bluuebunny/crossref_metadata_2025_split huggingface dataset:
The TLR7 agonist imiquimod mediates immune activation in primary Sjögren’s syndrome
Authors: Punnanitinont Achamaporn , Kasperek Eileen M , Kramer Jill M 
Published: January 2023

Abstract
Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by chronic inflammation of exocrine tissue, resulting in loss of tears and saliva. Patients also experience many extra-glandular disease manifestations. Treatment for pSS is palliative, and there are currently no treatments available that target disease etiology. Previous studies in our lab demonstrate that Myd88 is crucial for pSS pathogenesis in the NOD.B10Sn-H2b (NOD.B10) pSS mouse model, although the way in which Myd88-dependent pathways become activated in disease remains unknown. Based on its importance in other autoimmune diseases, we hypothesized that TLR7 activation accelerates pSS pathogenesis. We administered the TLR7 agonist Imiquimod (Imq) to pre-disease NOD.B10 females 3 times a week for 6 weeks (n = 8). Parallel experiments were performed in which age and sex-matched controls received a base cream lacking Imq (n = 9). Saliva was collected following pilocarpine injection before and after treatment. Animals were euthanized, spleens and cervical lymph nodes (cLNs) harvested, and flow cytometry was performed. Imq-treated animals exhibited lymphadenopathy, splenomegaly, and decreased salivary flow. Both cLNs and splenocytes from Imq-treated animals demonstrated an increase in the percentage of activated/memory T cells (CD4+, CD44+, CD62L−) and TLR7 expressing B cells (B220+, CD69+, TLR7+). The percentage of B and CD4+ T cells expressing TLR7 was increased in spleen and cLNs following Imq administration. Aged-associated B cells (ABCs) (B220+, CD23−, CD21−, T-bet+) were also expanded in the spleens of Imq-treated mice. In summary, activation of TLR7 mediates adaptive immune activation and promotes expansion of the ABC subset in pSS.
Supported by NIH/NIDCR R01DE29472
HLA Class II Polymorphisms Influence Gut Microbiota Composition and Modulate Disease in Transgenic Mice Model of Multiple Sclerosis
Authors: Shahi Shailesh K , Ali Soham , Lehman Peter , Ghimire Sudeep , Guseva Natalya V , Mangalam Ashutosh K 
Published: January 2023

Abstract
Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system with unknown etiology. The interaction of both genetic and environmental factors plays an important role in MS pathogenesis. Recently, gut microbiota has emerged as a potential environmental factor in MS pathology due to its ability to modulate host immune response. Yet, it is unknown whether genetic factors, such as HLA class II gene(s), can influence gut microbiota which then can modulate MS through regulation of the host immune response. In the present study, we investigated the involvement of gut microbiota in HLA class II genes mediated susceptibility and resistance to MS/experimental autoimmune encephalomyelitis-EAE (an animal model of MS). Previously, we showed that HLA-DR3 transgenic mice lacking endogenous mouse class II genes (AE-KO) were susceptible to proteolipid protein-PLP91–110 induced EAE, whereas AE-KO.HLA-DQ8 transgenic mice were resistant to PLP91–110. Surprisingly, HLA-DR3.DQ8 double transgenic mice showed increased EAE severity compared with HLA-DR3 mice. Distinct microbiota in HLA-DR3, HLA-DQ8, and HLA-DR3.DQ8 transgenic mice compared to AE-KO mice suggested an important role of HLA class-II gene in shaping the gut microbiota composition. We also observed that gut microbiota of HLA-DQ8 mice was more similar to HLA-DR3.DQ8 than HLA-DR3. As the presence of HLA-DQ8 on an HLA-DR3 background increases disease severity, our data suggest that HLA-DQ8 restricted microbiota may contribute to disease severity in HLA-DR3.DQ8 mice. Altogether, our study provides evidence that the HLA-DR and -DQ genes linked to specific gut microbiota may contribute to EAE susceptibility or resistance in a transgenic animal model of MS.
The authors acknowledge funding from the National Multiple Sclerosis Society (RG 5138A1/1T), NIAID/NIH (1R01AI137075-01), a Carver Trust Medical Research Initiative Grant, and the University of Iowa Environmental Health Sciences Research Center, NIEHS/NIH (P30 ES005605). SA was supported by the Emory Warner Fellowship, which provides medical students at the Carver College of Medicine the opportunity to take a full year out of their medical school curriculum to work in a laboratory in the University of Iowa Department of Pathology.
Risk factors for development of severe gastrointestinal dysmotility in patients with systemic sclerosis
Authors: Jakhar Ishaan , Singh Medha , Singh Annapoorna , Sahil Suman , Singh Daulath 
Published: January 2023

