bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional characterization of human T cells generated in vitro from hematopoietic stem cells
Authors: Awong Geneve , Sajic Rade , Motte‐Mohs Ross La , Cochrane Alan , Zúñiga‐Pflücker Juan Carlos 
Published: June 2021

T lymphocytes are a class of white blood cells that play a major role in the adaptive immune response. T cells are generated in the unique microenvironment of the thymus; however, the precise molecular signals enabling their differentiation are still being elucidated. Using the OP9‐DL1 stromal system we have demonstrated the generation of human T cells from umbilical cord‐blood (UCB) hematopoietic stem cells (HSCs). Here, we characterize T cell specification and commitment events induced at both the phenotypic and molecular level examined by the acquisition of T‐lineage cell surface markers and the induction of T cell associated genes, respectively. In addition, in vitro derived T cell subsets are mature and functional as they proliferate and secrete IFNγ following stimulation. Furthermore, we demonstrate the ability of in vitro‐derived human T cell progenitors to engraft and differentiate into a mouse host thymus in vitro. Finally, HSCs transduced to express an HIV (Human Immunodeficiency virus) inhibitory construct have been generated, and will be evaluated for decreased susceptibility to infection when challenged with HIV. This system has important clinical implications as it provides the foundation for a large supply of human T lymphocyte progenitors, which could be used for the immune‐reconstitution of T cell‐depleted individuals.Research supported by the Ontario HIV Treatment Network (OHTN) and the Canadian Institutes of Health Research (CIHR)
Molecular mechanism of allelic exclusion of TCR alpha chains
Authors: Rybakin Vasily , Gascoigne Nicholas R. J. 
Published: June 2021

Allelic exclusion is a mechanism whereby a product of single allele is selected for expression. In case of the T cell receptor, allelic exclusion takes place differently for TCRa and TCRb chains. For the TCRb chain, a successfully completed in‐frame rearrangement of one locus effectively inhibits the rearrangement of the second locus. This inhibition is achieved as a result of signaling originated from a successfully formed dimer of the b chain with pre‐Ta.In contrast, both TCRa alleles are rearranged, often multiple times, until the positive selection stage, when a single a chain in conjunction with a fixed b chain allows the thymocyte to differentiate. Majority of immature thymocytes express more than one a chain on the cell surface, while after positive selection only one chain is expressed.We developed and experimental system allowing to directly assess the fate of each of two specific a chains by flow cytometry and microscopy. Our studies are aimed at the better characterization of posttranslational modifications and signaling events leading to the selection of a single TCRa chain expressed at the cell surface.
Peroxiredoxin II Regulates CD8+ T Cell Expansion and Survival During Acute and Chronic Viral Infections
Authors: Michalek Ryan D , Weant Ashley E , Moon Eun‐Yi , Yu Dae‐Yeul , Grayson Jason M 
Published: June 2021

Reactive oxygen intermediates (ROI) generated in response to receptor stimulation play an important role in cellular responses. We examined the role of the antioxidant enzyme, Peroxiredoxin II (PrxII), during T cell activation and throughout the immune response to acute and chronic viral infections. Following TCR stimulation, PrxII levels increased 50‐fold by 30 hours. Examination of differentiated T cells demonstrated that effector cells possessed lower PrxII levels than naïve or memory CD8+ T cells. Utilizing mice deficient in PrxII, we determined that ROI levels measured in T cells, either directly ex vivo or in response to stimulation, were higher than wild‐type mice. Deletion of PrxII also increased in vitro T cell proliferation, but decreased cell survival during division. Acute infection of PrxII−/− mice with LCMV Armstrong revealed an increased expansion of effector CD8+ T cells on day 8, but yielded no significant difference in memory CD8+ T cells by day 97. Additionally, no differences were observed in virus‐specific CD4+ T cells or antibody secreting cells at any time during infection. In contrast, chronic infection with LCMV Clone 13 resulted in death by day 13 post infection. Together, these results demonstrate that redox regulation of T cell activation through PrxII is critical during acute and chronic viral infections.Supported by ACS‐ #RSG‐04‐066‐01‐MBC to J.G.
TGF‐beta enhances the laminin‐1‐induced production of IL‐16 in RA synovial fibroblasts by elevation of beta1‐integrin expression
Authors: Warstat Katrin , Tsui Shanli , Pap Thomas , Essl Mike , Smith Terry J , Cruikshank William W , Klein Gerd , Gay Steffen , Aicher Wilhelm K. 
Published: June 2021

