ResearchPad - white-blood-cells https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Differential expression of interferon-lambda receptor 1 splice variants determines the magnitude of the antiviral response induced by interferon-lambda 3 in human immune cells]]> https://www.researchpad.co/article/elastic_article_13835 Type III IFNs (IFN-λs) are antiviral cytokines that are thought to act on specific subsets of cells, especially to protect mucosal barriers. Here, we demonstrate that IFN-λ3 differentially binds multiple human immune cell subsets, indicating the specific receptor subunit, IFN-λR1, is more broadly expressed in the human immune system, compared to published mouse models. IFN-λR1 expression increased after cellular activation, and antiviral responses were inhibited by a soluble version of the receptor. The direct interaction of IFN-λs with human immune cells, and specific regulation of IFN-λR1 expression, has broad mechanistic implications in the modulation of inflammatory or anti-cancer immune responses, and future antiviral therapies.

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<![CDATA[Low LEF1 expression is a biomarker of early T-cell precursor, an aggressive subtype of T-cell lymphoblastic leukemia]]> https://www.researchpad.co/article/elastic_article_13868 Early T-cell precursor (ETP) is the only subtype of acute T-cell lymphoblastic leukemia (T-ALL) listed in the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia. Patients with ETP tend to have worse disease outcomes. ETP is defined by a series of immune markers. The diagnosis of ETP status can be vague due to the limitation of the current measurement. In this study, we performed unsupervised clustering and supervised prediction to investigate whether a molecular biomarker can be used to identify the ETP status in order to stratify risk groups. We found that the ETP status can be predicted by the expression level of Lymphoid enhancer binding factor 1 (LEF1) with high accuracy (AUC of ROC = 0.957 and 0.933 in two T-ALL cohorts). The patients with ETP subtype have a lower level of LEF1 comparing to the those without ETP. We suggest that incorporating the biomarker LEF1 with traditional immune-phenotyping will improve the diagnosis of ETP.

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<![CDATA[Murine gammaherpesvirus infection is skewed toward Igλ+ B cells expressing a specific heavy chain V-segment]]> https://www.researchpad.co/article/elastic_article_13826 Murine gammaherpesvirus 68 is a rodent pathogen that is closely related to the human gammaherpesviruses Epstein-Barr virus and Kaposi’s sarcoma-associated virus. All know gammaherpesviruses are associated with the development of lymphomas, as well as other cancers, in a small subset of infected individuals–particularly those with underlying defects in their immune system (i.e., transplant recipients and HIV infected patients). Because there are very limited small animal models for the human gammaherpesviruses, studies on murine gammaherepsviruses 68 can provide important insights into critical aspects of gammaherpesvirus infections and the association of these viruses with disease development. Another feature of all gammaherpesviruses is their ability to establish a chronic infection of their host–where the virus is maintained for the lifetime of the infected individual. The major target cell harboring chronic gammaherepsvirus infection are B lymphocytes–the cells in the immune system that produce antibodies in response to infections. Here we provide a detailed characterization of the populations of B lymphocytes that become infected by murine gammaherpesvirus 68. This has led to the identification of a specific population of B lymphocytes that is preferentially infected by the virus. This supports a model in which murine gammaherpesvirus infection of B lymphocytes is not random. However, it remains unclear why the virus targets this specific population of B cells for infection.

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<![CDATA[Inferring the immune response from repertoire sequencing]]> https://www.researchpad.co/article/elastic_article_7765 High-throughput immune repertoire sequencing (RepSeq) experiments are becoming a common way to study the diversity, structure and composition of lymphocyte repertoires, promising to yield unique insight into individuals’ past infection history. However, the analysis of these sequences remains challenging, especially when comparing two different temporal or tissue samples. Here we develop a new theoretical approach and methodology to extract the characteristics of the lymphocyte repertoire response from different samples. The method is specifically tailored to RepSeq experiments and accounts for the multiple sources of noise present in these experiments. Its output provides expansion parameters, as well as a list of potentially responding clonotypes. We apply the method to describe the response to yellow fever vaccine obtained from samples taken at different time points. We also use our results to estimate the diversity and clone size statistics from data.

