Infectious disease
Abstract
Severe asthma in children is notoriously difficult to treat, and its immunopathogenesis is complex. In particular, the contribution of T cells and relationships to antiviral immunity remain enigmatic. Here, we coupled deep phenotyping with machine learning methods to elucidate the dynamics of T cells in the lower airways of children with treatment-refractory recurrent wheeze, and examine rhinovirus (RV) as a driver. Our strategy revealed a T cell landscape dominated by type 1 and type 17 CD8+ signatures. Interrogation of phenotypic relationships coupled with trajectory mapping identified T cell migratory and differentiation pathways spanning the blood and airways that culminated in tissue residency, and involved transitions between type 1 and type 17 tissue-resident types. These dynamics were reflected in cytokine polyfunctionality. Use of machine learning tools to cross-compare T cell populations that were enriched in the airways of RV-positive children with those induced in the blood following experimental RV challenge precisely pinpointed RV-responsive signatures that contributed to T cell migratory and differentiation pathways. Despite their rarity, these signatures were also detected in the airways of RV-negative children. Together, our results underscore the aberrant nature of type 1 immunity in the airways of children with recurrent wheeze, and implicate an important viral trigger as a driver.
Authors
Naomi Bryant, Lyndsey M. Muehling, Kristin Wavell, W. Gerald Teague, Judith A. Woodfolk
Abstract
P.falciparum infection can trigger high levels of inflammation that lead to fever and sometimes severe disease. People living in malaria-endemic areas gradually develop resistance to symptomatic malaria and control both parasite numbers and the inflammatory response. We previously found that adaptive NK cells correlated with reduced parasite load and protection from symptoms. We also found that murine NK cell production of IL-10 protected mice from experimental cerebral malaria. Human NK cells can also secrete IL-10, but it is unknown what NK cell subsets produce IL-10 or if this is affected by malaria experience. We hypothesized that NK cell immunoregulation may lower inflammation and reduce fever induction. Here, we showed that NK cells from participants with malaria experience make significantly more IL-10 than participants with no malaria experience. We then determined the proportions of NK cells that are cytotoxic and produce IFN-γ and/or IL-10 and identified a signature of adaptive and checkpoint molecules on IL-10–producing NK cells. Lastly, we found that coculture with primary monocytes, Plasmodium-infected RBCs, and antibody induced IL-10 production by NK cells. These data suggest that NK cells may contribute to protection from malaria symptoms via IL-10 production.
Authors
Sarah A. McNitt, Jenna K. Dick, Maria Andrea Hernandez-Castaneda, Jules Sangala, Mark Pierson, Marissa Macchietto, Kristina S. Burrack, Peter D. Crompton, Karl Seydel, Sara E. Hamilton, Geoffrey T. Hart
Abstract
Measles remains one of the most important causes of worldwide morbidity and mortality in children. Measles virus (MeV) replicates extensively in lymphoid tissue and most deaths are due to other infectious diseases associated with MeV-induced loss of circulating antibodies to other pathogens. To determine whether remdesivir, a broad-spectrum direct-acting antiviral, affects MeV-induced loss of antibody to other pathogens, we expanded the VirScan technology to detect antibody to both human and macaque pathogens. We measured the antibody reactivity to MeV and non-MeV viral peptides using plasma from MeV-infected macaques that received remdesivir either as post-exposure prophylaxis (d3-14, PEP) or as late treatment (d11-22, LT) in comparison with macaques that were not treated. Remdesivir PEP, but not LT, limited the loss of antibody to non-MeV pathogens. Remdesivir PEP also limited the antibody response to MeV with a decrease in both the magnitude and breadth of the epitopes recognized. LT had little effect on the magnitude of the MeV-specific antibody response but affected the breadth of the response. Therefore, early, but not late, treatment of measles with the direct-acting antiviral remdesivir prevents the loss of antibody to other pathogens but decreases the response to MeV.
