels of inducible nitrous oxide synthose in the spleens of treated mice. In addition, in vivo depletion studies demonstrated that the ability of exogenous IL-18 to enhance resistance to T. gondii was dependent on IL-12, IFN-γ, and NK cells. Together, these studies demonstrate that although endogenous IL-18 appears to have a limited role in innate resistance to T. gondii, treatment with IL-18 can augment NK cell-mediated immunity to this pathogen.

scholarly journals Protective Immunity Against Neospora Caninum Infection Induced by 14-3-3 Protein in Mice

2020 ◽  
Author(s):  
Shan Li ◽  
Nan Zhang ◽  
Shaoxiong Liu ◽  
Jianhua Li ◽  
Li Liu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Neospora Caninum ◽  
Survival Rates ◽  
Parasite Burden ◽  
Mouse Serum ◽  
Intermediate Hosts ◽  
Caninum Infection ◽  
Wide Range ◽  
Ifn Γ

Abstract BackgroundNeospora caninum causes infections in a wide range of intermediate hosts and remains a threatening disease worldwide because of the lack of effective drugs and vaccines. Our previous studies demonstrated that N. caninum 14-3-3 protein (Nc14-3-3), which is included in N. caninum extracellular vesicles (NEVs), can induce effective immune responses and stimulate cytokine expression in mouse peritoneal macrophages. However, whether Nc14-3-3 has a protective effect and its mechanisms are poorly understood.MethodsHere, we evaluated immune responses and protective effects of Nc14-3-3 against 2×107 Nc-1 tachyzoites. Antibody (IgG, IgGl and IgG2a) levels and Th1-type (IFN-γ and IL-12) and Th2-type (IL-4 and IL-10) cytokines in mouse serum; survival rates; survival time; and parasite burdens were detected.ResultsIn the present study, the immunostimulatory effect of Nc14-3-3 was confirmed, as it triggered Th1-type cytokine (IFN-γ and IL-12) production in mouse serum two weeks after the final immunization. Moreover, the immunization of C57BL/6 mice with Nc14-3-3 induced high IgG antibody levels and significant increases in CD8+ T lymphocytes in the spleens of mice, indicating that a significant cellular immune response was induced. Mouse survival rates and survival times were significantly prolonged after immunization survival rates were 40% for Nc14-3-3 immunization and 60% for NEV immunization, while mice that received GST, PBS, or blank control all died at 13, 9, and 8 days after intraperitoneal N. caninum challenge. In addition, qPCR analysis indicated that there was a lower parasite burden and milder pathological changes in the mice immunized with Nc14-3-3.ConclusionsOur data demonstrate the vaccination of mice with Nc14-3-3 elicits both cellular and humoural immune responses and provides partial protection against acute neosporosis. Thus, Nc14-3-3 could be an effective antigen candidate for vaccine development for neosporosis.

scholarly journals Comparison of Cytokine Immune Responses to Brucella abortus and Yersinia enterocolitica Serotype O:9 Infections in BALB/c Mice

2013 ◽  
Vol 81 (12) ◽  
pp. 4392-4398 ◽  
Author(s):  
Wenpeng Gu ◽  
Xin Wang ◽  
Haiyan Qiu ◽  
Buyun Cui ◽  
Shiwen Zhao ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Yersinia Enterocolitica ◽  
Brucella Abortus ◽  
Interleukin 12 ◽  
Histopathological Changes ◽  
Content Type ◽  
Serotype O ◽  
Cytokine Responses ◽  
Ifn Γ

ABSTRACTBrucella abortusandYersinia enterocoliticaserotype O:9 serologically cross-react in the immune response with the host; therefore, our aim was to compare the immune responses to these two pathogens. We selected typicalB. abortusandY. enterocoliticaO:9 strains to study the cytokine immune response and the histopathological changes in livers and spleens of BALB/c mice. The data showed the cytokine responses to the two strains of pathogens were different, where the average levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma interferon (IFN-γ), interleukin-12 (IL-12), and tumor necrosis factor alpha (TNF-α) were higher withB. abortusinfections than withY. enterocoliticaO:9 infections, especially for IFN-γ, while the IL-10 level was lower and the levels of IL-1β, IL-4, IL-5, and IL-6 were similar. The histopathological effects in the livers and spleens of the BALB/c mice withB. abortusandY. enterocoliticaO:9 infections were similar; however, the pathological changes in the liver were greater withB. abortusinfections, while damage in the spleen was greater withY. enterocoliticaO:9 infections. These observations show that different cytokine responses and histopathological changes occur withB. abortusandY. enterocoliticaO:9 infections.

scholarly journals Macrophage Depletion Prior to Neospora caninum Infection Results in Severe Neosporosis in Mice