ObjectivesSynovial tissue of rheumatoid arthritis (RA) patients is characterized by strong expression of laminins and release of inflammatory cytokines, one of which is IL‐16. In this study we investigated regulatory pathways of IL‐16 in synovial fibroblasts (SF) from RA and osteoarthritis (OA) patients.MethodsWe analyzed attachment to LM‐111 and expression of integrins in SF. Expression of IL‐16 in SF grown on LM‐111 w/o TGF‐beta was quantified by qRT‐PCR and ELISA. Activity of IL‐16 was monitored in a cell migration assay. TGF‐induced signaling pathways were studied by immunoblotting and by blocking with p38MAPK‐, MEK‐, and Smad2 inhibitors.ResultsTGF‐activated SF showed an upregulation of beta1‐integrin and adhered more closely to LM‐111. This attachment to LM‐111 could be blocked by mAb to beta1‐integrin. Stimulation with TGF and growth on LM‐111 significantly increased IL‐16 mRNA and protein in RA‐SF. In OA‐SF, TGF failed to induce production of IL‐16. Expression of IL‐16 was regulated by p38MAPK, MEK‐ERK1/2 and Smad2 signaling.ConclusionThe adherence of RA‐SF to LM‐111 in the presence of TGF triggers a significant IL‐16 response and thus contributes to the infiltration of CD4+ lymphocytes into synovial tissues. This mode of induction of IL‐16 represents a novel pathway that results in IL‐16 production in RA‐SF but not in OA‐SF.
Neuropilin‐1 is a receptor for latent and active TGFβ‐1and is involved in suppression by regulatory T cells
Authors: Glinka Yelena , Prud’homme Gerald J. 
Published: June 2021

Neuropilin‐1 (Nrp1) is a receptor for the class 3 semaphorins and vascular endothelial growth factor (VEGF). It is also a marker of regulatory T cells (Tr), which often carry both Nrp1 and latency‐associated peptide‐TGFβ‐1. The signaling TGFβ‐1 receptors bind only active TGFβ‐1, and we hypothesized that Nrp1 binds the latent form.Indeed, we found that Nrp1 is a high affinity receptor for both latent and active TGFβ‐1. Free LAP and LAP‐TGFβ‐1 competed with VEGF165 for binding to Nrp1. LAP has a basic, arginine‐rich C‐terminal motif similar to VEGF and peptides, which bind to the b1 domain of Nrp1. A C‐terminal LAP peptide (QSSRHRR) bound to Nrp1 and inhibited the binding of VEGF and LAP‐TGFβ‐1.Compared to Nrp1‐ cells, sorted Nrp1+ T cells had a much greater capacity to capture LAP‐TGFβ‐1. Sorted Nrp1‐ T cells captured soluble Nrp1‐Fc, and this increased their ability to capture LAP‐TGFβ‐1.Conventional CD4+CD25‐Nrp1‐ T cells double‐coated with Nrp1‐Fc/LAP‐TGFβ‐1 acquired strong Tr activity. Moreover, LAP‐TGFβ‐1 was activated by Nrp1‐Fc, and also by a peptide of the b2 domain of Nrp1 (RKFK; similar to a thrombospondin‐1 KRFK peptide, which is involved in LAP‐TGFβ‐1 activation). Nrp1 also activated LAP‐TGFβ‐1 in cell‐free system.Thus, Nrp1 is a receptor for latent and active TGFβ‐1, and can contribute to Tr activity.
Atropine‐induced potentiation of airway hyperreactivity in antigen challenged guinea pigs is mediated by nerve growth factor
Authors: Verbout Norah G , Jacoby David B , Fryer Allison D 
Published: June 2021

