Interferon lambda restricts herpes simplex virus skin disease by suppressing neutrophil-mediated pathology

Type III interferons (IFN-λ) are antiviral and immunomodulatory cytokines that have been best characterized in respiratory and gastrointestinal infections, but the effects of IFN-λ against skin infections have not been extensively investigated. We sought to define the skin-specific effects of IFN-λ against the highly prevalent human pathogen, herpes simplex virus (HSV). We infected mice lacking the IFN-λ receptor (Ifnlr1-/-), both the IFN-λ and the IFN-α/β receptors (Ifnar1-/-Ifnlr1-/-), or IFN-λ cytokines (Ifnl2/3-/-) and found that IFN-λ restricts the severity of HSV-1 and HSV-2 skin lesions without affecting viral loads. We used RNAseq to define IFN-λ- and IFN-β-induced transcriptional responses in primary mouse keratinocytes. Using conditional knockout mice, we found that IFN-λ signaling in both keratinocytes and neutrophils was necessary to control HSV-1 skin lesion severity and that IFN-λ signaling in keratinocytes suppressed CXCL9-mediated neutrophil recruitment to the skin. Furthermore, depleting neutrophils or blocking CXCL9 protected against severe HSV-1 skin lesions in Ifnlr1-/- mice. Altogether, our results suggest that IFN-λ plays an immunomodulatory role in the skin that restricts neutrophil-mediated pathology during HSV infection and suggests potential applications for IFN-λ in treating viral skin infections.IMPORTANCEType III interferons (IFN-λ) have been shown to have antiviral and immunomodulatory effects at epithelial barriers such as the respiratory and gastrointestinal tracts, but their effects on the skin have not been extensively investigated. We used mice lacking IFN-λ signaling to investigate the skin-specific effects of IFN-λ against the herpes simplex virus (HSV), which targets epithelial tissues to cause cold sores and genital herpes. We found that IFN-λ limited the severity of HSV skin lesions without affecting viral load and that this protective effect required IFN-λ signaling in both keratinocytes and neutrophils. We found that IFN-λ signaling in keratinocytes suppressed neutrophil recruitment to the skin and that depleting neutrophils protected against severe HSV skin lesions in the absence of IFN-λ. Altogether, our results suggest that IFN-λ plays an immunomodulatory role in the skin that restricts neutrophil-mediated pathology during HSV infection and suggests potential applications for IFN-λ in treating viral skin infections.

Comparison of Novel and Traditional Bleeding Techniques in Neonatal and Juvenile Mice

Blood collection is frequently used for neonatal and juvenile mice in toxicology, developmental, and immunology studies and is often a terminal procedure. However, the use of nonterminal blood collection techniques, including the submandibular and the submental collection techniques described for adult mice, may offer opportunities to reduce animal numbers and refine current methods. The use of the submental technique has not been described for neonatal or juvenile mice. In this study, we compared the submental and submandibular blood collection techniques to determine their suitability for use in neonatal and juvenile mice. Male and female CD1 mice, ages 7, 14, 21, and 28 d, were randomized by sex into submental (n = 16), submandibular (n = 16), or control (n = 8) groups. Each mouse was weighed, bled per its assigned group (or only restrained in the case of control mice), and then decapitated without anesthesia for terminal blood collection. Blood collection volume and corticosterone concentrations were measured. The 2 methods showed significant differences in the volume of blood collected at ages 14 and 28, with the submandibular technique yielding significantly higher volumes. No significant differences were detected in corticosterone levels between the 2 techniques based on age or sex. A subset of mice (n = 8, 2 per age group) were bled via submental or submandibular technique and were evaluated 48 h later for gross and histopathologic evidence of trauma. Seven of the 8 mice showed expected inflammation and healing at the collection sites, with 4 mice having embedded strands of fur in the tissue. These data indicate that the submental blood collection is a viable method for nonterminal blood collection method in neonatal and juvenile mice, especially when smaller amounts of blood are needed.

Myeloid cell MHC I expression drives CD8+ T cell activation in nonalcoholic steatohepatitis

Background & aims

Activated CD8+ T cells are elevated in Nonalcoholic steatohepatitis (NASH) and are important for driving fibrosis and inflammation. Despite this, mechanisms of CD8+ T cell activation in NASH are largely limited. Specific CD8+ T cell subsets may become activated through metabolic signals or cytokines. However, studies in NASH have not evaluated the impact of antigen presentation or the involvement of specific antigens. Therefore, we determined if activated CD8+ T cells are dependent on MHC class I expression in NASH to regulate fibrosis and inflammation.

