Osteoimmunology in Periodontitis and Orthodontic Tooth Movement

PURPOSE OF REVIEW

To review the role of the immune cells and their interaction with cells found in gingiva, periodontal ligament, and bone that leads to net bone loss in periodontitis or bone remodeling in orthodontic tooth movement.

RECENT FINDINGS

Periodontal disease is one of the most common oral diseases causing inflammation in the soft and hard tissues of the periodontium and is initiated by bacteria that induce a host response. Although the innate and adaptive immune response function cooperatively to prevent bacterial dissemination, they also play a major role in gingival inflammation and destruction of the connective tissue, periodontal ligament, and alveolar bone characteristic of periodontitis. The inflammatory response is triggered by bacteria or their products that bind to pattern recognition receptors that induce transcription factor activity to stimulate cytokine and chemokine expression. Epithelial, fibroblast/stromal, and resident leukocytes play a key role in initiating the host response and contribute to periodontal disease. Single-cell RNA-seq (scRNA-seq) experiments have added new insight into the roles of various cell types in the response to bacterial challenge. This response is modified by systemic conditions such as diabetes and smoking. In contrast to periodontitis, orthodontic tooth movement (OTM) is a sterile inflammatory response induced by mechanical force. Orthodontic force application stimulates acute inflammatory responses in the periodontal ligament and alveolar bone stimulated by cytokines and chemokines that produce bone resorption on the compression side. On the tension side, orthodontic forces induce the production of osteogenic factors, stimulating new bone formation. A number of different cell types, cytokines, and signaling/pathways are involved in this complex process. Inflammatory and mechanical force-induced bone remodeling involves bone resorption and bone formation. The interaction of leukocytes with host stromal cells and osteoblastic cells plays a key role in both initiating the inflammatory events as well as inducing a cellular cascade that results in remodeling in orthodontic tooth movement or in tissue destruction in periodontitis.

Expression of down-regulated ERV LTR elements associates with immune activation in human small-cell lung cancers

Small-cell lung cancer (SCLC) is an aggressive cancer characterized by immunosuppressive features leading to poor responses to current immunotherapies. Activation of transposable elements (TE) can trigger an innate immune response, which can synergize with immunotherapeutic protocols in patients. However, TE activity in relation to immune gene response is not fully known in human SCLC. Here, we compared TE expression in 104 human SCLC and 24 normal tissues and established their involvement in innate immune responses. We observed that different intergenic TEs, mainly endogenous retroviral (ERV) families, are deregulated in SCLC. Similarly to other cancers, we detected a subset of LTRs that correlate with innate immune gene signatures and cytosolic RNA sensors, such as RIG-I. These LTRs are downregulated in SCLC tumors vs. normal tissues, and are mainly located at transcriptional repressed regions, marked with H3K4me2 in different cell lines. Analyses of different genomic datasets show that chromatin repression is likely due to de-methylase LSD1 activity. Moreover, high expression levels of ERV LTRs predict a better survival upon chemotherapy of SCLC patients. The findings reveal a specific pattern of TE-mediated activation of innate immune genes in SCLC, which can be exploited to establish more effective immunotherapeutic combinations.

The social environment alters neural responses to a lipopolysaccharide challenge

Sick animals display drastic changes in their behavioral patterns, including decreased activity, decreased food and water intake, and decreased interest in social interactions. These behaviors, collectively called "sickness behaviors", can be socially modulated. For example, when provided with mating opportunities, males of several species show reduced sickness behaviors. While the behavior is known to change, how the social environment affects neural molecular responses to sickness is not known. Here, we used a species, the zebra finch, Taeniopygia guttata, where males have been shown to decrease sickness behaviors when presented with novel females. Using this paradigm, we obtained samples from three brain regions (the hypothalamus, the bed nucleus of the stria terminalis, and the nucleus taeniae) from lipopolysaccharide (LPS) or control treated males housed under four different social environments. Manipulation of the social environment rapidly changed the strength and co-expression patterns of the neural molecular responses to the immune challenge in all brain regions tested, therefore suggesting that the social environment plays a significant role in determining the neural responses to an infection. In particular, brains of males paired with a novel female showed muted immune responses to LPS, as well as altered synaptic signaling. Neural metabolic activity in response to the LPS challenge was also affected by the social environment. Our results provide new insights into the effects of the social environment on brain responses to an infection, thereby improving our understanding of how the social environment can affect health.

