Receptor transfer between immune cells by autoantibody-enhanced, CD32-driven trogocytosis is hijacked by HIV-1 to infect resting CD4 T cells

Immune cell phenotyping frequently detects lineage-unrelated receptors. Here, we report that surface receptors can be transferred from primary macrophages to CD4 T cells and identify the Fcγ receptor CD32 as driver and cargo of this trogocytotic transfer. Filamentous CD32+ nanoprotrusions deposit distinct plasma membrane patches onto target T cells. Transferred receptors confer cell migration and adhesion properties, and macrophage-derived membrane patches render resting CD4 T cells susceptible to infection by serving as hotspots for HIV-1 binding. Antibodies that recognize T cell epitopes enhance CD32-mediated trogocytosis. Such autoreactive anti-HIV-1 envelope antibodies can be found in the blood of HIV-1 patients and, consistently, the percentage of CD32+ CD4 T cells is increased in their blood. This CD32-mediated, antigen-independent cell communication mode transiently expands the receptor repertoire and functionality of immune cells. HIV-1 hijacks this mechanism by triggering the generation of trogocytosis-promoting autoantibodies to gain access to immune cells critical to its persistence.

Fracture strenght and ribbond fibers: In vitro analysis of mod restorations

Background

Ribbond fibers are supposed to be a reinforcing material in restoration of compromised teeth. This study aims to compare MOD restorations with and without Ribbond Fiber in terms of fracture strength under axial loading; to identify the minimum depth of MOD cavities to use Ribbond Fiber (to improve the fracture strength under axial load.

Material and Methods

20 upper and lower molars extracted intact were used for the experiment. The teeth were prepared with 2 types of cavities and then divided into 4 groups: 1) 5 mm deep MOD cavities with residual interaxial dentin restored without Ribbond; 2) 5 mm deep MOD cavities with residual interaxial dentin restored with Ribbond; 3) 5 mm deep MOD cavities without residual interaxial dentin, restored without Ribbond; 4) 5 mm deep MOD cavities without residual interaxial dentin restored with Ribbond. The restored teeth were then subjected to thermal cycling and their fracture strength was evaluated using an Instron device. The Mann-Whitney statistical test was used to compare fracture strength among groups. Finally, a descriptive analysis of the verified fractures was performed.

Results

There was a statistically significant difference between groups 1 and 2 (P = 0.0090) in the loading force required for a fracture. In contrast, there was no statistically significant difference between groups 3 and 4 (P = 0.7540). Groups 1 and 2 had the fewest non-restorable fractures, in contrast to groups 3 and 4.

Conclusions

Ribbond fiber application in MOD cavities seems to be more effective in terms of strengthening where cavities have interaxial dentinal tissue. Key words:Ribbond fibers, fracture strenght, direct dental restorations.

Strategies of Epstein-Barr virus to evade innate antiviral immunity of its human host

Epstein-Barr virus (EBV) is a double-stranded DNA virus of the Herpesviridae family. This virus preferentially infects human primary B cells and persists in the human B cell compartment for a lifetime. Latent EBV infection can lead to the development of different types of lymphomas as well as carcinomas such as nasopharyngeal and gastric carcinoma in immunocompetent and immunocompromised patients. The early phase of viral infection is crucial for EBV to establish latency, but different viral components are sensed by cellular sensors called pattern recognition receptors (PRRs) as the first line of host defense. The efficacy of innate immunity, in particular the interferon-mediated response, is critical to control viral infection initially and to trigger a broad spectrum of specific adaptive immune responses against EBV later. Despite these restrictions, the virus has developed various strategies to evade the immune reaction of its host and to establish its lifelong latency. In its different phases of infection, EBV expresses up to 44 different viral miRNAs. Some act as viral immunoevasins because they have been shown to counteract innate as well as adaptive immune responses. Similarly, certain virally encoded proteins also control antiviral immunity. In this review, we discuss how the virus governs innate immune responses of its host and exploits them to its advantage.

C64 UNMASKING THE PREVALENCE OF AMYLOID CARDIOMYOPATHY IN THE REAL WORLD: RESULTS FROM PHASE 2 OF AC–TIVE STUDY, AN ITALIAN NATIONWIDE SURVEY

Background

Clinicians need to identify patients with amyloid cardiomyopathy (AC) at an early stage, due to the availability of disease–modifying therapies. Some echocardiographic findings may rise the suspicion of AC, also in patients with mild or no symptoms, addressing second level diagnostic tests.

Aim

To investigate the prevalence of AC in consecutive patients ≥55 years undergoing clinically indicated, routine transthoracic echocardiogram in Italy and presenting echocardiographic signs suggestive of AC.

Methods

This is a prospective multicentric study conducted in Italy. It comprises two phases: 1) a recording phase consisting in a national survey on prevalence of possible echocardiographic red flags of AC in consecutive unselected patients ≥55 years undergoing routine echocardiogram (previously published) and 2) an AC diagnostic phase involving a diagnostic work–up for AC to investigate AC prevalence among patients with at least one echocardiographic red flag (herein presented). Patients that in Phase 1 presented an “AC suggestive” echocardiogram (i.e., at least one red flag of AC in hypertrophic, non–dilated left ventricles with preserved ejection fraction) underwent clinical evaluation, blood and urine tests and scintigraphy with bone tracer. Diagnosis of transthyretin related–AC (ATTR–AC) was made in presence of grade 2–3 Perugini uptake at scintigraphy and absence of monoclonal protein. The study was registered at ClinicalTrials.gov (#NCT04738266).