Methods

We used H2Kb and H2Db deficient (MHC I KO), Kb transgenic mice, and myeloid cell Kb deficient mice (LysM Kb KO) to investigate how MHC class I impacts CD8+ T cell function and NASH. Flow cytometry, gene expression, and histology were used to examine hepatic inflammation and fibrosis. The hepatic class I immunopeptidome was evaluated by mass spectrometry.

Results

In NASH, MHC class I isoform H2Kb was upregulated in myeloid cells. MHC I KO demonstrated protective effects against NASH-induced inflammation and fibrosis. Kb mice exhibited increased fibrosis in the absence of H2Db while LysM Kb KO mice showed protection against fibrosis but not inflammation. H2Kb restricted peptides identified a unique NASH peptide Ncf2 capable of CD8+ T cell activation in vitro. The Ncf2 peptide was not detected during fibrosis resolution.

Conclusion

These results suggest that activated hepatic CD8+ T cells are dependent on myeloid cell MHC class I expression in diet induced NASH to promote inflammation and fibrosis. Additionally, our studies suggest a role of NADPH oxidase in the production of Ncf2 peptide generation.

Unique Presentations of Burkholderia gladioli Infections in Several Strains of Immunocompromised Mice

Four strains of experimentally naïve mice (NOD. Cg-Prkdc scid Il2rg tm1Wjl /SzJ [NSG], NOD. Cg- Rag1 tm1Mom Il2rg tm1Wjl /SzJ [NRG], B6.129S(Cg)-Stat1 tm1Dlv/J [STAT1 -/-], and B6.129S7- Ifngr1 tm1Agt/J[IFNγR -/-] housed in a barrier facility developed unusual and seemingly unrelated clinical signs. Young NSG/NRG mice (n = 49, mean age = 4 ± 0.4 mo) exhibited nonspecific clinical signs of moderate-to-severe lethargy, hunched posture, decreased body condition, and pallor. In contrast to the NSG/NRG mice, the STAT1-/- and IFNγ R-/- mice (n = 5) developed large subcutaneous abscesses on the head and neck. These mice were euthanized, and samples were collected for culture. NSG/NRG mice had moderate-markedly enlarged livers (20 of 49, 40%) and spleens (17 of 49, 35%). The livers contained multiple, variably-sized, tan regions throughout all lobes. Histology revealed necrotizing hepatitis (13 of 17, 77%), splenic and hepatic extramedullary hematopoiesis (17 of 17, 100%), glomerular histiocytosis (6 of 17, 35%), and metritis (6 of 11, 55%) with perivascular inflammation, suggesting hematogenous spread Differentials for these lesions included mouse hepatitis virus, ectromelia virus, Pseudomonas aeruginosa, Salmonella spp., and Clostridium piliforme. Burkholderia gladioli was cultured from liver lesions and subcutaneous abscesses and confirmed with 16S ribosomal RNA sequencing. After completing systematic testing of the environment, failure of the water autoclave cycle was suspected as the cause of the outbreak. To address the situation, individually ventilated racks were sanitized and new breeders were purchased; these actions dramatically reduced B. gladioli infections. The current literature contains few reports of B. gladioli infections in immunocompromised mice, and its typical presentation is torticollis and rolling. B. gladioli infection is a potential differential for subcutaneous abscesses, hepatitis, and splenomegaly in immunocompromised mice. Careful monitoring of sterilization techniques is essential to prevent such infections in a barrier facility.

Interferon lambda restricts herpes simplex virus skin disease by suppressing neutrophil-mediated pathology

Type III interferons (IFN-λ) are antiviral and immunomodulatory cytokines that have been best characterized in respiratory and gastrointestinal infections, but the effects of IFN-λ against skin infections have not been extensively investigated. We sought to define the skin-specific effects of IFN-λ against the highly prevalent human pathogen herpes simplex virus (HSV). We infected mice lacking the IFN-λ receptor (Ifnlr1-/-), both the IFN-λ and the IFN-αβ receptor (Ifnar1-/- Ifnlr1-/-), or IFN-λ cytokines (Ifnl2/3-/-) and found that IFN-λ restricts the severity of HSV-1 and HSV-2 skin lesions, independent of a direct effect on viral load. Using conditional knockout mice, we found that IFN-λ signaling in both keratinocytes and neutrophils was necessary to control HSV-1 skin lesion severity, and that IFN-λ signaling in keratinocytes suppressed CXCL9-mediated neutrophil recruitment to the skin. Furthermore, depleting neutrophils or blocking CXCL9 protected against severe HSV-1 skin lesions in Ifnlr1-/- mice. Altogether, our results suggest that IFN-λ plays an immunomodulatory role in the skin that restricts neutrophil-mediated pathology during HSV infection, and suggest potential applications for IFN-λ in treating viral skin infections.