Immunoregulatory mechanism of acute kidney injury in sepsis: A Narrative Review

Sepsis acute kidney injury (SAKI) is a common complication of sepsis, accounting for 26-50 % of all acute kidney injury (AKI). AKI is an independent risk factor for increased mortality risk in patients with sepsis. The excessive inflammatory cascade reaction in SAKI is one of the main causes of kidney damage. Both the innate immune system and the adaptive immune system are involved in the inflammation process of SAKI. Under the action of endotoxin, neutrophils, monocytes, macrophages, T cells and other complex immune network reactions occur, and a large number of endogenous inflammatory mediators are released, resulting in the amplification and loss of control of the inflammatory response. The study of immune cells in SAKI will help improve the understanding of the immune mechanisms of SAKI, and will lay a foundation for the development of new diagnostic and therapeutic targets. This article reviews the role of known immune mechanisms in the occurrence and development of SAKI, with a view to finding new targets for SAKI treatment.

Immuno-engineered mRNA combined with cell adhesive niche for synergistic modulation of the MSC secretome

In vitro transcribed (IVT-)mRNA has entered center stage for vaccine development due to its immune co-stimulating properties. Given the widely demonstrated safety of IVT-mRNA-based vaccines, we aimed to adopt IVT-mRNA encoding VEGF for secretory phenotype modulation of therapeutic cells. However, we observed that the immunogenicity of IVT-mRNA impairs the endogenous secretion of pro-angiogenic mediators from transfected mesenchymal stromal cells, instead inducing anti-angiogenic chemokines. This inflammatory secretome modulation limits the application potential of unmodified IVT-mRNA for cell therapy manufacturing, pro-angiogenic therapy and regenerative medicine. To uncouple immunogenicity from the protein expression functionality, we immuno-engineered IVT-mRNA with different chemically modified ribonucleotides. 5-Methoxy-uridine-modification of IVT-mRNA rescued the endogenous secretome pattern of transfected cells and prolonged secretion of IVT-mRNA-encoded VEGF. We found that high secretion of IVT-mRNA-encoded protein further depends on optimized cell adhesion. Cell encapsulation in a collagen-hyaluronic acid hydrogel increased secretion of IVT-mRNA-encoded VEGF and augmented the endogenous secretion of supporting pro-angiogenic mediators, such as HGF. Integrating minimally immunogenic mRNA technology with predesigned matrix-derived cues allows for the synergistic combination of multiple dimensions of cell manipulation and opens routes for biomaterial-based delivery of mRNA-engineered cell products. Such multimodal systems could present a more biologically relevant way to therapeutically address complex multifactorial processes such as tissue ischemia, angiogenesis, and regeneration.

The therapeutic role and mechanism of 4-Methoxycinnamic acid in fungal keratitis

Fungal keratitis is an infectious vision-threatening disease that has a poor prognosis, and the clinical therapeutic drugs have multiple limitations, such as epithelial toxicity and low bioavailability. Therefore, new antifungal treatment strategies must be developed. 4-Methoxycinnamic acid (MCA) is a widely occurring natural phenolic acid that has been proven to have multiple effects, such as antibacterial, antifungal, anti-inflammatory, neuroprotective, and inhibiting cancer. In this research, we explored the effects and underlying mechanisms of MCA on A. fumigatus keratitis and the antifungal effects of the combination of MCA and natamycin (NATA) on A. fumigatus. We found that MCA exerts antifungal effects by inhibiting the synthesis of the fungal cell wall, changing the permeability of fungal cell membranes. Moreover, the MCA-NATA combination exhibited synergy for A. fumigatus. In addition, MCA exerted an anti-inflammatory effect by downregulating the inflammatory factors (IL-1β, TNF-α, IL-6, and iNOS) in C57BL/6 mice and RAW264.7 cells. The anti-inflammatory mechanism of MCA was associated with the Mincle signal pathway. In summary, MCA acts as a potential therapeutic drug for fungal keratitis and a potential antifungal sensitizer for natamycin. MCA inhibits fungal cell wall synthesis, destroys the permeability of fungal cell membranes, and mediates the anti-inflammatory, immune response of the host.