Results

Of the 5315 screened echocardiograms, 381 exams (7.2%) were classified as “AC suggestive” and proceeded to Phase 2. 217 patients completed Phase 2 investigations. Main reasons for the 164 non–entering patients into Phase 2 were death (n = 49) and refusal to participate (n = 66). A final diagnosis of AC was made in 62 patients with an estimated prevalence of 28,6% (95% CI: 22,5%–34,7%). ATTR–AC was diagnosed in 51 and AL–AC in 11 patients, ascertaining a prevalence of 23,5% (95% CI: 17,8%–29,2%) and 5,1% (95% CI: 2,2%–8,0%), respectively.

Conclusion

Among a cohort of consecutive unselected patients ≥55 years with echocardiographic findings suggestive of AC, the prevalence of AC ranged from 23% up to 35%. Although ATTR–AC was predominant, AL–AC was diagnosed in a significant number of cases. Echocardiography has a fundamental role in screening patients, raising the suspicion of disease and orienting diagnostic work–up for AC.

Quantitation of SARS-CoV-2 neutralizing antibodies with a virus-free, authentic test

Neutralizing antibodies (NAbs), and their concentration in sera of convalescents and vaccinees are a correlate of protection from COVID-19. The antibody concentrations in clinical samples that neutralize SARS-CoV-2 are difficult and very cumbersome to assess with conventional virus neutralization tests (cVNTs), which require work with the infectious virus and biosafety level 3 containment precautions. Alternative virus neutralization tests currently in use are mostly surrogate tests based on direct or competitive enzyme immunoassays or use viral vectors with the spike protein as the single structural component of SARS-CoV-2. To overcome these obstacles, we developed a virus-free, safe and very fast (4.5 h) in vitro diagnostic test based on engineered yet authentic SARS-CoV-2 virus-like-particles (VLPs). They share all features of the original SARS-CoV-2 but lack the viral RNA genome and thus are non-infectious. NAbs induced by infection or vaccination, but also potentially neutralizing monoclonal antibodies can be reliably quantified and assessed with ease and within hours with our test, because they interfere and block the ACE2-mediated uptake of VLPs by recipient cells. Results from the VLP neutralization test (VLPNT) showed excellent specificity and sensitivity and correlated very well with a cVNT using fully infectious SARS-CoV-2. The results also demonstrated the reduced neutralizing capacity of COVID-19 vaccinee sera against variants of concern of SARS-CoV-2 including omicron B.1.1.529, BA.1.

Link between gut microbiota dysbiosis and chronic kidney disease

During chronic kidney disease (CKD), typical alterations in the gut microbiota are observed. The kidney no longer plays the role of the main excretory organ as this function is performed by the intestine. In CKD patients, an alteration of intestinal permeability and a degradation of the protective mucous layer are observed. These changes in the intestinal barrier allow the passage of bacterial material from the intestine to the bloodstream through the intestinal wall. This phenomenon contributes to the induction of the chronic inflammatory state, typical of CKD. In nephropathic patients, there is an increase in circulation of p-cresyl sulfate (p-CS), indoxyl sulphate (IS), indole-3 acetic acid (IAA) and trimethylamine-N-oxide (TMAO), all gut-derived uremic toxins. The changes in gut microbiota composition are related to CKD stage and this phenomenon is exacerbated in hemodialysis (HD) adult and pediatric patients. Interestingly, it is observed a positive shift in gut microbiota composition after renal transplantation and at the same time a reduction of circulating gut-derived uremic toxins. Either gut dysbiosis or uremic toxins accumulation contribute to the CKD onset and progression.

Gut-oriented interventions in patients with multiple sclerosis: fact or fiction?

OBJECTIVE

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, disimmune disease of the central nervous system whose etiology and pathogenesis remain poorly understood, due to its complex and multifactorial nature. Evidence of a bidirectional connection linking the gut microbiome with the intestinal barrier and the immune system (the gut-brain axis) may have implications for the pathogenesis of inflammatory demyelinating diseases such as MS. This narrative review summarizes the evidence for the gut-brain axis involvement in the pathogenesis of MS and examines the role of gut-oriented interventions in MS.

PATIENTS AND METHODS

We reviewed all available studies in PubMed concerning gut-directed interventions and MS. This research was conducted using different combinations of pertinent keywords (multiple sclerosis, immune-mediated inflammatory diseases, autoimmune diseases, first demyelinating event, neurocognition, neurological disorders, neurology practice, risk factors, taxonomic biomarkers, nutrition, diet, dietary additives, complementary treatment, gut bacteria, gut microbiome, microbiome, gut-brain axis, epidemiology, alpha-linolenic acid, fermentative metabolites, fat, saturated fat, monounsaturated fat, polyunsaturated fat, omega-3 fatty acids, calorie restricted diet, fasting, fecal microbiome, fecal microbiota transplantation, animal testing).

RESULTS

There is an emerging evidence that alterations in the gut microbiome and increased intestinal permeability may be causative factors in the complex interplay between nutrition, metabolic status and the immune-inflammatory response in patients with MS. This suggests the possibility that modification of lifestyle and the microbiome, for example by specific diets or fecal microbiota transplantation, supplementation with bile acids and intestinal barrier enhancers, may positively influence the pathogenesis of MS.

CONCLUSIONS

Although the role of nutritional factors in the pathogenesis of MS remains to be established, there is evidence that appropriate gut-directed interventions such as diet, nutritional supplementation or fecal transplantation may modulate the inflammatory response and improve the course of MS as a complementary treatment in the disease.

