Long COVID is associated with lower percentages of mature, cytotoxic NK cell phenotypes

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Authors

Tasha Tsao, Amanda M. Buck, Lilian Grimbert, Brian H. LaFranchi, Belen Altamirano Poblano, Emily A. Fehrman, Thomas Dalhuisen, Priscilla Y. Hsue, J. Daniel Kelly, Jeffrey N. Martin, Steven G. Deeks, Peter W. Hunt, Michael J. Peluso, Oscar A. Aguilar, Timothy J. Henrich

Pathobiont-driven antibody sialylation through IL-10 undermines vaccination

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The pathobiont Staphylococcus aureus (Sa) induces nonprotective antibody imprints that underlie ineffective staphylococcal vaccination. However, the mechanism by which Sa modifies antibody activity is not clear. Herein, we demonstrate that IL-10 is the decisive factor that abrogates antibody protection in mice. Sa-induced B10 cells drive antigen-specific vaccine suppression that affects both recalled and de novo developed B cells. Released IL-10 promotes STAT3 binding upstream of the gene encoding sialyltransferase ST3gal4 and increases its expression by B cells, leading to hyper-α2,3sialylation of antibodies and loss of protective activity. IL-10 enhances α2,3sialylation on cell-wall–associated IsdB, IsdA, and MntC antibodies along with suppression of the respective Sa vaccines. Consistent with mouse findings, human anti-Sa antibodies as well as anti-pseudomonal antibodies from cystic fibrosis subjects (high IL-10) are hypersialylated, compared with anti–Streptococcus pyogenes and pseudomonal antibodies from normal individuals. Overall, we demonstrate a pathobiont-centric mechanism that modulates antibody glycosylation through IL-10, leading to loss of staphylococcal vaccine efficacy.

Authors

Chih-Ming Tsai, Irshad A. Hajam, J.R. Caldera, Austin W.T. Chiang, Cesia Gonzalez, Xin Du, Biswa Choudhruy, Haining Li, Emi Suzuki, Fatemeh Askarian, Ty’Tianna Clark, Brian Lin, Igor H. Wierzbicki, Angelica M. Riestra, Douglas J. Conrad, David J. Gonzalez, Victor Nizet, Nathan E. Lewis, George Y. Liu

Clinical tolerance but no protective efficacy in a placebo-controlled trial of repeated controlled schistosome infection

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BACKGROUND. Partial protective immunity to schistosomiasis develops over time, following repeated praziquantel treatment. Moreover, animals develop protective immunity after repeated immunisation with irradiated cercariae. Here, we evaluated development of natural immunity through consecutive exposure-treatment cycles with Schistosoma mansoni (Sm) in healthy, Schistosoma-naïve participants using single-sex controlled human Sm infection. METHODS. Twenty-four participants were randomised double-blind (1:1) to either the reinfection group, which received three exposures (week 0,9,18) to 20 male cercariae or the infection control group, which received two mock exposures with water (week 0,9) prior to cercariae exposure (week 18). Participants were treated with praziquantel (or placebo) at week 8, 17 and 30. Attack rates after the final exposure (week 19-30) using serum circulating anodic antigen (CAA) positivity were compared between groups. Adverse events were collected for safety. RESULTS. Twenty-three participants completed follow-up. No protective efficacy was seen, given 82% (9/11) attack rate after the final exposure in the reinfection group and 92% (11/12) in the infection control group (protective efficacy 11%; 95% CI -24% to 35%; p =0.5). Related adverse events were higher after the first infection (45%), compared to the second (27%) and third infection (28%). Severe acute schistosomiasis was observed after the first infections only (2/12 in reinfection group and 2/12 in infection control group). CONCLUSION. Repeated Schistosoma exposure and treatment cycles resulted in apparent clinical tolerance, with fewer symptoms reported with subsequent infections, but did not result in protection against reinfection. TRIAL REGISTRATION. ClinicalTrials.gov NCT05085470. FUNDING. ERC Starting grant (no. 101075876).