Current status of hand-foot-and-mouth disease

Hand-foot-and-mouth disease (HFMD) is a viral illness commonly seen in young children under 5 years of age, characterized by typical manifestations such as oral herpes and rashes on the hands and feet. These symptoms typically resolve spontaneously within a few days without complications. Over the past two decades, our understanding of HFMD has greatly improved and it has received significant attention. A variety of research studies, including epidemiological, animal, and in vitro studies, suggest that the disease may be associated with potentially fatal neurological complications. These findings reveal clinical, epidemiological, pathological, and etiological characteristics that are quite different from initial understandings of the illness. It is important to note that HFMD has been linked to severe cardiopulmonary complications, as well as severe neurological sequelae that can be observed during follow-up. At present, there is no specific pharmaceutical intervention for HFMD. An inactivated Enterovirus A71 (EV-A71) vaccine that has been approved by the China Food and Drug Administration (CFDA) has been shown to provide a high level of protection against EV-A71-related HFMD. However, the simultaneous circulation of multiple pathogens and the evolution of the molecular epidemiology of infectious agents make interventions based solely on a single agent comparatively inadequate. Enteroviruses are highly contagious and have a predilection for the nervous system, particularly in child populations, which contributes to the ongoing outbreak. Given the substantial impact of HFMD around the world, this Review synthesizes the current knowledge of the virology, epidemiology, pathogenesis, therapy, sequelae, and vaccine development of HFMD to improve clinical practices and public health efforts.

Dengue Virus 2 NS2B Targets MAVS and IKKε to Evade the Antiviral Innate Immune Response

Dengue virus (DENV) is a widespread arbovirus. To efficiently establish infection, DENV evolves multiple strategies to hijack the host innate immune response. Herein, we examined the inhibitory effects of DENV serotype 2 (DENV2) nonstructural proteins on RIG-I-directed antiviral immune response. We found that DENV2 NS2A, NS2B, NS4A, and NS4B significantly inhibited RIG-I-mediated IFN-β promoter activation. The roles of NS2B in RIG-I-directed antiviral immune response are unknown. Our study further showed that NS2B could dose-dependently suppress RIG-I/MAVSinduced activation of IFN-β promoter. Consistently, NS2B significantly decreased RIG-I- and MAVSinduced transcription of IFNB1, ISG15, and ISG56. Mechanistically, NS2B was found to interact with MAVS and IKKε to impair RIG-I-directed antiviral response. Our findings demonstrated a previously uncharacterized function of NS2B in RIG-I-mediated antiviral response, making it a promising drug target for anti-DENV treatments.

Emerging Targets for Modulation of Immune Response and Inflammation in Stroke

The inflammatory and immunological responses play a significant role after stroke. The innate immune activation stimulated by microglia during stroke results in the migration of macrophages and lymphocytes into the brain and are responsible for tissue damage. The immune response and inflammation following stroke have no defined targets, and the intricacies of the immunological and inflammatory processes are only partially understood. Innate immune cells enter the brain and meninges during the acute phase, which can cause ischemia damage. Activation of systemic immunity is caused by danger signals sent into the bloodstream by injured brain cells, which is followed by a significant immunodepression that encourages life-threatening infections. Neuropsychiatric sequelae, a major source of post-stroke morbidity, may be induced by an adaptive immune response that is initiated by antigen presentation during the chronic period and is directed against the brain. Thus, the current review discusses the role of immune response and inflammation in stroke pathogenesis, their role in the progression of injury during the stroke, and the emerging targets for the modulation of the mechanism of immune response and inflammation that may have possible therapeutic benefits against stroke.