Role of the protease-activated receptor-2 (PAR2) in the exacerbation of house dust mite-induced murine allergic lung disease by multi-walled carbon nanotubes

BACKGROUND

Pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) has been reported to exert strong pro-inflammatory and pro-fibrotic adjuvant effects in mouse models of allergic lung disease. However, the molecular mechanisms through which MWCNTs exacerbate allergen-induced lung disease remain to be elucidated. We hypothesized that protease-activated receptor 2 (PAR2), a G-protein coupled receptor previously implicated in the pathogenesis of various diseases including pulmonary fibrosis and asthma, may play an important role in the exacerbation of house dust mite (HDM) allergen-induced lung disease by MWCNTs.

METHODS

Wildtype (WT) male C57BL6 mice and Par2 KO mice were exposed to vehicle, MWCNTs, HDM extract, or both via oropharyngeal aspiration 6 times over a period of 3 weeks and were sacrificed 3-days after the final exposure (day 22). Bronchoalveolar lavage fluid (BALF) was harvested to measure changes in inflammatory cells, total protein, and lactate dehydrogenase (LDH). Lung protein and RNA were assayed for pro-inflammatory or profibrotic mediators, and formalin-fixed lung sections were evaluated for histopathology.

RESULTS

In both WT and Par2 KO mice, co-exposure to MWCNTs synergistically increased lung inflammation assessed by histopathology, and increased BALF cellularity, primarily eosinophils, as well as BALF total protein and LDH in the presence of relatively low doses of HDM extract that alone produced little, if any, lung inflammation. In addition, both WT and par2 KO mice displayed a similar increase in lung Cc1-11 mRNA, which encodes the eosinophil chemokine CCL-11, after co-exposure to MWCNTs and HDM extract. However, Par2 KO mice displayed significantly less airway fibrosis as determined by quantitative morphometry compared to WT mice after co-exposure to MWCNTs and HDM extract. Accordingly, at both protein and mRNA levels, the pro-fibrotic mediator arginase 1 (ARG-1), was downregulated in Par2 KO mice exposed to MWCNTs and HDM. In contrast, phosphorylation of the pro-inflammatory transcription factor NF-κB and the pro-inflammatory cytokine CXCL-1 was increased in Par2 KO mice exposed to MWCNTs and HDM.

CONCLUSIONS

Our study indicates that PAR2 mediates airway fibrosis but not eosinophilic lung inflammation induced by co-exposure to MWCNTs and HDM allergens.

Combination of Polymeric Micelle Formulation of TGFβ Receptor Inhibitors and Paclitaxel Produce Consistent Response Across Different Mouse Models of TNBC

Triple-negative breast cancer (TNBC) is notoriously difficult to treat due to the lack of targetable receptors and sometimes poor response to chemotherapy. The transforming growth factor-beta (TGFβ) family of proteins and their receptors (TGFR) are highly expressed in TNBC and implicated in chemotherapy-induced cancer stemness. Here we evaluated combination treatments using experimental TGFR inhibitors (TGFβi), SB525334 (SB), and LY2109761 (LY) with Paclitaxel (PTX) chemotherapy. These TGFβi target TGFR-I (SB) or both TGFR-I&II (LY). Due to the poor water solubility of these drugs, we incorporated each of them in poly(2-oxazoline) (POx) high-capacity polymeric micelles (SB-POx and LY-POx). We assessed their anti-cancer effect as single agents and in combination with micellar Paclitaxel (PTX-POx) using multiple immunocompetent TNBC mouse models that mimic human subtypes (4T1, T11-Apobec and T11-UV). While either TGFβi or PTX showed a differential effect in each model as single agents, the combinations were consistently effective against all three models. Genetic profiling of the tumors revealed differences in the expression levels of genes associated with TGFβ, EMT, TLR-4, and Bcl2 signaling, alluding to the susceptibility to specific gene signatures to the treatment. Taken together, our study suggests that TGFβi and PTX combination therapy using high-capacity POx micelle delivery provides a robust anti-tumor response in multiple TNBC subtype mouse models.

