Trends and risk factors of SARS-CoV-2 infection in asymptomatic blood donors.

BACKGROUND: A large proportion of SARS-CoV-2-infected individuals does not develop severe symptoms. Serological tests help in evaluating the spread of infection and disease immunization. The aim of this study was to prospectively examine the trends and risk factors of SARS-CoV-2 infection in blood donors. STUDY DESIGN AND METHODS: We screened 8798 asymptomatic donors presenting in Milan from July 2020 to February 2021 (10,680 presentations) before the vaccination campaign for anti-nucleoprotein (NP) antibodies, and for anti-spike receptor-binding domain (RBD) antibodies and nasopharyngeal swab PCR in those who tested positive. RESULTS: The prevalence of anti-NP+/RBD+ tests increased progressively with time up to ~15% (p < .0001), preceded by a peak of PCR+ tests. Anti-RBD titers were higher in anti-NP IgG+/IgM+ than in IgG+/IgM- individuals and in those with a history of infection (p < .0001); of these 197/630 (31.2%) displayed high titers (>80 AU/ml). Anti-RBD titers declined during follow-up, depending on baseline titers (p < .0001) and time (p = .025). Risk factors for seroconversion were a later presentation date and non-O ABO blood group (p < .001). A positive PCR was detected in 0.7% of participants in the absence of SARS-CoV-2 viremia. CONCLUSIONS: During the second wave of SARS-CoV-2 infection in Northern Italy, we detected an increase in seroprevalence in healthy blood donors from ~4% to ~15%, with a trend paralleling that observed in the general population. Seroconversion was more frequent in carriers of non-O blood groups. The persistence of anti-RBD antibodies was short-lived.

Impact of SARS-CoV-2 infection on the recovery of peripheral blood mononuclear cells by density gradient.

SARS-CoV-2 virus infection is responsible for coronavirus disease (COVID-19), which is characterised by a hyperinflammatory response that plays a major role in determining the respiratory and immune-mediated complications of this condition. While isolating peripheral blood mononuclear cells (PBMCs) from whole blood of COVID-19 patients by density gradient centrifugation, we noticed some changes in the floating properties and in the sedimentation of the cells on density medium. Investigating this further, we found that in early phase COVID-19 patients, characterised by reduced circulating lymphocytes and monocytes, the PBMC fraction contained surprisingly high levels of neutrophils. Furthermore, the neutrophil population exhibited alterations in the cell size and in the internal complexity, consistent with the presence of low density neutrophils (LDNs) and immature forms, which may explain the shift seen in the floating abilities and that may be predictive of the severity of the disease. The percentage of this subset of neutrophils found in the PBMC band was rather spread (35.4 ± 27.2%, with a median 28.8% and IQR 11.6-56.1, Welch's t-test early phase COVID-19 versus blood donor healthy controls P < 0.0001). Results confirm the presence of an increased number of LDNs in patients with early stage COVID-19, which correlates with disease severity and may be recovered by centrifugation on a density gradient together with PBMCs.

Chromosome 3 cluster rs11385942 variant links complement activation with severe COVID-19.

BACKGROUND: Genetic variation at a multigene cluster at chromosome 3p21.31 and the ABO blood group have been associated with the risk of developing severe COVID-19, but the mechanism remains unclear. Complement activation has been associated with COVID-19 severity. OBJECTIVE: The aim of this study was to examine whether chromosome 3p21.31 and the ABO variants are linked to the activation of the complement cascade in COVID-19 patients. METHODS: We considered 72 unrelated European hospitalized patients with genetic data and evaluation of circulating C5a and soluble terminal complement complex C5b-9 (SC5b-9). Twenty-six (36.1%) patients carried the rs11385942 G>GA variant and 44 (66.1%) non-O blood group associated with increased risk of severe COVID-19. RESULTS: C5a and SC5-b9 plasma levels were higher in rs11385949 GA carriers than in non-carriers (P = 0.041 and P = 0.012, respectively), while C5a levels were higher in non-O group than in O group patients (P = 0.019). The association between rs11385949 and SC5b-9 remained significant after adjustment for ABO and disease severity (P = 0.004) and further correction for C5a (P = 0.018). There was a direct relationship between upper airways viral load and SC5b-9 in carriers of the rs11385949 risk allele (P = 0.032), which was not observed in non-carriers. CONCLUSIONS: The rs11385949 G>GA variant, tagging the chromosome 3 gene cluster variation and predisposing to severe COVID-19, is associated with enhanced complement activation, both with C5a and terminal complement complex, while non-O blood group with C5a levels. These findings provide a link between genetic susceptibility to more severe COVID-19 and complement activation.