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<![CDATA[ICOS signaling promotes a secondary humoral response after re-challenge with <i>Plasmodium chabaudi chabaudi</i> AS]]> https://www.researchpad.co/article/elastic_article_7745 Malaria, which is caused by the protozoan parasite Plasmodium, remains a major global health problem, as over 400,000 people die from this disease every year. Further understanding of the mechanisms that contribute to protective immunity against this parasite will serve to promote the development of an effective vaccine. Here, we describe the importance of the co-stimulatory molecule ICOS during secondary infection with the rodent parasite Plasmodium chabaudi chabaudi AS. We show that ICOS promotes the expansion of memory T cells, their acquisition of a secondary follicular helper T (Tfh) cell phenotype, and their ability to provide help to MBCs after reinfection. While ICOS deficient mice control the initial parasite load after re-challenge, the absence of ICOS leads to higher relapsing parasitemia compared to wild-type mice. We establish that the lack of expansion of effector cells with a Tfh cell phenotype in Icos-/- mice prevents germinal center formation after secondary infection. Thus, we show that ICOS signaling in T cells promotes an effective memory T cell response and suggests that the enhancement of this co-stimulatory pathway during vaccination may enhance protective immunity to blood-stage Plasmodium infection.

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<![CDATA[Post-stroke infections associated with spleen volume reduction: A pilot study]]> https://www.researchpad.co/article/elastic_article_7682 Spleen volume reduction followed by re-expansion has been described in acute ischemic stroke in both animal and human studies. Splenic contraction might be partially due to sympathetic hyperactivity and might be accompanied by release of splenocytes in the peripheral circulation, leading to immunodepression.AimsTo investigate whether spleen volume changes in the first week after stroke are associated with post-stroke infections, changes in lymphocytes count and autonomic dysfunction.MethodsIn patients with acute ischemic stroke, spleen sizes were calculated from abdominal CT images on day one and day seven. Spleen size reduction was defined as > 10% spleen size reduction between day one and day seven. Post stroke infections were diagnosed during the first seven days after stroke onset using the modified criteria of the US Center of Disease Control and Prevention. We assessed the time course of leukocyte subsets and analysed pulse rate variability (PRV) indices.ResultsPost-stroke infections occurred in six out of 11 patients (55%) with spleen size reduction versus in five out of 27 patients (19%) without spleen size reduction (p = 0,047). Spleen size reduction was associated with a drop in lymphocytes and several lymphocyte subsets from admission to day one, and a higher NIHSS at admission and at day three (p = 0,028 and p = 0,006 respectively). No correlations could be found between spleen volume change and PRV parameters.ConclusionPost-stroke infections and a drop in lymphocytes and several lymphocyte subsets are associated with spleen volume reduction in acute ischemic stroke. ]]> <![CDATA[Comparing in vitro and in vivo virulence phenotypes of Burkholderia pseudomallei type G strains]]> https://www.researchpad.co/article/5989db52ab0ee8fa60bdc780

Burkholderia pseudomallei (Bpm) is a saprophytic rod-shaped gram-negative bacterium and the causative agent of melioidosis. This disease has previously been described as endemic in areas such as northern Australia and Southeast Asia, but, more recently, a better understanding of the epidemiology of melioidosis indicated that the disease is distributed worldwide, including regions of the Americas and Africa. A 16S-23S rDNA internal transcribed spacer (ITS) typing system has been developed for Bpm and has revealed that ITS types C, E, and hybrid CE are mainly associated with Australia and Southeast Asia while type G strains are more associated with cases of melioidosis in the Western Hemisphere. The purpose of the current study was to determine the in vitro and in vivo virulence profiles of the understudied Bpm type G strains Ca2009, Ca2013a, Mx2013, and 724644 and compared such phenotypes to the commonly studied Bpm type C strain K96243. We evaluated virulence by measuring invasion/uptake and survival of these Bpm strains in murine respiratory epithelial LA-4 cells and alveolar macrophage MH-S cells using different multiplicity of infections (MOIs of 1 and 10). We also calculated the lethal dose 50 values (LD50) in BALB/c mice that were inoculated intranasally with either Ca2009, Ca2013a, or Mx2013. Overall, the virulence and lethality phenotypes of Bpm type G strains were similar to the Bpm type C strain K96243. Additional comparative analyses between the Bpm ITS types may lead to a better understanding of the contribution of the ITS type to the epidemiology and ecology of Bpm strains.

