Increased concentration of soluble leukocyte-associated immunoglobulin-like receptor in sera from patients with blistering diseases: possible pathophysiological implications?

BACKGROUND: Autoimmune blistering diseases (AIBD), are a heterogeneous group. Despite their pathogenesis is not completely understood, autoantibodies against directed adhesion molecules of the skin and adjacent mucous membranes could play a key role. The leukocyte-associated-Ig-like-receptor (LAIR) family is a small group of immunoreceptor-tyrosine-based-inhibition-motif-containing inhibitory receptors, recognizing collagens. LAIR-1 is a transmembrane glycoprotein expressed on human-peripheral-blood-leukocytes. LAIR-2 is a secreted receptor mainly produced by CD4+ T-lymphocytes, and is able to regulate the inhibitory potential of LAIR-1. Both LAIRs have been associated with several autoimmune diseases and inflammatory responses. METHODS: We evaluated circulating LAIRs in patients with different blistering skin diseases by ELISA. RESULTS: A significant increase of serum LAIR-2, and to a lesser extent of sLAIR-1 (with the exception of Pemphigus vulgaris), in the whole group of patients with bullous diseases, irrespective of the pathogenesis, compared to healthy controls was evident. CONCLUSIONS: Although the pathophysiological meaning of LAIR is not completely elucidated, the presence of increased concentration of LAIR proteins can somehow modulate the cascade of inflammatory phenomenon occurring in bullous skin diseases, in different way depending upon specific skin disease considered.

Bone marrow fibroblasts overexpress miR-27b and miR-214 in step with multiple myeloma progression, dependent on tumour cell-derived exosomes.

Aberrant microRNA (miR) expression has an important role in tumour progression, but its involvement in bone marrow fibroblasts of multiple myeloma patients remains undefined. We demonstrate that a specific miR profile in bone marrow fibroblasts parallels the transition from monoclonal gammopathy of undetermined significance (MGUS) to myeloma. Overexpression of miR-27b-3p and miR-214-3p triggers proliferation and apoptosis resistance in myeloma fibroblasts via the FBXW7 and PTEN/AKT/GSK3 pathways, respectively. Transient transfection of miR-27b-3p and miR-214-3p inhibitors demonstrates a cooperation between these two miRNAs in the expression of the anti-apoptotic factor MCL1, suggesting that miR-27b-3p and miR-214-3p negatively regulate myeloma fibroblast apoptosis. Furthermore, myeloma cells modulate miR-27b-3p and miR-214-3p expression in fibroblasts through the release of exosomes. Indeed, tumour cell-derived exosomes induce an overexpression of both miRNAs in MGUS fibroblasts not through a simple transfer mechanism but by de novo synthesis triggered by the transfer of exosomal WWC2 protein that regulates the Hippo pathway. Increased levels of miR-27b-3p and miR-214-3p in MGUS fibroblasts co-cultured with myeloma cell-derived exosomes enhance the expression of fibroblast activation markers αSMA and FAP. These data show that the MGUS-to-myeloma transition entails an aberrant miRNA profile in marrow fibroblasts and highlight a key role of myeloma cells in modifying the bone marrow microenvironment by reprogramming the marrow fibroblasts' behaviour. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Homotypic and Heterotypic Activation of the Notch Pathway in Multiple Myeloma-Enhanced Angiogenesis: A Novel Therapeutic Target?

Interactions of multiple myeloma (MM) cells with endothelial cells (ECs) enhance angiogenesis and MM progression. Here, we investigated the role of Notch signaling in the cross talk between ECs and MM cells enabling angiogenesis. MMECs showed higher expression of Jagged1/2 ligands, of activated Notch1/2 receptors, and of Hes1/Hey1 Notch target genes than ECs from monoclonal gammopathy of undetermined significance patients, suggesting that homotypic activation of Notch pathway occurs in MM. MM cells co-cultured with MMECs triggered Notch activation in these cells through a cell-to-cell contact-dependent way via Jagged1/2, resulting in Hes1/Hey1 overexpression. The angiogenic effect of Notch pathway was analyzed through Notch1/2·siRNAs and the γ-secretase inhibitor MK-0752 by in vitro (adhesion, migration, chemotaxis, angiogenesis) and in vivo (Vk12598/C57B/6 J mouse model) studies. Activated Notch1/2 pathway was associated with the overangiogenic MMEC phenotype: Notch1/2 knockdown or MK-0752 treatment reduced Hes1/Hey1 expression, impairing in vitro angiogenesis of both MMECs alone and co-cultured with MM cells. MM cells were unable to restore angiogenic abilities of treated MMECs, proving that MMEC angiogenic activities closely rely on Notch pathway. Furthermore, Notch1/2 knockdown affected VEGF/VEGFR2 axis, indicating that the Notch pathway interferes with VEGF-mediated control on angiogenesis. MK-0752 reduced secretion of proangiogenic/proinflammatory cytokines in conditioned media, thus inhibiting blood vessel formation in the CAM assay. In the Vk12598/C57B/6 J mouse, MK-0752 treatment restrained angiogenesis by reducing microvessel density. Overall, homotypic and heterotypic Jagged1/2-mediated Notch activation enhances MMECs angiogenesis. Notch axis inhibition blocked angiogenesis in vitro and in vivo, suggesting that the Notch pathway may represent a novel therapeutic target in MM.