2014 ◽  
Vol 21 (8) ◽  
pp. 1185-1188 ◽  
Author(s):  
Chisa Abe ◽  
Sachi Tanaka ◽  
Fumiaki Ihara ◽  
Yoshifumi Nishikawa
Keyword(s):  
Interferon Gamma ◽  
Interleukin 6 ◽  
Protective Immunity ◽  
Neospora Caninum ◽  
Caninum Infection ◽  
Content Type ◽  
Murine Macrophages ◽  
Macrophage Depletion ◽  
Increased Sensitivity ◽  
Ifn Γ

ABSTRACTWe observed that murine macrophages showed greater activation and increased interleukin 6 (IL-6), IL-12p40, and interferon gamma (IFN-γ) production duringNeospora caninuminfection. Many macrophages migrated to the site of infection. Furthermore, macrophage-depleted mice exhibited increased sensitivity toN. caninuminfection. This study indicates that macrophages are required for achieving protective immunity againstN. caninum.

scholarly journals Protective Immunity Against Neospora caninum Infection Induced by 14-3-3 Protein in Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Shan Li ◽  
Nan Zhang ◽  
Shaoxiong Liu ◽  
Jianhua Li ◽  
Li Liu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Neospora Caninum ◽  
Survival Rates ◽  
Parasite Burden ◽  
Mouse Serum ◽  
Protective Effects ◽  
Igg Antibody ◽  
Caninum Infection ◽  
Ifn Γ

Neospora caninum is an apicomplexan parasite that infects many mammals and remains a threatening disease worldwide because of the lack of effective drugs and vaccines. Our previous studies demonstrated that N. caninum 14-3-3 protein (Nc14-3-3), which is included in N. caninum extracellular vesicles (NEVs), can induce effective immune responses and stimulate cytokine expression in mouse peritoneal macrophages. However, whether Nc14-3-3 has a protective effect and its mechanisms are poorly understood. Here, we evaluated the immune responses and protective effects of Nc14-3-3 against exposure to 2 × 107 Nc-1 tachyzoites. Antibody (IgG, IgGl, and IgG2a) levels and Th1-type (IFN-γ and IL-12) and Th2-type (IL-4 and IL-10) cytokines in mouse serum, survival rates, survival times, and parasite burdens were detected. In the present study, the immunostimulatory effect of Nc14-3-3 was confirmed, as it triggered Th1-type cytokine (IFN-γ and IL-12) production in mouse serum 2 weeks after the final immunization. Moreover, the immunization of C57BL/6 mice with Nc14-3-3 induced high IgG antibody levels and significant increases in CD8+ T lymphocytes in the spleens of mice, indicating that the cellular immune response was significantly stimulated. Mouse survival rates and times were significantly prolonged after immunization; the survival rates were 40% for Nc14-3-3 immunization and 60% for NEV immunization, while mice that received GST, PBS, or blank control all died at 13, 9, or 8 days, respectively, after intraperitoneal N. caninum challenge. In addition, qPCR analysis indicated that there was a reduced parasite burden and diminished pathological changes in the mice immunized with Nc14-3-3. Our data demonstrate that vaccination of mice with Nc14-3-3 elicits both cellular and humoral immune responses and provides partial protection against acute neosporosis. Thus, Nc14-3-3 could be an effective antigen candidate for vaccine development for neosporosis.

scholarly journals TLR3-TRIF pathway activation by Neospora caninum RNA enhances infection control

2018 ◽  
Author(s):  
Vanessa dos Santos Miranda ◽  
Flávia Batista Ferreira França ◽  
Mylla Spirandelli da Costa ◽  
Vanessa Resende Souza Silva ◽  
Caroline Martins Mota ◽  
...  
Keyword(s):  
Immune Responses ◽  
Neospora Caninum ◽  
Parasitophorous Vacuole ◽  
Parasite Burden ◽  
Protozoan Parasite ◽  
Economic Losses ◽  
Pathway Activation ◽  
Ifn Γ ◽  
Th1 Immune Responses

AbstractNeospora caninum is a protozoan parasite closely related to Toxoplasma gondii and has been studied for causing neuromuscular disease in dogs and abortions in cattle. It is recognized as the major cause of economic losses in bovine products. In that sense, this study aimed to evaluate the role of TLR3-TRIF dependent resistance against N. caninum infection. We observed that TLR3−/− and TRIF−/− mice presented higher parasite burden, increased inflammatory lesions and reduced production of IL-12p40, TNF, IFN-γ, and NO. Differently from T. gondii, N. caninum tachyzoites and its RNA recruited TLR3 and IRF3 to the parasitophorous vacuole (PV). We observed that N. caninum upregulated the expression of TRIF in macrophages, which by its turn upregulated IFN-α and IFN-β in the presence of the parasite. Furthermore, TRIF−/− infected macrophages produced lower levels of IL-12p40 and IFN-α replacement was able to completely restore the production of this key cytokine. Our results have shown that TLR3-TRIF signaling pathway enhances resistance against N. caninum infection, since it improves Th1 immune responses that control parasitism and tissue inflammation, which are hallmarks of the disease.