Anti-rotavirus Properties and Mechanisms of Selected Gram-Positive and Gram-Negative Probiotics on Polarized Human Colonic (HT-29) Cells

Probiotics have been investigated to improve the universal rotavirus (RV) vaccination as well as to ameliorate the RV infection. However, underlying mechanisms how probiotics mediate beneficial effects needs more investigation. Thus, in the present study, we used polarized HT-29 cells to assess the anti-RV properties of Gram-positive, (Lactobacillus acidophilus, Lacticaseibacillus rhamnosus GG, and Bifidobacterium subsp. Lactis Bb12) and Gram negative, (Escherichia coli Nissle 1917) probiotics and study their underlying mechanisms. Our results showed that pre-treatment of HT-29 cells for 4 h with probiotics, significantly reduced (p < 0.05) human RV replication and this effect was most pronounced for E. coli Nissle followed by L. acidophilus and L. rhamnosus GG. Strikingly, only pre-treatment with live bacteria or their supernatants demonstrated anti-RV properties. Except Gram negative E. coli Nissle, the Gram-positive probiotics tested did not bind to RV. Ingenuity pathway analysis of tight junction (TJ)- and innate immune-associated genes indicated that E. coli Nissle or E. coli Nissle + RV treatments improved cell-cell adhesion and cell contact, while L. acidophilus or L. acidophilus + RV treatments also activated cell-cell contact but inhibited cell movement functions. RV alone inhibited migration of cells event. Additionally, E. coli Nissle activated pathways such as the innate immune and inflammatory responses via production of TNF, while RV infection activated NK cells and inflammatory responses. In conclusion, E. coli Nissle's ability to bind RV, modulate expression of TJ events, innate immune and inflammatory responses, via specific upstream regulators may explain superior anti-RV properties of E. coli Nissle. Therefore, prophylactic use of E. coli Nissle might help to reduce the RV disease burden in infants in endemic areas.

American-Asian- and African lineages of Zika virus induce differential pro-inflammatory and Interleukin 27-dependent antiviral responses in human monocytes

Zika virus (ZIKV) is an arbovirus that belongs to the Flaviviridae family and inflammatory responses play a critical role in ZIKV pathogenesis. As a first-line defense, monocytes are key components of innate immunity and host response to viruses. Monocytes are considered the earliest blood cell type to be infected by ZIKV and have been shown to be associated with ZIKV pathogenesis. The first ZIKV epidemic was reported in Africa and Asia although, it is less well known whether African- and Asian- lineages of ZIKV have different impacts on host immune response. We studied the pro-inflammatory and antiviral response of ZIKV-infected monocytes using publicly available RNA-seq analysis (GSE103114). We compared the transcriptomic profiles of human monocytes infected with ZIKV Puerto Rico strain (PRVABC59), American-Asian lineage, and ZIKV Nigeria strain (IBH30656), African lineage. We validated RNA-seq results by ELISA or RT-qPCR, in human monocytes infected with a clinical isolate of ZIKV from Colombia (American-Asian lineage), or with ZIKV from Dakar (African lineage). The transcriptomic analysis showed that ZIKV Puerto Rico strain promotes a higher pro-inflammatory response through TLR2 signaling and NF-kB activation and induces a strong IL27-dependent antiviral activity than ZIKV Nigeria strain. Furthermore, human monocytes are more susceptible to infection with ZIKV from Colombia than ZIKV from Dakar. Likewise, Colombian ZIKV isolate activated IL27 signaling and induced a robust antiviral response in an IFN-independent manner. Moreover, we show that treatment of monocytes with IL27 results in decreased release of ZIKV particles in a dose-dependent manner with an EC50 =2.870 ng/mL for ZIKV from Colombia and EC50 =10.23 ng/mL to ZIKV from Dakar. These findings highlight the differential inflammatory response and antiviral activity of monocytes infected with different lineages of ZIKV and may help better management of ZIKV-infected patients.

Nuclear access of DNlg3 c-terminal fragment and its function in regulating innate immune response genes

Neuroligins (NLGNs) are one of the autism susceptibility genes, however, the mechanism that how dysfunction of NLGNs leads to Autism remains unclear. More and more studies have shown that the transcriptome alteration may be one of the important factors to generate Autism. Therefore, we are very concerned about whether Neuroligins would affect transcriptional regulation, which may at last lead to Autism. As a single-transmembrane receptor, proteolytic cleavage is one of the most important posttranslational modifications of NLGN proteins. In this study, we demonstrated the existence of DNlg3 C-terminal fragment. Studies in the S2 cells and HEK293T cells showed the evidence for nuclear access of the DNlg3 C-terminal fragment. Then we identified the possible targets of DNlg3 C-terminal fragment after its nuclear access by RNA-seq. The bioinformatics analysis indicated the transcriptome alteration between dnlg3 null flies and wild type flies focused on genes for the innate immune responses. These results were consistent with the infection hypotheses for autism. Our study revealed the nuclear access ability of DNlg3 c-terminal fragment and its possible function in transcriptional regulation of the innate immune response genes. This work provides the new links between synaptic adhesion molecule NLGNs and immune activation, which may help us to get a deeper understanding on the relationship between NLGNs and Autism.