Three exposures to the spike protein of SARS-CoV-2 by either infection or vaccination elicit superior neutralizing immunity to all variants of concern

Infection-neutralizing antibody responses after SARS-CoV-2 infection or COVID-19 vaccination are an essential component of antiviral immunity. Antibody-mediated protection is challenged by the emergence of SARS-CoV-2 variants of concern (VoCs) with immune escape properties, such as omicron (B.1.1.529) that is rapidly spreading worldwide. Here, we report neutralizing antibody dynamics in a longitudinal cohort of COVID-19 convalescent and infection-naive individuals vaccinated with mRNA BNT162b2 by quantifying anti-SARS-CoV-2-spike antibodies and determining their avidity and neutralization capacity in serum. Using live-virus neutralization assays, we show that a superior infection-neutralizing capacity against all VoCs, including omicron, developed after either two vaccinations in convalescents or after a third vaccination or breakthrough infection of twice-vaccinated, naive individuals. These three consecutive spike antigen exposures resulted in an increasing neutralization capacity per anti-spike antibody unit and were paralleled by stepwise increases in antibody avidity. We conclude that an infection-plus-vaccination-induced hybrid immunity or a triple immunization can induce high-quality antibodies with superior neutralization capacity against VoCs, including omicron.

LFA1 and ICAM1 are critical for fusion and spread of murine leukemia virus in vivo

Murine leukemia virus (MLV)-presenting cells form stable intercellular contacts with target cells during infection of lymphoid tissue, indicating a role of cell-cell contacts in retrovirus dissemination. Whether host cell adhesion proteins are required for retrovirus spread in vivo remains unknown. Here, we demonstrate that the lymphocyte-function-associated-antigen-1 (LFA1) and its ligand intercellular-adhesion-molecule-1 (ICAM1) are important for cell-contact-dependent transmission of MLV between leukocytes. Infection experiments in LFA1- and ICAM1-deficient mice demonstrate a defect in MLV spread within lymph nodes. Co-culture of primary leukocytes reveals a specific requirement for ICAM1 on donor cells and LFA1 on target cells for cell-contact-dependent spread through trans- and cis-infection. Importantly, adoptive transfer experiments combined with a newly established MLV-fusion assay confirm that the directed LFA1-ICAM1 interaction is important for retrovirus fusion and transmission in vivo. Taken together, our data provide insights on how retroviruses exploit host proteins and the biology of cell-cell interactions for dissemination.

Rapid, efficient and activation-neutral gene editing of polyclonal primary human resting CD4+ T cells allows complex functional analyses

CD4+ T cells are central mediators of adaptive and innate immune responses and constitute a major reservoir for human immunodeficiency virus (HIV) in vivo. Detailed investigations of resting human CD4+ T cells have been precluded by the absence of efficient approaches for genetic manipulation limiting our understanding of HIV replication and restricting efforts to find a cure. Here we report a method for rapid, efficient, activation-neutral gene editing of resting, polyclonal human CD4+ T cells using optimized cell cultivation and nucleofection conditions of Cas9-guide RNA ribonucleoprotein complexes. Up to six genes, including HIV dependency and restriction factors, were knocked out individually or simultaneously and functionally characterized. Moreover, we demonstrate the knock in of double-stranded DNA donor templates into different endogenous loci, enabling the study of the physiological interplay of cellular and viral components at single-cell resolution. Together, this technique allows improved molecular and functional characterizations of HIV biology and general immune functions in resting CD4+ T cells.

MicroRNAs are minor constituents of extracellular vesicles that are rarely delivered to target cells

Mammalian cells release different types of vesicles, collectively termed extracellular vesicles (EVs). EVs contain cellular microRNAs (miRNAs) with an apparent potential to deliver their miRNA cargo to recipient cells to affect the stability of individual mRNAs and the cells’ transcriptome. The extent to which miRNAs are exported via the EV route and whether they contribute to cell-cell communication are controversial. To address these issues, we defined multiple properties of EVs and analyzed their capacity to deliver packaged miRNAs into target cells to exert biological functions. We applied well-defined approaches to produce and characterize purified EVs with or without specific viral miRNAs. We found that only a small fraction of EVs carried miRNAs. EVs readily bound to different target cell types, but EVs did not fuse detectably with cellular membranes to deliver their cargo. We engineered EVs to be fusogenic and document their capacity to deliver functional messenger RNAs. Engineered fusogenic EVs, however, did not detectably alter the functionality of cells exposed to miRNA-carrying EVs. These results suggest that EV-borne miRNAs do not act as effectors of cell-to-cell communication.

The majority of metazoan cells release vesicles of different types and origins, such as exosomes and microvesicles, now collectively termed extracellular vesicles (EVs). EVs have gained much attention because they contain microRNAs (miRNAs) and thus could regulate their specific mRNA targets in recipient or acceptor cells that take up EVs. Using a novel fusion assay with superior sensitivity and specificity, we revisited this claim but found no convincing evidence for an efficient functional uptake of EVs in many different cell lines and primary human blood cells. Even EVs engineered to fuse and deliver their miRNA cargo to recipient cells had no measurable effect on target mRNAs in very carefully controlled, quantitative experiments. Our negative results clearly indicate that EVs do not act as vehicles for miRNA-based cell-to-cell communication.

In-depth profiling of COVID-19 risk factors and preventive measures in healthcare workers

Purpose

To determine risk factors for coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs), characterize symptoms, and evaluate preventive measures against SARS-CoV-2 spread in hospitals.

