Detection of N-glycolyl-neuraminic acid-containing glycolipids in human skin

Humans lack the enzyme that produces the sialic acid N-glycolyl neuraminic acid (Neu5Gc), but several lines of evidence have shown that Neu5Gc can be taken up by mammalian food sources and replace the common human sialic acid N-acetyl neuraminic acid (Neu5Ac) in glycans. Cancer tissue has been shown to have increased the presence of Neu5Gc and Neu5Gc-containing glycolipids such as the ganglioside GM3, which have been proposed as tumor-specific antigens for antibody treatment. Here, we show that a previously described antibody against Neu5Gc-GM3 is binding to Neu5GC-containing gangliosides and is strongly staining different cancer tissues. However, we also found a strong intracellular staining of keratinocytes of healthy skin. We confirmed this staining on freshly isolated keratinocytes by flow cytometry and detected Neu5Gc by mass spectrometry. This finding implicates that non-human Neu5Gc can be incorporated into gangliosides in human skin, and this should be taken into consideration when targeting Neu5Gc-containing gangliosides for cancer immunotherapy

A pan-metazoan concept for adult stem cells : the wobbling Penrose landscape

Funding: EU COST action MARISTEM. Grant Number: 16203 Marie Skłodowska-Curie COFUND program ARDRE. Grant Number: 847681 National Research Agency, ANR. Grant Numbers: ANR-15-IDEX-01, ANR-19-PRC United States-Israel Binational Science Foundation. Grant Number: 2015012Adult stem cells (ASCs) in vertebrates and model invertebrates (e.g. Drosophila melanogaster) are typically long-lived, lineage-restricted, clonogenic and quiescent cells with somatic descendants and tissue/organ-restricted activities. Such ASCs are mostly rare, morphologically undifferentiated, and undergo asymmetric cell division. Characterized by ‘stemness’ gene expression, they can regulate tissue/organ homeostasis, repair and regeneration. By contrast, analysis of other animal phyla shows that ASCs emerge at different life stages, present both differentiated and undifferentiated phenotypes, and may possess amoeboid movement. Usually pluri/totipotent, they may express germ-cell markers, but often lack germ-line sequestering, and typically do not reside in discrete niches. ASCs may constitute up to 40% of animal cells, and participate in a range of biological phenomena, from whole-body regeneration, dormancy, and agametic asexual reproduction, to indeterminate growth. They are considered legitimate units of selection. Conceptualizing this divergence, we present an alternative stemness metaphor to the Waddington landscape: the ‘wobbling Penrose’ landscape. Here, totipotent ASCs adopt ascending/descending courses of an ‘Escherian stairwell’, in a lifelong totipotency pathway. ASCs may also travel along lower stemness echelons to reach fully differentiated states. However, from any starting state, cells can change their stemness status, underscoring their dynamic cellular potencies. Thus, vertebrate ASCs may reflect just one metazoan ASC archetype.Publisher PDFPeer reviewe

Stem Cells and Innate Immunity in Aquatic Invertebrates: Bridging Two Seemingly Disparate Disciplines for New Discoveries in Biology

The scopes related to the interplay between stem cells and the immune system are broad and range from the basic understanding of organism's physiology and ecology to translational studies, further contributing to (eco)toxicology, biotechnology, and medicine as well as regulatory and ethical aspects. Stem cells originate immune cells through hematopoiesis, and the interplay between the two cell types is required in processes like regeneration. In addition, stem and immune cell anomalies directly affect the organism's functions, its ability to cope with environmental changes and, indirectly, its role in ecosystem services. However, stem cells and immune cells continue to be considered parts of two branches of biological research with few interconnections between them. This review aims to bridge these two seemingly disparate disciplines towards much more integrative and transformative approaches with examples deriving mainly from aquatic invertebrates. We discuss the current understanding of cross-disciplinary collaborative and emerging issues, raising novel hypotheses and comments. We also discuss the problems and perspectives of the two disciplines and how to integrate their conceptual frameworks to address basic equations in biology in a new, innovative way