Modeling senecavirus a replication in immortalized porcine alveolar macrophages triggers a robust interferon-mediated immune response that conversely constrains viral replication

Senecavirus A (SVA) is a newly emerging causative agent of vesicular diseases in swine characterized with wide genetic diversity and rapid evolution. The lack of immunologically active cell culture model impedes the study of SVA-specific innate immunity. Here, an immortalized porcine alveolar macrophages 3D4/21 strongly and productively supported replication of two SVA strains. To elaborate global and dynamic host immune response, we demonstrated that 3D4/21 intrinsically expressed canonical ISGs which were important for pre-empting viral infection. Moreover, 3D4/21 were constitutively abundant in RIG-I-like receptors (RLRs) RIG-I and MDA5 necessary for sensing RNA virus infection, thereby enabling 3D4/21 cells to establish persistent and efficient antiviral status, in particular the most dramatic and sustained expression of type I/II interferons and inflammatory and innate immune genes critical for constraining SVA replication. Our study reveals a pivotal regulatory connection between virus and host that points to the SVA pathogenesis and potential vaccine development.

Tools to Investigate the Peroxisome-Dependent Antiviral Response

The importance of peroxisomes in the context of viral infections has been increasingly demonstrated in recent years. The discovery that MAVS localizes at peroxisomes and that peroxisomal and mitochondrial MAVS perform complementing functions within the antiviral response has raised the interest in studying the peroxisome-dependent signaling in the context of infection by different viruses. To that end, specific experimental procedures should be applied, taking into consideration the endogenous localization of MAVS at both organelles. The analysis of peroxisomal MAVS activation requires, hence, the preliminar generation and validation of cell lines where MAVS localizes solely at peroxisomes, as well as other specific cellular tools. Here, we present a detailed protocol to analyse the peroxisome-dependent antiviral response, using virus-specific and virus-unspecific stimuli.

Pattern recognition receptor mediated innate immune response requires a Rif-dependent pathway

Small GTPases play critical roles in cell morphology, movement, and adhesion by dynamic regulation of actin cytoskeleton. The small Rho GTPase Rif/RhoF (Rho in filopodia) regulates the formation of filopodia and stress fibers in cells. Rif is highly expressed in a number of cell types in the immune system; however, it's role in immune system function is unclear. In this research, we found that Rif expression is necessary for NF-κB activation in primary immune cells, and mature dendritic cell (mature DCs) induced from Bone Marrow-Derived Dendritic Cells (BMDCs) isolated from Rif knock out (Rif KO) mice displayed impaired degradation of I-κBα, as well as reduced TNF-α secretion and p38 MAPK phosphorylation under LPS stimulation. Interestingly, we revealed that TLR agonists, such as LPS and poly (I:C), as well as bacterial virulence factor SopE could induce a transient increase in Rif activation in monocytes THP-1 cells. Furthermore, Rif was found to be an integral part of the TLR4, TLR3 and nodosome signaling complex. We further identified Src tyrosine kinases as upstream activator of Rif in both bacterial and viral induced immune responses. Moreover, activated Rif induces activation of transcription factors, such as NF-κB, AP-1 and IRF-3, and mediates inflammation through secretion of IL-6, IL-8 or TNFα. Rif activation by PRRs contributes in a variety of ways to protective host responses against invading microbes. Taken together, this study reveals that Rif is indispensable for both extracellular and intracellular pattern-recognition receptor-mediated innate immune responses. Rif possess broad anti-pathogenic effect and understanding of the molecular mechanisms by which this small Rho GTPase interferes with innate immune system will be beneficial to develop therapies against infectious agents.

