Wolbachia mediates crosstalk between miRNA and Toll pathways to enhance resistance to dengue virus in Aedes aegypti.

The obligate endosymbiont Wolbachia induces pathogen interference in the primary disease vector Aedes aegypti, facilitating the utilization of Wolbachia-based mosquito control for arbovirus prevention, particularly against dengue virus (DENV). However, the mechanisms underlying Wolbachia-mediated virus blockade have not been fully elucidated. Here, we report that Wolbachia activates the host cytoplasmic miRNA biogenesis pathway to suppress DENV infection. Through the suppression of the long noncoding RNA aae-lnc-2268 by Wolbachia wAlbB, aae-miR-34-3p, a miRNA upregulated by the Wolbachia strains wAlbB and wMelPop, promoted the expression of the antiviral effector defensin and cecropin genes through the Toll pathway regulator MyD88. Notably, anti-DENV resistance induced by Wolbachia can be further enhanced, with the potential to achieve complete virus blockade by increasing the expression of aae-miR-34-3p in Ae. aegypti. Furthermore, the downregulation of aae-miR-34-3p compromised Wolbachia-mediated virus blockade. These findings reveal a novel mechanism by which Wolbachia establishes crosstalk between the cytoplasmic miRNA pathway and the Toll pathway via aae-miR-34-3p to strengthen antiviral immune responses against DENV. Our results will aid in the advancement of Wolbachia for arbovirus control by enhancing its virus-blocking efficiency.

A mechanical-assisted post-bioprinting strategy for challenging bone defects repair.

Bioprinting that can synchronously deposit cells and biomaterials has lent fresh impetus to the field of tissue regeneration. However, the unavoidable occurrence of cell damage during fabrication process and intrinsically poor mechanical stability of bioprinted cell-laden scaffolds severely restrict their utilization. As such, on basis of heart-inspired hollow hydrogel-based scaffolds (HHSs), a mechanical-assisted post-bioprinting strategy is proposed to load cells into HHSs in a rapid, uniform, precise and friendly manner. HHSs show mechanical responsiveness to load cells within 4 s, a 13-fold increase in cell number, and partitioned loading of two types of cells compared with those under static conditions. As a proof of concept, HHSs with the loading cells show an enhanced regenerative capability in repair of the critical-sized segmental and osteoporotic bone defects in vivo. We expect that this post-bioprinting strategy can provide a universal, efficient, and promising way to promote cell-based regenerative therapy.

Differential detection of H1N1 virus spiker proteins by two hexaphenylbutadiene isomers based on size-matching principle.

As one of the high pathogenic influenza viruses, H1N1 virus easily induces to serious diseases, even leading to death. To date, all detection methods for H1N1 virus had shortcomings, including high equipment cost, time consumption, and etc. Therefore, a novel detection method should be established to achieve more convenient, rapid, and low-cost detection. In this work, an isomer of HPBmN-I with aggregation-induced emission characteristic was firstly synthesized on the basis of our previous reported HPBpN-I. The results showed that HPBmN-I only selectively binds to N1 in the presence of H1, while HPBpN-I can exhibit total fluorescence response to H1 and N1 in H1/N1 mixture. The limited of detection (LOD) of HPBmN-I to N1 was estimated to be 20.82 ng/mL in normal saline (NS) according to the IUPAC-based approach. The simulation calculations based on molecular docking revealed that four HPBmN-I molecules combine well with the hydrophobic cavity of N1 and achieve the fluorescence enhancement due to size matching with each other. The combination of HPBpN-I and HPBmN-I as probes was successfully used to quantitatively detect H1 and N1 in real H1N1 virus. Compared to enzyme-linked immunosorbent assay (ELISA) method, the established method not only showed the same detection accuracy but also had the advantages of real-time, ease of preparation, and low-cost, demonstrating potential market prospects.

Association of Atrial Fibrillation with Remote Intracerebral Hemorrhage After Intravenous Thrombolysis: Results from a Multicenter Study in China.

