Protection against Lethal Toxoplasmosis in Mice by an Avirulent Strain of Toxoplasma gondii: Stimulation of IFN-γ and TNF-α Response

1999 ◽  
Vol 93 (4) ◽  
pp. 231-240 ◽  
Author(s):  
Sakhina Haque ◽  
Jacqueline Franck ◽  
Henri Dumon ◽  
Lloyd H. Kasper ◽  
Azizul Haque
2017 ◽  
Vol 44 (2) ◽  
pp. 751-762 ◽  
Author(s):  
Yuwei Gao ◽  
Baixue Xu ◽  
Peng Zhang ◽  
Yanlong He ◽  
Xin Liang ◽  
...  

Background/Aims: The aim of this study was to investigate the involvement of inducible co-stimulatory ligand (ICOSL) expression in stimulation of mast cells (MCs) by TNF-α and the ability of TNF-α stimulation of MCs to influence CD4+ T cell differentiation and function. The mechanisms underlying TNF-α stimulation of MCs were also explored. Methods: Mast cells and CD4+ T cells were prepared from C57BL/6 mice (aged 6–8 weeks). ICOSL expression by MCs was measured by real-time PCR and flow cytometry, and levels of IL-4, IL-10 and IFN-γ were measured by ELISA. Results: ICOSL expression by MCs was increased by TNF-α stimulation, and resulted in interaction with CD4+ T cells. The IL-4 and IL-10 levels in the co-culture system increased, while IFN-γ levels decreased. Furthermore, CD4+CD25+Foxp3+ T cell proliferation was induced by co-culture with TNF-α-stimulated MCs. The mechanism by which TNF-α stimulated MCs was dependent on the activation of the MAPK signaling pathway. Conclusion: TNF-α upregulated the expression of ICOSL on mast cells via a mechanism that is dependent on MAPK phosphorylation. TNF-α-treated MCs promoted the differentiation of regulatory T cells and induced a shift in cytokine expression from a Th1 to a Th2 profile by up-regulation ICOSL expression and inhibition of MC degranulation. Our study reveals a novel mechanism by which mast cells regulate T cell function.


2020 ◽  
Vol 15 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Amir Keyhani ◽  
Mojtaba Shakibaie ◽  
Hossein Mahmoudvand ◽  
Sareh Jahanbakhsh ◽  
Amir T. Kareshk ◽  
...  

Background: Studies showed that biogenic selenium nanoparticles (SeNPs) have a number of pharmacological properties, such as antimicrobial ones. Objective: The present investigation assesses the efficacy of biogenic selenium nanoparticles (SeNPs) as a new patent against latent toxoplasmosis in a mice model. Methods: Male BALB/c mice were orally treated with SeNPs at the doses of 2.5, 5, 10 mg/kg once a day for 14 days. On the 15th day, the mice were infected with the intraperitoneal inoculation of 20-25 tissue cysts from the Tehran strain of Toxoplasma gondii. The mean numbers of brain tissue cysts and the mRNA levels of TNF-α, IL-12, IL-10, IFN-γ, and inducible nitric oxide synthase (iNOS) in mice of each tested group were measured. Moreover, serum clinical chemistry factors in treated mice were examined to determine the safety of SeNPs. Results: The mean number of the brain tissue cysts was significantly (P<0.001) decreased in mice treated with SeNPs at doses 2.5 (n=37), 5 (n=11), and 10 mg/kg (n=3) based on a dose dependent manner compared with the control group (n=587). The mRNA levels of IFN-γ, TNF-α, IL-12, and iNO were significantly increased in mice treated with SeNPs at the doses 10 mg/kg compared with control subgroups (p<0.05). No significant variation (p>0.05) was observed in the clinical chemistry parameters among the mice in the control subgroups compared with groups treated with SeNPs. Conclusion: The results of the present study showed a new patent in the treatment of toxoplasmosis; so that taking the biogenic selenium nanoparticles in concentrations of 2.5-10 mg/kg for 2 weeks was able to prevent severe symptoms of the toxoplasmosis in a mice model. This indicated the prophylactic effects of SeNPs with no considerable toxicity against latent toxoplasmosis. However, more studies are required to elucidate the correct anti-Toxoplasma mechanisms of SeNPs.