The acute phase response in bats (Carollia perspicillata) varies with time and dose of the immune challenge

The acute phase response (APR) is a core component of the innate immune response and represents the first line of immune defense used in response to infections. Although several studies with vertebrates reported fever, a decrease in food intake and body mass, and an increase in neutrophil/lymphocyte ratio and total white blood cell count after lipopolysaccharide (LPS) inoculation, there was great variability in the magnitude of these responses. Some of these differences might reflect, to some extent, differences in the time of endotoxin inoculation (during active or rest periods) and dose. Therefore, our study tested the interplay between LPS dose and time of injection on selected physiological (fever and increase in total white blood cell count and neutrophil/lymphocyte ratio) and behavioral (food intake) components of the APR using a Neotropical fruit-eating bat (Carollia perspicillata) as a model organism. We predicted that LPS would trigger a dose- and time-dependent response in APR components. APR components were assessed in rest and active periods after injection of three doses of LPS (5, 10 and 15 mg kg-1 LPS). The results indicate a more robust decrease in food intake at higher doses during the active period, while increased neutrophil/lymphocyte ratio was more robust during the active period regardless of dose. Furthermore, the skin temperature increase lasted longer at higher doses regardless of the timing of injections. Our study offers important insights into the dependence of time as well as the LPS dosage effect in the APR of bats, and how they deal with the magnitude of infections at different times of day.

Innate Immune Response in Orthopedic Implant Failure

The total joint replacement is recognized as one of the most effective medical arbitrations leading to increased mobility, pain relief, and an overall restored function of the joint. Unfortunately, prosthetic debris accumulates after long-term wear of the implant leading to activation of the innate immune response and periprosthetic osteolysis. Understanding the intricate biological mechanisms underlying the innate immune response to implant debris would support the development of novel pharmacological treatments to prolong the life span of the implant. This article provides a detailed description on the role of the innate immune system in response to implant debris, emphasizing the most recent research and outstanding questions. Furthermore, a critical discussion is presented on the novel pharmacological treatments currently under investigation to prevent implant failure.

Bioaccumulation of trace metal elements and biomarker responses in caged juvenile flounder at a polluted site: Effects of fish density and time exposure

This study investigates the effect of fish density and exposure duration on trace metal elements (TME) bioaccumulation and several biomarkers response. Juvenile flounders were caged at low, medium and high densities and exposed during 15 or 30 days in the Seine estuary. The concentrations of the TME measured in the muscle of the caged fish were all in agreement with their bioavailability percentage in the sediments. Higher concentrations of TME were found in flounders' muscle exposed for 15 days compared with those caged for 30 days. For the same exposure time, the density of fish had no effect on the accumulation of the TME in the flounders' muscle. Biomarkers responses varied according to density and duration of exposure. Special care should be taken in their interpretation. We underline that for an optimal assessment of TME pollution in the field, 15 days with low densities of fish per cage are sufficient.

Infection, pathology and interferon treatment of the SARS-CoV-2 Omicron BA.1 variant in juvenile, adult and aged Syrian hamsters

The new predominant circulating SARS-CoV-2 variant, Omicron, can robustly escape current vaccines and neutralizing antibodies. Although Omicron has been reported to have milder replication and disease manifestations than some earlier variants, its pathogenicity in different age groups has not been well elucidated. Here, we report that the SARS-CoV-2 Omicron BA.1 sublineage causes elevated infection and lung pathogenesis in juvenile and aged hamsters, with more body weight loss, respiratory tract viral burden, and lung injury in these hamsters than in adult hamsters. Juvenile hamsters show a reduced interferon response against Omicron BA.1 infection, whereas aged hamsters show excessive proinflammatory cytokine expression, delayed viral clearance, and aggravated lung injury. Early inhaled IFN-α2b treatment suppresses Omicron BA.1 infection and lung pathogenesis in juvenile and adult hamsters. Overall, the data suggest that the diverse patterns of the innate immune response affect the disease outcomes of Omicron BA.1 infection in different age groups.