Methods

In a cross-sectional study conducted between May 27 and August 12, 2020, after the first wave of the COVID-19 pandemic, we obtained serological, epidemiological, occupational as well as COVID-19-related data at a quaternary care, multicenter hospital in Munich, Germany.

Results

7554 HCWs participated, 2.2% of whom tested positive for anti-SARS-CoV-2 antibodies. Multivariate analysis revealed increased COVID-19 risk for nurses (3.1% seropositivity, 95% CI 2.5–3.9%, p = 0.012), staff working on COVID-19 units (4.6% seropositivity, 95% CI 3.2–6.5%, p = 0.032), males (2.4% seropositivity, 95% CI 1.8–3.2%, p = 0.019), and HCWs reporting high-risk exposures to infected patients (5.5% seropositivity, 95% CI 4.0–7.5%, p = 0.0022) or outside of work (12.0% seropositivity, 95% CI 8.0–17.4%, p < 0.0001). Smoking was a protective factor (1.1% seropositivity, 95% CI 0.7–1.8% p = 0.00018) and the symptom taste disorder was strongly associated with COVID-19 (29.8% seropositivity, 95% CI 24.3–35.8%, p < 0.0001). An unbiased decision tree identified subgroups with different risk profiles. Working from home as a preventive measure did not protect against SARS-CoV-2 infection. A PCR-testing strategy focused on symptoms and high-risk exposures detected all larger COVID-19 outbreaks.

Conclusion

Awareness of the identified COVID-19 risk factors and successful surveillance strategies are key to protecting HCWs against SARS-CoV-2, especially in settings with limited vaccination capacities or reduced vaccine efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01672-z.

Contribution of Heptose Metabolites and the cag Pathogenicity Island to the Activation of Monocytes/Macrophages by Helicobacter pylori

The human gastric pathogen Helicobacter pylori activates human epithelial cells by a particular combination of mechanisms, including NOD1 and ALPK1-TIFA activation. These mechanisms are characterized by a strong participation of the bacterial cag pathogenicity island, which forms a type IV secretion system (CagT4SS) that enables the bacteria to transport proteins and diverse bacterial metabolites, including DNA, glycans, and cell wall components, into human host cells. Building on previous findings, we sought to determine the contribution of lipopolysaccharide inner core heptose metabolites (ADP-heptose) in the activation of human phagocytic cells by H. pylori. Using human monocyte/macrophage-like Thp-1 cells and human primary monocytes and macrophages, we were able to determine that a substantial part of early phagocytic cell activation, including NF-κB activation and IL-8 production, by live H. pylori is triggered by bacterial heptose metabolites. This effect was very pronounced in Thp-1 cells exposed to bacterial purified lysates or pure ADP-heptose, in the absence of other bacterial MAMPs, and was significantly reduced upon TIFA knock-down. Pure ADP-heptose on its own was able to strongly activate Thp-1 cells and human primary monocytes/macrophages. Comprehensive transcriptome analysis of Thp-1 cells co-incubated with live H. pylori or pure ADP-heptose confirmed a signature of ADP-heptose-dependent transcript activation in monocyte/macrophages. Bacterial enzyme-treated lysates (ETL) and pure ADP-heptose–dependent activation differentiated monocytes into macrophages of predominantly M1 type. In Thp-1 cells, the active CagT4SS was less required for the heptose-induced proinflammatory response than in epithelial cells, while active heptose biosynthesis or pure ADP-heptose was required and sufficient for their early innate response and NF-κB activation. The present data suggest that early activation and maturation of incoming and resident phagocytic cells (monocytes, macrophages) in the H. pylori–colonized stomach strongly depend on bacterial LPS inner core heptose metabolites, also with a significant contribution of an active CagT4SS.

Multiple Viral microRNAs Regulate Interferon Release and Signaling Early during Infection with Epstein-Barr Virus

Epstein-Barr virus (EBV), a human herpesvirus, encodes 44 microRNAs (miRNAs), which regulate many genes with various functions in EBV-infected cells. Multiple target genes of the EBV miRNAs have been identified, some of which play important roles in adaptive antiviral immune responses. Using EBV mutant derivatives, we identified additional roles of viral miRNAs in governing versatile type I interferon (IFN) responses upon infection of human primary mature B cells. We also found that Epstein-Barr virus-encoded small RNAs (EBERs) and LF2, viral genes with previously reported functions in inducing or regulating IFN-I pathways, had negligible or even contrary effects on secreted IFN-α in our model. Data mining and Ago PAR-CLIP experiments uncovered more than a dozen previously uncharacterized, direct cellular targets of EBV miRNA associated with type I IFN pathways. We also identified indirect targets of EBV miRNAs in B cells, such as TRL7 and TLR9, in the prelatent phase of infection. The presence of epigenetically naive, non-CpG methylated viral DNA was essential to induce IFN-α secretion during EBV infection in a TLR9-dependent manner. In a newly established fusion assay, we verified that EBV virions enter a subset of plasmacytoid dendritic cells (pDCs) and determined that these infected pDCs are the primary producers of IFN-α in EBV-infected peripheral blood mononuclear cells. Our findings document that many EBV-encoded miRNAs regulate type I IFN response in newly EBV infected primary human B cells in the prelatent phase of infection and dampen the acute release of IFN-α in pDCs upon their encounter with EBV.IMPORTANCE Acute antiviral functions of all nucleated cells rely on type I interferon (IFN-I) pathways triggered upon viral infection. Host responses encompass the sensing of incoming viruses, the activation of specific transcription factors that induce the transcription of IFN-I genes, the secretion of different IFN-I types and their recognition by the heterodimeric IFN-α/β receptor, the subsequent activation of JAK/STAT signaling pathways, and, finally, the transcription of many IFN-stimulated genes (ISGs). In sum, these cellular functions establish a so-called antiviral state in infected and neighboring cells. To counteract these cellular defense mechanisms, viruses have evolved diverse strategies and encode gene products that target antiviral responses. Among such immune-evasive factors are viral microRNAs (miRNAs) that can interfere with host gene expression. We discovered that multiple miRNAs of Epstein-Barr virus (EBV) control over a dozen cellular genes that contribute to the antiviral states of immune cells, specifically B cells and plasmacytoid dendritic cells (pDCs). We identified the viral DNA genome as the activator of IFN-α and question the role of abundant EBV EBERs, that, contrary to previous reports, do not have an apparent inducing function in the IFN-I pathway early after infection.