Complement activation and endothelial perturbation parallel COVID-19 severity and activity.

BACKGROUND: Animal models and few clinical reports suggest the involvement of the complement system in the onset of severe manifestations of coronavirus disease-2019 (COVID-19). However, complement contribution to endotheliopathy and hypercoagulability has not been elucidated yet. OBJECTIVE: To evaluate the association among complement activation, endothelial damage and disease severity or activity in COVID-19 patients. METHODS: In this single-centre cohort study, 148 patients with COVID-19 of different severity were evaluated upon hospital admission and 30 days later. Markers of complement activation (SC5b-9 and C5a) and endothelial perturbation (von Willebrand factor [vWF], tissue-type plasminogen activator [t-PA], plasminogen activator inhibitor-1 [PAI-1], soluble thrombomodulin [sTM], and soluble endothelial selectin [sE-selectin]) were measured in plasma. RESULTS: The patients had high plasma levels of SC5b-9 and C5a (p = 0.0001 for both) and vWF, t-PA and PAI-1 (p = 0.0001 for all). Their SC5b-9 levels correlated with those of vWF (r = 0.517, p = 0.0001) and paralleled disease severity (severe vs mild p = 0.0001, severe vs moderate p = 0.026 and moderate vs mild p = 0.001). The levels of sE-selectin were significantly increased only in the patients with severe disease. After 30 days, plasma SC5b-9, C5a and vWF levels had significantly decreased (p = 0.0001 for all), and 43% of the evaluated patients had normal levels. CONCLUSIONS: Complement activation is boosted during the progression of COVID-19 and dampened during remission, thus indicating its role in the pathophysiology of the disease. The association between complement activation and the biomarkers of endothelial damage suggests that complement may contribute to tissue injury and could be the target of specific therapy.

Early Phases of COVID-19 Are Characterized by a Reduction in Lymphocyte Populations and the Presence of Atypical Monocytes.

Background: Severe acute respiratory syndrome coronavirus 2 is a recently discovered pathogen responsible of coronavirus disease 2019 (COVID-19). The immunological changes associated with this infection are largely unknown. Methods: We evaluated the peripheral blood mononuclear cells profile of 63 patients with COVID-19 at diagnosis. We also assessed the presence of association with inflammatory biomarkers and the 28-day mortality. Results: Lymphocytopenia was present in 51 of 63 (80.9%) patients, with a median value of 720 lymphocytes/µl (IQR 520-1,135). This reduction was mirrored also on CD8+ (128 cells/µl, IQR 55-215), natural killer (67 cells/µl, IQR 35-158) and natural killer T (31 cells/µl, IQR 11-78) cells. Monocytes were preserved in total number but displayed among them a subpopulation with a higher forward and side scatter properties, composed mainly of cells with a reduced expression of both CD14 and HLA-DR. Patients who died in the 28 days from admission (N=10, 15.9%), when compared to those who did not, displayed lower mean values of CD3+ (337.4 cells/µl vs 585.9 cells/µl; p=0.028) and CD4+ cells (232.2 cells/µl vs 381.1 cells/µl; p=0.042) and an higher percentage of CD8+/CD38+/HLA-DR+ lymphocytes (13.5% vs 7.6%; p=0.026). Discussion: The early phases of COVID-19 are characterized by lymphocytopenia, predominance of Th2-like lymphocytes and monocytes with altered immune profile, which include atypical mononuclear cells.

Generation of induced pluripotent stem cell line CSSi008-A (4698) from a patient affected by advanced stage of Dentato-Rubral-Pallidoluysian atrophy (DRPLA).

Dentato-Rubral-pallidoluysian atrophy (DRPLA) is a rare autosomal, dominant, progressive neurodegenerative disease that causes involuntary movements, mental and emotional problems. DRPLA is caused by a mutation in the ATN1 gene that encodes for an abnormal polyglutamine stretch in the atrophin-1 protein. DRPLA is most common in the Japanese population, where it has an estimated incidence of 2 to 7 per million people. This condition has also been seen in families from North America and Europe. We obtained a reprogrammed iPSC line from a Caucasian patient with a juvenile onset of the disease, carrying 64 CAG repeat expansion in the ATN1 gene.