Epizootic Yersinia enterocolitica in captive African green monkeys (Chlorocebus aethiops sabaeus)

Yersinia enterocolitica is a Gram-negative bacterium that typical results in enterocolitis in humans and poses significant worldwide risks to public health. An outbreak of yersiniosis in the Vervet/African green monkey colony at the WFSM during the winter of 2015-2016 accounted for widespread systemic infection with high morbidity and mortality. Most of the cases had extensive necrosis with suppuration and large colonies of bacilli in the large bowel and associated lymph nodes; however, the small intestine, stomach, and other organs were also regularly affected. Positive cultures of Yersinia enterocolitica were recovered from affected tissues in 20 of the 23 cases. Carrier animals in the colony were suspected as the source of the infection because many clinically normal animals were culture-positive during and after the outbreak. In this study, we describe the gross and histology findings and immune cell profiles in different organs of affected animals. We found increased numbers of myeloid-derived phagocytes and CD11C-positive antigen-presenting cells and fewer adaptive T and B lymphocytes, suggesting an immunocompromised state in these animals. The pathogen-mediated microenvironment may have contributed to the immunosuppression and rapid spread of the infection in the vervets. Further studies in vervets could provide a better understanding of Yersinia-mediated pathogenesis and immunosuppression, which could be fundamental to understanding chronic and systemic inflammatory diseases in humans.

Pulmonary exposure of mice to ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX) suppresses the innate immune response to carbon black nanoparticles and stimulates lung cell proliferation

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) have been associated with respiratory diseases in humans, yet the mechanisms through which PFAS cause susceptibility to inhaled agents is unknown. Herein, we investigated the effects of ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), an emerging PFAS, on the pulmonary immune response of mice to carbon black nanoparticles (CBNP). We hypothesized that pulmonary exposure to GenX would increase susceptibility to CBNP through suppression of innate immunity.

METHODS

Male C57BL/6 mice were exposed to vehicle, 4 mg/kg CBNP, 10 mg/kg GenX, or CBNP and GenX by oropharyngeal aspiration. Bronchoalveolar lavage fluid (BALF) was collected at 1 and 14 days postexposure for cytokines and total protein. Lung tissue was harvested for histopathology, immunohistochemistry (Ki67 and phosphorylated (p)-STAT3), western blotting (p-STAT3 and p-NF-κB), and qRT-PCR for cytokine mRNAs.

RESULTS

CBNP increased CXCL-1 and neutrophils in BALF at both time points evaluated. However, GenX/CBNP co-exposure reduced CBNP-induced CXCL-1 and neutrophils in BALF. Moreover, CXCL-1, CXCL-2 and IL-1β mRNAs were increased by CBNP in lung tissue but reduced by GenX. Western blotting showed that CBNP induced p-NF-κB in lung tissue, while the GenX/CBNP co-exposed group displayed decreased p-NF-κB. Furthermore, mice exposed to GenX or GenX/CBNP displayed increased numbers of BALF macrophages undergoing mitosis and increased Ki67 immunostaining. This was correlated with increased p-STAT3 by western blotting and immunohistochemistry in lung tissue from mice co-exposed to GenX/CBNP.

CONCLUSIONS

Pulmonary exposure to GenX suppressed CBNP-induced innate immune response in the lungs of mice yet promoted the proliferation of macrophages and lung epithelial cells.

Neurological chikungunya virus infection induces corpus callosum degeneration associated with resident immune cell activation and peripheral immune cell infiltration

Chikungunya virus (CHIKV) is an Old World alphavirus that typically induces arthralgia and rash. However, CHIKV is also capable of infecting the central nervous system (CNS), resulting in encephalitis, myelitis, and peripheral neuropathy. Patients who survive acute infection typically have long lasting neurological effects. To date, an immunocompetent small animal model that recapitulates CHIKV CNS disease has not been established. To develop a mouse model of CNS CHIKV infection, we intracranially inoculated 4–6 week old C57BL/6J mice with 1 of 3 clinical CHIKV isolates: Asian lineage strains SM2013 and AF15561, and ECSA lineage strain SL15649. CHIKV CNS disease is most commonly reported in regions where ECSA lineage strains circulate; in agreement with observations in humans, SL15649 was associated with more severe neurological disease, while SM2013 induced minimal to no disease, and AF15561 induced an intermediate clinical phenotype. At 7dpi when mice demonstrated signs of CNS disease but infectious virus was cleared from the brain, significant corpus callosum degeneration was observed in mice infected with SL15649, and to a lesser extent AF15561. Recruited CD4+ T cells and B cells were significantly elevated in the corpus callosum of mice infected with SL15649 compared to mice infected with SM2013. SL1549 infected mice also had significant micro- and astrogliosis in this area. At 3dpi, prior to neurological signs, the corpus callosum in SL1549 infected mice did not show significant degeneration but did have an influx of peripheral immune cells and increased gliosis. These results suggest that the CNS manifestations of CHIKV are associated with corpus callosum degeneration driven by both peripheral and CNS resident immune cells.