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<![CDATA[Highly efficient serum-free manipulation of miRNA in human NK cells without loss of viability or phenotypic alterations is accomplished with TransIT-TKO]]> https://www.researchpad.co/article/N4e6e8e95-63ae-420d-a6d7-c2f1aa3d99e6

Natural killer (NK) cells are innate lymphocytes with functions that include target cell killing, inflammation and regulation. NK cells integrate incoming activating and inhibitory signals through an array of germline-encoded receptors to gauge the health of neighbouring cells. The reactive potential of NK cells is influenced by microRNA (miRNA), small non-coding sequences that interfere with mRNA expression. miRNAs are highly conserved between species, and a single miRNA can have hundreds to thousands of targets and influence entire cellular programs. Two miRNA species, miR-155-5p and miR-146a-5p are known to be important in controlling NK cell function, but research to best understand the impacts of miRNA species within NK cells has been bottlenecked by a lack of techniques for altering miRNA concentrations efficiently and without off-target effects. Here, we describe a non-viral and straightforward approach for increasing or decreasing expression of miRNA in primary human NK cells. We achieve >90% transfection efficiency without off-target impacts on NK cell viability, education, phenotype or function. This opens the opportunity to study and manipulate NK cell miRNA profiles and their impacts on NK cellular programs which may influence outcomes of cancer, inflammation and autoimmunity.

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<![CDATA[Blood co-expression modules identify potential modifier genes of diabetes and lung function in cystic fibrosis]]> https://www.researchpad.co/article/N07a3560c-fa96-4eb5-821e-9292b7a2bef0

Cystic fibrosis (CF) is a rare genetic disease that affects the respiratory and digestive systems. Lung disease is variable among CF patients and associated with the development of comorbidities and chronic infections. The rate of lung function deterioration depends not only on the type of mutations in CFTR, the disease-causing gene, but also on modifier genes. In the present study, we aimed to identify genes and pathways that (i) contribute to the pathogenesis of cystic fibrosis and (ii) modulate the associated comorbidities. We profiled blood samples in CF patients and healthy controls and analyzed RNA-seq data with Weighted Gene Correlation Network Analysis (WGCNA). Interestingly, lung function, body mass index, the presence of diabetes, and chronic P. aeruginosa infections correlated with four modules of co-expressed genes. Detailed inspection of networks and hub genes pointed to cell adhesion, leukocyte trafficking and production of reactive oxygen species as central mechanisms in lung function decline and cystic fibrosis-related diabetes. Of note, we showed that blood is an informative surrogate tissue to study the contribution of inflammation to lung disease and diabetes in CF patients. Finally, we provided evidence that WGCNA is useful to analyze–omic datasets in rare genetic diseases as patient cohorts are inevitably small.

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<![CDATA[Age-related transcriptional modules and TF-miRNA-mRNA interactions in neonatal and infant human thymus]]> https://www.researchpad.co/article/Ne5173bb6-5611-4e9c-b8d8-f6fe9062bcd6

The human thymus suffers a transient neonatal involution, recovers and then starts a process of decline between the 1st and 2nd years of life. Age-related morphological changes in thymus were extensively investigated, but the genomic mechanisms underlying this process remain largely unknown. Through Weighted Gene Co-expression Network Analysis (WGCNA) and TF-miRNA-mRNA integrative analysis we studied the transcriptome of neonate and infant thymic tissues grouped by age: 0–30 days (A); 31days-6 months (B); 7–12 months (C); 13–18 months (D); 19-31months (E). Age-related transcriptional modules, hubs and high gene significance (HGS) genes were identified, as well as TF-miRNA-hub/HGS co-expression correlations. Three transcriptional modules were correlated with A and/or E groups. Hubs were mostly related to cellular/metabolic processes; few were differentially expressed (DE) or related to T-cell development. Inversely, HGS genes in groups A and E were mostly DE. In A (neonate) one third of the hyper-expressed HGS genes were related to T-cell development, against one-twentieth in E, what may correlate with the early neonatal depletion and recovery of thymic T-cell populations. This genomic mechanism is tightly regulated by TF-miRNA-hub/HGS interactions that differentially govern cellular and molecular processes involved in the functioning of the neonate thymus and in the beginning of thymic decline.