Left atrial remodeling after Mitraclip implantation

Objective

Changes in left atrial (LA) size and function are associated with major adverse cardiovascular outcomes such as atrial fibrillation, heart failure, stroke, and death. Reverse LA remodelling occurs after successful surgical mitral valve repair for severe MR. Changes in LA volumes after MV repair have reported in several studies. However, LA data are limited in the setting of transcatheter repair.

Materials an methods

From November 2016 to July 2018, clinical and echocardiographic data of 42 patients with mitral regurgitation who underwent Mitraclip implantation in our division were evaluated for LA function: LA global longitudinal strain (LA GLS); LAESV (Left atrial end-systolic volume), LAEDV (Left atrial end-diastolic volume); LA emptying Fraction at baseline, at 1 month, at 6 months and 1 year of follow up were assessed. The variation of continuous variables was evaluated using a student T test for paired data or the Wilcoxon matched-pair signed rank test when appropriate. The categorical variables between two groups were evaluated using the chi-square test (χ2). P values &lt;0.05 were considered significant.

Results

The etiology of the mitral regurgitation was primary in 33,3% and secondary in 66,7% of the included patients. The MR degree was 3+ in 21,4% of patients and 4+ in 78,6%. When compared to baseline at 6 months and 1 year a statistically significant reduction was observed for both LAESV (p&lt;0.001) and LAEDV (p&lt;0.001). At 6 months, compared to baseline, the LA GLS reached statistic relevance (p 0.05) with a significant improvement at 1 year (p 0.001). Finally, we did not find significant differences in LA emptying fraction at different time point analyzed.

Conclusions

A successful MitraClip procedure can reverse the process of LA remodeling within 12 months, and this can be detected by Two-dimensional speckle tracking echocardiography (2D STE) through an improvement in the LA reservoir function. These data generate the hypothesis that the GLS, compared to conventional echocardiographic parameters, represents an advanced method that quantify atrial function in Mitraclip implanted patients.

Funding Acknowledgement

Type of funding source: Public hospital(s)

CARD8 inflammasome activation triggers pyroptosis in human T cells

Inflammasomes execute a unique type of cell death known as pyroptosis. Mostly characterized in myeloid cells, caspase‐1 activation downstream of an inflammasome sensor results in the cleavage and activation of gasdermin D (GSDMD), which then forms a lytic pore in the plasma membrane. Recently, CARD8 was identified as a novel inflammasome sensor that triggers pyroptosis in myeloid leukemia cells upon inhibition of dipeptidyl‐peptidases (DPP). Here, we show that blocking DPPs using Val‐boroPro triggers a lytic form of cell death in primary human CD4 and CD8 T cells, while other prototypical inflammasome stimuli were not active. This cell death displays morphological and biochemical hallmarks of pyroptosis. By genetically dissecting candidate components in primary T cells, we identify this response to be dependent on the CARD8‐caspase‐1‐GSDMD axis. Moreover, DPP9 constitutes the relevant DPP restraining CARD8 activation. Interestingly, this CARD8‐induced pyroptosis pathway can only be engaged in resting, but not in activated T cells. Altogether, these results broaden the relevance of inflammasome signaling and associated pyroptotic cell death to T cells, central players of the adaptive immune system.

Trans-nasal endoscopic and intra-oral combined approach for odontogenic cysts

Maxillary cysts are a common finding in maxillofacial surgery, dentistry and otolaryngology. Treatment is surgical; a traditional approach includes Caldwell-Luc and other intra-oral approaches. In this article, we analyse the outcomes of 9 patients operated on using a combined intra-oral and trans-nasal approach to the aforementioned disease. Although the number of patients is small, the good results of this study suggest that the combined approach might be a reliable treatment option.

Evaluation of pain, swelling and trismus after extraction of impacted third molars relative to the use of betamethasone in submucusal infiltration

The aim of this study was to evaluate the anti-inflammatory effect of a single 4 mg injection of submucosal betamethasone after extraction of impacted third molars. Single-centre, single-blinded, parallel group study; Forty-three patients were submitted to impacted third molar extraction. In this study, 4 mg single-dose submucosal betamethasone was injected in the interventional group, while in the control group nothing was injected. Postoperative measurement included pain via the VAS scale, swelling and trismus with facial measurements and maximum mouth openings, and finally nerve sensitivity. There was a significant difference between the two groups regarding trismic pain and edema. The use of a single 4 mg submucosal betamethasone injection leads to a reduction of oedema, trismus and pain in patients undergoing impacted third molar extraction. .