Risk of Getting COVID-19 in People With Multiple Sclerosis

Background and Objectives Several studies have assessed risk factors associated with the severity of COVID-19 outcomes in people with multiple sclerosis (PwMS). The potential role of disease-modifying therapies (DMTs) and demographic and clinical factors on the risk of acquiring SARS-CoV-2 infection has not been evaluated so far. The objective of this study was to assess risk factors of contracting SARS-CoV-2 infection in PwMS by using data collected in the Italian MS Register (IMSR). Methods Acase-control (1:2) studywas set up. Cases included PwMSwith a confirmed diagnosis ofCOVID-19, and controls included PwMS without a confirmed diagnosis of COVID-19. Both groups were propensity score–matched by the date of COVID-19 diagnosis, the date of last visit, and the region of residence. No healthy controls were included in this study. COVID-19 risk was estimated by multivariable logistic regression models including demographic and clinical covariates. The impact of DMTs was assessed in 3 independent logistic regression models including one of the following covariates: last administeredDMT, previousDMTsequences, or the place where the last treatment was administered. Results A total of 779 PwMS with confirmed COVID-19 (cases) were matched to 1,558 PwMS without COVID-19 (controls). In all 3 models, comorbidities, female sex, and a younger age were significantly associated (p < 0.02)with a higher risk of contractingCOVID-19. Patients receiving natalizumab as last DMT(OR[95%CI]: 2.38 [1.66–3.42], p < 0.0001) and those who underwent an escalation treatment strategy (1.57 [1.16–2.13], p = 0.003) were at significantly higher COVID-19 risk. Moreover, PwMS receiving their last DMT requiring hospital access (1.65 [1.34–2.04], p < 0.0001) showed a significant higher risk than those taking self-administered DMTs at home. Discussion This case-control study embedded in the IMSR showed that PwMS at higher COVID-19 risk are younger, more frequently female individuals, and with comorbidities. Long-lasting escalation approach and last therapies that expose patients to the hospital environment seem to significantly increase the risk of SARS-CoV2 infection in PwMS. Classification of Evidence This study provides Class III evidence that among patients with MS, younger age, being female individuals, having more comorbidities, receiving natalizumab, undergoing an escalating treatment strategy, or receiving treatment at a hospital were associated with being infected with COVID-19. Among patients with MS who were infected with COVID-19, a severe course was associated with increasing age and having a progressive form of MS, whereas not being on treatment or receiving an interferon beta agent was protective

Fluoroquinolone resistance: relation between drug use and evolution of resistance in some Units of the “San Bassiano” hospital from 2007 to 2008

There is substantial evidence that the overuse of antibiotics is a major cause for the emergence in antimicrobial resistance. This study analyzes the evolution of antimicrobial resistance to ciprofloxacin and levofloxacin from 2007 to 2008 in some Units of the “San Bassiano” hospital and compares this evolution among the consumption of the same antibiotics. The study involved the collection of all first isolates in blood, urine and transtracheal samples between 2007 and 2008; three microorganisms were chosen: Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Microorganisms investigations concerned Geriatrics, Medicine, Surgery and Intensive Care Unit (ICU) with 48, 48, 44 and 10 beds respectively. Identification and antimicrobial susceptibility testing was performed using the Phoenix automated system (Becton Dickinson). If the ciprofloxacin susceptibility was (S) and levofloxacin susceptibility was (I/R) antimicrobial susceptibility was confirmed by the E-Test method (bioMérieux) on Muller Hilton agar and cell density of 0.5 MacFarland. Control strains were E. Coli ATCC 25922, P. aeruginosa ATCC 27853 and S. aureus ATCC 29213. The antibiotics consumed in the hospital between January 2007 and December 2008 were transformed into Defined Daily Dose (DDD), which corresponds to the quantity of antibiotics consumed by a patient in 24 h. Ciprofloxacin and levofloxacin demonstrated a similar pattern of increasing resistance in some units between 2007 and 2008. Fluoroquinolone resistance increase for E. coli, varies from 10% in Geriatrics to 15% in ICU, for S. aureus varies from 15% in Medicine Unit to 5% in ICU. P. aeruginosa maintained the same percentage of resistance from 2007 to 2008, but there was a significantly increase of strains with intermediate sensitivity (I) up to 30%. The consumption of Ciprofloxacin didn’t increase in any of the units and in some case decreased. The consumption of levofloxacin increased in every units and particularly in ICU it raised from 5100 ev doses in 2007 to 6480 in 2008 and from 0 to 300 doses os (DDD). The increased consumption of levofloxacin in 2008 in ICU could explain the increased of Pseudomonas aeruginosa strains with intermediate sensitivity (I)

