Profiling whole-tissue metabolic reprogramming during cutaneous poxvirus infection and clearance.

IMPORTANCE: Human poxvirus infections have caused significant public health burdens both historically and recently during the unprecedented global Mpox virus outbreak. Although vaccinia virus (VACV) infection of mice is a commonly used model to explore the anti-poxvirus immune response, little is known about the metabolic changes that occur in vivo during infection. We hypothesized that the metabolome of VACV-infected skin would reflect the increased energetic requirements of both virus-infected cells and immune cells recruited to sites of infection. Therefore, we profiled whole VACV-infected skin using untargeted mass spectrometry to define the metabolome during infection, complementing these experiments with flow cytometry and transcriptomics. We identified specific metabolites, including nucleotides, itaconic acid, and glutamine, that were differentially expressed during VACV infection. Together, this study offers insight into both virus-specific and immune-mediated metabolic pathways that could contribute to the clearance of cutaneous poxvirus infection.

Widespread and dynamic expression of granzyme C by skin-resident antiviral T cells.

After recognition of cognate antigen (Ag), effector CD8+ T cells secrete serine proteases called granzymes in conjunction with perforin, allowing granzymes to enter and kill target cells. While the roles for some granzymes during antiviral immune responses are well characterized, the function of others, such as granzyme C and its human ortholog granzyme H, is still unclear. Granzyme C is constitutively expressed by mature, cytolytic innate lymphoid 1 cells (ILC1s). Whether other antiviral effector cells also produce granzyme C and whether it is continually expressed or responsive to the environment is unknown. To explore this, we analyzed granzyme C expression in different murine skin-resident antiviral lymphocytes. At steady-state, dendritic epidermal T cells (DETCs) expressed granzyme C while dermal γδ T cells did not. CD8+ tissue-resident memory T cells (TRM) generated in response to cutaneous viral infection with the poxvirus vaccinia virus (VACV) also expressed granzyme C. Both DETCs and virus-specific CD8+ TRM upregulated granzyme C upon local VACV infection. Continual Ag exposure was not required for maintained TRM expression of granzyme C, although re-encounter with cognate Ag boosted expression. Additionally, IL-15 treatment increased granzyme C expression in both DETCs and TRM. Together, our data demonstrate that granzyme C is widely expressed by antiviral T cells in the skin and that expression is responsive to both environmental stimuli and TCR engagement. These data suggest that granzyme C may have functions other than killing in tissue-resident lymphocytes.

Zika virus spreads through infection of lymph node-resident macrophages.

To disseminate through the body, Zika virus (ZIKV) is thought to exploit the mobility of myeloid cells, in particular monocytes and dendritic cells. However, the timing and mechanisms underlying shuttling of the virus by immune cells remains unclear. To understand the early steps in ZIKV transit from the skin, at different time points, we spatially mapped ZIKV infection in lymph nodes (LNs), an intermediary site en route to the blood. Contrary to prevailing hypotheses, migratory immune cells are not required for the virus to reach the LNs or blood. Instead, ZIKV rapidly infects a subset of sessile CD169+ macrophages in the LNs, which release the virus to infect downstream LNs. Infection of CD169+ macrophages alone is sufficient to initiate viremia. Overall, our experiments indicate that macrophages that reside in the LNs contribute to initial ZIKV spread. These studies enhance our understanding of ZIKV dissemination and identify another anatomical site for potential antiviral intervention.

Characteristics of adverse event reporting of Xeljanz/Xeljanz XR, Olumiant, and Rinvoq to the US Food and Drug Administration.