Eosinophils accumulate around airway nerves and cause airway hyperreactivity in antigen challenged guinea pigs. Anticholinergic drugs such as atropine reverse airway hyperreactivity in challenged animals. Similarly, anticholinergics reverse asthma exacerbations in man; however, they are less effective in managing chronic asthma. Conversely, atropine administration to sensitized guinea pigs 1h before challenge significantly potentiates airway hyperreactivity measured 24h later and is mediated by eosinophils. Since eosinophils produce nerve growth factor (NGF), we tested whether NGF causes atropine‐potentiated hyperreactivity. Sensitized guinea pigs were given antibody to NGF (AbNGF) 1h before challenge. Electrical stimulation of both vagus nerves caused bronchoconstriction that was potentiated in challenged animals. Atropine pretreatment further potentiated vagally induced bronchoconstriction in challenged animals, an effect blocked by AbNGF. Atropine‐induced increase in eosinophil protein deposition (assessed by immunohistochemistry) in challenged animals was blocked by AbNGF. Thus, NGF mediates atropine‐induced potentiation of airway hyperreactivity, possibly due to increased eosinophil activation. These data suggest that anticholinergics enhance eosinophil interactions with airway nerves via neurotrophins.NIH HL55543 HL54659 ES014601 HL071795 AHA 0515486Z
Protection from vaccinia virus‐induced severe skin lesions by natural killer cells in a mouse model of eczema vaccinatum
Authors: Kawakami Yuko , Hasegawa Shunji , Yumoto Kenji , Yao Libo , Tomimori Yoshiaki , Tagaya Yutaka , Crotty Shane , Kawakami Toshiaki 
Published: June 2021

Threats of bioterrorism have recently renewed efforts to better understand the disease mechanism of smallpox and to develop a safer vaccine against this dreadful disease. Individuals with atopic dermatitis (AD) are excluded from smallpox vaccination due to their propensity to develop eczema vaccinatum, a disseminated vaccinia virus infection. To study the underlying mechanism of the vulnerability of atopic patients to vaccinia virus infection, we developed a mouse model of eczema vaccinatum by infecting eczematous skin with virus. Virus infection induced severe erosive skin lesions in mice with preexisting dermatitis, but not in mice with healthy skin. The former mice exhibited lower natural killer (NK) cell activity, but similar cytotoxic T lymphocyte activity and humoral immune responses, as compared to the latter mice. The role for NK cells in suppressing vaccinia virus‐induced development of erosive and satellite skin lesions was demonstrated by depletion and adoptive transfer of NK cells. Consistent with low NK cell activities in AD patients, these results can at least partly explain the increased susceptibility of AD patients to eczema vaccinatum.Funded by the NIH through the ADVN consortium.
Endotoxin Tolerance Dysregulates MyD88‐Dependent and TRIF‐Dependent Signaling Pathways and Increases Expression of Negative Regulators of TLR Signaling
Authors: Medvedev Andrei E. , Chen Haiyan , Piao Wenji 
Published: June 2021