Production and characterization of human induced pluripotent stem cells (iPSC) CSSi007-A (4383) from Joubert Syndrome.

Joubert syndrome (JS) is an autosomal recessive neurodevelopmental disorder, characterized by congenital cerebellar and brainstem defects, belonging to the group of disorders known as ciliopathies, which are caused by mutations in genes encoding proteins of the primary cilium and basal body. Human induced pluripotent stem cells (hiPSCs) from a patient carrying a homozygous missense mutation (c.2168G > A) in AHI1, the first gene to be associated with JS, were produced using a virus-free protocol.

EphB2 stem-related and EphA2 progression-related miRNA-based networks in progressive stages of CRC evolution: clinical significance and potential miRNA drivers.

EphB2 and EphA2 control stemness and differentiation in the intestinal mucosa, but the way they cooperate with the complex mechanisms underlying tumor heterogeneity and how they affect the therapeutic outcome in colorectal cancer (CRC) patients, remain unclear. MicroRNA (miRNA) expression profiling along with pathway analysis provide comprehensive information on the dysregulation of multiple crucial pathways in CRC.Through a network-based approach founded on the characterization of progressive miRNAomes centered on EphA2/EphB2 signaling during tumor development in the AOM/DSS murine model, we found a miRNA-dependent orchestration of EphB2-specific stem-like properties in earlier phases of colorectal tumorigenesis and the EphA2-specific control of tumor progression in the latest CRC phases. Furthermore, two transcriptional signatures that are specifically dependent on the EphA2/EphB2 signaling pathways were identified, namely EphA2, miR-423-5p, CREB1, ADAMTS14, and EphB2, miR-31-5p, mir-31-3p, CRK, CXCL12, ARPC5, SRC.EphA2- and EphB2-related signatures were validated for their expression and clinical value in 1663 CRC patients. In multivariate analysis, both signatures were predictive of survival and tumor progression.The early dysregulation of miRs-31, as observed in the murine samples, was also confirmed on 49 human tissue samples including preneoplastic lesions and tumors. In light of these findings, miRs-31 emerged as novel potential drivers of CRC initiation.Our study evidenced a miRNA-dependent orchestration of EphB2 stem-related networks at the onset and EphA2-related cancer-progression networks in advanced stages of CRC evolution, suggesting new predictive biomarkers and potential therapeutic targets.

Establishment of stable iPS-derived human neural stem cell lines suitable for cell therapies.

Establishing specific cell lineages from human induced pluripotent stem cells (hiPSCs) is vital for cell therapy approaches in regenerative medicine, particularly for neurodegenerative disorders. While neural precursors have been induced from hiPSCs, the establishment of hiPSC-derived human neural stem cells (hiNSCs), with characteristics that match foetal hNSCs and abide by cGMP standards, thus allowing clinical applications, has not been described. We generated hiNSCs by a virus-free technique, whose properties recapitulate those of the clinical-grade hNSCs successfully used in an Amyotrophic Lateral Sclerosis (ALS) phase I clinical trial. Ex vivo, hiNSCs critically depend on exogenous mitogens for stable self-renewal and amplification and spontaneously differentiate into astrocytes, oligodendrocytes and neurons upon their removal. In the brain of immunodeficient mice, hiNSCs engraft and differentiate into neurons and glia, without tumour formation. These findings now warrant the establishment of clinical-grade, autologous and continuous hiNSC lines for clinical trials in neurological diseases such as Huntington's, Parkinson's and Alzheimer's, among others.

Copy number variations in healthy subjects. Case study: iPSC line CSSi005-A (3544) production from an individual with variation in 15q13.3 chromosome duplicating gene CHRNA7.

CHRNA7, encoding the neuronal alpha7 nicotinic acetylcholine receptor (a7nAChR), is highly expressed in the brain, particularly in the hippocampus. It is situated in the 15q13.3 chromosome region, frequently associated with a Copy Number Variation (CNV), which causes its duplication or deletion. The clinical significance of CHRNA7 duplications is unknown so far, but there are several research data suggesting that they may be pathogenic, with reduced penetrance. We have produced an iPS cell line from a single healthy donor's fibroblasts carrying a 15q13.3 CNV, including CHRNA7 in order to study the exact role of this CNV during the neurodevelopment.