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<![CDATA[Opposing effects of HNP1 (α-defensin-1) on plasma cholesterol and atherogenesis]]> https://www.researchpad.co/article/Ndf7081dd-c312-4392-aa9c-ddf6cf67dfa0

Atherosclerosis, the predominant cause of death in well-resourced countries, may develop in the presence of plasma lipid levels within the normal range. Inflammation may contribute to lesion development in these individuals, but the underlying mechanisms are not well understood. Transgenic mice expressing α-def-1 released from activated neutrophils develop larger lipid and macrophage-rich lesions in the proximal aortae notwithstanding hypocholesterolemia caused by accelerated clearance of α-def-1/low-density lipoprotein (LDL) complexes from the plasma. The phenotype does not develop when the release of α-def-1 is prevented with colchicine. However, ApoE-/- mice crossed with α-def-1 mice or given exogenous α-def-1 develop smaller aortic lesions associated with reduced plasma cholesterol, suggesting a protective effect of accelerated LDL clearance. Experiments were performed to address this seeming paradox and to determine if α-def-1 might provide a means to lower cholesterol and thereby attenuate atherogenesis. We confirmed that exposing ApoE-/- mice to α-def-1 lowers total plasma cholesterol and decreases lesion size. However, lesion size was larger than in mice with total plasma cholesterol lowered to the same extent by inhibiting its adsorption or by ingesting a low-fat diet. Furthermore, α-def-1 levels correlated independently with lesion size in ApoE-/- mice. These studies show that α-def-1 has competing effects on atherogenesis. Although α-def-1 accelerates LDL clearance from plasma, it also stimulates deposition and retention of LDL in the vasculature, which may contribute to development of atherosclerosis in individuals with normal or even low plasma levels of cholesterol. Inhibiting α-def-1 may attenuate the impact of chronic inflammation on atherosclerotic vascular disease.

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<![CDATA[Host immune responses during Taenia solium Neurocysticercosis infection and treatment]]> https://www.researchpad.co/article/Nc0d0d75e-fba6-45d6-a2e4-1505f9de6f1c

Taenia solium cysticercosis and taeniasis (TSCT), caused by the tapeworm T. solium, is a foodborne and zoonotic disease classified since 2010 by WHO as a neglected tropical isease. It causes considerable impact on health and economy and is one of the leading causes of acquired epilepsy in most endemic countries of Latin America, Sub-Saharan Africa, and Asia. There is some evidence that the prevalence of TSCT in high-income countries has recently increased, mainly due to immigration from endemic areas. In regions endemic for TSCT, human cysticercosis can manifest clinically as neurocysticercosis (NCC), resulting in epileptic seizures and severe progressive headaches, amongst other neurological signs and/or symptoms. The development of these symptoms results from a complex interplay between anatomical cyst localization, environmental factors, parasite’s infective potential, host genetics, and, especially, host immune responses. Treatment of individuals with active NCC (presence of viable cerebral cysts) with anthelmintic drugs together with steroids is usually effective and, in the majority, reduces the number and/or size of cerebral lesions as well as the neurological symptoms. However, in some cases, treatment may profoundly enhance anthelmintic inflammatory responses with ensuing symptoms, which, otherwise, would have remained silent as long as the cysts are viable. This intriguing silencing process is not yet fully understood but may involve active modulation of host responses by cyst-derived immunomodulatory components released directly into the surrounding brain tissue or by the induction of regulatory networks including regulatory T cells (Treg) or regulatory B cells (Breg). These processes might be disturbed once the cysts undergo treatment-induced apoptosis and necrosis or in a coinfection setting such as HIV. Herein, we review the current literature regarding the immunology and pathogenesis of NCC with a highlight on the mobilization of immune cells during human NCC and their interaction with viable and degenerating cysticerci. Moreover, the immunological parameters associated with NCC in people living with HIV/AIDS and treatments are discussed. Eventually, we propose open questions to understand the role of the immune system and its impact in this intriguing host–parasite crosstalk.

