Pathogenesis and outcome of VA1 astrovirus infection in the human brain are defined by disruption of neural functions and imbalanced host immune responses.
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ABSTRACT: Infections of the central nervous system (CNS) in humans are on the rise due to changing environmental conditions and increase in vulnerable populations comprised of immunocompromised subjects with primary (genetic) or secondary (acquired) immunodeficiency. Many viruses take the opportunity to invade the CNS by capitalizing on impaired immunity of the host. Here we investigate neuropathogenesis of a rare CNS infection in immunocompromised patients caused by the astrovirus and show that it shares many features with another opportunistic infection of the CNS associated with human immunodeficiency virus. We show that astrovirus infects CNS neurons with a major impact on the brainstem. This leads to disrupted synaptic integrity loss of afferent innervation related to infected neurons and global impairment of both excitatory and inhibitory neurotransmission. In the settings of impaired peripheral adaptive immunity host responses to astrovirus infection are dominated by the microglia-macrophage-phagocytosis axis which may be a common compensatory defense mechanism employed by the CNS against opportunistic infections.
Project description:Opportunistic infections of the respiratory tract often succeed under a weakened immune response caused by an underlying illness or hospitalization. The human fungal pathogen, Cryptococcus neoformans, and the bacterial pathogen, Klebsiella pneumoniae, are both well-characterized microbes that cause severe infections within immunocompromised individuals. In this study, we simulate a concentration-dependent pulmonary coinfection of a bacterial and fungal pathogen, and profile the proteomic changes by DDA vs. DIA. Dual perspective profiling provides new insights into host defense regulation of infection and pathogenic mechanisms of invasion.
Project description:Toxoplasma gondii (T. gondii) is an opportunistic parasite that can infect the central nervous system, causing severe toxoplasmosis and behavioral cognitive impairment. Mortality is high in immunocompromised individuals with toxoplasmosis, most commonly due to reactivation of infection in the central nervous system (CNS). There are still no effective vaccines and drugs for the prevention and treatment of toxoplasmosis. There are five developmental stages for T. gondii to complete life cycle, of which the tachyzoite and bradyzoite stages are the key to the acute and chronic infection. In this study, to better understanding of how T. gondii interacts with the host central nervous system at different stages of infection, we constructed acute and chronic infection models of T. gondii in astrocytes, and used lab-free proteomics to detect the proteome changes before and after infection, respectively.
Project description:Viral infections of the CNS are of increasing concern, especially among immunocompromised populations. Rodent models are often inappropriate for studies of CNS infection, as many viruses, including JC Virus (JCV) and HIV, cannot replicate in rodent cells. Consequently, human fetal brain-derived multipotential CNS progenitor cells (NPCs) that can be differentiated into neurons, oligodendrocytes, or astrocytes, have served as a model for CNS studies. NPCs can be non-productively infected by JCV, while infection of progenitor-derived astrocytes (PDAs) is robust. We profiled cellular gene expression at multiple times during differentiation of NPCs to PDAs. Several activated transcription factors show commonality between cells of the brain in which JCV replicates and lymphocytes in which JCV is likely latent. Bioinformatic analysis determined transcription factors that may influence the favorable transcriptional environment for JCV in PDAs. This study attempts to provide a framework for understanding the functional transcriptional profile necessary for productive JCV infection. 19 Human samples: 4 Human Fetal Brain NPC 0h, 4 Human Fetal Brain NPC in Serum 1h, 4 Human Fetal Brain NPC in Serum 1d, 4 Human Fetal Brain NPC in Serum 7d, 3 Human Fetal Brain NPC in Serum 30d.
Project description:KSHV-related primary effusion lymphoma is mostly seen in immunocompromised individuals such as HIV+ patients, who frequently suffering polymicrobial infections including different opportunistic pathogens. It is interesting to explore the host gene profile in PEL altered by bacterial quorum sensing molecules, the key systems regulating virulence factors in many bacteria.
Project description:KSHV-related primary effusion lymphoma is mostly seen in immunocompromised individuals such as HIV+ patients, who frequently suffering polymicrobial infections including different opportunistic pathogens. It is interesting to explore the host gene profile in PEL altered by bacterial quorum sensing molecules, the key systems regulating virulence factors in many bacteria.
Project description:KSHV-related primary effusion lymphoma is mostly seen in immunocompromised individuals such as HIV+ patients, who frequently suffering polymicrobial infections including different opportunistic pathogens. It is interesting to explore the host gene profile in PEL altered by bacterial quorum sensing molecules, the key systems regulating virulence factors in many bacteria.
Project description:KSHV-related primary effusion lymphoma is mostly seen in immunocompromised individuals such as HIV+ patients, who frequently suffering polymicrobial infections including different opportunistic pathogens. It is interesting to explore the host gene profile in PEL altered by bacterial quorum sensing molecules, the key systems regulating virulence factors in many bacteria.
Project description:Viral infections of the CNS are of increasing concern, especially among immunocompromised populations. Rodent models are often inappropriate for studies of CNS infection, as many viruses, including JC Virus (JCV) and HIV, cannot replicate in rodent cells. Consequently, human fetal brain-derived multipotential CNS progenitor cells (NPCs) that can be differentiated into neurons, oligodendrocytes, or astrocytes, have served as a model for CNS studies. NPCs can be non-productively infected by JCV, while infection of progenitor-derived astrocytes (PDAs) is robust. We profiled cellular gene expression at multiple times during differentiation of NPCs to PDAs. Several activated transcription factors show commonality between cells of the brain in which JCV replicates and lymphocytes in which JCV is likely latent. Bioinformatic analysis determined transcription factors that may influence the favorable transcriptional environment for JCV in PDAs. This study attempts to provide a framework for understanding the functional transcriptional profile necessary for productive JCV infection.
Project description:An IRF4 de novo mutation affecting the DNA binding domain of encoded IRF4 protein (mutDBD) was identified in a patient presenting with combined immunodeficiency. The patient exhibited profound susceptibility to opportunistic infections notably Pneumocystis jirovecii and humoral immunodeficiency caused by a failure of terminal B cell differentiation. A heterozygous IRF4 missense variant resulting in a phenylalanine-to-leucine replacement within the interferon activation domain of the encoded IRF4 protein (mutIAD) was identified in three patients from a multigenerational family suffering from a novel autosomal dominant disease predominantly presenting as a hypogammaglobulinemia with recurrent infections. In this experiment we aimed to investigate the effect of the two different mutations on IRF4 regulated transcription.
Project description:An IRF4 de novo mutation affecting the DNA binding domain of encoded IRF4 protein (mutDBD) was identified in a patient presenting with combined immunodeficiency. The patient exhibited profound susceptibility to opportunistic infections notably Pneumocystis jirovecii and humoral immunodeficiency caused by a failure of terminal B cell differentiation. A heterozygous IRF4 missense variant resulting in a phenylalanine-to-leucine replacement within the interferon activation domain of the encoded IRF4 protein (mutIAD) was identified in three patients from a multigenerational family suffering from a novel autosomal dominant disease predominantly presenting as a hypogammaglobulinemia with recurrent infections. In this experiment we aimed to investigate the effect of the two different mutations on IRF4 genomic binding.