Generation of the induced pluripotent stem cell line CSSi006-A (3681) from a patient affected by advanced-stage Juvenile Onset Huntington's Disease.

Juvenile Onset Huntington's Disease (JOHD) is a rare variant of HD withage of onset ≤20 years, accounting for 3-10% of all HD patients. The rarity occurrence of JOHD cases, who severely progress towards mental and physical disability with atypical clinical manifestations compared to classical HD, are responsible of general lack of knowledge about this variant. We obtained a fully reprogrammed iPS cell line from fibroblasts of a JOHD patient carrying 65 CAG repeats and age at onset at age 15. At the biopsy time, the patient showed an advanced stage after 10 years of disease.

Production and characterization of CSSI003 (2961) human induced pluripotent stem cells (iPSCs) carrying a novel puntiform mutation in RAI1 gene, Causative of Smith-Magenis syndrome.

Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by developmental delay, behavioural problems and circadian rhythm dysregulation. About 90% of SMS cases are due to a 17p11.2 deletion containing retinoic acid induced1 (RAI1) gene, 10% are due to heterozygous mutations affecting RAI1 coding region. Little is known about RAI1 role.

Generation of induced pluripotent stem cell line, CSSi004-A (2962), from a patient diagnosed with Huntington's disease at the presymptomatic stage.

Huntington's disease (HD) is an incurable, autosomal dominant, hereditary neurodegenerative disorder that typically manifests itself in midlife. This pathology is linked to the deregulation of multiple, as yet unknown, cellular processes starting before HD onset. A human iPS cell line was generated from skin fibroblasts of a subject at the presymptomatic life stage, carrying a polyglutamine expansion in HTT gene codifying Huntingtin protein. The iPSC line contained the expected CAG expansion, expressed the expected pluripotency markers, displayed in vivo differentiation potential to the three germ layers and had a normal karyotype.

Production and characterization of human induced pluripotent stem cells (iPSCs) from Joubert Syndrome: CSSi001-A (2850).

Joubert Syndrome (JS) is a rare autosomal recessive or X-linked condition characterized by a peculiar cerebellar malformation, known as the molar tooth sign (MTS), associated with other neurological phenotypes and multiorgan involvement. JS is a ciliopathy, a spectrum of disorders whose causative genes encode proteins involved in the primary cilium apparatus. In order to elucidate ciliopathy-associated molecular mechanisms, human induced pluripotent stem cells (hiPSCs) were derived from a patient affected by JS carrying a homozygous missense mutation in the AHI1 gene (p.H896R) that encodes a protein named Jouberin.

Generation of induced pluripotent stem cell line, CSSi002-A (2851), from a patient with juvenile Huntington Disease.

Huntington Disease (HD) is an autosomal dominant disorder characterized by motor, cognitive and behavioral features caused by a CAG expansion in the HTT gene beyond 35 repeats. The juvenile form (JHD) may begin before the age of 20years and is associated with expanded alleles as long as 60 or more CAG repeats. In this study, induced pluripotent stem cells were generated from skin fibroblasts of a 8-year-old child carrying a large size mutation of 84 CAG repeats in the HTT gene. HD appeared at age 3 with mixed psychiatric (i.e. autistic spectrum disorder) and motor (i.e. dystonia) manifestations.

Dysregulation of EGFR Pathway in EphA2 Cell Subpopulation Significantly Associates with Poor Prognosis in Colorectal Cancer.

PURPOSE: EphA2 receptor is involved in multiple cross-talks with other cellular networks, including EGFR, FAK, and VEGF pathways, with which it collaborates to stimulate cell migration, invasion, and metastasis. Colorectal cancer (CRC) EphA2 overexpression has also been correlated to stem-like properties of cells and tumor malignancy. We investigated the molecular cross-talk and miRNAs modulation of the EphA2 and EGFR pathways. We also explored the role of EphA2/EGFR pathway mediators as prognostic factors or predictors of cetuximab benefit in patients with CRC. EXPERIMENTAL DESIGN: Gene expression analysis was performed in EphA2high cells isolated from CRC of the AOM/DSS murine model by FACS-assisted procedures. Six independent cohorts of patients were stratified by EphA2 expression to determine the potential prognostic role of a EphA2/EGFR signature and its effect on cetuximab treatment response. RESULTS: We identified a gene expression pattern (EphA2, Efna1, Egfr, Ptpn12, and Atf2) reflecting the activation of EphA2 and EGFR pathways and a coherent dysregulation of mir-26b and mir-200a. Such a pattern showed prognostic significance in patients with stage I-III CRC, in both univariate and multivariate analysis. In patients with stage IV and WT KRAS, EphA2/Efna1/Egfr gene expression status was significantly associated with poor response to cetuximab treatment. Furthermore, EphA2 and EGFR overexpression showed a combined effect relative to cetuximab resistance, independently from KRAS mutation status. CONCLUSIONS: These results suggest that EphA2/Efna1/Egfr genes, linked to a possible control by miR-200a and miR-26b, could be proposed as novel CRC prognostic biomarkers. Moreover, EphA2 could be linked to a mechanism of resistance to cetuximab alternative to KRAS mutations. Clin Cancer Res; 23(1); 159-70. ©2016 AACR.