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<![CDATA[The inhibitor of apoptosis proteins antagonist Debio 1143 promotes the PD-1 blockade-mediated HIV load reduction in blood and tissues of humanized mice]]> https://www.researchpad.co/article/N65563527-6ce7-4ff1-862d-df2c817374ce

The immune checkpoint programmed cell death protein 1 (PD-1) plays a major role in T cell exhaustion in cancer and chronic HIV infection. The inhibitor of apoptosis protein antagonist Debio 1143 (D1143) enhances tumor cell death and synergizes with anti-PD-1 agents to promote tumor immunity and displayed HIV latency reversal activity in vitro. We asked in this study whether D1143 would stimulate the potency of an anti-human PD-1 monoclonal antibody (mAb) to reduce HIV loads in humanized mice. Anti-PD-1 mAb treatment decreased PD-1+ CD8+ cell population by 32.3% after interruption of four weeks treatment, and D1143 co-treatment further reduced it from 32.3 to 73%. Anti-PD-1 mAb administration reduced HIV load in blood by 94%, and addition of D1143 further enhanced this reduction from 94 to 97%. D1143 also more profoundly promoted with the anti-PD-1-mediated reduction of HIV loads in all tissues analyzed including spleen (71 to 96.4%), lymph nodes (64.3 to 80%), liver (64.2 to 94.4), lung (64.3 to 80.1%) and thymic organoid (78.2 to 98.2%), achieving a >5 log reduction of HIV loads in CD4+ cells isolated from tissues 2 weeks after drug treatment interruption. Ex vivo anti-CD3/CD28 stimulation increased the ability to activate exhausted CD8+ T cells in infected mice having received in vivo anti-PD-1 treatment by 7.9-fold (5 to 39.6%), and an additional increase by 1.7-fold upon D1143 co-treatment (39.6 to 67.3%). These findings demonstrate for the first time that an inhibitor of apoptosis protein antagonist enhances in a statistically manner the effects of an immune check point inhibitor on antiviral immunity and on HIV load reduction in tissues of humanized mice, suggesting that the combination of two distinct classes of immunomodulatory agents constitutes a promising anti-HIV immunotherapeutic approach.

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<![CDATA[Switchable resolution in soft x-ray tomography of single cells]]> https://www.researchpad.co/article/N83fafb3a-9522-40a6-a68c-b2c601c68e90

The diversity of living cells, in both size and internal complexity, calls for imaging methods with adaptable spatial resolution. Soft x-ray tomography (SXT) is a three-dimensional imaging technique ideally suited to visualizing and quantifying the internal organization of single cells of varying sizes in a near-native state. The achievable resolution of the soft x-ray microscope is largely determined by the objective lens, but switching between objectives is extremely time-consuming and typically undertaken only during microscope maintenance procedures. Since the resolution of the optic is inversely proportional to the depth of focus, an optic capable of imaging the thickest cells is routinely selected. This unnecessarily limits the achievable resolution in smaller cells and eliminates the ability to obtain high-resolution images of regions of interest in larger cells. Here, we describe developments to overcome this shortfall and allow selection of microscope optics best suited to the specimen characteristics and data requirements. We demonstrate that switchable objective capability advances the flexibility of SXT to enable imaging cells ranging in size from bacteria to yeast and mammalian cells without physically modifying the microscope, and we demonstrate the use of this technology to image the same specimen with both optics.

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<![CDATA[Microglia exit the CNS in spinal root avulsion]]> https://www.researchpad.co/article/5c79a3e5d5eed0c4841d1bf2

Microglia are central nervous system (CNS)-resident cells. Their ability to migrate outside of the CNS, however, is not understood. Using time-lapse imaging in an obstetrical brachial plexus injury (OBPI) model, we show that microglia squeeze through the spinal boundary and emigrate to peripheral spinal roots. Although both macrophages and microglia respond, microglia are the debris-clearing cell. Once outside the CNS, microglia re-enter the spinal cord in an altered state. These peripheral nervous system (PNS)-experienced microglia can travel to distal CNS areas from the injury site, including the brain, with debris. This emigration is balanced by two mechanisms—induced emigration via N-methyl-D-aspartate receptor (NMDA) dependence and restriction via contact-dependent cellular repulsion with macrophages. These discoveries open the possibility that microglia can migrate outside of their textbook-defined regions in disease states.

