The transcription factor STAT1 plays a critical role in modulating the differentiation of CD4+ T cells producing IL-17 and GM-CSF, which promote the development of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). The protective role of STAT1 in MS and EAE has been largely attributed to its ability to limit pathogenic Th cells and promote Tregs. Using mice with selective deletion of STAT1 in T cells (STAT1CD4-Cre), we identified a potentially novel mechanism by which STAT1 regulates neuroinflammation independently of Foxp3+ Tregs. STAT1-deficient effector T cells became the target of NK cell–mediated killing, limiting their capacity to induce EAE. STAT1-deficient T cells promoted their own killing by producing more IL-2 that, in return, activated NK cells. Elimination of NK cells restored EAE susceptibility in STAT1CD4-Cre mice. Therefore, our study suggests that the STAT1 pathway can be manipulated to limit autoreactive T cells during autoimmunity directed against the CNS.
Carlos A. Arbelaez, Pushpalatha Palle, Jonathan Charaix, Estelle Bettelli
Nontuberculous mycobacteria (NTM) are an increasingly common cause of respiratory infection in people with cystic fibrosis (PwCF). Relative to those with no history of NTM infection (CF-NTMNEG), PwCF and a history of NTM infection (CF-NTMPOS) are more likely to develop severe lung disease and experience complications over the course of treatment. In other mycobacterial infections (e.g., tuberculosis), an overexuberant immune response causes pathology and compromises organ function; however, since the immune profiles of CF-NTMPOS and CF-NTMNEG airways are largely unexplored, it is unknown which, if any, immune responses distinguish these cohorts or concentrate in damaged tissues. Here, we evaluated lung lobe–specific immune profiles of 3 cohorts (CF-NTMPOS, CF-NTMNEG, and non-CF adults) and found that CF-NTMPOS airways are distinguished by a hyperinflammatory cytokine profile. Importantly, the CF-NTMPOS airway immune profile was dominated by B cells, classical macrophages, and the cytokines that support their accumulation. These and other immunological differences between cohorts, including the near absence of NK cells and complement pathway members, were enriched in the most damaged lung lobes. The implications of these findings for our understanding of lung disease in PwCF are discussed, as are how they may inform the development of host-directed therapies to improve NTM disease treatment.
Don Hayes Jr., Rajni Kant Shukla, Yizi Cheng, Emrah Gecili, Marlena R. Merling, Rhonda D. Szczesniak, Assem G. Ziady, Jason C. Woods, Luanne Hall-Stoodley, Namal P.M. Liyanage, Richard T. Robinson
Abundance of Faecalibacterium prausnitzii, a dominant bacterium of the human microbiota that exhibits antiinflammatory effects, is decreased in patients with inflammatory bowel diseases (IBD). In humans, colonic lamina propria contains IL-10–secreting, Foxp3– Tregs characterized by a double expression of CD4 and CD8α (DP8α) and a specificity for F. prausnitzii. This Treg subset is decreased in IBD. The in vivo effect of DP8α cells has not been evaluated yet to our knowledge. Here, using a humanized model of a NSG immunodeficient mouse strain that expresses the HLA D–related allele HLA-DR*0401 but not murine class II (NSG-Ab° DR4) molecules, we demonstrated a protective effect of a HLA-DR*0401–restricted DP8α Treg clone combined with F. prausnitzii administration in a colitis model. In a cohort of patients with IBD, we showed an independent association between the frequency of circulating DP8α cells and disease activity. Finally, we pointed out a positive correlation between F. prausnitzii–specific DP8α Tregs and the amount of F. prausnitzii in fecal microbiota in healthy individuals and patients with ileal Crohn’s disease.
Sothea Touch, Emmanuelle Godefroy, Nathalie Rolhion, Camille Danne, Cyriane Oeuvray, Marjolène Straube, Chloé Galbert, Loïc Brot, Iria Alonso Salgueiro, Sead Chadi, Tatiana Ledent, Jean-Marc Chatel, Philippe Langella, Francine Jotereau, Frédéric Altare, Harry Sokol
Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there are limited data comparing vaccine- and infection-induced neutralizing Abs (nAbs) against COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals. Thirty women vaccinated with mRNA vaccines (from December 2020 through August 2021) were matched with 30 naturally infected women (from March 2020 through January 2021) by gestational age of exposure. Neutralization activity against the 5 SARS-CoV-2 spike sequences was measured by a SARS-CoV-2–pseudotyped spike virion assay. Effective nAbs against SARS-CoV-2 were present in maternal and cord plasma after both infection and vaccination. Compared with WT spike protein, these nAbs were less effective against the Delta and Mu spike variants. Vaccination during the third trimester induced higher cord-nAb levels at delivery than did infection during the third trimester. In contrast, vaccine-induced nAb levels were lower at the time of delivery compared with infection during the first trimester. The transfer ratio (cord nAb level divided by maternal nAb level) was greatest in mothers vaccinated in the second trimester. SARS-CoV-2 vaccination or infection in pregnancy elicits effective nAbs with differing neutralization kinetics that are influenced by gestational time of exposure.