Endotoxin tolerance represses expression of proinflammatory cytokines and chemokines while not affecting anti‐inflammatory cytokines and anti‐microbial effectors (reprogramming). Septic shock patients often develop increased susceptibility to infections and decreased responsiveness to LPS, which closely resembles the endotoxin‐tolerant phenotype. Little is known regarding molecular mechanisms of induction and maintenance of endotoxin tolerance. In this study, we examined LPS‐mediated activation of MyD88‐dependent and TRIF‐dependent pathways, as well as expression levels of negative regulators of TLR signaling in control and endotoxin‐tolerant human monocytes. Tolerization resulted in decreased LPS‐inducible dimerization, phosphorylation and nuclear translocation of interferon regulatory factor (IRF)‐3. Consistent with the importance of IRF‐3 for activation of MyD88‐independent, TRIF‐dependent genes, real‐time PCR analyses of endotoxin‐tolerant cells revealed suppressed expression of RANTES and IFN‐β mRNA in response to LPS. Reduced LPS‐inducible IRAK‐1 and p38 phosphorylation, IκB‐α degradation, and nuclear translocation of IRF‐5 noted in LPS‐tolerant cells were accompanied by inhibited TNF‐α and IL‐8 mRNA expression. Real‐time PCR and immunoblotting analyses of negative regulators of TLR signaling documented increased expression levels of Tollip mRNA and protein, as well as accumulation of SOCS‐1, SHIP‐1, IRAK‐M, and ST‐2 mRNA in endotoxin‐tolerant monocytes. Taken together, these data demonstrate TLR4‐triggered MyD88‐dependent, TRAM/TRIF‐dependent intermediates, transcription factors, cytokines, and regulators of TLR signaling that are subject to modulation by endotoxin tolerance.This work was supported by NIH grant AI‐059524 (to A.E.M.).
Critical role of IgG receptors (FcγRs) in LPS‐induced severe lung inflammation
Authors: Krupa Agnieszka , Fudala Rafal , Stankowska Dorota , Kurdowska Anna 
Published: June 2021

Previously we showed that anti‐IL‐8:IL‐8 complexes (IL‐8 associated with anti‐IL‐8 autoantibodies) present in lungs of patients with ALI/ARDS correlate with both the development and outcome of ALI/ARDS. We also demonstrated that anti‐KC autoantibody:KC immune complexes (KC ‐ functional IL‐8) are present in the alveolar spaces of mice treated with LPS. Activity of these complexes is mediated by IgG receptors (FcγRs) because alveolar inflammatory response was substantially diminished in γ‐chain deficient (KO) mice that lack these receptors. In the current study we established that the expression of TLR4 and FcγRs is increased in lungs of mice treated with LPS, and that these receptors partially co‐localize. Further, Yes/Src was activated in neutrophils obtained from LPS treated mice at 6 and 14 h but not 2h, and was not detected in KO mice. Thus, activation of Yes at 6 and 14 h is a consequence of engagement of FcγRs by anti‐KC:KC complexes which are formed in lungs at around 6 h after LPS administration, and is unique for the FcγR signaling pathway. In contrast, we detected phosphorylated Syk already at 2 h since Syk is also activated through TLR4. Lack of activated Syk in KO mice at 6 and 14h indicates that activation of Syk is induced via FcγRs, by the anti‐KC:KC complexes that appear in the lungs at 6 h. Our results suggest a possible crosstalk between TLR4 and FcγRs in lung inflammation.Supported by the NIH grant HL073245.
IL‐23 aids in defense against Francisella infection
Authors: Butchar Jonathan P. , Rajaram Murugesan V.S. , Parsa Kishore V.L. , Clay Corey D. , Gunn John S. , Schlesinger Larry S. , Tridandapani Susheela 
Published: June 2021

Francisella tularensis is the causative agent of tularemia and is classified as a Category A bioterrorism threat. It primarily invades monocytes and macrophages, where it escapes the phagosome and replicates in the cytosol. We performed a microarray screen to study human monocyte responses to F. tularensis novicida, a related subspecies lethal to mice. We identified IL‐23, a recently discovered cytokine related to IL‐12, and confirmed its upregulation using Western blotting and ELISAs. Functional studies showed that this infection‐induced IL‐23 could elicit IFNg production in natural killer cells. Hence, IL‐23 is important during infection, since IFNg is needed for IL‐12 production and blockage of both IL‐23 and IL‐12 leads to higher infectivity.Monocyte infection with virulent Francisella (SCHU S4) also led to IL‐23 production, but at much lower levels than from F. novicida. Further studies showed that IL‐23 production requires PI3 Kinase and NFkB activation, which are negatively regulated by the inositol phosphatase SHIP. Interestingly, SHIP was downregulated by F. novicida but not by SCHU S4 infection. This may account for the reduced IL‐23 response to the more virulent strain.
High opinions of fruits and vegetables (F&V) are associated with lower risk of overweight in African American children
Authors: Lakkakula Anantha P , Zanovec Michael , Murphy Ellen P , Tuuri Georgianna 
Published: June 2021

