Infectious disease
Abstract
Authors
Giang Pham, Raymond E. Diep, Lucien H. Turner, David B. Haslam, Sing Sing Way
Abstract
Human cytomegalovirus (HCMV) profoundly impacts host T and natural killer (NK) cells across the lifespan, yet how this common congenital infection modulates developing fetal immune cell compartments remains underexplored. Using cord blood from neonates with and without congenital HCMV (cCMV) infection, we identify an expansion of Fcγ receptor III (FcγRIII)-expressing CD8+ T cells following HCMV exposure in utero. Most FcγRIII+ CD8+ T cells express the canonical αβ T cell receptor (TCR) but a proportion express non-canonical γδ TCR. FcγRIII+ CD8+ T cells are highly differentiated and have increased expression of NK cell markers and cytolytic molecules. Transcriptional analysis reveals FcγRIII+ CD8+ T cells upregulate T-bet and downregulate BCL11B, known transcription factors that govern T/NK cell fate. We show that FcγRIII+ CD8+ T cells mediate antibody-dependent IFNγ production and degranulation against IgG-opsonized target cells, similar to NK cell antibody-dependent cellular cytotoxicity (ADCC). FcγRIII+ CD8+ T cell Fc effector functions were further enhanced by interleukin-15 (IL-15), as has been observed in neonatal NK cells. Our study reveals that FcγRIII+ CD8+ T cells elicited in utero by HCMV infection can execute Fc-mediated effector functions bridging cellular and humoral immunity and may be a promising target for antibody-based therapeutics and vaccination in early life.
Authors
Eleanor C. Semmes, Danielle R. Nettere, Ashley N. Nelson, Jillian H. Hurst, Derek W. Cain, Trevor D. Burt, Joanne Kurtzberg, R. Keith Reeves, Carolyn B. Coyne, Genevieve G. Fouda, Justin Pollara, Sallie R. Permar, Kyle M. Walsh
Abstract
Respiratory syncytial virus (RSV) selectively targets ciliated cells in human bronchial epithelium and can cause bronchiolitis and pneumonia, mostly in infants. To identify molecular targets of intervention during RSV infection in infants, we investigated how age regulates RSV interaction with the bronchial epithelium barrier. Employing precision-cut lung slices and air-liquid interface cultures generated from infant and adult human donors, we found robust RSV virus spread and extensive apoptotic cell death only in infant bronchial epithelium. In contrast, adult bronchial epithelium showed no barrier damage and limited RSV infection. Single nuclear RNA-Seq revealed age-related insufficiency of an antiapoptotic STAT3 activation response to RSV infection in infant ciliated cells, which was exploited to facilitate virus spread via the extruded apoptotic ciliated cells carrying RSV. Activation of STAT3 and blockade of apoptosis rendered protection against severe RSV infection in infant bronchial epithelium. Lastly, apoptotic inhibitor treatment of a neonatal mouse model of RSV infection mitigated infection and inflammation in the lung. Taken together, our findings identify a STAT3-mediated antiapoptosis pathway as a target to battle severe RSV disease in infants.
Authors
Caiqi Zhao, Yan Bai, Wei Wang, Gaurang M. Amonkar, Hongmei Mou, Judith Olejnik, Adam J. Hume, Elke Mühlberger, Nicholas W. Lukacs, Rachel Fearns, Paul H. Lerou, Xingbin Ai
Abstract
Authors
Andrés R. Muñoz-Rojas, Adam C. Wang, Lisa E. Pomeranz, Elizabeth L. Reizis, Heather W. Stout-Delgado, Ileana C. Miranda, Krishnan Rajagopalan, Tadiwanashe Gwatiringa, Roger R. Fan, Ahmad A. Huda, Neha Maskey, Roseline P. Olumuyide, Aryan S. Patel, Jeffrey M. Friedman, Diane Mathis, Kartik N. Rajagopalan
Abstract
Impaired fatty acid oxidation (FAO) and the therapeutic benefits of FAO restoration have been revealed in sepsis. However, the regulatory factors contributing to FAO dysfunction during sepsis remain inadequately clarified. In this study, we identified a subset of lipid-associated macrophages characterized by high expression of trigger receptor expressed on myeloid cells 2 (TREM2) and demonstrated that TREM2 acted as a suppressor of FAO to increase the susceptibility to sepsis. TREM2 expression was markedly up-regulated in sepsis patients and correlated with the severity of sepsis. Knock out of TREM2 in macrophages improved the survival rate and reduced inflammation and organ injuries of sepsis mice. Notably, TREM2-deficient mice exhibited decreased triglyceride accumulation and an enhanced FAO rate. Further observations showed that the blockade of FAO substantially abolished the alleviated symptoms observed in TREM2 knockout mice. Mechanically, we demonstrated that TREM2 interacted with the phosphatase SHP1 to inhibit Bruton tyrosine kinas (BTK)-mediated FAO in sepsis. Our findings expand the understanding of FAO dysfunction in sepsis and reveal TREM2 as a critical regulator of FAO, which may provide a promising target for the clinical treatment of sepsis.