Authors

Jan Pieter R. Koopman, Emma L. Houlder, Jacqueline J. Janse, Olivia A.C. Lamers, Geert V.T. Roozen, Jeroen C. Sijtsma, Miriam Casacuberta-Partal, Stan T. Hilt, M.Y. Eileen C. van der Stoep, Inge M. van Amerongen-Westra, Eric A.T. Brienen, Linda J. Wammes, Lisette van Lieshout, Govert J. van Dam, Paul L.A.M. Corstjens, Angela van Diepen, Maria Yazdanbakhsh, Cornelis H. Hokke, Meta Roestenberg

Ferumoxytol nanozymes effectively target chronic biofilm infections in apical periodontitis

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Bacterial biofilms are pervasive and recalcitrant to current antimicrobials, causing numerous infections. Iron oxide-nanozymes, including an FDA-approved formulation (ferumoxytol, FMX), show potential against biofilm infections via catalytic activation of hydrogen peroxide (H2O2). However, clinical evidence on its efficacy and therapeutic mechanisms is lacking. Here, we investigate whether FMX-nanozymes can treat chronic biofilm infections and compare their bioactivity to gold-standard sodium hypochlorite (NaOCl), a potent but caustic disinfectant. Clinical performance was assessed in patients with apical periodontitis, an intractable endodontic infection affecting half of the global adult population. Data show robust antibiofilm activity by a single application of FMX with H2O2 achieving results comparable to NaOCl without adverse effects. FMX binds efficiently to bacterial pathogens Enterococcus faecalis and Fusobacterium nucleatum and remains catalytically active without being affected by dental tissues. This allows for effective eradication of endodontic biofilms via on-site free-radical generation without inducing cytotoxicity. Unexpectedly, FMX promotes growth of stem cells of apical papilla (SCAP), with transcriptomic analyses revealing upregulation of proliferation-associated pathways and downregulation of cell-cycle suppressor genes. Notably, FMX activates SCAP pluripotency and WNT/NOTCH signaling that induces its osteogenic capacity. Together, we show FMX nanozymes are clinically effective against severe chronic biofilm infection with pathogen targeting and unique stem cell-stimulatory properties, offering a regenerative approach to antimicrobial therapy.

Authors

Alaa Babeer, Yuan Liu, Zhi Ren, Zhenting Xiang, Min Jun Oh, Nil Kanatha Pandey, Aurea Simon-Soro, Ranran Huang, Bekir Karabucak, David P. Cormode, Chider Chen, Hyun Koo

Neisseria gonorrhoeae induces local secretion of IL-10 at the human cervix to promote colonization

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Gonorrhea, caused by the human-restricted pathogen Neisseria gonorrhoeae, is a commonly reported sexually transmitted infection. Since most infections in women are asymptomatic, the true number of infections is likely much higher than reported. How gonococci (GC) colonize women’s cervixes without triggering symptoms remains elusive. Using a human cervical tissue explant model, we found that GC inoculation increased the local secretion of both pro- (IL-1β and TNF-α) and anti-inflammatory (IL-10) cytokines during the first 24-h. Cytokine induction required GC expression of Opa isoforms that bind the host receptors carcinoembryonic antigen-related cell adhesion molecules (CEACAMs). GC inoculation induced NF-κB activation in both cervical epithelial and subepithelial cells. However, inhibition of NF-κB activation, which reduced GC-induced IL-1β and TNF-α, did not affect GC colonization. Neutralizing IL-10 or blocking IL-10 receptors by antibodies reduced GC colonization by increasing epithelial shedding and epithelial cell-cell junction disassembly. Inhibition of the CEACAM downstream signaling molecule SHP1/2, which reduced GC colonization and increased epithelial shedding, decreased GC-induced IL-10 secretion. These results show that GC induce local secretion of IL-10, a potent anti-inflammatory cytokine, at the cervix by engaging the host CEACAMs to prevent GC-colonizing epithelial cells from shedding, providing a potential mechanism for GC asymptomatic colonization in women.

Authors

Yiwei Dai, Vonetta L. Edwards, Qian Yu, Hervé Tettelin, Daniel C. Stein, Wenxia Song

Complement-producing maternal microchimeric cells override infection susceptibility in complement-deficient murine offspring

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Authors

Giang Pham, Raymond E. Diep, Lucien H. Turner, David B. Haslam, Sing Sing Way

In utero human cytomegalovirus infection expands NK-like FcγRIII⁺ CD8⁺ T cells that mediate Fc antibody functions

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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

Activation of STAT3-mediated ciliated cell survival protects against severe infection by respiratory syncytial virus

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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

Leptin signaling maintains autonomic stability during severe influenza infection in mice

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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

TREM2 aggravates sepsis by inhibiting fatty acid oxidation via the SHP1/BTK axis

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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