Supported by the following grants: K01 OD026529 (VKB) T32AI0075151 (ACK) AAI Careers in Immunology Fellowship (VKB, ACK) UNC SOM Junior Investigator Development Award (VKB) UNC Department of Pathology and Laboratory Medicine (VKB)

Exclusion of Expert Contributors From Authorship Limits the Quality of Scientific Articles

Veterinary pathologists are key contributors to multidisciplinary biomedical research. However, they are occasionally excluded from authorship in published articles despite their substantial intellectual and data contributions. To better understand the potential origins and implications of this practice, we identified and analyzed 29 scientific publications where the contributing pathologist was excluded as an author. The amount of pathologist-generated data contributions were similar to the calculated average contributions for authors, suggesting that the amount of data contributed by the pathologist was not a valid factor for their exclusion from authorship. We then studied publications with pathologist-generated contributions to compare the effects of inclusion or exclusion of the pathologist as an author. Exclusion of the pathologist from authorship was associated with significantly lower markers of rigor and reproducibility compared to articles in which the pathologist was included as author. Although this study did not find justification for the exclusion of pathologists from authorship, potential consequences of their exclusion on data quality were readily detectable.

Antibody Titers and Seroconversion Kinetics of Outbred Swiss and Heterozygous Nude Soiled-bedding Sentinels for Murine Norovirus and Mouse Hepatitis Virus

Sentinel animals remain a common means of evaluating rodent health in research colonies. An evaluation of our sentinel program revealed that using Crl:CD1(ICR)-Elite (CD1-E) mice was expensive, occasionally disrupted by limited supply, and minimally responsive to the 3Rs. This evaluation prompted us to explore the use of CRL:NU-Foxn1^nu/+ (Het-nude) mice as soiled-bedding sentinel (SBS) animals. Het-nude mice are a byproduct of breeding outbred athymic nude mice and are reared in isolators, with similar health status as CD1-E. Het-nude mice have a thymus, but may have smaller thymic size and fewer bone marrow stem cells than do wildtype controls, suggesting that Het-nude mice might not be immunologically normal. This study compared the antibody titer and seroconversion kinetics of Het-nude and CD1-E SBS to murine norovirus (MNV) and mouse hepatitis virus (MHV). Het-nude and CD1-E female SBS (n = 22 mice of each stock) were housed continuously on soiled bedding collected from MNV-positive or MNV- and MHV-positive colonies at cage changes. Blood was collected for serology at 3, 9 and 12 to 19 wk after the start of soiled bedding exposure. Antibody titers to MNV or MHV did not differ significantly between Het-nude and CD1-E mice. A significant relationship was found between weeks of exposure and titer levels with an increase in titer over the testing period. This study supports the possible use of Het-nude mice as SBS, given that their antibody responses to MNV and MHV are equivalent to those of CD1-E mice.

Antibody-Mediated Immune Subset Depletion Modulates the Immune Response in a Rabbit (Oryctolagus cuniculus) Model of Epstein-Barr Virus Infection