INTRODUCTION: This study aimed to investigate the association between atrial fibrillation (AF), particularly newly diagnosed AF, and remote intracerebral hemorrhage (rICH) in patients with ischemic stroke who were treated with intravenous thrombolysis (IVT). METHODS: This observational study was conducted on patients with ischemic stroke who received IVT with recombinant tissue-type plasminogen activator. The data were taken from a multicenter prospective registry of a Chinese population. rICH was defined as any extraischemic hemorrhage detected on computerized tomography (CT) 24 h after intravenous thrombolysis. We collected and compared the demographic data and clinical characteristics of all the patients with rICH to those of patients without any type of hemorrhagic transformation. The association between AF and rICH was analyzed using univariate analysis and binary logistic regression. RESULTS: A total of 20,697 patients were included in the study, with 1566 (7.6%) experiencing intracerebral hemorrhage (ICH), 586 (2.8%) experiencing rICH, and 19,131 (92.4%) not experiencing any form of hemorrhagic transformation. Univariate analysis revealed significant differences in age, pre-thrombolysis systolic blood pressure, baseline National Institute of Health Stroke Scale score, previously known AF, newly diagnosed AF, coronary heart disease, congestive heart failure, hyperhomocysteinemia, and history of thrombolysis between the rICH and control groups (P < 0.05). Further multivariate logistic regression analysis indicated that total AF (OR 1.821, 95% CI 1.082-3.065, P < 0.05), previously known AF (OR 1.470, 95% CI 1.170-1.847), and newly diagnosed AF (OR 1.920, 95% CI 1.304-2.825) were independently associated with rICH. CONCLUSIONS: This study suggests that AF, regardless of whether it is newly diagnosed or previously known, may be associated with the occurrence of rICH following intravenous thrombolysis. Interestingly, our findings suggest that newly diagnosed AF may have a stronger impact on rICH than previously known AF, although confirmation from more studies is needed.

Effects of emergency medical services on timely treatment and outcome in stroke patients with intravenous thrombolysis among the severity of neurologic deficits: A retrospective observational study.

Whether emergency medical service (EMS) improves the outcome of acute ischemic stroke (AIS) patients after intravenous thrombolysis (IVT) is still unknown among the severity of neurologic deficits. This study is to investigate the impact of EMS use on timely treatment and outcomes of AIS with IVT. This is a retrospective observational study. Clinical data after IVT from January 2017 to May 2020 were retrospectively analyzed, including onset-to-needle time (ONT), onset-to-door time (ODT). The patients were divided into EMS and non-EMS groups according to the method of admission. A good outcome was defined as a modified Rankin scale score of ≤2 at 3 months. The severity of neurological deficits was assessed using the national institutes of health stroke scale. A total of 2303 patients were analyzed (906 [(39.3%] female; mean age, 68 ±â€…13 year), and 1028 (44.6%) patients were transported by EMS and 1418 (67.9%) patients achieved good outcome. Among all patients, compared with non-EMS patients, EMS patients had shorter ONT (148 minutes vs 155 minutes, P = .002) and ODT (95 minutes vs 104 minutes, P < .001), but lower rate of good outcome (61.7% vs 73.0%, P < .001). The multivariate analysis showed that the use of EMS was negatively associated with ONT (ρ = -0.041, P = .048) and ODT (ρ = -0.051, P = .014). Among moderate to severe stroke patients, EMS was related with good outcome independently (OR: 3.101, 95%CI: 1.367-7.038, P = .007). In ischemic stroke, EMS can shorten the pre-hospital delay. Among moderate to severe stroke patients, EMS can further improve the outcome. But the study needs further validation.

A standalone incompatible insect technique enables mosquito suppression in the urban subtropics.

