scholarly journals Acute and Chronic Phases of Toxoplasma gondii Infection in Mice Modulate the Host Immune Responses

1998 ◽  
Vol 66 (6) ◽  
pp. 2991-2995 ◽  
Author(s):  
T. D. Nguyen ◽  
G. Bigaignon ◽  
J. Van Broeck ◽  
M. Vercammen ◽  
T. N. Nguyen ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Soluble Protein ◽  
Chronic Phase ◽  
Antibody Responses ◽  
Protein Antigen ◽  
Host Immune Responses ◽  
Toxoplasma Gondii Infection ◽  
Igg1 Isotype ◽  
Murine Antibody

ABSTRACT Murine antibody responses to soluble proteins are generally restricted to the immunoglobulin G1 (IgG1) isotype. When mice were infected with Toxoplasma gondii Beverley and concomitantly immunized with a soluble unrelated protein antigen, a modification in the isotypic distribution of antibodies directed against this nonparasite antigen was observed, with a preferential production of IgG2a. Interestingly, when mice were immunized with a soluble protein antigen during the chronic phase (day 40) of infection with T. gondii Beverley, a similar modification in the isotypic distribution of antiprotein antibodies was observed.

scholarly journals Immune profiling reveals early disease trajectories associated with COVID-19 mortality: a sub-study from the ACTT-1 trial

2021 ◽  
Author(s):  
Joshua M Thiede ◽  
Abigail R Gress ◽  
Samuel D Libby ◽  
Christine E Ronayne ◽  
William E Matchett ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antiviral Therapy ◽  
Symptom Onset ◽  
Antibody Responses ◽  
Early Disease ◽  
Host Immune Responses ◽  
Study Enrollment ◽  
Cytokine Responses ◽  
Study Participants ◽  
Immune Profiling

Abstract COVID-19 outcomes are linked to host immune responses and may be impacted by antiviral therapy. We investigated antibody and cytokine responses in ACTT-1 study participants enrolled at our center. We studied serum specimens from 19 hospitalized adults with COVID-19 randomized to treatment with remdesivir or placebo. We assessed SARS-CoV-2 antibody responses and identified cytokine signatures using hierarchical clustering. We identified no clear immunologic trends attributable to remdesivir treatment. Seven subjects were initially seronegative at study enrollment, and all four deaths occurred in this group with more recent symptom onset. We identified three dominant cytokine signatures, demonstrating different disease trajectories.

scholarly journals Innate, adaptive, and cell-autonomous immunity against Toxoplasma gondii infection

2019 ◽  
Vol 51 (12) ◽  
pp. 1-10 ◽  
Author(s):  
Miwa Sasai ◽  
Masahiro Yamamoto
Keyword(s):  
Immune Response ◽  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Parasitophorous Vacuole ◽  
Interferon Γ ◽  
Protective Role ◽  
Ifn Γ ◽  
Acquired Immune Responses ◽  
Toxoplasma Gondii Infection ◽  
Antimicrobial Immunity

AbstractHosts have been fighting pathogens throughout the evolution of all infectious diseases. Toxoplasma gondii is one of the most common infectious agents in humans but causes only opportunistic infection in healthy individuals. Similar to antimicrobial immunity against other organisms, the immune response against T. gondii activates innate immunity and in turn induces acquired immune responses. After activation of acquired immunity, host immune cells robustly produce the proinflammatory cytokine interferon-γ (IFN-γ), which activates a set of IFN-γ-inducible proteins, including GTPases. IFN-inducible GTPases are essential for cell-autonomous immunity and are specialized for effective clearance and growth inhibition of T. gondii by accumulating in parasitophorous vacuole membranes. Recent studies suggest that the cell-autonomous immune response plays a protective role in host defense against not only T. gondii but also various intracellular bacteria. Moreover, the negative regulatory mechanisms of such strong immune responses are also important for host survival after infection. In this review, we will discuss in detail recent advances in the understanding of host defenses against T. gondii and the roles played by cell-autonomous immune responses.

scholarly journals Transcriptome Analysis of Mouse Brain Infected with Toxoplasma gondii

2013 ◽  
Vol 81 (10) ◽  
pp. 3609-3619 ◽  
Author(s):  
Sachi Tanaka ◽  
Maki Nishimura ◽  
Fumiaki Ihara ◽  
Junya Yamagishi ◽  
Yutaka Suzuki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Mouse Brain ◽  
Transcriptome Analysis ◽  
Host Cells ◽  
Content Type ◽  
Host Immune Responses ◽  
Wide Range ◽  
The Brain

ABSTRACTToxoplasma gondiiis an obligate intracellular parasite that invades a wide range of vertebrate host cells. Chronic infections withT. gondiibecome established in the tissues of the central nervous system, where the parasites may directly or indirectly modulate neuronal function. However, the mechanisms underlying parasite-induced neuronal disorder in the brain remain unclear. This study evaluated host gene expression in mouse brain following infection withT. gondii. BALB/c mice were infected with the PLK strain, and after 32 days of infection, histopathological lesions in the frontal lobe were found to be more severe than in other areas of the brain. Total RNA extracted from infected and uninfected mouse brain samples was subjected to transcriptome analysis using RNA sequencing (RNA-seq). In theT. gondii-infected mice, 935 mouse brain genes were upregulated, whereas 12 genes were downregulated. GOstat analysis predicted that the upregulated genes were primarily involved in host immune responses and cell activation. Positive correlations were found between the numbers of parasites in the infected mouse brains and the expression levels of genes involved in host immune responses. In contrast, genes that had a negative correlation with parasite numbers were predicted to be involved in neurological functions, such as small-GTPase-mediated signal transduction and vesicle-mediated transport. Furthermore, differential gene expression was observed between mice exhibiting the clinical signs of toxoplasmosis and those that did not. Our findings may provide insights into the mechanisms underlying neurological changes duringT. gondiiinfection.

Host immune responses to Toxoplasma gondii

2018 ◽  
Vol 30 (3) ◽  
pp. 113-119 ◽  
Author(s):  
Miwa Sasai ◽  
Ariel Pradipta ◽  
Masahiro Yamamoto
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Host Immune Responses
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