Epstein-Barr Virus (EBV) is a γ-herpesvirus which infects over 90% of the adult human population. Most notably, this virus causes infectious mononucleosis but it is also associated with cancers such as Hodgkin and Burkitt lymphoma. EBV is a species-specific virus and has been studied in many animal models, including nonhuman primates, guinea pigs, humanized mice, and tree shrews. However, none of these animal models are considered the "gold standard" for EBV research. Recently, rabbits have emerged as a viable alternative model, as they are susceptible to EBV infection. In addition, the EBV infection progresses after immune suppression with cyclosporine A (CsA), modeling the reactivation of EBV after latency. We sought to refine this model for acute or active EBV infections by performing antibody-mediated depletion of certain immune subsets in rabbits. Fourteen 16 to 20-wk old, NZW rabbits were intravenously inoculated with EBV and concurrently treated with either anti-CD4 T-cell antibody, anti-pan-T-cell antibody (anti CD45), CSA, or, as a control, anti-HPV antibody. Rabbits that received the depleting antibodies were treated with CsA 3 times at a dose of 15 mg/kg SC once per day for 4 d starting at the time of EBV inoculation then the dose was increased to 20 mg/kg SC twice weekly for 2 wk. Weights, temperatures, and clinical signs were monitored, and rabbits were anesthetized once weekly for blood collection. When compared with the control group, anti-CD4-treated rabbits had fewer clinical signs and displayed higher levels of viral DNA via qPCR in splenocytes; however, flow cytometry results showed only a partial depletion of CD4 T-cells. Treatment with anti-pan-T-cell antibody did not result in noticeable T-cell depletion. These data suggest the EBV-infected rabbit is a promising model for testing antiviral medications and prophylactic vaccines for EBV.

Serine Phosphorylation of the STAT1 Transactivation Domain Promotes Autoreactive B Cell and Systemic Autoimmunity Development

Although STAT1 tyrosine-701 phosphorylation (designated STAT1-pY701) is indispensable for STAT1 function, the requirement for STAT1 serine-727 phosphorylation (designated STAT1-pS727) during systemic autoimmune and antipathogen responses remains unclear. Using autoimmune-prone B6.Sle1b mice expressing a STAT1-S727A mutant in which serine is replaced by alanine, we report in this study that STAT1-pS727 promotes autoimmune Ab-forming cell (AFC) and germinal center (GC) responses, driving autoantibody production and systemic lupus erythematosus (SLE) development. In contrast, STAT1-pS727 is not required for GC, T follicular helper cell (Tfh), and Ab responses to various foreign Ags, including pathogens. STAT1-pS727 is also not required for gut microbiota and dietary Ag-driven GC and Tfh responses in B6.Sle1b mice. By generating B cell-specific bone marrow chimeras, we demonstrate that STAT1-pS727 plays an important B cell-intrinsic role in promoting autoimmune AFC, GC, and Tfh responses, leading to SLE-associated autoantibody production. Our analysis of the TLR7-accelerated B6.Sle1b.Yaa SLE disease model expressing a STAT1-S727A mutant reveals STAT1-pS727-mediated regulation of autoimmune AFC and GC responses and lupus nephritis development. Together, we identify previously unrecognized differential regulation of systemic autoimmune and antipathogen responses by STAT1-pS727. Our data implicate STAT1-pS727 as a therapeutic target for SLE without overtly affecting STAT1-mediated protection against pathogenic infections.

Serine phosphorylation of the STAT1 transactivation domain promotes autoreactive B cell and systemic autoimmunity development

Although STAT1 tyrosine-701 phosphorylation (STAT1-pY701) is indispensable for STAT1 function, the requirement for STAT1 serine-727 phosphorylation (STAT1-pS727) during autoimmune and anti-pathogen responses remains unclear. Here we report that STAT1-pS727 promotes autoimmune antibody-forming cell (AFC) and germinal center (GC) responses, driving systemic lupus erythematosus (SLE) development. STAT1-pS727, however, is not required for GC and antibody responses to foreign-antigens including pathogens or gut microbiota. STAT1-pS727 plays an important B cell-intrinsic role in driving autoimmunity. Transcriptomic analysis of B cells from TLR7-accelerated SLE-prone mice reveals STAT1-pS727-mediated gene regulation of cellular pathways known to be involved in autoimmune GC and AFC responses. Mechanistically, TLR7 activation in B cells induces STAT1-pS727 and during autoimmune responses TLR7 signaling converges with IFNγ-STAT1 signaling in B cells by recruiting STAT1 into the MyD88 signaling complex. Together, we identify previously unappreciated differential regulation of autoimmune and anti-pathogen responses by STAT1-pS727, and implicate STAT1-pS727 as a therapeutic target for SLE.

Endometrium and endometriosis tissue mitochondrial energy metabolism in a nonhuman primate model

BACKGROUND

Endometriosis is the growth of uterine lining (endometrium) outside of the uterus. In other chronic inflammatory diseases, mitochondrial dysfunction is suspected of playing a role in disease pathogenesis. However, little is known about endometriosis mitochondrial function or its effects on tissue metabolism. The objectives of this study were to analyze mitochondrial function in nonhuman primate (NHP) endometrium and endometriosis tissue and to identify the metabolic features of these tissues that may contribute to disease.