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<![CDATA[FBXO7 sensitivity of phenotypic traits elucidated by a hypomorphic allele]]> https://www.researchpad.co/article/5c89776ad5eed0c4847d2c3f

FBXO7 encodes an F box containing protein that interacts with multiple partners to facilitate numerous cellular processes and has a canonical role as part of an SCF E3 ubiquitin ligase complex. Mutation of FBXO7 is responsible for an early onset Parkinsonian pyramidal syndrome and genome-wide association studies have linked variants in FBXO7 to erythroid traits. A putative orthologue in Drosophila, nutcracker, has been shown to regulate the proteasome, and deficiency of nutcracker results in male infertility. Therefore, we reasoned that modulating Fbxo7 levels in a murine model could provide insights into the role of this protein in mammals. We used a targeted gene trap model which retained 4–16% residual gene expression and assessed the sensitivity of phenotypic traits to gene dosage. Fbxo7 hypomorphs showed regenerative anaemia associated with a shorter erythrocyte half-life, and male mice were infertile. Alterations to T cell phenotypes were also observed, which intriguingly were both T cell intrinsic and extrinsic. Hypomorphic mice were also sensitive to infection with Salmonella, succumbing to a normally sublethal challenge. Despite these phenotypes, Fbxo7 hypomorphs were produced at a normal Mendelian ratio with a normal lifespan and no evidence of neurological symptoms. These data suggest that erythrocyte survival, T cell development and spermatogenesis are particularly sensitive to Fbxo7 gene dosage.

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<![CDATA[Determination of essential phenotypic elements of clusters in high-dimensional entities—DEPECHE]]> https://www.researchpad.co/article/5c8accc7d5eed0c48498ffa7

Technological advances have facilitated an exponential increase in the amount of information that can be derived from single cells, necessitating new computational tools that can make such highly complex data interpretable. Here, we introduce DEPECHE, a rapid, parameter free, sparse k-means-based algorithm for clustering of multi- and megavariate single-cell data. In a number of computational benchmarks aimed at evaluating the capacity to form biologically relevant clusters, including flow/mass-cytometry and single cell RNA sequencing data sets with manually curated gold standard solutions, DEPECHE clusters as well or better than the currently available best performing clustering algorithms. However, the main advantage of DEPECHE, compared to the state-of-the-art, is its unique ability to enhance interpretability of the formed clusters, in that it only retains variables relevant for cluster separation, thereby facilitating computational efficient analyses as well as understanding of complex datasets. DEPECHE is implemented in the open source R package DepecheR currently available at github.com/Theorell/DepecheR.

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<![CDATA[Swainsonine, an alpha-mannosidase inhibitor, may worsen cervical cancer progression through the increase in myeloid derived suppressor cells population]]> https://www.researchpad.co/article/5c897787d5eed0c4847d2ef3

Cervical cancer, caused by high oncogenic risk Human Papillomavirus (HPV) infection, continues to be a public health problem, mainly in developing countries. Using peptide phage display as a tool to identify potential molecular targets in HPV associated tumors, we identified α-mannosidase, among other enriched sequences. This enzyme is expressed in both tumor and inflammatory compartment of the tumor microenvironment. Several studies in experimental models have shown that its inhibition by swainsonine (SW) led to inhibition of tumor growth and metastasis directly and indirectly, through activation of macrophages and NK cells, promoting anti-tumor activity. Therefore, the aim of this work was to test if swainsonine treatment could modulate anti-tumor immune responses and therefore interfere in HPV associated tumor growth. Validation of our biopanning results showed that cervical tumors, both tumor cells and leukocytes, expressed α-mannosidase. Ex vivo experiments with tumor associated macrophages showed that SW could partially modulate macrophage phenotype, decreasing CCL2 secretion and impairing IL-10 and IL-6 upregulation, which prompted us to proceed to in vivo tests. However, in vivo, SW treatment increased tumor growth. Investigation of the mechanisms leading to this result showed that SW treatment significantly induced the accumulation of myeloid derived suppressor cells in the spleen of tumor bearing mice, which inhibited T cell activation. Our results suggested that SW contributes to cervical cancer progression by favoring proliferation and accumulation of myeloid cells in the spleen, thus exacerbating these tumors systemic effects on the immune system, therefore facilitating tumor growth.