The health benefits of fruit and vegetable consumption are well established and the Dietary Guidelines for Americans 2005 recommends sufficient intake of these foods to prevent childhood overweight. Our objective was to examine the relationship between African American children's opinions of F&V and their BMI‐for‐age percentiles. 341 4th and 5th grade children (43% boys; 68% 4th graders) attending low‐income, public elementary schools in southeastern Louisiana participated. Children were measured for height and weight and completed a survey which sought their opinions of 38 different F&V. There was a preference for fruits over vegetables and a negative association between mean F&V opinion score and BMI‐for‐age percentile (r = ‐0.26, p = 0.01). Students were placed in 4 groups based upon F&V opinion scores: very low (1‐1.5), low (1.6‐2.0), moderate (2.1‐ 2.5) and high (2.6‐3.0). Students with very low opinions of F&V were 5.5 times more likely to be at risk of overweight or overweight compared to those with high opinions (OR= 5.5, 95% CI = 1.97, 15.44; p< 0.01). Food preferences are established early in life, therefore nutritionists and other health care professionals should promote children's acceptance and intake of F&V as a measure to reduce the prevalence of overweight among children.Grant Funding Source: Blue Cross Blue Shield of Louisiana Foundation and LSU AgCenter
Caffeine Intake and Plasma Zinc Levels among HIV+ Adult Drug Users in Miami
Authors: Campa Adriana , Le Katherine , Rafie Carlin , Sales Sabrina , Baum Marianna K. 
Published: June 2021

ObjectivePlasma zinc deficiency, the most common nutrient deficiency in HIV, is linked to disease progression. This study investigated the relationship between caffeine intake and plasma zinc levels of HIV+ drug users.MethodsInformed consent, medical history, physical examination, viral load and dietary intakes were collected. 24‐hour recalls were analyzed using Nutritionist IV Diet Analysis program.ResultsOf the 225 participants, 78% were African American, 62% received ART, and 72% were men. The mean age was 42.6±7.0. The mean caffeine intake was 115 mg. Plasma zinc was inversely correlated with caffeine intake (r = −0.146, p = <0.036). Participants who did not consume caffeine had significantly higher plasma zinc levels compared to those who consumed caffeine (0.673±0.143 μg/ml vs. 0.628±0.125 μg/ml, p = 0.017). Plasma zinc was also higher in participants whose caffeine intakes were below the median (25 mg) compared to those above the median (0.666±0.141 μg/ml vs. 0.630±0.126 μg/ml, p = 0.059). After controlling for age, gender, CD4 count, viral load and ART, caffeine remained significantly associated with plasma zinc, p = 0.0131.ConclusionsCaffeine intake during the previous 24 hours was associated with decreased plasma zinc levels. Further research is needed to determine the role of caffeine in affecting plasma zinc levels of HIV+ drug users.Support: Funded by NIDA
SOX2: A Glioma‐Specific Marker and a Potential Target for Therapy
Authors: Eschbacher Jennifer Mary , Yeh Ru‐Fang , Smirnov Ivan , Feuerstein Burt , Coons Stephen 
Published: June 2021