METHODS

Mitochondrial function in endometriosis tissue and endometrium was measured using mitochondrial respirometry analysis to determine if changes in oxidative phosphorylation exist in endometrium and endometriosis tissue compared to control endometrium from clinically healthy NHPs. Targeted metabolomics and multidimensional statistical analysis were applied to quantify key metabolites in energy and amino acid biosynthesis pathways.

RESULTS

Mitochondrial respirometry assays showed endometrium from NHPs with endometriosis had reduced complex II-mediated oxygen consumption rates (OCR) across all energy states (basal, p = 0.01; state 3, p = 0.02; state 3u, p = 0.04; state 4o, p = 0.008) and endometriosis tissue had reduced state 3, complex I-mediated OCR (p = 0.02) and respiratory control rates (p = 0.01) compared to normal endometrium. Targeted metabolomics performed on tissue revealed carnitine (p = 0.001), creatine phosphate (p = 0.01), NADH (p = 0.0001), FAD (p = 0.001), tryptophan (p = 0.0009), and malic acid (p = 0.005) were decreased in endometriosis tissue compared to normal endometrium samples. FAD (p = 0.004), tryptophan (p = 0.0004) and malic acid (p = 0.03) were significantly decreased in endometrium from NHPs with endometriosis compared to normal endometrium. Significant metabolites identified in endometriosis and endometrium samples from animals with endometriosis were part of amino acid biosynthesis or energy metabolism pathways.

CONCLUSIONS

Here, endometrial mitochondrial energy production and metabolism were decreased in endometrium and endometriosis tissue. Decreased mitochondrial energy production may be due to oxidative stress-induced damage to mitochondrial DNA or membranes, a shift in cell metabolism, or decreased energy substrate; however, the exact cause remains unknown. Additional research is needed to determine the implications of reduced mitochondrial energy production and metabolism on endometriosis and endometrium.

Systemic Iron Deficiency in a Nonhuman Primate Model of Endometriosis

Endometriosis is characterized by endometrial tissue development outside the uterus. Anemia and iron depletion do not commonly accompany endometriosis in women, despite chronic abdominal inflammation and heavy menstrual bleeding. The objective of this study was to examine iron kinetics associated with endometriosis by using a NHP model, to better understand the underlying mechanism of abnormal hematogram values in women with endometriosis. Hematologic data from 46 macaques with endometriosis were examined for signs of iron depletion. Bone marrow, liver, and serum were used to elucidate whether iron loss or inflammation best explained the hematologic findings. Additional serum markers and intestinal biopsies from NHP with and without endometriosis were evaluated for patterns in iron kinetics across the menstrual cycle and for relative dietary iron-absorbing capacity. Almost half of the NHP with endometriosis were anemic. Overall, NHP had decreased RBC counts, increased MCV, increased percentage of reticulocytes, decreased serum hepcidin, and decreased hepatic and bone marrow iron. Intestinal expression of ferroportin 1, a mediator of iron absorption, was increased, indicating that despite high dietary iron, intestinal iron absorption did not compensate for iron losses. We concluded that use of oral iron supplementation alone does not replenish iron stores in endometriosis. Consequently, iron stores should be evaluated in women with endometriosis, even without overt clinical signs of anemia.

Labyrinthitis Ossificans in a Cynomolgus Macaque (Macaca fascicularis)

Labyrinthitis is inflammation of the membranous and bony labyrinth of the inner ear. Typical portals of entry includehematogenous spread from the cochlear vasculature, passage of otitis media pathogens through the round window, and mostcommonly, meningogenic spread from the subarachnoid space. The sequela of chronic inner ear inflammation is labyrinthitisossificans, in which inner ear structures are replaced by fibrous and osseous tissues. Labyrinthitis in humans has been reportedconcurrently with infection due to various viruses (for example, varicella-zoster, measles, mumps) and bacteria (for example,Treponema pallidum, Streptococcus pneumoniae) and may be associated with vertebrobasilar ischemia and meningitis. Profoundsensorineural hearing loss is a common, serious complication of this disease. Here, we report a case of labyrinthitisossificans in a cynomolgus macaque (Macaca fascicularis) with a potential infectious etiology. Historically, this animal hadan indwelling femoral intravenous catheter for more than 4 y. He presented with a right-sided head tilt and incoordinationof 2 mo duration. The macaque was treated with NSAID and antibiotics, which corrected the incoordination but not the headtilt. MRI revealed right-sided labyrinthitis, and euthanasia was elected due to clinical signs that were refractory to treatment.Gross pathology was unremarkable, but histopathology revealed chronic labyrinthitis ossificans with local fibroplasia andvestibuloauditory neuritis. We describe here the clinical features, imaging, and histologic lesions of labyrinthitis in a macaque.