Bi-layered collagen nano-structured membrane prototype collagen matrix CM-10826 for oral soft tissue regeneration: an in vivo ultrastructural study on 13 patients

A new developed collagen matrix CM-10826 (CM) of porcine origin designed to be used as oral soft tissue substitute was investigated before and after implantation by light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In a case series biopsy specimens were harvested from thirteen patients at 10, 20, 30, 43 days after abutment surgery for uncovering dental implants. The in vivo histological evaluations of each patient were performed via micro-coring of newly formed oral mucosa in the area covered by CM (test side) or left uncovered (control). Results showed that CM can be integrated in connective and epithelial tissues within 10 days, can be completely resorbed within 20 days and it is able to reduce inflammatory infiltrates and to stimulate both fibroblast/epithelial cell proliferation and neo-angiogenesis. Generally it seems to be superior in promoting soft tissue healing compared to that induced by secondary intention healing. Furthermore, it is able to act as a scaffold for soft-tissue regeneration, allowing the proliferation of keratinocytes from the wound edges and favoring neovascularization and growth of connective tissue in the mesh of porous layer. It appears that a CM might function in oral surgery as a substitute for autologous grafts and to avoid secondary intention healing in soft tissue defects.

An overview of socket preservation

Socket preservation is a surgical procedure whose aim is to limit the physiological resorption of the alveolar ridge that occurs after a dental extraction, in order to have sufficient bone to perform an implant placement. 16 articles regarding socket preservation procedures were identified through scientific archives and analysed. The biological rationale, the graft materials and the predictive factors are identified to help the clinicians in their practice. Socket preservation is an effective treatment to prevent bone resorption if performed after an atraumatic extraction with the use of biomaterials and membranes. It is also important not to forget local and systemic predictive factors.

Efficacy of the Andresen activator before peak growth in class II patients

Andresen activator (AA) is a functional appliance used to correct Class II malocclusion in growing patients. It corrects the malocclusion stimulating mandibular growth and determining a palatoversion of the upper incisors and a vestibularization of the lower incisors. The aim of this study was to analyze the treatment efficacy of class II malocclusion due to mandibular hypodevelopment before peak growth. Fourteen subjects with class II relationship of the skeletal bases and cervical vertebrae maturation stage 1 or 2 were enrolled in the study. Cephalometric analyses were carried out using landmarks derived from the analyses of Pancherz, Ricketts, Tweed and Steiner. A significant decrease (P less than 0.05) in ANB angle was found (-2.29±3.05°) after treatment, which was expression of an improvement in maxillo-mandibular sagittal skeletal relationships. There was also a significant reduction of OJ after treatment (-4.44±2.36 mm; P less than 0.001), indicating a vestibularization of the mandibular incisors and a palatoversion of the maxillary incisors, and a correction of the molar relationship. The favorable effects of the Andresen activator for the correction of the mandibular defect can be found even prior to peak growth; the achieved class I relationship maintains a correct mandible position in time, ensuring a proper skeletal growth. .

Tooth agenesis: part 2. Orthodontic treatment and prosthetic possibilities

Dental agenesis has a great clinical significance due to its frequency during daily practice and the therapeutic problems that can arise from it. This paper will explore all the aspects to consider in order creating a proper multidisciplinary treatment plan: in particular, orthodontic, prosthetic and implantologic therapeutic alternatives are described for the rehabilitation of the different areas of the dental arches. In fact, dental agenesis is a problem that often requires the intervention of specialists from the different fields of dentistry and its treatment must meet aesthetics needs, stomatognathic function and patient satisfaction.

Tooth agenesis: part 1. Incidence and diagnosis in orthodontics

Dental agenesis has a great clinical significance due to its frequency during daily practice and the therapeutic problems that can arise from it. This paper will explore the incidence of dental agenesis, its diagnosis and how this anomaly affects the teeth differently. The second subsequent paper will look at its treatment and management.

Spatiotemporally Skewed Activation of Programmed Cell Death Receptor 1-Positive T Cells after Epstein-Barr Virus Infection and Tumor Development in Long-Term Fully Humanized Mice

Humanized mice developing functional human T cells endogenously and capable of recognizing cognate human leukocyte antigen–matched tumors are emerging as relevant models for studying human immuno-oncology in vivo. Herein, mice transplanted with human CD34⁺ stem cells and bearing endogenously developed human T cells for >15 weeks were infected with an oncogenic recombinant Epstein-Barr virus (EBV), encoding enhanced firefly luciferase and green fluorescent protein. EBV–firefly luciferase was detectable 1 week after infection by noninvasive optical imaging in the spleen, from where it spread rapidly and systemically. EBV infection resulted into a pronounced immunologic skewing regarding the expansion of CD8⁺ T cells in the blood outnumbering the CD4⁺ T and CD19⁺ B cells. Furthermore, within 10 weeks of infections, mice developing EBV-induced tumors had significantly higher absolute numbers of CD8⁺ T cells in lymphatic tissues than mice controlling tumor development. Tumor outgrowth was paralleled by an up-regulation of the programmed cell death receptor 1 on CD8⁺ and CD4⁺ T cells, indicative for T-cell dysfunction. Histopathological examinations and in situ hybridizations for EBV in tumors, spleen, liver, and kidney revealed foci of EBV-infected cells in perivascular regions in close association with programmed cell death receptor 1–positive infiltrating lymphocytes. The strong spatiotemporal correlation between tumor development and the T-cell dysfunctional status seen in this viral oncogenesis humanized model replicates observations obtained in the clinical setting.