Yusuke Matsui, Lin Li, Mary Prahl, Arianna G. Cassidy, Nida Ozarslan, Yarden Golan, Veronica J. Gonzalez, Christine Y. Lin, Unurzul Jigmeddagva, Megan A. Chidboy, Mauricio Montano, Taha Y. Taha, Mir M. Khalid, Bharath Sreekumar, Jennifer M. Hayashi, Pei-Yi Chen, G. Renuka Kumar, Lakshmi Warrier, Alan H.B. Wu, Dongli Song, Priya Jegatheesan, Daljeet S. Rai, Balaji Govindaswami, Jordan Needens, Monica Rincon, Leslie Myatt, Ifeyinwa V. Asiodu, Valerie J. Flaherman, Yalda Afshar, Vanessa L. Jacoby, Amy P. Murtha, Joshua F. Robinson, Melanie Ott, Warner C. Greene, Stephanie L. Gaw
The Aedes aegypti mosquito transmits both dengue virus (DENV) and Zika virus (ZIKV) . Individuals in endemic areas are at risk for infection with both viruses, as well as for repeated DENV infection. In the presence of anti-DENV antibodies, outcomes of secondary DENV infection range from mild to life threatening. Furthermore, the role of cross-reactive antibodies on the course of ZIKV infection remains unclear. We assessed the ability of cross-reactive DENV mAbs or polyclonal immunoglobulin isolated after DENV vaccination to upregulate type I IFN production by plasmacytoid DCs (pDCs) in response to both heterotypic DENV- and ZIKV-infected cells. We found a range in the ability of antibodies to increase pDC IFN production and a positive correlation between IFN production and the ability of an antibody to bind to the infected cell surface. Engagement of Fc receptors on the pDC and engagement of epitope on the infected cell by the Fab portion of the same antibody molecule was required to mediate increased IFN production by providing specificity to and promoting pDC sensing of DENV or ZIKV. This represents a mechanism independent of neutralization by which preexisting cross-reactive DENV antibodies could protect a subset of individuals from severe outcomes during secondary heterotypic DENV or ZIKV infection.
Laura K. Aisenberg, Kimberly E. Rousseau, Katherine Cascino, Guido Massaccesi, William H. Aisenberg, Wensheng Luo, Kar Muthumani, David B. Weiner, Stephen S. Whitehead, Michael A. Chattergoon, Anna P. Durbin, Andrea L. Cox
Disruption of the neurovascular unit (NVU) underlies the pathophysiology of various CNS diseases. One strategy to repair NVU dysfunction uses stem/progenitor cells to provide trophic support to the NVU’s functionally coupled and interdependent vasculature and surrounding CNS parenchyma. A subset of endothelial progenitor cells, endothelial colony-forming cells (ECFCs) with high expression of the CD44 hyaluronan receptor (CD44hi), provides such neurovasculotrophic support via a paracrine mechanism. Here, we report that bioactive extracellular vesicles from CD44hi ECFCs (EVshi) are paracrine mediators, recapitulating the effects of intact cell therapy in murine models of ischemic/neurodegenerative retinopathy; vesicles from ECFCs with low expression levels of CD44 (EVslo) were ineffective. Small RNA sequencing comparing the microRNA cargo from EVshi and EVslo identified candidate microRNAs that contribute to these effects. EVshi may be used to repair NVU dysfunction through multiple mechanisms to stabilize hypoxic vasculature, promote vascular growth, and support neural cells.
Kyle V. Marra, Edith Aguilar, Wei Guoqin, Ayumi Usui-Ouchi, Yochiro Ideguchi, Susumu Sakimoto, Martin Friedlander
Tertiary lymphoid structures (TLS) are transient ectopic lymphoid aggregates whose formation might be caused by chronic inflammation states, such as cancer. However, how TLS are induced in the tumor microenvironment (TME) and how they affect patient survival are not well understood. We investigated TLS distribution in relation to tumor infiltrating lymphocytes (TILs) and related gene expression in high-grade serous ovarian cancer (HGSC) specimens. CXCL13 gene expression correlated with TLS presence and the infiltration of T cells and B cells, and it was a favorable prognostic factor for patients with HGSC. Coexistence of CD8+ T cells and B cell lineages in the TME significantly improved the prognosis of HGSC and was correlated with the presence of TLS. CXCL13 expression was predominantly coincident with CD4+ T cells in TLS and CD8+ T cells in TILs, and it shifted from CD4+ T cells to CD21+ follicular DCs as TLS matured. In a mouse ovarian cancer model, recombinant CXCL13 induced TLS and enhanced survival by the infiltration of CD8+ T cells. These results suggest that TLS formation was associated with CXCL13-producing CD4+ T cells and that TLS facilitated the coordinated antitumor response of cellular and humoral immunity in ovarian cancer.