Authors
Andy Kwan Pui Chan, Liting Liu, William R. Morgenlander, Manjusha Thakar, Nadine A. Peart Akindele, Jacqueline Brockhurst, Shristi Ghimire, Maggie L. Bartlett, Kelly A. Metcalf Pate, Victor C. Chu, Meghan S. Vermillion, Danielle P. Porter, Tomas Cihlar, Michael J. Mina, H. Benjamin Larman, Diane E. Griffin
Abstract
Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM) is a rare neurodegenerative disease with largely elusive molecular mechanisms, impeding targeted therapeutic advancements. This study aimed to identify the critical molecule responsible for neuronal damage in HAM, its source, and the regulatory mechanisms controlling its expression. Utilizing patient-derived cells and established cell lines, we discovered that HTLV-1 Tax, in conjunction with Specificity Protein 1 (Sp1), enhanced the expression of repulsive guidance molecule A (RGMa), a molecule known to contribute to neuronal damage. RGMa expression was specifically upregulated in HTLV-1-infected cells from HAM patients, particularly in those expressing HTLV-1 Tax. Furthermore, in CD4+ cells from HAM patients, the level of H3K27me3 methylation upstream of the RGMA gene locus was reduced, making RGMA more prone to constitutive expression. We demonstrated that HTLV-1-infected cells in HAM inflict neuronal damage via RGMa. Crucially, the neutralizing antibody against RGMa, unasnemab/MT-3921, effectively mitigated this damage in a dose-responsive manner, highlighting RGMa's pivotal role in neuronal damage and its potential as a therapeutic target for alleviating neuronal damage in HAM.
Authors
Natsumi Araya, Makoto Yamagishi, Makoto Nakashima, Naomi Asahara, Kazuhiro Kiyohara, Satoko Aratani, Naoko Yagishita, Erika Horibe, Izumi Ishizaki, Toshiki Watanabe, Tomoo Sato, Kaoru Uchimaru, Yoshihisa Yamano
Abstract
Pf bacteriophages, lysogenic viruses that infect Pseudomonas aeruginosa (Pa), are implicated in the pathogenesis of chronic Pa infections; phage-infected (Pf+) strains are known to predominate in people with cystic fibrosis (pwCF) who are older and have more severe disease. However, the transmission patterns of Pf underlying the progressive dominance of Pf+ strains are unclear. In particular, it is unknown whether phage transmission commonly occurs horizontally between bacteria via viral particles within the airway or if Pf+ bacteria are mostly acquired via de novo Pseudomonas infections. Here, we studied Pa genomic sequences from 3 patient cohorts totaling 662 clinical isolates from 105 pwCF. We identified Pf+ isolates and analyzed transmission patterns of Pf within patients between genetically similar groups of bacteria called “clone types”. We found that Pf was predominantly passed down vertically within Pa clone types and rarely via horizontal transfer between clone types within the airway. Conversely, we found extensive evidence of Pa de novo infection by a new, genetically distinct Pf+ Pa. Finally, we observed that clinical isolates showed reduced activity of the type IV pilus and reduced susceptibility to Pf in vitro. These results cast new light on the transmission of virulence-associated phages in the clinical setting.
Authors
Julie D. Pourtois, Naomi L. Haddock, Aditi Gupta, Arya Khosravi, Hunter A. Martinez, Amelia K. Schmidt, Prema S. Prakash, Ronit Jain, Piper Fleming, Tony H. Chang, Carlos Milla, Patrick R. Secor, Giulio A. De Leo, Paul L. Bollyky, Elizabeth B. Burgener
Abstract
We developed a 29-color spectral cytometry panel to enhance nonhuman primate (NHP) models for cross-reactive immunophenotyping. This panel is suitable for biosafety level 4 (BSL-4) viruses and can be used with both human and NHP samples in BSL-2 research settings. Tissues from humans, rhesus monkeys (RhMs), crab-eating macaques (CEMs), and green monkeys (GMs) were stained with a 29-color immunophenotyping panel requiring only two clone substitutions. Comparable staining was observed for all samples. Unbiased analysis showed acceptable overlap in T-cell phenotypes across samples, with differences in human and NHP B cells and granulocytes. In CEMs, most circulating CD8+ T cells were from effector memory cells, with significantly higher levels than in humans (p<0.0001), RhMs (p<0.05), and GMs (p<0.01). Analysis of samples from various anatomical sites revealed distinct location-specific phenotypes. In Nipah-virus-exposed animals, splenocytes showed a substantial increase in IgM+ B cells (p<0.0001) and a reduction in effector memory CD8+ T cells (p<0.0001) compared to unexposed controls. Lymph nodes from Ebola-virus-exposed animals showed a loss of CXCR3+CD8+ T cells vs unexposed controls. This panel may guide the development of additional multi-color panels in preclinical and clinical settings and potentially increase understanding of the pathogenesis of diseases caused by emerging and re-emerging viruses.