Ependymoma stem cells are highly sensitive to temozolomide in vitro and in orthotopic models.

BACKGROUND: Ependymoma management remains challenging because of the inherent chemoresistance of this tumor. To determine whether ependymoma stem cells (SCs) might contribute to therapy resistance, we investigated the sensitivity of ependymoma SCs to temozolomide and etoposide. METHODS: The efficacies of the two DNA damaging agents were explored in two ependymoma SC lines in vitro and in vivo models. RESULTS: Ependymoma SC lines were highly sensitive to temozolomide and etoposide in vitro, but only temozolomide impaired tumor-initiation properties. Consistently, temozolomide but not etoposide showed significant antitumoral activity on ependymoma SC-driven subcutaneous and orthotopic xenografts by reducing the mitotic fraction. In vitro temozolomide at the EC50 (10 µM) induced accumulation of cells in the G2/M phase that was unexpectedly accompanied by downregulation of p27 and p21 without modulation of full-length p53 (FLp53). Differentiation-committed ependymoma SCs acquired resistance to temozolomide. Inhibition of proliferation was partly due to apoptosis, that occurred earlier in differentiated cells as compared to neurospheres. The activation of apoptosis correlated with an increase in p53ß/γ isoforms without modulation of FLp53 under both serum-free and differentiation-promoting media. Incubation of cells in both conditions with temozolomide resulted in increased glioneuronal differentiation exhibiting elevated glial fibrillary acidic protein, galactosylceramidase, and ßIII-tubulin expression compared to untreated controls. O(6)-methylguanine DNA methyltransferase (MGMT) transcript levels were very low in SCs, and were increased by treatment and, epigenetically, by differentiation through MGMT promoter unmethylation. CONCLUSION: Ependymoma growth might be impaired by temozolomide through preferential depletion of a less differentiated, more tumorigenic, MGMT-negative cell population with stem-like properties.

A variant in the carboxyl-terminus of connexin 40 alters GAP junctions and increases risk for tetralogy of Fallot.

GJA5 gene (MIM no. 121013), localized at 1q21.1, encodes for the cardiac gap junction protein connexin 40. In humans, copy number variants of chromosome 1q21.1 have been associated with variable phenotypes comprising congenital heart disease (CHD), including isolated TOF. In mice, the deletion of Gja5 can cause a variety of complex CHDs, in particular of the cardiac outflow tract, corresponding to TOF in many cases. In the present study, we screened for mutations in the GJA5 gene 178 unrelated probands with isolated TOF. A heterozygous nucleotide change (c.793C>T) in exon 2 of the gene leading to the p.Pro265Ser variant at the carboxyl-terminus of the protein was found in two unrelated sporadic patients, one with classic anatomy and one with pulmonary atresia. This GJA5 missense substitution was not observed in 1568 ethnically-matched control chromosomes. Immunofluorescent staining and confocal microscopy revealed that cells expressing the mutant protein form sparse or no visible gap-junction plaques in the region of cell-cell contact. Moreover, analysis of the transfer of the gap junction permanent tracer lucifer yellow showed that cells expressing the mutant protein have a reduced rate of dye transfer compared with wild-type cells. Finally, use of a zebrafish model revealed that microinjection of the GJA5-p.Pro265Ser mutant disrupts overall morphology of the heart tube in the 37% (22/60) of embryos, compared with the 6% (4/66) of the GJA5 wild-type-injected embryos. These findings implicate GJA5 gene as a novel susceptibility gene for TOF.