Definition of a new cut-off for the anti-phospholipase A2 receptor (PLA2R) autoantibody immunoassay in patients affected by idiopathic membranous nephropathy.

Autoantibodies against phospholipase A2 receptor (PLA2R) are a sensitive and specific marker for idiopathic membranous nephropathy (IMN). The aim of our study was to redefine the cut-off value for the measurement of anti-PLA2R autoantibody levels by an automated enzyme immunoassay, in a large single-center cohort of Italian IMN patients at the time of diagnosis. Sixty-seven consecutive incident patients, with biopsy-proven IMN, were recruited. All patients were naïve to preceding immunosuppressive therapeutic regimens. The patient population had a mean age of 57 years and included 48 males and 19 females. Also, 200 patients with other renal diseases and 36 healthy subjects were studied as controls. The anti-PLA2R autoantibody levels were measured using the commercial enzyme-linked immunosorbent assay kit at the time of renal biopsy. At a cut-off value of 2.7 RU/ml (significantly lower than the manufacturer's recommended value of 14 RU/ml), calculated by receiver operating characteristic curves, the sensitivity and specificity of anti-PLA2R autoantibodies in the diagnosis of IMN was 88.1 and 96% respectively. The adapted cut-off value of 2.7 UI/ml increased sensitivity without affecting the specificity and it should be the recommended value for this method. Additionally our study confirmed the correlation, at baseline, between anti-PLA2R autoantibody levels and other biomarkers of disease activity.

Bullous Pemphigoid and Neurologic Diseases: Toward a Specific Serologic Profile?

BACKGROUND: The association of bullous pemphigoid (BP) and neurologic disease (ND) has been proven. OBJECTIVE: To investigate the presence of specific markers for the association between BP and ND. METHOD: A total of 47 patients with PB, at the onset of the disease, were retrospectively recruited from January 2015 to October 2017 in a single center (Dermatology Unit, University of Bari "Aldo Moro", Bari, Italy). RESULTS: We have found an association between BP, ND and specific serologic profile characterized by higher levels of anti-BP180 and anti-BP230 (t(45)=2.319, p=0.025 and t(45)= 2.486, p=0.017, respectively), as compared to BP patients without ND. Furthermore, the univariate analysis revealed a significant association between ND and anti-BP230 positivity (P= 0.043). In detail, we observed a 4-time increased risk to have ND in BP patients showing anti-BP230 positivity. CONCLUSION: BP230 (BPAG1) is a member of the plakine family that links hemidemosomes to keratin filaments, being expressed at neuronal level. Thus, we hypothesized that alterations induced in ND could lead to the impairment of the "immune privilege", thus provoking the exposition of BP230 neuronal isoform.

IL-6/IL-10 Ratio as A Prognostic and Predictive Marker of the Severity of Inherited Epidermolysis Bullosa.

BACKGROUND: Recent studies have shown that cytokines have an important role in the pathogenesis of inflammatory diseases and can be used as prognostic markers. OBJECTIVE: To evaluate the IL-6/IL-10 ratio in patients with Inherited Epidermolysis Bullosa (EB) as a prognostic marker. METHODS: Serum levels of IL-6 and IL-10 were measured in 13 patients with recessive dystrophic EB (RDEB) as well as 10 with EB Simplex (EBS), and in 18 healthy subjects. Receiver Operating Characteristics (ROC) analyses were used to assess the diagnostic accuracy of the IL-6/IL-10 ratio for detecting severe form of EB. RESULTS: The IL-6/IL-10 ratio was statistically higher in RDEB patients than in EBS patients and healthy subjects. The IL-6/IL-10 ratio significantly correlated with BEBS score. CONCLUSION: Our findings suggest that IL-6/IL-10 ratio >5.6 has a good diagnostic accuracy to identify patients with the highest severity of disease.

Microenvironment drug resistance in multiple myeloma: emerging new players.