Authors
Andrew P. Platt, Bobbi Barr, Anthony Marketon, Rebecca Bernbaum, Deja F.P. Rivera, Vincent J. Munster, Daniel S. Chertow, Michael R. Holbrook, Scott M. Anthony, Bapi Pahar
Abstract
Invasive aspergillosis is characterized by lung hemorrhage and release of extracellular heme, which promotes fungal growth. Heme can also mediate tissue injury directly, and both fungal growth and lung injury may induce hemorrhage. To assimilate these interdependent processes, we hypothesized that, during aspergillosis, heme mediates direct lung injury independent of fungal growth, leading to worse infection outcomes, and the scavenger protein, hemopexin, mitigates these effects. Mice with neutropenic aspergillosis were found to have a time-dependent increase in lung extracellular heme and a corresponding hemopexin induction. Hemopexin deficiency resulted in markedly increased lung injury, fungal growth, and lung hemorrhage. Using a computational model of the interactions of Aspergillus, heme, and the host, we predicted a critical role for heme-mediated generation of neutrophil-extracellular traps in this infection. We tested this prediction using a fungal strain unable to grow at body temperature, and found that extracellular heme and fungal exposure synergize to induce lung injury by promoting NET release, and disruption of NETs was sufficient to attenuate lung injury and fungal burden. These data implicate heme-mediated NETosis in both lung injury and fungal growth during aspergillosis, resulting in a detrimental positive feedback cycle that can be interrupted by scavenging heme or disrupting NETs.
Authors
Ganlin Qu, Henrique A.L. Ribeiro, Angelica L. Solomon, Luis Sordo Vieira, Yana Goddard, Nickolas G. Diodati, Arantxa V. Lazarte, Matthew Wheeler, Reinhard Laubenbacher, Borna Mehrad
Abstract
The SARS-CoV-2 pandemic highlighted the potential of mRNA vaccines in rapidly responding to emerging pathogens. However, immunity induced by conventional mRNA vaccines wanes quickly, requiring frequent boosters. Self-amplifying RNA (saRNA) vaccines, which extend antigen expression via self-replication, offer a promising strategy to induce more durable immune responses. In this study, we developed an saRNA vaccine encoding Zika virus (ZIKV) membrane and envelope (M/E) proteins and evaluated its efficacy in mice. A single vaccination elicited strong humoral and cellular immune responses and reduced viral loads, but only for 28 days. By day 84, antibody titers and T cell responses had significantly declined, resulting in reduced efficacy. To address this, we evaluated agonist antibodies targeting the T cell costimulatory molecules OX40 and 4-1BB. Co-administration of agonist antibodies enhanced CD8+ T cell responses to vaccination, resulting in sustained protection and reduced viral loads at day 84. Depletion and passive transfer studies confirmed that long-term protection was primarily CD8+ T cell-dependent, with minimal contributions from antibody responses. These findings suggest that agonists targeting members of the tumor necrosis receptor superfamily, such as OX40 and 4-1BB, might enhance the durability of saRNA vaccine-induced protection, addressing a key limitation of current mRNA vaccine platforms.