BACKGROUND: On September 9, 2021, the US Food and Drug Administration (FDA) issued a drug safety communication and required revisions to the Boxed Warning for Xeljanz/Xeljanz XR (tofacitinib), Olumiant (baricitinib), and Rinvoq (upadacitinib) to include information about the risk of serious heart-related events, cancer, blood clots, and death. The Boxed Warning was based on a large safety randomized clinical trial of tofacitinib, but neither baricitinib nor upadacitinib has been studied in similar large safety clinical trials. OBJECTIVE: To evaluate characteristics of adverse event (AE) reporting of tofacitinib/XR, baricitinib, and upadacitinib to the FDA. METHODS: We analyzed the public FDA's Adverse Event Reporting System data to examine reported AEs that were related to any of the 3 drugs between January 1, 2019, and September 30, 2021. Both brand and generic names of these drugs were used to identify these AEs. Frequencies of AE reports were evaluated by patient demographics (age and sex), type of reporter, reporter region, seriousness, and reactions related to death, cardiovascular, cancer, and blood clots. Chi-square tests were used to compare the proportion of characteristics of AEs between these drugs at P < 0.05. RESULTS: We identified 56,833 AE reports of tofacitinib/XR, 2,318 reports of baricitinib, and 5,359 reports of upadacitinib. Higher proportions of patients reporting AEs for tofacitinib/XR were older and female than for baricitinib and upadacitinib. Higher proportions of tofacitinib/XR and baricitinib AEs were reported by health professionals than for upadacitinib. Higher proportions of upadacitinib AEs were in the United States and more serious than those of tofacitinib/XR and baricitinib AEs (all group and paired comparisons at P < 0.05). Regarding reactions, baricitinib AEs had highest proportions of death (7.2%) and cancer-related (4.1%) events, whereas tofacitinib/XR AEs had the highest proportions of cardiovascular-related (14.1%) and blood clot-related (14.8%) events. CONCLUSIONS: Although baricitinib and upadacitinib are in the same drug class as tofacitinib/XR, their risk of serious cardiovascular events, cancer, blood clots, and death might not be similar. Findings from this hypothesis-generating study suggest that there may be differential AEs between Janus kinase inhibitors, and therefore, future research for robust comparative safety is warranted.

Poxviruses and paramyxoviruses use a conserved mechanism of STAT1 antagonism to inhibit interferon signaling.

The induction of interferon (IFN)-stimulated genes by STATs is a critical host defense mechanism against virus infection. Here, we report that a highly expressed poxvirus protein, 018, inhibits IFN-induced signaling by binding to the SH2 domain of STAT1, thereby preventing the association of STAT1 with an activated IFN receptor. Despite encoding other inhibitors of IFN-induced signaling, a poxvirus mutant lacking 018 was attenuated in mice. The 2.0 Å crystal structure of the 018:STAT1 complex reveals a phosphotyrosine-independent mode of 018 binding to the SH2 domain of STAT1. Moreover, the STAT1-binding motif of 018 shows similarity to the STAT1-binding proteins from Nipah virus, which, similar to 018, block the association of STAT1 with an IFN receptor. Overall, these results uncover a conserved mechanism of STAT1 antagonism that is employed independently by distinct virus families.

Protocol for analyzing and visualizing antiviral immune responses after acute infection of the murine oral mucosa.

The oral mucosa is an important site for virus infection and transmission, yet few animal models exist to examine the virology, pathology, and immunology of acute oral mucosal viral infection. Here, we provide a protocol for infecting and imaging the inner lip (labial mucosa) of mice with the poxvirus vaccinia virus (VACV). Inoculation of the labial mucosa with a bifurcated needle results in viral replication and priming of an adaptive antiviral response that can be imaged using intravital microscopy. For complete details on the use and execution of this protocol, please refer to Shannon et al. (2021).

Response to Comments on "Aberrant type 1 immunity drives susceptibility to mucosal fungal infections".

Puel and Casanova and Kisand et al. challenge our conclusions that interferonopathy and not IL-17/IL-22 autoantibodies promote candidiasis in autoimmune polyendocrinopathy­candidiasis­ectodermal dystrophy. We acknowledge that conclusive evidence for causation is difficult to obtain in complex human diseases. However, our studies clearly document interferonopathy driving mucosal candidiasis with intact IL-17/IL-22 responses in Aire-deficient mice, with strong corroborative evidence in patients.

A sand fly salivary protein acts as a neutrophil chemoattractant.

Apart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.

"Keep Your Move in the Tube" safely increases discharge home following cardiac surgery.