Authors
Siqi Ming, Xingyu Li, Qiang Xiao, Siying Qu, Qiaohua Wang, Qiongyan Fang, Pingping Liang, Yating Xu, Jingwen Yang, Yongqiang Yang, Xi Huang, Yongjian Wu
Abstract
Authors
Lorenza Bellusci, Hana Golding, Surender Khurana
Abstract
Microglia are recognized as the main cells in the central nervous system responsible for phagocytosis. The current study demonstrated that in prion disease, microglia effectively phagocytose prions or PrPSc during early preclinical stages. However, a critical shift occured in microglial activity during the late preclinical stage, transitioning from PrPSc uptake to establishing extensive neuron-microglia body-to-body cell contacts. This change was followed by a rapid accumulation of PrPSc in the brain. Microglia that enveloped neurons exhibited hypertrophic, cathepsin D-positive lysosomal compartments. However, most neurons undergoing envelopment were only partially encircled by microglia. Despite up to 40% of cortical neurons being partially enveloped at clinical stages, only a small percentage of envelopment proceeded to full engulfment. Partially enveloped neurons lacked apoptotic markers but showed signs of functional decline. Neuronal envelopment was independent of the CD11b pathway, previously associated with phagocytosis of newborn neurons during neurodevelopment. This phenomenon of partial envelopment was consistently observed across multiple prion-affected brain regions, various mouse-adapted strains, and different subtypes of sporadic Creutzfeldt-Jakob disease (sCJD) in humans. The current work describes a new phenomenon of partial envelopment of neurons by reactive microglia in the context of an actual neurodegenerative disease, not a disease model.
Authors
Natallia Makarava, Tarek Safadi, Olga Bocharova, Olga Mychko, Narayan P. Pandit, Kara Molesworth, Simone Baiardi, Li Zhang, Piero Parchi, Ilia V. Baskakov
Abstract
A leading cause of mortality after influenza infection is the development of a secondary bacterial pneumonia. In the absence of a bacterial superinfection, prescribing antibacterial therapies is not indicated but has become a common clinical practice for those presenting with a respiratory viral illness. In a murine model, we found that antibiotic use during influenza infection impaired the lung innate immunologic defenses toward a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA). Antibiotics augment lung eosinophils, which have inhibitory effects on macrophage function through the release of major basic protein. Moreover, we demonstrated antibiotic treatment during influenza infection causes a fungal dysbiosis that drive lung eosinophilia and impair MRSA clearance. Finally, we evaluated three cohorts of hospitalized patients and found eosinophils positively correlated with antibiotic use, systemic inflammation, and worsened outcomes. Altogether, our work demonstrates a detrimental effect of antibiotic treatment during influenza infection that has harmful immunologic consequences via recruitment of eosinophils to the lungs thereby increasing the risk of developing a secondary bacterial infection.