Abstract

Background
Systemic Sclerosis (SSc) is an autoimmune condition of unknown etiology. We aim to investigate incidence, characteristics, and risk factors for gastrointestinal (GI) dysmotility in patients diagnosed with SSc using Cerner HealthFacts, a national longitudinal database representing approximately 69 million patients.

Methods
All patients over 18 years of age with SSc were included in our analysis. Incidence of GI dysmotility was identified using ICD coding. Patient characteristics were evaluated as potential risk factors for development of GI dysmotility using multivariable regression built using all variables with p&lt;0.1 on univariable analysis.

Results
Overall, 0.4% (58/13,930) of patients with SSc developed GI dysmotility. Mean age was 57.23±15.22 years and 16% (2,228/13,930) were male and 86.1% (11,502/13,930) were female. In terms of race, 70.15% (9,772/13,930) were white and 14.82% (2,064/13,930) were African American. 92.51% (12,886/13,930) received care at an acute care facility and 81.51% (11,354/13,930) received care at an urban facility. The variables which conferred the highest odds of developing GI dysmotility included presence of hepatic comorbidities (OR 2.35), digestive comorbidities (OR 6.8), muscular dystrophy (OR 569.2), and Raynaud (OR 1.98). In univariable analysis and multivariable regression with 95% CI; 4 variables were predictive for GI dysmotility, and none were protective against GI dysmotility.

Conclusions
In this longitudinal national database study of patient with diagnosed SSc - hepatic, digestive comorbidities, muscular dystrophy, and Raynaud were noted to be associated with high risk of developing GI dysmotility. Careful evaluation and follow up is advised for SSc patients.
Supported by None
Bi-allelic TTC21A mutations in common variable immunodeficiency patients
Authors: Zhang Zinan , Lenardo Michael J , Smith Kenneth G C 
Published: January 2023

Abstract
Very little is known about the gene TTC21A – it was first described as a gene in the AP20 sub-region of chr3p.21.3 in which deletions were associated with cancer. Initially, TTC21A mRNA expression was only found in the testis, consistent with a recent study linking homozygous TTC21A mutations to decreased fertility due to structural defects in sperm flagella. Interestingly, the gene is also expressed in B lymphocytes with several smaller predicted protein coding transcripts enriched particularly in naïve and memory B cells. Here we report four individuals of one kindred with common variable immunodeficiency (CVID) with two different sets of rare biallelic TTC21A variants. Based on whole genome sequencing analysis, TTC21A was the only candidate gene that co-segregated with disease across three generations and eight individuals of this family with an autosomal recessive mode of inheritance. The affected individuals had low serum IgG and a significant defect in class-switching. In-depth B cell immunophenotyping revealed that, relative to healthy family controls, the patients had significant skewing of increased transitional (CD27− IgD+ CD24+ CD38+) B cells and markedly reduced terminally differentiated plasmablasts (IgD− CD20low CD38+). The patients with the rare homozygous variant also had significantly reduced expression of the B cell specific TT21A variant relative to the family controls and patients with the compound heterozygous variants. Initial immunization experiments of Ttc21a CRISPR knock-in mice mirrored the patients’ phenotype with decreased class switching; however subsequent repeats have been inconclusive. Additional work is necessary to further elucidate the immune function of TTC21A in B cells.
Supported by the NIH Oxford-Cambridge MD/PhD Scholarship
T cell extrinsic mechanics explaining the T cell hyperactivation seen in Activated PI3K δ Syndrome
Authors: Bier Julia , Brink Robert , Tangye Stuart , Deenick Elissa K 
Published: January 2023