Eight TRIM32 isoforms from oriental river prawn Macrobrachium nipponense are involved in innate immunity during white spot syndrome virus infection

Tripartite motif (TRIM) proteins comprise a large family of RING-type ubiquitin E3 ligases that regulate important biological processes. In this study, full-length MnTRIM32 cDNA was obtained from oriental river prawn Macrobrachium nipponense, and eight MnTRIM32 isoforms generated by alternative splicing were identified. The open reading frames of the eight MnTRIM32 isoforms were predicted to be separately composed of 402, 346, 347, 346, 414, 358, 359, and 358 amino acid residues. Protein structural analysis revealed that all MnTRIM32 isoforms contained a RING domain and a coiled coil region. MnTRIM32 was ubiquitously expressed in all tissues tested, with the highest expression in the hepatopancreas. The mRNA levels of MnTRIM32 in the gills, stomach, and intestine of prawns were found to undergo time-dependent enhancement following white spot syndrome virus (WSSV) stimulation. Double-stranded RNA interference studies revealed that MnTRIM32 silencing significantly downregulated the expression levels of interferon (IFN) regulatory factor MnIRF, IFN-like factor MnVago4, and tumor necrosis factor MnTNF. Furthermore, knockdown of MnTRIM32 in WSSV-challenged prawns increased the expression of VP28 and the number of WSSV copies, suggesting that MnTRIM32 plays a positive role in limiting WSSV infection. These findings provided strong evidence for the important role of MnTRIM32 in the antiviral innate immunity of M. nipponense.

Impact of sleep restriction in B-1 cells activation and differentiation

B-1 lymphocytes are a subtype of B cells with functional and phenotypic features that differ from conventional B lymphocytes. These cells are mainly located in mice's pleural and peritoneal cavities and express unconventional B cell surface markers. B-1 cells participate in immunity by producing antibodies, cytokines, and chemokines and physically interacting with other immune cells. In addition, B-1 cells can differentiate into mononuclear phagocyte-like cells and phagocytize several pathogens. However, the activation and differentiation of B-1 cells are not entirely understood. It is known that several factors can influence B-1 cells, such as pathogens components and the immune response. This work aimed to evaluate the influence of chronic stress on B-1 cell activation and differentiation into phagocytes. The experimental sleep restriction was used as a stress model since the sleep alteration alters several immune cells' functions. Thus, mice were submitted to sleep restriction for 21 consecutive days, and the activation and differentiation of B-1 cells were analyzed. Our results demonstrated that B-1 cells initiated the differentiation process into mononuclear phagocytes after the period of sleep restriction. In addition, we detected a significant decrease in lymphoid lineage commitment factors (EBF, E2A, Blnk) (*P < 0.05) and an increase in the G-CSFR gene (related to the myeloid lineage commitment factor) (****P < 0.0001), as compared to control mice no submitted to sleep restriction. An increase in the co-stimulatory molecules CD80 and CD86 (**P < 0.01 and *P < 0.05, respectively) and a higher production of nitric oxide (NO) (*P < 0.05) and reactive oxygen species (ROS) (*P < 0.05) were also observed in B-1 cells from mice submitted to sleep restriction. Nevertheless, B-1 cells from sleep-restricted mice showed a significant reduction in the Toll-like receptors (TLR)-2, -6, and -9, and interleukine-10 (IL-10) cytokine expression (***P < 0.001) as compared to control. Sleep-restricted mice intraperitoneally infected withL. amazonensispromastigotes showed a reduction in the average internalized parasites (*P < 0.05) by B-1 cells. These findings suggest that sleep restriction interferes with B-1 lymphocyte activation and differentiation. In addition, b-1 cells assumed a more myeloid profile but with a lower phagocytic capacity in this stress condition.

Keap 1: The new Janus word on the block

Here we draw insights from the latest serendipitous findings made on the opposing roles of a proposed drug-target protein Keap1. We weigh up how natural reactive electrophiles and electrophilic small-molecule drugs in clinical use directly impinge on seemingly conflicting, yet both Keap1-electrophile-modification-dependent, cell-survival- vs. cell-death-promoting behaviors. In the process, we convey how understanding reactive chemical-signal regulation at the single-protein-specific level is an enabling necessity in deconstructing otherwise intricate reactive-small-molecule-responsive cellular pathways. We hope this opinion piece further spurs the broader interests of basic and pharmaceutical research communities toward better understanding of molecular mechanisms underpinning reactive small-molecule-regulated signaling subsystems.