IRF4-Dependent and IRF4-Independent Pathways Contribute to DC Dysfunction in Lupus

<div><p>Interferon Regulatory Factors (IRFs) play fundamental roles in dendritic cell (DC) differentiation and function. In particular, IRFs are critical transducers of TLR signaling and dysregulation in this family of factors is associated with the development of autoimmune disorders such as Systemic Lupus Erythematosus (SLE). While several IRFs are expressed in DCs their relative contribution to the aberrant phenotypic and functional characteristics that DCs acquire in autoimmune disease has not been fully delineated. Mice deficient in both DEF6 and SWAP-70 (= Double-knock-out or DKO mice), two members of a unique family of molecules that restrain IRF4 function, spontaneously develop a lupus-like disease. Although autoimmunity in DKO mice is accompanied by dysregulated IRF4 activity in both T and B cells, SWAP-70 is also known to regulate multiple aspects of DC biology leading us to directly evaluate DC development and function in these mice. By monitoring Blimp1 expression and IL-10 competency in DKO mice we demonstrate that DCs in these mice exhibit dysregulated IL-10 production, which is accompanied by aberrant Blimp1 expression in the spleen but not in the peripheral lymph nodes. We furthermore show that DCs from these mice are hyper-responsive to multiple TLR ligands and that IRF4 plays a differential role in in these responses by being required for the TLR4-mediated but not the TLR9-mediated upregulation of IL-10 expression. Thus, DC dysfunction in lupus-prone mice relies on both IRF4-dependent and IRF4-independent pathways.</p></div

Selective requirement for IRF4 in TLR stimulated DKO BMDCs.

<p>(<b>A</b>) WT, DKO and CD11c-Cre IRF4^fl/fl DKO BMDCs were generated <i>in vitro</i> in presence of GM-CSF for 7–9 days prior to FACS analysis of MHCII, CD86 and PDL2. Histograms show relative expression of the indicated marker on WT (red), DKO (blue) and CD11c-Cre IRF4^fl/fl DKO (green) total CD11c⁺DCs or GFP⁺CD11c⁺DCs. One representative experiment out of 3 independent experiments is shown. <b>(B-C)</b> BMDCs were generated <i>in vitro</i> for 7 days. CD11c⁺DCs were purified by magnetic sorting followed by in vitro stimulation with 0.1<b>μ</b>g/ml LPS or 3<b>μ</b>M CpG, for 24h. IL-10 and IFN<b>β</b> gene expression in LPS treated (<b>□</b>) or CpG treated (<b>C</b>) WT, DKO and CD11c-Cre IRF4^fl/fl DKO BMDCs were assayed by qPCR. One representative experiment out of 4 independent experiments is shown. *: p<0.05; **: p<0.01, ***: p<0.001.</p

Relative expansion of CD11b⁺ DCs in DKO mice.

<p>Spleen (SPL) (<b>A</b>) and skin draining lymph nodes (SDLN) (<b>B</b>) of 8 weeks old WT and DKO female mice were assayed for DC populations by flow cytometry. Splenocytes were gated on MHCII⁺CD11c⁺ conventional DCs and analyzed for the proportion of CD8⁺DCs and CD11b⁺DCs. In SDLNs, MHCII^HiCD11c⁺ migratory DCs were also examined. Spleen (<b>C</b>) and skin draining lymph nodes (<b>D</b>) of >24 weeks old mice were also assayed for DC populations by flow cytometry. Cells were gated on MHCII⁺CD11c⁺B220^- conventional DCs and analyzed for the proportion of CD8+DCs and CD11b⁺DCs. In lymph nodes, MHCII^HiCD11c⁺ migratory DC frequencies were also examined. Scatter plots show data of individual mice and mean value of at least 3 independent experiments. *: p<0.05; **: p<0.01, ***: p≤0.0001. <b>(E)</b> CD86, PDL2 and PDL1 cell surface expression was analyzed by flow cytometry on conventional CD11b⁺DCs and CD8⁺ DCs in the spleen of >24 weeks old WT (red) and DKO (blue) mice. Histograms show relative expression of the indicated marker. Representative data of 2–4 independent experiments with a total of 5–9 mice per group are shown.</p