Multi-Step Regulation of the TLR4 Pathway by the miR-125a~99b~let-7e Cluster

An appropriate immune response requires a tight balance between pro- and anti-inflammatory mechanisms. IL-10 is induced at late time-points during acute inflammatory conditions triggered by TLR-dependent recognition of infectious agents and is involved in setting this balance, operating as a negative regulator of the TLR-dependent signaling pathway. We identified miR-125a~99b~let-7e as an evolutionary conserved microRNA cluster late-induced in human monocytes exposed to the TLR4 agonist LPS as an effect of this IL-10-dependent regulatory loop. We demonstrated that microRNAs generated by this cluster perform a pervasive regulation of the TLR signaling pathway by direct targeting receptors (TLR4, CD14), signaling molecules (IRAK1), and effector cytokines (TNFα, IL-6, CCL3, CCL7, CXCL8). Modulation of miR-125a~99b~let-7e cluster influenced the production of proinflammatory cytokines in response to LPS and the IL-10-mediated tolerance to LPS, thus identifying this gene as a previously unrecognized major regulatory element of the inflammatory response and endotoxin tolerance.

Epstein-Barr viral miRNAs inhibit antiviral CD4+ T cell responses targeting IL-12 and peptide processing

EBV reduces the activation of cytotoxic CD4⁺ effector T cells by inducing a state of reduced immunogenicity in infected B cells. EBV-derived miRNAs suppress release of proinflammatory cytokines, interfere with peptide processing and presentation on HLA class II, repress differentiation of naive CD4⁺ T cells to Th1 cells, and ultimately avoid killing of infected B cells.

Epstein-Barr virus (EBV) is a tumor virus that establishes lifelong infection in most of humanity, despite eliciting strong and stable virus-specific immune responses. EBV encodes at least 44 miRNAs, most of them with unknown function. Here, we show that multiple EBV miRNAs modulate immune recognition of recently infected primary B cells, EBV's natural target cells. EBV miRNAs collectively and specifically suppress release of proinflammatory cytokines such as IL-12, repress differentiation of naive CD4⁺ T cells to Th1 cells, interfere with peptide processing and presentation on HLA class II, and thus reduce activation of cytotoxic EBV-specific CD4⁺ effector T cells and killing of infected B cells. Our findings identify a previously unknown viral strategy of immune evasion. By rapidly expressing multiple miRNAs, which are themselves nonimmunogenic, EBV counteracts recognition by CD4⁺ T cells and establishes a program of reduced immunogenicity in recently infected B cells, allowing the virus to express viral proteins required for establishment of life-long infection.

Predicting seizures in untreated temporal lobe epilepsy using point-process nonlinear models of heartbeat dynamics

Symptoms of temporal lobe epilepsy (TLE) are frequently associated with autonomic dysregulation, whose underlying biological processes are thought to strongly contribute to sudden unexpected death in epilepsy (SUDEP). While abnormal cardiovascular patterns commonly occur during ictal events, putative patterns of autonomic cardiac effects during pre-ictal (PRE) periods (i.e. periods preceding seizures) are still unknown. In this study, we investigated TLE-related heart rate variability (HRV) through instantaneous, nonlinear estimates of cardiovascular oscillations during inter-ictal (INT) and PRE periods. ECG recordings from 12 patients with TLE were processed to extract standard HRV indices, as well as indices of instantaneous HRV complexity (dominant Lyapunov exponent and entropy) and higher-order statistics (bispectra) obtained through definition of inhomogeneous point-process nonlinear models, employing Volterra-Laguerre expansions of linear, quadratic, and cubic kernels. Experimental results demonstrate that the best INT vs. PRE classification performance (balanced accuracy: 73.91%) was achieved only when retaining the time-varying, nonlinear, and non-stationary structure of heartbeat dynamical features. The proposed approach opens novel important avenues in predicting ictal events using information gathered from cardiovascular signals exclusively.

Inclusion of all permanent mandibular molars and all maxillary second and third molars: a case report and review of the literature

Simultaneous impactions of first, second, and third permanent molars on both mandibular sides together with the all maxillary second and third molars is a clinical situation never reported before in the literature and it might be a difficult challenge for maxillofacial surgeons and dentists. Early diagnosis and treatment of eruption disturbances contributes to optimal outcomes. This article reports the treatment of an adult with severe impaction of all mandibular first, second, and third molars together with all maxillary second and third molars, which limits the masticatory function and dental arch integrity. The impacted molars were surgically removed as the patients declined orthodontic treatment. The combined surgical-orthodontic approach represents a challenging treatment and the optimal one as it eliminates the need for prosthetic rehabilitation and implant replacement of the impacted molars, when accepted.

Blood levels of interleukins in patients with ameloblastoma

The aim of study was to determine and compare serum concentrations of interleukin 1 beta (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in patients with oral ameloblastoma and healthy controls. Sixteen patients with ameloblastoma and 16 healthy controls were enrolled in this study. Cytokine concentrations were measured by chemiluminescent enzyme linked immunoassay. Serum concentrations of IL-1β were below level of detection in all but four participants. No significant differences between the groups were observed in serum concentrations of IL-6. Serum TNF-α was significantly higher in control subjects than in ameloblastoma patients. Patients diagnosed with ameloblastoma have relatively normal levels of inflammatory cytokines in their blood and thus cannot be used as indicators of disease severity or for monitoring the treatment outcomes.