Abstract
Activated PI3K Delta Syndrome (APDS) is a rare condition caused by heterozygous gain of function mutations in PIK3CD, which encodes the leukocyte-restricted p110δ catalytic subunit of phosphoinositol 3-kinase (PI3K). PI3K is activated downstream of many surface receptors expressed by T cells and has been implicated in the control of CD4+ T cell helper differentiation, activation, and proliferation. APDS patients have increased PI3K activity leading to several immune manifestations with the some of the most common features being lymphoproliferation, respiratory tract infections, Th2-related pathologies, and impaired antibody responses.
We previously analysed a CRISPR/Cas9 mouse model (Pik3cdE1020K). This showed intrinsic changes impacting on T cell function (increased Th2 cytokines and poor Tfh function) but also extrinsic factors driving a decrease in frequency of naïve and a concurrent increase in memory T cells and Tfh cells, indicating T cell hyperactivation. Here we investigated these extrinsic components further. We found that PI3K B cells are driving Tfh differentiation. We also explored the role of PI3K in maintaining Treg function and identity and determined if Treg dysregulation was driving T cell hyperactivation.
These studies reveal an important role of PI3K in modulating T cell differentiation, activation, and function through both T cell intrinsic and extrinsic mechanisms. An improved understanding of T cell hyperactivation can provide insight into the lymphoproliferation that affects most APDS patients. Overall, these results reveal the potential to dissect the mechanisms underlying disease, providing grounds to define new drug targets and ultimately improve the clinical management of these patients.
22q11.2 Deletion Syndrome Causes a Thymus Hypoplasia Corrected by Mesenchymal Cell Replacement
Authors: van Oers Nicolai S , Bhalla Pratibha , Moses Angela , Kumar Ashwani , Xing Chao , Wysocki Christian , Cleaver Ondine , Markert M Louise , de la Morena M Teresa 
Published: January 2023

Abstract
Thymus hypoplasia occurs in several clinical conditions including 22q11.2 deletion syndrome (22q11.2DS). 22q11.2DS is the most common human microdeletion disorder, affecting 1/4000. Thymuses from 60–70% 22q11.2DS patients are small and produce fewer T cells than normal. For individuals with a severe hypoplasia, an allogenic thymus tissue graft is needed to restore thymopoiesis. To determine the molecular mechanisms contributing to a small thymus in 22q11.2DS, we compared the development of the thymus in embryos from various 22q11.DS mouse models, normal controls and Foxn1 mutant mice. Reaggregate fetal thymic organ culture assays reveal that replacing mesenchymal cells from 22q11.2del hypoplastic lobes with normal ones restores tissue expansion and thymopoiesis. Thymic epithelial cells used as substitutes cannot. This is distinct from the Foxn1 mutant mice, wherein defective thymic epithelial cell functions lead to thymus hypoplasia/aplasia. Single cell RNA sequencing of normal and hypoplastic thymus lobes revealed differential expression of transcripts that primarily impacted 5 distinct mesenchymal cell subsets in 22q11.2DS. These transcripts are involved in cell-cell interactions, collagen deposition and growth. Elevated levels of collagen are present in the hypoplastic thymus tissues, suggesting a structural restriction. Mesenchymal and epithelial cell differentiation/expansion assays reveal a selective reduction in mesenchymal tissue expansion due to 22q11.2DS
Supported by grants from the National Institutes of Health (R01AI114523, R21AI144140) and the Jeffrey Modell Foundation (MdlM, CAW)
Characterization of Human FOXN1 Mutations Uncovers both Loss- and Gain-of-Function Outcomes
Authors: van Oers Nicolai S , Moses Angela , Bhalla Pratibha , Wysocki Christian , Seroogy Christine , Markert M Louise , de la Morena M Teresa 
Published: January 2023