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<![CDATA[Dynamics of leukocyte telomere length in pregnant women living with HIV, and HIV-negative pregnant women: A longitudinal observational study]]> https://www.researchpad.co/article/5c897779d5eed0c4847d2db4

Background

HIV-mediated inflammation and immune activation can accelerate telomere attrition. In addition, antiretrovirals can inhibit telomerase, possibly shortening telomeres. We examined the longitudinal dynamics of leukocyte telomere length (LTL) during pregnancy in a unique cohort of women living with HIV (WLWH) treated with combination antiretroviral therapy (cART), and HIV-negative control women.

Methods

Blood was collected at three visits during pregnancy, at 13–23, >23–30, and >30–40 weeks of gestation, and for WLWH only, at 6 weeks post-partum. LTL was measured by qPCR and both cross-sectional and longitudinal (MANOVA) models were used to examine possible predictors of LTL among participants who attended all three visits during pregnancy.

Results

Among WLWH (n = 64) and HIV-negative women (n = 41), within participant LTL were correlated throughout pregnancy (p<0.001). LTL was shorter among WLWH at first visit, but this difference waned by the second visit. WLWH who discontinued cART post-partum experienced a decrease in LTL. Longitudinally, LTL was similar in both groups and increased as gestation progressed, a change that was more pronounced among women under 35 years. Among WLWH, both smoking throughout pregnancy (p = 0.04) and receiving a ritonavir-boosted protease inhibitor-based regimen (p = 0.03) were independently associated with shorter LTL.

Conclusions

LTL increases as pregnancy progresses; the reasons for this are unknown but may relate to changes in blood volume, hormones, and/or cell subset distribution. While our observations need confirmation in an independent cohort, our data suggest that although some cART regimens may influence LTL, being on cART appears overall protective and that stopping cART post-partum may negatively impact LTL. The effect of smoking on LTL is clearly negative, stressing the importance of smoking cessation.

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<![CDATA[Ex vivo-expanded highly purified natural killer cells in combination with temozolomide induce antitumor effects in human glioblastoma cells in vitro]]> https://www.researchpad.co/article/5c89771fd5eed0c4847d24e7

Glioblastoma is the leading malignant glioma with a poor prognosis. This study aimed to investigate the antitumor effects of natural killer cells in combination with temozolomide as the standard chemotherapeutic agent for glioblastoma. Using a simple, feeder-less, and chemically defined culture method, we expanded human peripheral blood mononuclear cells and assessed the receptor expression, natural killer cell activity, and regulatory T cell frequency in expanded cells. Next, using the standard human glioblastoma cell lines (temozolomide-sensitive U87MG, temozolomide-resistant T98G, and LN-18), we assessed the ligand expressions of receptors on natural killer cells. Furthermore, the antitumor effects of the combination of the expanded natural killer cells and temozolomide were assessed using growth inhibition assays, apoptosis detection assays, and senescence-associated β-galactosidase activity assays in the glioblastoma cell lines. Novel culture systems were sufficient to attain highly purified (>98%), expanded (>440-fold) CD3/CD56+ peripheral blood-derived natural killer cells. We designated the expanded population as genuine induced natural killer cells. Genuine induced natural killer cells exhibited a high natural killer activity and low regulatory T cell frequency compared with lymphokine-activated killer cells. Growth inhibition assays revealed that genuine induced natural killer cells inhibited the glioblastoma cell line growth but enhanced temozolomide-induced inhibition effects in U87MG. Apoptosis detection assays revealed that genuine induced natural killer cells induced apoptosis in the glioblastoma cell lines. Furthermore, senescence-associated β-galactosidase activity assays revealed that temozolomide induced senescence in U87MG. Genuine induced natural killer cells induce apoptosis in temozolomide-sensitive and temozolomide-resistant glioblastoma cells and enhances temozolomide-induced antitumor effects in different mechanisms. Hence, the combination of genuine induced natural killer cells and temozolomide may prove to be a promising immunochemotherapeutic approach in patients with glioblastoma if the antitumor effects in vivo can be demonstrated.

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