BACKGROUND: Restrictive sternal precautions intended to prevent cardiac surgery patients from damaging healing sternotomies lack supporting evidence and may decrease independence and increase postacute care utilization. Data regarding the impact of alternative approaches on safety and outcomes are needed to guide evidence-based best practices. OBJECTIVE: To examine whether an approach allowing greater freedom during activities of daily living than permitted under commonly used restrictive sternal precautions can safely decrease postacute care utilization. DESIGN: Before-and-after study, using propensity score adjustment to account for differences in patient clinical and demographic characteristics, surgery type, and surgeon. SETTING: 600-bed acute care hospital. INTERVENTION: Beginning March 2016, the acute care hospital replaced traditional weight- and time-based precautions given to patients who underwent median sternotomy with the "Keep Your Move in the Tube" (KMIT) approach for mindfully performing movements involved in the activities of daily living, guided by pain. MAIN OUTCOME MEASURES: The study compared sternal wound complications, discharge disposition, 30-day readmission, and functional status between consecutive cardiac surgery patients with "independent" or "modified independent" preoperative functional status who underwent median sternotomy in the 1.5 years before (n = 627, standard precautions group) and after (n = 477, KMIT group) KMIT implementation. RESULTS: The odds of discharge to home, versus to inpatient rehabilitation or skilled nursing facility, were ~3 times higher for KMIT than standard precautions patients (risk-adjusted odds ratio [rOR], 95% confidence interval [CI] = 2.90, 1.95-4.32, and 3.03, 1.57-5.86, respectively). KMIT patients also had significantly higher odds of demonstrating "independent" or "modified independent" functional status on final inpatient physical therapy treatment for bed mobility (rOR, 95% CI = 7.51, 5.48-10.30) and transfers (rOR, 95% CI = 3.40, 2.62-4.42). No significant difference was observed in sternal wound complications (in-hospital or causing readmission) (rOR, 95% CI = 1.27, 0.52-3.09) or all-cause 30-day readmissions (rOR, 95% CI = 0.55, 0.23-1.33). CONCLUSIONS: KMIT increases discharge-to-home for cardiac surgery patients without increasing risk for adverse events and reducing utilization of expensive institutional postacute care.

Aberrant type 1 immunity drives susceptibility to mucosal fungal infections.

Human monogenic disorders have revealed the critical contribution of type 17 responses in mucosal fungal surveillance. We unexpectedly found that in certain settings, enhanced type 1 immunity rather than defective type 17 responses can promote mucosal fungal infection susceptibility. Notably, in mice and humans with AIRE deficiency, an autoimmune disease characterized by selective susceptibility to mucosal but not systemic fungal infection, mucosal type 17 responses are intact while type 1 responses are exacerbated. These responses promote aberrant interferon-γ (IFN-γ)- and signal transducer and activator of transcription 1 (STAT1)-dependent epithelial barrier defects as well as mucosal fungal infection susceptibility. Concordantly, genetic and pharmacologic inhibition of IFN-γ or Janus kinase (JAK)-STAT signaling ameliorates mucosal fungal disease. Thus, we identify aberrant T cell-dependent, type 1 mucosal inflammation as a critical tissue-specific pathogenic mechanism that promotes mucosal fungal infection susceptibility in mice and humans.

Group 1 innate lymphoid-cell-derived interferon-γ maintains anti-viral vigilance in the mucosal epithelium.

The oropharyngeal mucosa serves as a perpetual pathogen entry point and a critical site for viral replication and spread. Here, we demonstrate that type 1 innate lymphoid cells (ILC1s) were the major immune force providing early protection during acute oral mucosal viral infection. Using intravital microscopy, we show that ILC1s populated and patrolled the uninfected labial mucosa. ILC1s produced interferon-γ (IFN-γ) in the absence of infection, leading to the upregulation of key antiviral genes, which were downregulated in uninfected animals upon genetic ablation of ILC1s or antibody-based neutralization of IFN-γ. Thus, tonic IFN-γ production generates increased oral mucosal viral resistance even before infection. Our results demonstrate barrier-tissue protection through tissue surveillance in the absence of rearranged-antigen receptors and the induction of an antiviral state during homeostasis. This aspect of ILC1 biology raises the possibility that these cells do not share true functional redundancy with other tissue-resident lymphocytes.

Persistent Oxidative Stress and Inflammasome Activation in CD14highCD16- Monocytes From COVID-19 Patients.