Abstract
Thymus hypoplasia is reported for individuals with autosomal recessive, compound heterozygous and single allelic FOXN1 mutations. FOXN1 is the master transcriptional regulator of thymus epithelial cell development. Autosomal recessive mutations in FOXN1 lead to a Nude/SCID phenotype due to the ensuing T cell lymphopenia and impaired hair follicle extrusion. Targeted exome and whole genome sequencing for patients with low TRECs (measure of T cell output) has increased the number of diverse FOXN1 mutations to over 40. The consequence of these FOXN1 mutations on patients is varied and somewhat complicated by some individuals having only a transient delay in T cell development that corrects over time. We compared the functions of the FOXN1 mutants with luciferase reporter assays and nuclear localization experiments. For selected FOXN1 mutations, mice were developed to genocopy these to assess impacts on thymopoiesis. We identify partial and complete loss-of-function mutations along with gain-of-function and dominant negatives. Comparative analyses of murine thymopoiesis reveal some compound het Foxn1 mutations cause a transient thymus hypoplasia while others cause a permanent small thymus. Taken together, our findings establish FOXN1 genotype-phenotype relationships and suggest rapid functional screening approaches can be used to define the impact of different mutations of clinical relevance.
Supported by grants from NIH (R01AI114523, R21AI144140) and the Jeffrey Modell Foundation (MdlM, CAW)
Unraveling the mechanism of sepsis-mediated multiple organ dysfunction syndrome by RNA sequencing analysis in the pediatric population
Authors: Bermudez Marie , Yuki Koichi , Koutsogiannaki Sophia 
Published: January 2023

Abstract
Sepsis is a significant healthcare burden, with high morbidities and mortalities and no specific therapy is yet available. More than 42,000 children develop severe sepsis each year in the U.S and 67% of those patients develop multiple organ dysfunction syndrome (MODS). In this study we aim to elucidate the mechanism of sepsis-mediated MODS by RNAseq analysis in PBMCs from the peripheral blood of pediatric patients. Comparison between control and septic patients revealed that transcriptomic signatures associated with receptor-mediated endocytosis (Iglc3, Igkv3d-20), anaphase-promoting complex (APC)-dependent catabolic process (Pttg1, Cdc20) heme-metabolism (Alas2, Slc25a39) and oxygen transport (hemoglobulin pathway) (Hbb, Hba2, Hbq1) were upregulated in sepsis. Heme/hemoglobulin related genes were downregulated in the recovery phase of those patients. In addition, neutrophil chemotaxis (CCL3L1, IL1B, CCL4L2, CCL3), phagocytosis (IGLL5, IGHG1, IGHG2), and interleukin-1 receptor binding (IL1RN, IL1B) pathways were upregulated in the recovery phase, while T cell activation (CD2, ITK, ZAP70, CD8A, TREML2) and differentiation (LCK, IL7R), and negative regulation of NIK/NF-kappaB signaling (SPAN6, CPNE1, ADIPOR1) pathways were downregulated. Many of those genes upregulated in the septic patients are associated with lower survival probability in the adult population, while genes upregulated in the recovery phase are associated with higher survival probability, based on the Biological Information Database of Sepsis (BIDOS). Given data on the pediatric population are scarce, our study reveals unique gene signatures of PBMCs associated with pediatric sepsis that could be novel targets for therapeutic intervention.
Supported by R21HD099194-01A1, NICHD The Anesthesia Research Distinguished Trailblazer Award, Boston Children’s Hospital
CEACAM1 is an IL-2R-dependent biomarker in patients with multiple autoimmune-diseases undergoing low-dose IL-2 therapy
Authors: Yu Aixin , Moro Alejandro , Rosenzwajg Michelle , Tchitchet Nicolas , Klatzmann David , Malek Thomas R 
Published: January 2023