scholarly journals Essential Role of mGBP7 for Survival of Toxoplasma gondii Infection

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nora Steffens ◽  
Cornelia Beuter-Gunia ◽  
Elisabeth Kravets ◽  
Artur Reich ◽  
Larissa Legewie ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Interferon Gamma ◽  
Parasitophorous Vacuole ◽  
Acute Infection ◽  
Intracellular Pathogen ◽  
Content Type ◽  
Replication Control ◽  
Complete Failure ◽  
Ifn Γ ◽  
Toxoplasma Gondii Infection

ABSTRACT Members of the murine guanylate-binding protein family (mGBP) are induced by interferon gamma (IFN-γ) and have been shown to be important factors in cell-autonomous immunity toward the intracellular pathogen Toxoplasma gondii. Previously, we identified that mGBP2 mediates disruption of the parasitophorous vacuole membrane (PVM) and directly assaults the plasma membrane of the parasite. Here, we show that mGBP7-deficient mice are highly susceptible to T. gondii infection. This is demonstrated by the loss of parasite replication control, pronounced development of ascites, and death of the animals in the acute infection phase. Interestingly, live-cell microscopy revealed that mGBP7 recruitment to the PVM occurs after mGBP2 recruitment, followed by disruption of the PVM and T. gondii integrity and accumulation of mGBP7 inside the parasite. This study defines mGBP7 as a crucial effector protein in resistance to intracellular T. gondii. IMPORTANCE Guanylate-binding proteins (GBPs) are induced by the inflammatory cytokine interferon gamma (IFN-γ) and have been shown to be important factors in the defense of the intracellular pathogen Toxoplasma gondii. In previous studies, we showed that members of the mouse GBP family, such as mGBP2 and mGBP7, accumulate at the parasitophorous vacuole of T. gondii, which is the replicatory niche of the parasite. In this study, we show that mice deficient in mGBP7 succumb early after infection with T. gondii, showing a complete failure of resistance to the pathogen. On a molecular level, mGBP7 is found directly at the parasite, likely mediating its destruction.

scholarly journals Interleukin-17A-Deficient Mice Are Highly Susceptible to Toxoplasma gondii Infection Due to Excessively Induced T. gondii HSP70 and Interferon Gamma Production

2017 ◽  
Vol 85 (12) ◽  
Author(s):  
Masataka Moroda ◽  
Masaya Takamoto ◽  
Yoichiro Iwakura ◽  
Jun Nakayama ◽  
Fumie Aosai
Keyword(s):  
Toxoplasma Gondii ◽  
Interferon Gamma ◽  
Acute Phase ◽  
Host Defense ◽  
Hsp70 Expression ◽  
Mesenteric Lymph Nodes ◽  
Content Type ◽  
Ifn Γ ◽  
Toxoplasma Gondii Infection ◽  
Deficient Mice

ABSTRACT Interleukin17A (IL-17A) is known to be involved in the host defense against pathogens and the pathogenesis of autoimmune diseases. Previously, we showed that excessive amounts of interferon gamma (IFN-γ) play an important role in the pathogenesis of the lethal effects of Toxoplasma gondii by inducing anaphylactic responses. In the study described in this report, we examined the effects of IL-17A deficiency on murine host defense against oral T. gondii infection. IL-17A-deficient C57BL/6 (B6) mice exhibited higher rates of mortality than wild-type (WT) mice during the acute phase of T. gondii infection. CD4+ T cells in the mesenteric lymph nodes (mLNs) and ileum of T. gondii-infected IL-17A-deficient mice produced higher levels of IFN-γ than did those of WT mice. In addition, the level of T. gondii HSP70 (T.g.HSP70) expression was also significantly increased in the ileum, mLNs, liver, and spleen of infected IL-17A-deficient mice compared with that in WT mice. These elevated levels of expression of T.g.HSP70 and IFN-γ in infected IL-17A-deficient mice were presumably linked to the IL-17A defect since they decreased to WT levels after treatment with recombinant IL-17A. Furthermore, IL-17A-deficient mice were highly susceptible to the anaphylactic effect of T.g.HSP70, and the survival of IL-17A-deficient mice during the acute phase was improved by treatment with an anti-T.g.HSP70 monoclonal antibody. These results suggest that IL-17A plays an important role in host survival against T. gondii infection by protecting the host from an anaphylactic reaction via the downregulation of T.g.HSP70 and IFN-γ production.

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