The poor outcome of the coronavirus disease-2019 (COVID-19), caused by SARS-CoV-2, is associated with systemic hyperinflammatory response and immunopathology. Although inflammasome and oxidative stress have independently been implicated in COVID-19, it is poorly understood whether these two pathways cooperatively contribute to disease severity. Herein, we found an enrichment of CD14highCD16- monocytes displaying inflammasome activation evidenced by caspase-1/ASC-speck formation in severe COVID-19 patients when compared to mild ones and healthy controls, respectively. Those cells also showed aberrant levels of mitochondrial superoxide and lipid peroxidation, both hallmarks of the oxidative stress response, which strongly correlated with caspase-1 activity. In addition, we found that NLRP3 inflammasome-derived IL-1ß secretion by SARS-CoV-2-exposed monocytes in vitro was partially dependent on lipid peroxidation. Importantly, altered inflammasome and stress responses persisted after short-term patient recovery. Collectively, our findings suggest oxidative stress/NLRP3 signaling pathway as a potential target for host-directed therapy to mitigate early COVID-19 hyperinflammation and also its long-term outcomes.

Disruption of a hedgehog-foxf1-rspo2 signaling axis leads to tracheomalacia and a loss of sox9+ tracheal chondrocytes.

Congenital tracheomalacia, resulting from incomplete tracheal cartilage development, is a relatively common birth defect that severely impairs breathing in neonates. Mutations in the Hedgehog (HH) pathway and downstream Gli transcription factors are associated with tracheomalacia in patients and mouse models; however, the underlying molecular mechanisms are unclear. Using multiple HH/Gli mouse mutants including one that mimics Pallister-Hall Syndrome, we show that excessive Gli repressor activity prevents specification of tracheal chondrocytes. Lineage tracing experiments show that Sox9+ chondrocytes arise from HH-responsive splanchnic mesoderm in the fetal foregut that expresses the transcription factor Foxf1. Disrupted HH/Gli signaling results in 1) loss of Foxf1 which in turn is required to support Sox9+ chondrocyte progenitors and 2) a dramatic reduction in Rspo2, a secreted ligand that potentiates Wnt signaling known to be required for chondrogenesis. These results reveal a HH-Foxf1-Rspo2 signaling axis that governs tracheal cartilage development and informs the etiology of tracheomalacia.

Single cell transcriptomics identifies a signaling network coordinating endoderm and mesoderm diversification during foregut organogenesis.

Visceral organs, such as the lungs, stomach and liver, are derived from the fetal foregut through a series of inductive interactions between the definitive endoderm (DE) and the surrounding splanchnic mesoderm (SM). While DE patterning is fairly well studied, the paracrine signaling controlling SM regionalization and how this is coordinated with epithelial identity is obscure. Here, we use single cell transcriptomics to generate a high-resolution cell state map of the embryonic mouse foregut. This identifies a diversity of SM cell types that develop in close register with the organ-specific epithelium. We infer a spatiotemporal signaling network of endoderm-mesoderm interactions that orchestrate foregut organogenesis. We validate key predictions with mouse genetics, showing the importance of endoderm-derived signals in mesoderm patterning. Finally, leveraging these signaling interactions, we generate different SM subtypes from human pluripotent stem cells (hPSCs), which previously have been elusive. The single cell data can be explored at: https://research.cchmc.org/ZornLab-singlecell .

The in vivo genetic program of murine primordial lung epithelial progenitors.

Multipotent Nkx2-1-positive lung epithelial primordial progenitors of the foregut endoderm are thought to be the developmental precursors to all adult lung epithelial lineages. However, little is known about the global transcriptomic programs or gene networks that regulate these gateway progenitors in vivo. Here we use bulk RNA-sequencing to describe the unique genetic program of in vivo murine lung primordial progenitors and computationally identify signaling pathways, such as Wnt and Tgf-ß superfamily pathways, that are involved in their cell-fate determination from pre-specified embryonic foregut. We integrate this information in computational models to generate in vitro engineered lung primordial progenitors from mouse pluripotent stem cells, improving the fidelity of the resulting cells through unbiased, easy-to-interpret similarity scores and modulation of cell culture conditions, including substratum elastic modulus and extracellular matrix composition. The methodology proposed here can have wide applicability to the in vitro derivation of bona fide tissue progenitors of all germ layers.