Background: The Central Brain Tumor Registry of the United States reports that gliomas account for 78% of malignant brain tumors. (CBTRUS, 2006. Gliomas are currently diagnosed by histopathologic features. We have identified a transcription factor, SOX2, which appears to be a sensitive and specific marker of gliomas. This transcription factor functions to maintain pluripotency in the stem cell of the developing embryo and is expressed during neurogenesis in the adult human CNS. Design: We analyzed 120 glial tumors and 60 non‐glial primary CNS tumors by immunohistochemistry for expression of SOX2 protein. We also evaluated expression array data for SOX2 in 181 separate glioblastomas. Results: SOX2 expression (>75% malignant cells) was found in 105/120 gliomas, including astrocytomas (WHO grades 1–4), oligodendrogliomas (WHO grade 2, 3), ependymomas (WHO grades 1–3) and oligoastrocytomas (WHO grade 2). Of 60 non‐glial primary CNS tumors, 56 were nonreactive (<10% cells) for SOX2, including 40/44 tumors with neuronal features. Our expression array data showed strong SOX2 expression in 156/181 glioblastomas. Conclusion: Our preliminary data suggest that SOX2 is expressed in the great majority of gliomas but only rarely in neuronal tumors. The fact that SOX2 is believed to regulate stem cell self‐renewal suggests that inhibiting its function may have a therapeutic effect in gliomas.*This research was funded by Barrow Neurological Institute
Unusual cerebellopontine angle (CPA) tumors: report of three cases
Authors: Kozarski Tzvetan Borissov , Rao Chandrakant 
Published: June 2021

CPA tumors have origins from various tissue types present in the area. Schwannoma (75%), meningioma (13%) and epidermoid cyst (5%) are the most common tumors.Reflecting the anatomic diversity, many uncommon tumors are reported in this location and we present three such cases.A 51‐year‐old woman presented with difficulty swallowing and unilateral hearing deficit. The tumor extended from petrous bone into the CPA and was diagnosed as myxoid chondrosarcoma. Chondrosarcomas account for 0.048% of intracranial tumors, 37% occurring in the CPA and 8–12% being myxoid type.A 37‐year‐old woman presented with unilateral hearing loss. An irregular mass destroying left petrous bone and extending into the CPA revealed to be a papillary tumor with blood filled spaces lined by cuboidal epithelium characteristic of endolymphatic sac tumor (EST). No stigmata of von Hippel‐Lindau syndrome were present. EST commonly enters the differential diagnosis of CPA tumors and can mimic choroid plexus papilloma or vascular malformation.A 65‐year‐old woman presented with severe headache and dizziness. A large mass destroying the temporal bone and extending into the CPA showed classical cribriform pattern of adenoid cystic carcinoma (ACC) focally and solid pattern diffusely. Intracranial ACC is an uncommon tumor, 5–7% occurring in CPA either from a direct extension, or perineural extension or heterotopic salivary gland tissue.
Comparison of pre‐clinical pharmacokinetic (PK) and pharmacodynamic (PD) relationships of cannabinoid CB1 receptor antagonists in a drug development program for weight loss (WL) management
Authors: Scott Dennis O , Hadcock John R , Black Shawn C 
Published: June 2021

Background: Establishing PK/PD relationships is critical for drug development. The PK/PD relationship for a CB1 receptor antagonist program for WL was assessed.Methods: An analysis of PK and PD of in‐house CB1 antagonists and SR141716 in rats was performed.Results: Receptor occupancy, total plasma and brain concentration, and efficacy (% reduction in food intake [FI] in 2 models of feeding behavior and energy expenditure measured by changes in oxygen consumption [VO2]) were determined in rats. There was a common concentration‐effect relationship across compounds for unbound brain, but not plasma concentrations (Fig 1), that was maintained across efficacy models. Predicted human unbound efficacious plasma concentrations are presented in Table 1.Conclusions: These studies demonstrate that the novel and highly selective CB1 receptor antagonists CP‐945,598, CE‐178,253, and PF‐431,499 will increase our understanding of the role of CB1 receptor antagonism in metabolic disease.