Masayo Ukita, Junzo Hamanishi, Hiroyuki Yoshitomi, Koji Yamanoi, Shiro Takamatsu, Akihiko Ueda, Haruka Suzuki, Yuko Hosoe, Yoko Furutake, Mana Taki, Kaoru Abiko, Ken Yamaguchi, Hidekatsu Nakai, Tsukasa Baba, Noriomi Matsumura, Akihiko Yoshizawa, Hideki Ueno, Masaki Mandai
Understanding the reorganization of neural circuits spared after spinal cord injury in the motor cortex and spinal cord would provide insights for developing therapeutics. Using optogenetic mapping, we demonstrated a transhemispheric recruitment of neural circuits in the contralateral cortical M1/M2 area to improve the impaired forelimb function after a cervical 5 right-sided hemisection in mice, a model mimicking the human Brown-Séquard syndrome. This cortical reorganization can be elicited by a selective cortical optogenetic neuromodulation paradigm. Areas of whisker, jaw, and neck, together with the rostral forelimb area, on the motor cortex ipsilateral to the lesion were engaged to control the ipsilesional forelimb in both stimulation and nonstimulation groups 8 weeks following injury. However, significant functional benefits were only seen in the stimulation group. Using anterograde tracing, we further revealed a robust sprouting of the intact corticospinal tract in the spinal cord of those animals receiving optogenetic stimulation. The intraspinal corticospinal axonal sprouting correlated with the forelimb functional recovery. Thus, specific neuromodulation of the cortical neural circuits induced massive neural reorganization both in the motor cortex and spinal cord, constructing an alternative motor pathway in restoring impaired forelimb function.
Wei Wu, Tyler Nguyen, Josue D. Ordaz, Yiping Zhang, Nai-Kui Liu, Xinhua Hu, Yuxiang Liu, Xingjie Ping, Qi Han, Xiangbing Wu, Wenrui Qu, Sujuan Gao, Christopher B. Shields, Xiaoming Jin, Xiao-Ming Xu
Chronic lymphocytic leukemia (CLL) results from expansion of a CD5+ B cell clone that requires interactions with other cell types, including T cells. Moreover, patients with CLL have elevated levels of circulating IL-17A+ and IL-17F+ CD4+ T (Th17) cells, with higher numbers of IL-17A+ Th17 cells correlating with better outcomes. We report that CLL Th17 cells expressed more miR155, a Th17-differentiation regulator, than control Th17 cells, despite naive CD4+ T (Tn) cell basal miR155 levels being similar in both. We also found that CLL cells directly regulated miR155 levels in Tn cells, thereby affecting Th17 differentiation, by documenting that coculturing Tn cells with resting or activated (Bact) CLL cells altered the magnitude and direction of T cell miR155 levels; CLL Bact cells promoted IL-17A+ and IL-17F+ T cell generation by an miR155-dependent mechanism, confirmed by miR155 inhibition; coculture of Tn cells with CLL Bact cells led to a linear correlation between the degree and direction of T cell miR155 expression changes and production of IL-17F but not IL-17A; and Bact cell–mediated changes in Tn cell miR155 expression correlated with outcome, irrespective of IGHV mutation status, a strong prognostic indicator. These results identify a potentially unrecognized CLL Bact cell–dependent mechanism, upregulation of Tn cell miR155 expression and subsequent enhancement of IL-17F+ Th17 generation, that favors better clinical courses.
Byeongho Jung, Gerardo Ferrer, Pui Yan Chiu, Rukhsana Aslam, Anita Ng, Florencia Palacios, Michael Wysota, Martina Cardillo, Jonathan E. Kolitz, Steven L. Allen, Jacqueline C. Barrientos, Kanti R. Rai, Nicholas Chiorazzi, Barbara Sherry
Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e., resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We found the percentages of solids and protein content were greatly elevated in COVID-19 compared with heathy control samples and closely resembled levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) were major components of respiratory secretions in COVID-19 and were likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibited heterogeneous rheological behaviors, with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observed increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor–stimulated gene-6 staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicated that increases in HA and DNA in COVID-19 respiratory secretion samples correlated with enhanced inflammatory burden and suggested that DNA and HA may be viable therapeutic targets in COVID-19 infection.
Michael J. Kratochvil, Gernot Kaber, Sally Demirdjian, Pamela C. Cai, Elizabeth B. Burgener, Nadine Nagy, Graham L. Barlow, Medeea Popescu, Mark R. Nicolls, Michael G. Ozawa, Donald P. Regula, Ana E. Pacheco-Navarro, Samuel Yang, Vinicio A. de Jesus Perez, Harry Karmouty-Quintana, Andrew M. Peters, Bihong Zhao, Maximilian L. Buja, Pamela Y. Johnson, Robert B. Vernon, Thomas N. Wight, Stanford COVID-19 Biobank Study Group, Carlos E. Milla, Angela J. Rogers, Andrew J. Spakowitz, Sarah C. Heilshorn, Paul L. Bollyky
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