Multiple myeloma (MM) drug resistance (DR) is a multistep transformation process based on a powerful interplay between bone marrow stromal cells and MM cells that allows the latter to escape anti-myeloma therapies. Here we present an overview of the role of the bone marrow microenvironment in both soluble factors-mediated drug resistance (SFM-DR) and cell adhesion-mediated drug resistance (CAM-DR), focusing on the role of new players, namely miRNAs, exosomes and cancer-associated fibroblasts.

Myeloma cells act as tolerogenic antigen-presenting cells and induce regulatory T cells in vitro.

Regulatory T cells (Tregs) are essential for maintenance of self-tolerance; however, tumor cells can exploit the tolerance to escape the immune system. We investigated the Tregs frequency in patients with multiple myeloma (MM) and in those with monoclonal gammopathy of undetermined significance (MGUS), and found that CD4(+) FoxP3(+) and CD8(+) FoxP3(+) Tregs were significantly increased in patients with MM and correlated with the active phase. Both Tregs subsets were expanded in cocultures of CD3(+) lymphocytes and fresh CD138(+) MM plasma cells or RPMI8226 and U266 cell lines and functioned as natural (n) and inducible (i) Tregs insofar as they inhibited the proliferation of stimulated CD3 lymphocytes via contact-dependent and contact-independent pathways. Induction of Tregs by MM plasma cells required a contact-dependent pathway, implying antigen recognition by T cells. MM plasma cells acted as immature and tolerogenic antigen-presenting cells (APCs), in that they displayed low CD80/CD86 expression associated with a phagocytic activity. By acting as immature APCs, MM plasma cells plausibly expand (n)Tregs and (i)Tregs both through conversion of CD3(+) FoxP3(-) into CD3(+) FoxP3(+) T cells and proliferation of CD3(+) FoxP3(+) T cells, which may suppress the anti-MM immune response.

Increase in interleukin-8 production from circulating neutrophils upon antibiotic therapy in cystic fibrosis patients.

BACKGROUND: It is not known whether antibiotic therapy for lung disease in cystic fibrosis (CF) has an influence on circulating polymorphonuclear neutrophil (PMN) function and apoptosis. PATIENTS AND METHODS: Blood PMNs were obtained from 14 CF patients before and after antibiotic treatment for an acute exacerbation, and from 10 healthy controls. PMNs were evaluated for production of reactive oxygen species (ROS) by spectrophotometry, of cytokines in the conditioned medium by ELISA, and apoptotic response by cytofluorimetry. RESULTS: ROS and interleukin (IL)-8 were produced at higher levels by CF PMNs pre-therapy than control PMNs under basal conditions. IL-8 levels further increased after therapy. Early apoptotic response was higher in CF PMNs pre-therapy than in control PMNs, and this pattern did not change after antibiotic treatment. CONCLUSIONS: Circulating PMNs are primed in CF acute patients. Further studies are needed to consider PMN-produced IL-8 as a biomarker to evaluate response to antibiotic therapy in CF patients.

Exogenous factors in the immunotoxicity of oral PMN.

Current evidence indicates that periodontal disease is frequently due to inappropriate levels of gingival granulocyte functions. Reason of this failure may be the toxic effects of a number of local or systemic exogenous factors, capable of spreading through the gingival crevice environment, and strongly conditioning the granulocyte activities. The wide list includes bacteria and granulotoxic products, hedonistic drugs (mainly tobacco), and chemotherapeutic agents (especially antimicrobials used for preventing or reducing the accumulation of dental plaque). Almost always, their presence induces a time- and/or dose-dependent toxicity.

Survivin promoter -31G/C polymorphism in oral cancer cell lines.

Survivin (SVV) is a protein that belongs to the inhibitor of apoptosis proteins (IAP) family and is involved in the G2/M phase progression of the cell cycle as a spindle­associated molecule. The biological features of this protein are well documented and its activity appears to be involved in mitochondria-dependent and -independent antiapoptotic pathways. Overexpression of SVV at the transcriptional and translational level has been associated with cancer, a multifactorial disorder in which the occurrence of a -31G to C polymorphism in the promoter region may significantly contribute to the development of this pathology. To verify this hypothesis, the occurrence of a single nucleotide polymorphism (SNP) in cis-acting cell cycle-dependent elements (CDEs) and in cell cycle homology regions (CHRs) of the survivin TATA-less promoter was investigated. A total of 23 oral squamous cell carcinoma (OSCC) cell lines and normal epithelium-derived normal human epidermal keratinocyte (NHEK) cell lines were analyzed by RFLP and direct DNA sequencing of their promoter region. Furthermore, survivin expression at the transcriptional and translational levels was evaluated in these cells by RT-PCR and Western blotting, respectively. The findings indicate that the presence of a G or C allele is not directly correlated to survivin expression, at the mRNA or at the protein level, at least in the OSCC lines analyzed in this study.