Abstract
Low-dose (LD) IL-2 is a promising strategy to boost Tregs in patient with autoimmune diseases. This therapeutic strategy would benefit by identifying biomarkers that are highly and selectively responsive to IL-2R signaling in Treg and Teff cells. To initially address this point, RNA-seq was used to screen for genes that are induced in CD4+ Foxp3+ Treg and CD4+ CD45RO+ T effector/memory (TEM) cells from normal subjects in vitro by IL-2R, but not TCR/CD28, signaling. CEACAM1 was identified as a candidate gene in Tregs 4 and 24 hours post-stimulation. However, CEACAM1 was optimally upregulated in Treg and TEM cells after an extended 5 day culture with anti-CD3/CD28 and IL-2. Notably, anti-IL-2 essentially completely inhibited this upregulation, indicating that CEACAM1 expression was strictly IL-2 dependent. Tregs were shown to express the long isoform of CEACAM1 with inhibitory ITIM domains and the ITIMs may be functionally active as most in vitro activated CEACAM1+ Tregs did not express Ki67. To assess CEACAM1 as an IL-2-dependent biomarker during LD-IL-2 therapy, CD25 and CEACAM1 were evaluated at the protein and RNA levels for patient samples from eight distinct autoimmune diseases. In all samples, CEACAM1 was upregulated after a 5-day induction course of LD-IL-2 in Tregs but not TEM cells. This finding correlated with the effect of LD-IL-2 on CD25. CEACAM1 levels returned to baseline 14 days post-LD-IL-2 treatment. After the induction course of LD-IL-2, most CEACAM1+ Tregs were Ki67−, consisting with an inhibitory role for CEACAM1. Collectively, our findings indicate that CEACAM1 is a biomarker for LD-IL-2 therapy whose expression is highly dependent on IL-2R signaling and suggest that CEACAM1 may function to regulate Treg homeostasis.
Supported by R01AI131643
Bacillus anthracis peptidoglycan alters human M2-like macrophage phenotype and efferocytic function in the presence of human serum
Authors: Mytych Josh S , Pan Zijian , Lopez-Davis Charmaine , Lawrence Christina , James Judith , Popescu Narcis , Coggeshall Mark , Farris Darise 
Published: January 2023

Abstract
Bacillus anthracis peptidoglycan (PGN) is a major component of the bacterial cell wall and a key pathogen associated molecular pattern contributing to anthrax pathology including coagulopathy in late stage disease. Lymphocyte apoptosis is an established phenomenon in bacterial sepsis, including fulminant anthrax. Clearance of apoptotic cells (efferocytosis) is thought to be mediated by tissue-resident macrophages (MF), modeled in vitro as M2-like MF. Circulating innate cells need serum opsonization of PGN for cellular activation, but opsonization requirements for human MF activation have not been reported. Herein, we tested the hypothesis that PGN requires human serum opsonization for MF activation and inhibits human M2-like MF efferocytosis of apoptotic human neutrophils.
MF were differentiated in vitro with M-CSF and polarized to M2 phenotype with dexamethasone. Cytokine and soluble receptor levels were assessed by ELISA and Luminex assays. Cell surface markers and fraction of MF containing fluorescently-labeled apoptotic human neutrophils were assessed by flow cytometry. M2-like MF recognition of PGN was enhanced in the presence of human but not bovine serum, noted by increased secretion of TNF-a and IL-10 in PGN-treated culture supernatants. Efferocytosis, and cell surface expression of MerTK, Tyro3, Axl, αVβ5, CD36 and Tim-3, all pro-efferocytic receptors, was significantly downregulated by pre-treatment of MF with PGN. Increases in soluble pro-efferocytic receptors were detected in PGN-treated MF culture supernatants.
We conclude that PGN impairs efferocytosis by human M2-like macrophages, likely by down-regulating the expression of cell surface receptors known to signal apoptotic cell engulfment.
Supported by NIH (U19AI062629).
IL-27 modulates T cell cytokines in the T cell-osteoclast crosstalk during HIV infection
Authors: Li Tong , Hadigan Colleen , Kumar Jai , Kumar Princy , Catalfamo Marta 
Published: January 2023