Natural medicine HLXL targets multiple pathways of amyloid-mediated neuroinflammation and immune response in treating alzheimer's disease

BACKGROUND

Based on the complex pathology of AD, a single chemical approach may not be sufficient to deal simultaneously with multiple pathways of amyloid-tau neuroinflammation. A polydrug approach which contains multiple bioactive components targeting multiple pathways in AD would be more appropriate. Here we focused on a Chinese medicine (HLXL), which contains 56 bioactive natural products identified in 11 medicinal plants and displays potent anti-inflammatory and immuno-modulatory activity.

HYPOTHESIS/PURPOSE

We investigated the neuroimmune and neuroinflammation mechanisms by which HLXL may attenuate AD neuropathology. Specifically, we investigated the effects of HLXL on the neuropathology of AD using both transgenic mouse models as well as microglial cell-based models.

STUDY DESIGN

The 5XFAD transgenic animals and microglial cell models were respectively treated with HLXL and Aβ42, and/or lipopolysaccharide (LPS), and then analyzed focusing on microglia mediated Aβ uptake and clearance, as well as pathway changes.

METHODS

We showed that HLXL significantly reduced amyloid neuropathology by upregulation of microglia-mediated phagocytosis of Aβ both in vivo and in vitro. HLXL displayed multi-modal mechanisms regulating pathways of phagocytosis and energy metabolism.

RESULTS

Our results may not only open a new avenue to support pharmacologic modulation of neuroinflammation and the neuroimmune system for AD intervention, but also identify HLXL as a promising natural medicine for AD.

CONCLUSION

It is conceivable that the traditional wisdom of natural medicine in combination with modern science and technology would be the best strategy in developing effective therapeutics for AD.

Small-molecule screening of ribonuclease L binders for RNA degradation

Small molecules targeting the ubiquitous latent ribonuclease (RNase L), which has limited sequence specificity toward single-stranded RNA substrates, hold great potential to be developed as broad-spectrum antiviral drugs by modulating the RNase L-mediated innate immune responses. The recent development of proximity-inducing bifunctional molecules, as described in the strategy of ribonuclease targeting chimeras, demonstrated that small-molecule RNase L activators can function as the essential RNase L-recruiting component to design bifunctional molecules for targeted RNA degradation. However, only a single screening study on small-molecule RNase L activators with poor potency has been reported to date. Herein, we established a FRET assay and conducted a screening of 240,000 small molecules to identify new RNase L activators with improved potency. The extremely low hit rate of less than 0.03% demonstrated the challenging nature of RNase L activation by small molecules available from current screening collections. A few hit compounds induced enhanced thermal stability of RNase L upon binding, although validation assays did not lead to the identification of compounds with significantly improved RNase L activating potency. The sulfonamide compound 17 induced a thermal shift of ~ 0.9 °C upon binding to RNase L, induced significant apoptosis in cancer cells, and showed single-digit micromolar inhibitory activity against cancer cell proliferation. This study paves the way for future structural optimization for the development of small-molecule RNase L binders.

On virus and nanomaterials - Lessons learned from the innate immune system - ACE activation in the invertebrate model Enchytraeus crypticus

Current human research on COVID-19 - SARS-CoV-2 (Severe Acute Respiratory Syndrome-Corona Virus) showed that ACE2 (Angiotensin Converting Enzyme 2) is a functional receptor to which the spike proteins attach. Invertebrates have been exposed to a wide array of threats for millennia and their immune system has evolved to deal with these efficiently. The annelid Enchytraeus crypticus, a standard ecotoxicological species, is an invertebrate species where extensive mechanisms of response studies are available, covering all levels from gene to population responses. Nanomaterials (NMs) are often perceived as invaders (e.g. virus) and can enter the cell covered by a corona, triggering similar responses. We created a database on E. crypticus ACE gene expression, aiming to analyse the potential knowledge transfer between invertebrates and vertebrates. Total exposure experiments sum 87 stress conditions for 18 different nanomaterials (NMs). ACE expression following TiO₂ NM exposure was clearly different from other NMs showing a clear (6-7 fold) ACE down-regulation, not observed for any other NMs. Other NMs, notably Ag NMs, and to some extent Cu NMs, caused ACE up-regulation (up to 4 fold). The extensive knowledge from response to NMs can support the immuno-research community, especially to develop therapies for virus that trigger the innate immune system.