Authors
Hsueh-Han Lu, Rúbens Prince dos Santos Alves, Qin Hui Li, Luke Eder, Julia Timis, Henry Madany, Kantinan Chuensirikulchai, Krithik V. Varghese, Aditi Singh, Linda Le Tran, Audrey Street, Annie Elong Ngono, Michael Croft, Sujan Shresta
Abstract
The soluble variant of the ectopeptidase CD13 (sCD13), released from the cell surface by matrix metalloproteinase 14 (MMP14), is a potent pro-inflammatory mediator, displaying chemotactic, angiogenic, and arthritogenic properties through bradykinin receptor B1 (B1R). We reveal a link between sCD13 and amplified neutrophil-mediated inflammatory responses in SARS-CoV-2 infection. sCD13 was markedly elevated in COVID-19 patients and correlated with disease severity, variants, ethnicity, inflammation markers, and NETosis. Neutrophils treated with sCD13 showed heightened NETosis and chemotaxis which were inhibited by sCD13 receptor blockade. Meanwhile sCD13 did not induce platelet aggregation. Single-cell analysis of COVID-19 lungs revealed co-expression of CD13 and MMP14 by various cell types, and higher CD13 expression compared to controls. Neutrophils with high CD13 mRNA were enriched for genes associated with immaturity, though CD13 protein expression was lower. Histological examination of COVID-19 lungs revealed CD13-positive leukocytes trapped in vessels with fibrin thrombi. Flow cytometry confirmed the presence of B1R and a second sCD13 receptor, protease-activated receptor 4, on monocytes and neutrophils. These findings identify sCD13 as a potential instigator of COVID-19-associated NETosis, potentiating vascular stress and thromboembolic complications. The potent pro-inflammatory effects of sCD13 may contribute to severe COVID-19, suggesting that sCD13 and its receptors might be therapeutic targets.
Authors
Pei-Suen Tsou, Ramadan A. Ali, Chenyang Lu, Gautam Sule, Carmelo Carmona-Rivera, Serena Lucotti, Yuzo Ikari, Qi Wu, Phillip Campbell, Mikel Gurrea-Rubio, Kohei Maeda, Sharon E. Fox, William D. Brodie, Megan N. Mattichak, Caroline Foster, Ajay Tambralli, Srilakshmi Yalavarthi, M. Asif Amin, Katarina Kmetova, Bruna Mazetto Fonseca, Emily Chong, Yu Zuo, Michael Maile, Luisa Imberti, Arnaldo Caruso, Francesca Caccuri, Virginia Quaresima, Alessandra Sottini, Douglas B. Kuhns, Danielle L. Fink, Riccardo Castagnoli, Ottavia Delmonte, Heather Kenney, Yu Zhang, Mary Magliocco, Helen C. Su, Luigi D. Notarangelo, Rachel L. Zemans, Yang Mao-Draayer, Irina Matei, Mirella Salvatore, David C. Lyden, Yogendra Kanthi, Mariana J. Kaplan, Jason S. Knight, David A. Fox
Abstract
Urinary tract infections (UTIs) are one of the most commonly encountered infections in clinical practice, in which psychological stress is a critical pathological contributor to modulate immune function. However, mechanistic pathways linking stress networks in the brain to bladder infection remain poorly understood. In this study, we discovered that acute stress treatment suppressed bladder inflammation in mice with UTIs, and a significant number of neurons showing overlap between inflammation-associated markers and retrograde labeling were observed in the paraventricular nucleus (PVN) brain region of these mice. Activation of PVN alleviated UPEC-induced bladder inflammatory response. Moreover, blocked hypothalamic-pituitary-adrenal (HPA) axis reversed the anti-inflammatory reflex mediated by acute stress, suggesting that the potential of glucocorticoids levels through the brain-body circuits to ameliorate UTIs. Single cell-RNAseq of bladder immune cells revealed that type 2 innate lymphoid cells (ILC2) expressed abundant levels of glucocorticoid receptor (GR). The activation of PVN effectively inhibited the expression of the proinflammatory cytokine Csf2 by ILC2 through direct regulation of cell-intrinsic glucocorticoids signaling. Ultimately, our study has implications for the positioning of brain-body circuit for UTIs treatment.
Authors
Yaxiao Liu, Jinhua Wang, Junyang Lin, Dingqi Sun, Kejia Zhu, Tongxiang Diao, Qiang Fu, Qingyu Ren
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