Salivary levels of IgA in healthy subjects undergoing active orthodontic treatment

It has been reported that the immune system undergoes changes due to various factors, inflammation, surgery, medication, age and gender. The aim of this study was to investigate therapy-dependent changes of salivary IgA among healthy subjects undergoing active orthodontic treatment. The levels of IgA were determined at the beginning, and after 1,4, 8,16 weeks and 32 weaks of active orthodontic treatment. A total of 100 healthy individuals (aged 15-42 years) were enrolled in the study. Two milliliters of saliva were collected from all participants, and salivary IgA levels were measured by the ELISA technique. Mean salivary IgA levels were significantly higher in subjects after 1 week as compared to subjects at the beginning of orthodontic treatment (P < 0.01).. The mean levels of salivary IgA were significantly higher after 4 and 8 weeks of therapy than those observed in the control group (P < 0.00001 and P < 0.05, respectively) and reached the highest level at 16 weeks and then remained stable during treatment. Gender had no effect on the salivary levels of IgA as any significant differences were observed between men and women. The results highlight the importance of the salivary defense mechanism, translated through the increase in the levels of IgA, once orthodontic treatment is started.

The benefits of Quercitin for dentistry and maxillofacial surgery: a systematic review

Quercetin (3,3',4',5,7-pentahydroxyflavone) is the major bioflavonoid in the human diet and belongs to an extensive class of polyphenolic flavonoid compounds almost ubiquitous in plants and plant food sources. The estimated average daily dietary intake of quercetin by an individual in the United States is 25 mg. In recent years, research about quercetin has evolved from animal studies to in vitro and in vivo studies and to human clinical studies and trials in order to establish its real properties and effects. In oral medicine, quercetin has been extensively studied, as a real increase in major diseases like cancers, periodontal disease, oral lesions, tooth decay and infections have been reported worldwide by health providers.It has been thus established that quercetin exhibits beneficial effects on oral health with its broad pharmacological properties, as preventive and therapeutic agent in dental caries with anti-inflammatory effect against oral pathogens, as well as an antioxidant and anti-cancer agent .The aim of the review is to present evidence-based aspect of treatment with quercetin in order to validate its tremendous role in dentistry and maxillofacial surgery.

Salivary calcium levels during orthodontic treatment

Saliva contains many defense factors and plays a key role in oral metabolism. Salivary calcium, due to its affinity to be readily taken up by plaque, is an important factor not only with regard to the onset of periodontitis but also significantly with regard to dental health. The aim of this study was to estimate the salivary concentration of calcium, in a group of adults undergoing active orthodontic treatment. The levels of salivary calcium were determined at the beginning, and after 16 weeks of active orthodontic treatment. A total of 40 healthy individuals with a mean age of 23.9 years were enrolled in the study group, while 40 subjects served as controls. Two milliliters of saliva were collected from all participants, and salivary calcium levels were measured by biochemical assay. Mean salivary calcium levels were significantly higher in subjects after 16 weeks as compared to subjects at the beginning of orthodontic treatment and to the control group (p= 0.001). A significant association between higher salivary calcium levels and orthodontic treatment has been established, therefore, monitoring salivary calcium levels might be a useful tool to establish periodontal health status during active orthodontic treatment along with other inflammatory parameters.

Bimaxillary distraction osteogenesis used for treatment of crowding in non-growing individuals. Case report

Dental crowding is frequently associated with transverse jaw discrepancies, resulting in a less-than-ideal position of the teeth in the basal bone. The classic aproach for correcting bimaxillary crowding are extractions or arch expansion. Rapid maxilla-mandibular expansion was used to treat transverse discrepancies in growing patients, but with aging, the upper and lower jaw bones become increasingly resistant to expansion. The surgically assisted rapid maxillary expansion (SARME) and the mandibular midsymphyseal distraction osteogenesis procedure overcome this age limitation and are of great importance for the treatment of transverse discrepancies in adults. The aim of this paper is to report a case with a severe transverse deficiency treated with SARME, mandibular midsymphyseal distraction together with orthodontic treatment in an adult patient. The case highlights the esthetic advantages of increasing the transversal dimension of both jaws in patients with severe crowding associated with constricted dental arches and recommends the maxillo-mandibular transverse distraction osteogenesis as an and effective form of surgical treatment for patients with malocclusions or dentofacial deformities featuring severe transverse discrepancies, combined with a carefully monitored orthodontic treatment.

Dental white spots associated with bulimia nervosa in orthodontic patients

Bulimia nervosa is an eating disorder characterized by consuming a large amount of food in a short amount of time followed by an attempt to rid oneself of the food consumed (purging), typically by vomiting, taking a laxative, diuretic, or stimulant, and/or excessive exercise, because of an extensive concern for body weight. The frequent contact between teeth and gastric acid, in particular, may cause: severe dental erosion, perimolysis, or the erosion of tooth enamel and swollen salivary glands. Constant vomiting can lead to gastroesophageal reflux. The aim of this article is to report two cases of patients with severe dental demineralization associated with bulimia nervosa during orthodontic treatment. Diagnosis and prevention aspects are highlighted and discussed.

Non-traumatic unilateral bifid mandibular condyle and multiple inclusions: a case report

Simultaneous impactions of first, second, and third permanent molars on both mandibular sides together with the all maxillary second and third molars is a clinical situation never reported before in the literature and it might be a difficult challenge for maxillofacial surgeons and dentists. Early diagnosis and treatment of eruption disturbances contributes to optimal outcomes. This article reports the treatment of an adult with severe impaction of all mandibular first, second, and third molars together with all maxillary second and third molars, which limits the masticatory function and dental arch integrity. The impacted molars were surgically removed as the patients declined orthodontic treatment. The combined surgical-orthodontic approach represents a challenging treatment and the optimal one as it eliminates the need for prosthetic rehabilitation and implant replacement of the impacted molars, when accepted.