The Bone Marrow Protects and Optimizes Immunological Memory during Dietary Restriction.

Mammals evolved in the face of fluctuating food availability. How the immune system adapts to transient nutritional stress remains poorly understood. Here, we show that memory T cells collapsed in secondary lymphoid organs in the context of dietary restriction (DR) but dramatically accumulated within the bone marrow (BM), where they adopted a state associated with energy conservation. This response was coordinated by glucocorticoids and associated with a profound remodeling of the BM compartment, which included an increase in T cell homing factors, erythropoiesis, and adipogenesis. Adipocytes, as well as CXCR4-CXCL12 and S1P-S1P1R interactions, contributed to enhanced T cell accumulation in BM during DR. Memory T cell homing to BM during DR was associated with enhanced protection against infections and tumors. Together, this work uncovers a fundamental host strategy to sustain and optimize immunological memory during nutritional challenges that involved a temporal and spatial reorganization of the memory pool within "safe haven" compartments.

Prescribing Associated with High-Risk Opioid Exposures Among Non-cancer Chronic Users of Opioid Analgesics: a Social Network Analysis.

BACKGROUND: The continued rise in fatalities from opioid analgesics despite a steady decline in the number of individual prescriptions directing ≥ 90 morphine milligram equivalents (MME)/day may be explained by patient exposures to redundant prescriptions from multiple prescribers. OBJECTIVES: We evaluated prescribers' specialty and social network characteristics associated with high-risk opioid exposures resulting from single-prescriber high-daily dose prescriptions or multi-prescriber discoordination. DESIGN: Retrospective cohort study. PARTICIPANTS: A cohort of prescribers with opioid analgesic prescription claims for non-cancer chronic opioid users in an Illinois Medicaid managed care program in 2015-2016. MAIN MEASURES: Per prescriber rates of single-prescriber high-daily-dose prescriptions or multi-prescriber discoordination. KEY RESULTS: For 2280 beneficiaries, 36,798 opioid prescription claims were submitted by 3532 prescribers. Compared to 3% of prescriptions (involving 6% of prescribers and 7% of beneficiaries) that directed ≥ 90 MME/day, discoordination accounted for a greater share of high-risk exposures-13% of prescriptions (involving 23% of prescribers and 24% of beneficiaries). The following specialties were at highest risk of discoordinated prescribing compared to internal medicine: dental (incident rate ratio (95% confidence interval) 5.9 (4.6, 7.5)), emergency medicine (4.7 (3.8, 5.8)), and surgical subspecialties (4.2 (3.0, 5.8)). Social network analysis identified 2 small interconnected prescriber communities of high-volume pain management specialists, and 3 sparsely connected groups of predominantly low-volume primary care or emergency medicine clinicians. Using multivariate models, we found that the sparsely connected sociometric positions were a risk factor for high-risk exposures. CONCLUSION: Low-volume prescribers in the social network's periphery were at greater risk of intended or discoordinated prescribing than interconnected high-volume prescribers. Interventions addressing discoordination among low-volume opioid prescribers in non-integrated practices should be a priority. Demands for enhanced functionality and integration of Prescription Drug Monitoring Programs or referrals to specialized multidisciplinary pain management centers are potential policy implications.

Growth and Purification of Vaccinia Virus Stocks for MPM Imaging.

This chapter provides methods for the propagation, purification, and titration of vaccinia virus (VACV) and the highly attenuated strain-modified vaccinia Ankara (MVA). Additionally, we provide information on VACV recombinants we have used for intravital imaging with multiphoton excitation.

Intravital Imaging of Vaccinia Virus-Infected Mice.

Intravital multiphoton microscopy (MPM) allows the direct visualization of viral infections in real time as they occur in living animals. Here we describe the routes and considerations for murine infection with vaccinia virus (VACV) for imaging, and the preparation of the skin and inner lip (labial mucosa) of infected animals for MPM. Using different recombinant VACVs expressing fluorescent proteins in combination with transgenic fluorescent reporter mice, MPM imaging can be used to examine the movements, interactions, and functions of virus-infected cells or selected immune cell populations after infection.