Cytokine ◽  
1992 ◽  
Vol 4 (6) ◽  
pp. 568-575 ◽  
Author(s):  
P.F. Zangerle ◽  
D. De Groote ◽  
M. Lopez ◽  
R.J. Meuleman ◽  
Y. Vrindts ◽  
...  

Cytokine ◽  
1992 ◽  
Vol 4 (3) ◽  
pp. 239-248 ◽  
Author(s):  
D. De Groote ◽  
P.F. Zangerle ◽  
Y. Gevaert ◽  
M.F. Fassotte ◽  
Y. Beguin ◽  
...  

1998 ◽  
Vol 66 (10) ◽  
pp. 4989-4993 ◽  
Author(s):  
S. K. Halonen ◽  
F.-C. Chiu ◽  
L. M. Weiss

ABSTRACT Cytokines play a significant role in the regulation ofToxoplasma gondii in the central nervous system. Cytokine-activated microglia are important host defense cells in central nervous system infections. Recent evidence indicates that astrocytes can also be activated by cytokines to inhibit intracellular pathogens. In this study, we examined the effect of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-1 on the growth of T. gondii in a primary murine astrocyte culture. Pretreatment of astrocytes with IFN-γ resulted in 65% inhibition of T. gondii growth. Neither TNF-α, IL-1, nor IL-6 alone had any effect on T. gondii growth. IFN-γ in combination with either TNF-α, IL-1, or IL-6 caused a 75 to 80% inhibition of growth. While nitric oxide was produced by astrocytes treated with these cytokines, inhibition of T. gondiigrowth was not reversed by the addition of the nitric oxide synthase inhibitor N G-monomethyl-l-arginine. Furthermore, IFN-γ in combination with IL-1, IL-6, or TNF-α also induced inhibition in astrocytes derived from syngeneic mice deficient in the enzyme inducible nitric oxide synthase. This finding suggests that the mechanism of cytokine inhibition is not nitric oxide mediated. Similarly, the addition of tryptophan had no effect on inhibition, indicating that the mechanism was not mediated via induction of the enzyme indoleamine 2,3-dioxygenase. The mechanism of inhibition remains to be elucidated. Results from this study demonstrate that cytokine-activated astrocytes are capable of significantly inhibiting the growth of T. gondii. These data indicate that astrocytes may be important host defense cells in controlling toxoplasmosis in the brain.


1998 ◽  
Vol 66 (8) ◽  
pp. 3959-3963 ◽  
Author(s):  
Neide M. Silva ◽  
Ricardo T. Gazzinelli ◽  
Deise A. O. Silva ◽  
Eloisa A. V. Ferro ◽  
Lloyd H. Kasper ◽  
...  

ABSTRACT Stage conversion between bradyzoites and tachyzoites was investigated in C57BL/6 mice chronically infected with the ME-49 strain of Toxoplasma gondii. In order to promote bradyzoite-tachyzoite conversion, mice were treated in vivo with neutralizing doses of anti-gamma interferon (IFN-γ) or anti-tumor necrosis factor alpha (TNF-α) antibodies. Expression of parasite-specific antigens SAG-1, SAG-2, and heat shock protein 70 (Hsp-70) was visualized in the central nervous system by immunocytochemistry and measured by photometric assay. The immunosuppressive effect of anti-IFN-γ or anti-TNF-α treatment was immediate, leading to parasite stage conversion as indicated by the increased expression of tachyzoite-specific antigens (SAG-1 and SAG-2) and by rapid parasite replication. We also observed expression of high levels of Hsp-70 during a short period of conversion of bradyzoites to tachyzoites. Our data suggest that Hsp-70 may have an important role in the process of bradyzoite-tachyzoite conversion during the reactivation of chronic toxoplasmosis.


Cytokine ◽  
1995 ◽  
Vol 7 (5) ◽  
pp. 408-416 ◽  
Author(s):  
Angela M Deakin ◽  
Adrian N. Payne ◽  
Brendan J.R. Whittle ◽  
Salvador Moncada
Keyword(s):  
Tnf Α ◽  
Ifn Γ ◽  

1994 ◽  
Vol 78 (2) ◽  
pp. 217-229 ◽  
Author(s):  
R.T. Gazzinelli ◽  
A. Brezin ◽  
Q. Li ◽  
R.B. Nussenblatt ◽  
C.C. Chan

1992 ◽  
Vol 144 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Anita S.-F. Chong ◽  
Ian A. Boussy ◽  
Lloyd H. Graf ◽  
Philip Scuderi

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