The strong suppression of Aedes albopictus on two Guangzhou islands in China has been successfully achieved by releasing males with an artificial triple-Wolbachia infection. However, it requires the use of radiation to sterilize residual females to prevent population replacement. To develop a highly effective tool for dengue control, we tested a standalone incompatible insect technique (IIT) to control A. albopictus in the urban area of Changsha, an inland city where dengue recently emerged. Male mosquitoes were produced in a mass rearing facility in Guangzhou and transported over 670 km under low temperature to the release site. After a once-per-week release with high numbers of males (phase I) and a subsequent twice-per-week release with low numbers of males (phase II), the average numbers of hatched eggs and female adults collected weekly per trap were reduced by 97% and 85%, respectively. The population suppression caused a 94% decrease in mosquito biting at the release site compared to the control site. Remarkably, this strong suppression was achieved using only 28% of the number of males released in a previous trial. Despite the lack of irradiation to sterilize residual females, no triple-infected mosquitoes were detected in the field post release based on the monitoring of adult and larval A. albopictus populations for two years, indicating that population replacement was prevented. Our results support the feasibility of implementing a standalone IIT for dengue control in urban areas.

Paroxysmal speech disorder as the initial symptom in a young adult with anti-N-methyl-D-aspartate receptor encephalitis: A case report.

BACKGROUND: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable but frequently misdiagnosed autoimmune disease. Speech dysfunction, as one of the common manifestations of anti-NMDAR encephalitis, is usually reported as a symptom secondary to psychiatric symptoms or seizures rather than the initial symptom in a paroxysmal form. We report a case of anti-NMDAR encephalitis with paroxysmal speech disorder as a rare initial manifestation, and hope that it will contribute to the literature. CASE SUMMARY: A 39-year-old man with anti-NMDAR encephalitis initially presented with paroxysmal nonfluent aphasia and was misdiagnosed with a transient ischemic attack and cerebral infarction successively. The patient subsequently presented with seizures, but no abnormalities were found on brain magnetic resonance imaging or electroencephalogram. Cerebrospinal fluid (CSF) analysis revealed mild pleocytosis and increased protein levels. Anti-NMDAR antibodies in serum and CSF were detected for a conclusive diagnosis. After immunotherapy, the patient made a full recovery. CONCLUSION: This case suggests that paroxysmal speech disorder may be the presenting symptom of anti-NMDAR encephalitis in a young patient.

Development of Graphene-Based Materials in Bone Tissue Engineaering.

Bone regeneration-related graphene-based materials (bGBMs) are increasingly attracting attention in tissue engineering due to their special physical and chemical properties. The purpose of this review is to quantitatively analyze mass academic literature in the field of bGBMs through scientometrics software CiteSpace, to demonstrate the rules and trends of bGBMs, thus to analyze and summarize the mechanisms behind the rules, and to provide clues for future research. First, the research status, hotspots, and frontiers of bGBMs are analyzed in an intuitively and vividly visualized way. Next, the extracted important subjects such as fabrication techniques, cytotoxicity, biodegradability, and osteoinductivity of bGBMs are presented, and the different mechanisms, in turn, are also discussed. Finally, photothermal therapy, which is considered an emerging area of application of bGBMs, is also presented. Based on this approach, this work finds that different studies report differing opinions on the biological properties of bGBMS due to the lack of consistency of GBMs preparation. Therefore, it is necessary to establish more standards in fabrication, characterization, and testing for bGBMs to further promote scientific progress and clinical translation.

The Effect of Tissue Stromal Vascular Fraction as Compared to Cellular Stromal Vascular Fraction to Treat Anal Sphincter Incontinence.

BACKGROUND: The long-term prognosis of current treatments for anal sphincter incontinence (ASI) is poor. Here, we explored the efficacy of tissue adipose stromal vascular fraction SVF (tSVF) on ASI and compared it to that of cellular SVF (cSVF). We then investigated possible mechanisms. METHODS: Rat cSVF and tSVF were isolated and labeled with DIL. One day after modeling, three groups received phosphate-buffered saline (PBS), cSVF, tSVF, respectively. The control group received nil modeling nor any treatments. The effect was assessed by function test for anal pressure and electromyography, and staining for fiber content, proliferation and differentiation at day 5 and day 10. RESULTS: cSVF injection resulted in faster healing than tSVF. The cSVF group showed significant improvement on anal pressure on day 10. For the electromyography test, cSVF showed significant improvement for the frequencies on day 10, and for the peak values on both time points, while tSVF showed significant improvement for the peak values on day 10. The two SVF both alleviated fibrosis. Immunofluorescence tracing identified differentiation of some injected cells towards myosatellite cells and smooth muscle cells in both SVF groups. For all the tests, the tSVF group tends to have similar or lower effects than the cSVF group with no significant difference. CONCLUSION: cSVF and tSVF are both safe and effective in treating ASI, while the effect of cSVF is slighter higher than tSVF.