Abstract
In People with HIV (PWH), chronic immune activation and systemic inflammation are associated with increased risk to develop comorbidities including bone loss. IL-27 has been shown to modulate osteoclastogenesis and T cell function, however, the roles of IL-27 and T cell activation in the setting of HIV infection are largely unknown. In the present study, we evaluated the effects of IL-27 in modulating T cell function during T cells:Osteoclasts (OCs) crosstalk in PWH and healthy controls. We developed an in vitro coculture system of T cells with OCs from PWH and healthy controls. T cells and autologous OCs were isolated from frozen PBMCs of PWH (n= 26) and healthy controls (n= 10). We found that the stimulation of T cells from PWH and healthy controls cultured in the presence of OCs significantly enhanced T cell secretion of pro- (IFN-γ, TNF-α, IL-17) and anti-inflammatory (IL-10) cytokines. IL-27 down-regulated secretion of IL-17 (p&lt; 0.001) and IL-10 (p= 0.003) from PWH but not in healthy controls and had a weak effect reducing RANKL surface expression in CD4 T cells (p= 0.047) when T cells were cultured with OCs. In addition, the level of IFN-γ secreted by stimulated T cells cultured alone was negatively associated with T score in absence (R= −0.59, p= 0.013) or in presence of IL-27 (R= −0.64, p= 0.007). All together these results suggest that in the context of HIV infection IL-27 may promote a dominant Th1 response (IFN-γ and TNF-α secretion) generating a “pro-osteoclastic” environment.
Supported by NIH R01AI145549-02
SARS-CoV-2 infection reduces the frequencies of angiogenic CD4 and CD8 T cells (Tang)
Authors: AbdusSamad Maryam , Li Tong , Timpone Joseph , Kumar Jai , Kumar Princy , Hunt Ryan C , Catalfamo Marta 
Published: January 2023

Abstract
SARS-CoV-2 is one of the leading causes of mortality worldwide with rising death toll over 5.4 million. The severe presentation of the disease is associated with systemic inflammation, activation of the coagulation cascade and immunological dysfunction. Numerous studies implicate endothelial activation and dysfunction as playing an important role; however, the pathways involved are not well-understood. Endothelial injury and damage trigger a mechanism of vascular repair mediated by bone marrow derived endothelial progenitor cells and recently discovered a type of T cells with angiogenic properties. In this study, we hypothesize that SARS-COV-2 alters this pathway. To address this hypothesis, we determined changes in the frequency and phenotype of these two cell types, the circulating endothelial progenitor (EPC) (LIN4− CD45− CD34+) and Tang cells (CXCR4+ CD31+) using PBMCs from hospitalized COVID-19 positive (n = 10) and healthy (n = 11) donors. Our results indicate a decrease in the frequency of CD4 and CD8 Tang cells compared with healthy controls (p=0.003; p=0.01). In addition, Tang cells showed a significant increase in the expression of progenitor marker (CD49f) (p&lt;0.001; p=0.016), and no changes were observed in the frequency and phenotype of the LIN4− CD45− CD34+. Moreover, a negative association was observed between Tang cells and plasma levels of the procoagulant PAI-1 biomarker (r=−0.806, p=0.007; r=−0.818, p=0.006), and CD8 Tang cells were inversely correlated with the levels of MMP9 and TNFa, (r=−0.879, p=0.002; r=−0.709, p=0.027). Altogether these data suggest that SARS-CoV-2 infection reduces the frequency of Tang cells and promote activation and may interfere with their vascular repair function.