Abdominal Wall Endometriosis in a Rhesus Macaque (Macaca mulatta)

Endometriosis is the presence of endometrium outside of the uterus. Although endometriosis occurs in both pelvic and extrapelvic locations, extrapelvic locations are less common. The development of abdominal wall or incisional endometriosis in women is associated with gynecologic surgeries and is often misdiagnosed. Because they naturally develop endometriosis similar to women, Old World NHP, including rhesus macaques, provide excellent opportunities for studying endometriosis. Here, we describe a case of abdominal wall endometriosis in a rhesus macaque that had undergone cesarean section. Microscopically, the tissue consisted of pseudocolumnar epithelium-lined glands within a decidualized stroma, which dissected through the abdominal wall musculature and into the adjacent subcutaneous tissue. The stroma was strongly positive for vimentin and CD10 but was rarely, weakly positive for estrogen receptors and negative for progesterone. Close examination of extrapelvic endometriosis in rhesus macaques and other NHP may promote increased understanding of endometriosis in women.

Decidualization of Endometriosis in Macaques

The decidua is the superficial portion of endometrium that transforms, or decidualizes, under the influence of progesterone to nourish the early embryo during pregnancy. Deciduae outside the uterus are found in nearly 100% of human pregnancies. This condition, known as deciduosis, may mimic malignancy, resulting in additional diagnostic procedures that place the mother, baby, or both at risk. Deciduosis has been described in both Old World and New World nonhuman primates in conjunction with pregnancy and after treatment with exogenous progestins. Here the authors present 6 cases of deciduosis associated with endometriotic lesions in female rhesus and cynomolgus macaques (Macaca mulatta and Macaca fascicularis). Full diagnostic necropsies with histologic analyses were performed on all animals. Deciduae were stained with hematoxylin and eosin and by immunohistochemistry for vimentin, CD10, progesterone receptor, estrogen receptor, desmin, cytokeratin, kermix P8, chorionic gonadotropin, human placental lactogen, and calretinin. The most common clinical signs were abdominal pain (4 of 6) and anorexia (2 of 6). At necropsy, macaque uteri were often enlarged or disfigured (4 of 6) with abundant fibrous adhesions (5 of 6). Affected tissue consisted of epithelial-lined cysts and decidualized stroma with scattered gamma/delta T cells. Decidualized stromal cells were large and polyhedral with abundant cytoplasm and round vesicular nuclei. They stained positive for vimentin, CD10, progesterone, and estrogen. In summary, these cases illustrate deciduosis in 6 nonhuman primates with endometriosis. Understanding decidualization in nonhuman primates will aid in elucidating the pathophysiology of deciduosis during pregnancy or endometriosis and potentially lead to new interventions.

Characterization of ovarian aging and reproductive senescence in vervet monkeys (Chlorocebus aethiops sabaeus)

Female vervet monkeys (Chlorocebus aethiops sabaeus) are used as an experimental model for chronic diseases relevant to women's health. However, reproductive senescence (menopause) has not yet been characterized for vervet monkeys. Here we describe the histologic, hormonal, and menstrual markers of reproductive senescence in vervet monkeys from the Wake Forest Vervet Research Colony. Ovaries from monkeys (age, 0 to 27 y) were serially sectioned (5 μm), stained, and photographed. In every 100th section, the numbers of primordial, primary, and secondary follicles were determined, and triplicate measurements were used to calculate mean numbers of follicles per ovary. Antimüllerian hormone (AMH), follicle stimulating hormone, and menstrual cycle length were measured in additional monkeys. Primordial follicles and AMH decreased significantly with age, and significant correlations between numbers of primordial and primary follicles and between numbers of primary and secondary follicles were noted. Histologic evaluation revealed that ovaries from 4 aged monkeys (older than 23 y) were senescent. One aged monkey transitioned to menopause, experiencing cycle irregularity over 4 y, eventual cessation of menses, and plasma AMH below the level of detection. Finally, with increasing age, the percentage of female vervets with offspring declined significantly. The present study provides insight into ovarian aging and reproductive senescence in vervet monkeys. Results highlight the importance of considering this nonhuman primate as a model to investigate the relationships between ovarian aging and chronic disease risk.