Authors
Marilia Sanches Santos Rizzo Zuttion, Tanyalak Parimon, Stephanie A. Bora, Changfu Yao, Katherine Lagree, Catherine A. Gao, Richard G. Wunderink, Georgios D. Kitsios, Alison Morris, Yingze Zhang, Bryan J. McVerry, Matthew E. Modes, Alberto M. Marchevsky, Barry R. Stripp, Christopher M. Soto, Ying Wang, Kimberly Merene, Silvia Cho, Blandine L. Victor, Ivan Vujkovic-Cvijin, Suman Gupta, Suzanne Cassel, Fayyaz S. Sutterwala, Suzanne Devkota, David M. Underhill, Peter Chen
Abstract
Intestinal dysmotility syndromes have been epidemiologically associated with several antecedent bacterial and viral infections. To model this phenotype, we previously infected mice with the neurotropic flavivirus, West Nile Virus (WNV) and demonstrated intestinal transit defects. Here, we find that within one week of WNV infection, enteric neurons and glia become damaged, resulting in sustained reductions of neuronal cells and their networks of connecting fibers. Using cell-depleting antibodies, adoptive transfer experiments, and mice lacking specific immune cells or immune functions, we show that infiltrating WNV-specific CD4+ and CD8+ T cells damage the enteric nervous system (ENS) and glia, which leads to intestinal dysmotility; these T cells use multiple and redundant effector functions including perforin and Fas ligand. In comparison, WNV-triggered ENS injury and intestinal dysmotility appears to not require infiltrating monocytes and damage may be limited by resident muscularis macrophages. Overall, our experiments support a model whereby antigen specific T cell subsets and their effector molecules responding to WNV infection direct immune pathology against enteric neurons and supporting glia that results in intestinal dysmotility.
Authors
Hana Janova, Fang R. Zhao, Pritesh Desai, Matthias Mack, Larissa B. Thackray, Thaddeus S. Stappenbeck, Michael S. Diamond
Abstract
Background. Most humans have been infected by Cytomegalovirus (CMV) by the time they reach forty years of age. Whereas most of these CMV infections are well controlled by the immune system, congenital infection can lead to serious health effects and death for the fetus and neonate. Most humans have been infected bywith cytomegalovirus (CMV) by the time they reach mid-life without clinical signs of disease. However, in settings in which the immune system is undeveloped or compromised, the virus is not adequately controlled, and consequently presents a major infectious cause of both congenital disease during pregnancy as well as opportunistic infection in children and adults. With clear evidence that risk to the fetus is lower during chronic maternal infection, and varies in association with gestational age at the time of primary maternal infection, further research on humoral immune responses to primary CMV infection during pregnancy is needed. Methods. Here, systems serology tools were applied to characterize antibody responses to CMV infection inamong pregnant and non-pregnant women experiencing either primary or chronic infection. Results. Whereas strikingly different antibody profiles were observed depending on infection status, more limited differences were associated with pregnancy status. Beyond known differences in IgM responses that are used clinically for identification of primary infection, distinctions observed in IgA and FcγR- binding antibodiesy responses and among viral antigen specificities accurately predicted infection status in a cross-sectional cohort. Leveraging machine Machine learning, longitudinal samples were also was used to define an immunological clock of CMV infectionthe transition from primary to chronic states and predict time since primary infection with high accuracy. Humoral responses diverged over time in an antigen-specific manner, with IgG3 responses toward tegument decreasing over time as is typical of viral infections, while those directed to pentamer and glycoprotein B were lower during acute and greatest during chronic infection. Conclusion. In sum, this work provides new insights into the antibody response associated with CMV infection status in the context of pregnancy, revealing aspects of humoral immunity that have the potential to improve CMV diagnostics and to support clinical trials of interventions to reduce mother-to-fetus transmission of CMV. Trial registration. Not applicable Funding. CYMAF consortium and National Institutes of Health
Authors
Andrew P. Hederman, Christopher J. Remmel, Shilpee Sharma, Harini Natarajan, Joshua A. Weiner, Daniel Wrapp, Catherine Donner, Marie-Luce Delforge, Piera d'Angelo, Milena Furione, Chiara Fornara, Jason S. McLellan, Daniele Lilleri, Arnaud Marchant, Margaret E. Ackerman
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ISSN: 0021-9738 (print), 1558-8238 (online)