Molecular pathways in cancer-related inflammation.

Accumulating evidence shows that chronic inflammation is associated to increased risk of cancer. An inflammatory component is present also in the microenvironment of tumours epidemiologically unrelated to inflammation. Extensive investigations over the past decade have uncovered many of the important mechanistic pathways underlying cancer-related inflammation. Pathways linking inflammation and cancer have been identified: an intrinsic one (driven by genetic events that cause neoplasia) and an extrinsic one (driven by inflammatory conditions which predispose to cancer). Smouldering inflammation is a component of the tumour microenvironment and is a recognized hallmark of cancer. Key orchestrators at the intersection of the intrinsic and extrinsic pathways include transcription factors (e.g. Nuclear Factor kappa-B, NFKB) that modulate the inflammatory response through soluble mediators (cytokines, chemokines) and cellular components (e.g. tumor-associated macrophages), promoting tumorigenesis. NFKB aids in the proliferation and survival of malignant cells, promotes angiogenesis and metastasis, subverts adaptive immunity, and alters responses to hormones and chemotherapeutic agents. Emerging evidence also suggests that persistent inflammation promotes genetic instability. Thus, cancer-related inflammation represents a target for innovative diagnostic and therapeutic strategies.

Streptococcus pneumoniae modulates the respiratory burst response in human neutrophils.

The gram-positive pathogen Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and is responsible for high morbidity and mortality worldwide. A major feature of pneumococcal pneumonia is an abundant neutrophil infiltration. In this work we observed that the R6 nonencapsulated S. pneumoniae strain induced a higher oxidative burst in neutrophils compared with its capsulated progenitor D39, by triggering neutrophil NADPH oxidase to produce more reactive oxygen intermediates (ROI) and by interfering with the neutrophil kinase signalling pathway. In addition, we evaluated the possibility that the capsule, lacking in R6 but present in D39, could modulate the S. pneumoniae-induced neutrophil respiratory burst. In this respect, three knock-out isogenic mutants (D39ΔCPS2E, D39ΔCPS-R6 and R6ΔCPS-R6) that were unable to synthesize the capsule, were tested for their capability of inducing the release of neutrophil-ROIs. The results indicate that the mutants behaved similarly to their wild-type parental strains in enhancing respiratory burst activity, suggesting that the capsule itself is not directly involved in modulating the neutrophil oxidative burst induced by S. pneumoniae, but that other genetic differences between D39 and R6 present elsewhere in the genome could be responsible for these mechanisms.

In vitro effects of polyamines on polymorphonuclear cell apoptosis and implications in the pathogenesis of periodontal disease.

Apoptosis provides a mechanism for clearance of unwanted cells in a variety of situations in which programmed or physiological cell death occurs; but the premature death of defensive cells could promote infection, inflammation and concomitant diseases. Polymorphonuclear cells (PMN) of gingival sulcus play an important role in host defense against periodontal tissue-invading bacteria, but their phagocytic activity is conditioned by several virulence factors released by oral pathogens. Polyamines derived from oral bacteria frequently occur at concentrations approaching 1 mM in gingival fluid at diseased periodontal sites. Brief exposure of PMN to polyamines shortened the lag culture time required to observe microscopical or DNA fragmentation traces. Increase of Fas/Apo-1 expression and caspase-8 and caspase-3 activation focused two typical steps in the pathway of the pro-apoptotic mechanism exhibited by polyamines, even if to a different extent: spermine > spermidine > putrescine. The possible role played by polyamines in the pathogenesis of periodontal disease by dysregulating apoptosis of gingival PMN is discussed.

Neutrophil recruitment and airway epithelial cell involvement in chronic cystic fibrosis lung disease.

The pathological hallmark of cystic fibrosis (CF) chronic inflammatory response is the massive neutrophil influx into the airways. This dysregulated neutrophil emigration may be caused by the abnormal secretion of chemoattractants by respiratory epithelial cells and polarised lymphocyte T-helper response. Neutrophils from CF patients have a different response to inflammatory mediators than neutrophils from normal subjects, indicating that they are primed in vivo before entering the CF airways. CF neutrophils secrete more myeloperoxidase and elastase, mobilise less opsonin receptors and release less L-selectin than non-CF neutrophils. Moreover, they show altered cytokine production and a dysregulated chemotaxis response. Laboratory studies now suggest that CFTR is involved in regulating some neutrophil functions and indicate that altered properties of CF neutrophils may depend on genetic factors. Current gene therapy approaches are targeted to the respiratory epithelium, but many hurdles oppose an efficient and efficacious CFTR gene transfer. The possibility of CFTR gene therapy-based approach targeting CF neutrophils at the hematopoietic stem cell level is discussed.