The complete mitochondrial genome of Sarcophaga tsinanensis (Diptera: Sarcophagidae).

Sarcophaga tsinanensis (Fan, 1964) (Diptera: Sarcophagidae), a species from subgenus Heteronychia. In this study, we report the complete mitochondrial genome (mitogenome) of S. tsinanensis. The length of this mitogenome was 14,972 bp in total, containing 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a non-coding control region. The arrangement of genes was the same as that of ancestral metazoan. Sarcophaga tsinanensis has a high nucleotide bias in A/T accounting for 76.80% of total nucleotides (A 39.9%, G 9.2%, C 13.9%, and T 36.9%). The result of phylogenetic analysis revealed that S. tsinanensis cluster together with species from the same subgenus Heteronychia, showing a clear monophyletic relationship. Sarcophaga tsinanensis is closely related to its sister species Sarcophaga depressifrons, Sarcophaga plotnikovi, and Sarcophaga shnitnikovi. This study provides the mitochondrial data of S. tsinanensis for further research on evolutionary relationships and species identification of flesh flies.

Post-salpingectomy interstitial heterotopic pregnancy after in vitro fertilization and embryo transfer: A case report.

BACKGROUND: Heterotopic pregnancy (HP) refers to the coexistence of ectopic pregnancy and intrauterine pregnancy. Salpingectomy is proposed as a pretreatment before in vitro fertilization and embryo transfer (IVF-ET) to reduce the risk of HP. HP after IVF-ET occurs in women who had already underwent bilateral salpingectomy, even though it is extremely rare. CASE SUMMARY: A case of a 29-year-old woman with recurrent interstitial HP after IVF-ET following salpingectomy is presented. The main symptom was a sudden and worsening pelvic pain. Physical examinations revealed signs of peritoneal bleeding and irritation with stable vital signs. Transvaginal ultrasound showed a live intrauterine pregnancy and another live embryo with cardiac activity in the left cornu extending beyond the lateral edge of the uterus. Her hemoglobin concentration was 8.0 g/dL, and serum human chorionic gonadotropin value was 171116.9 mIU/mL. With the diagnosis of ruptured HP with internal bleeding, an emergency laparoscopic resection of left cornu was performed. The interstitial pregnancy was removed with caution to protect the intrauterine pregnancy. After the surgical treatment, the intrauterine pregnancy continued with no complications. A healthy baby was delivered by caesarean section at 39 wk. Outcomes of another three cases are further summarized. CONCLUSION: Post-salpingectomy HP is a rare but challenging condition. Surgical treatment is preferred in the case with a viable intrauterine pregnancy.

The risk factors of autogenous arteriovenous fistula dysfunction in maintenance hemodialysis patients and the curative effect of personalized nursing.

OBJECTIVE: To explore the effect of individualized nursing intervention on autologous arteriovenous fistula (AVF) dysfunction and the risk factors leading to failures in maintenance hemodialysis (MHD) patients. METHODS: A total of 196 patients undergoing MHD in our hospital from March 2017 to May 2019 were recruited as the study cohort and divided into two groups according to the nursing method each patient underwent. The patients who underwent individualized nursing intervention were placed in the research group (RG, n = 107), and the patients who underwent routine nursing intervention were placed in the control group (CG, n = 89). The proportion of patients with primary dysfunction in the use of AVF was recorded, and the patients' psychological states, treatment compliance, and self-nursing abilities in the two groups before and after the nursing intervention were observed. The complications, the life treatment scores, and the patients' nursing satisfaction were recorded after the nursing intervention. A logistic regression analysis was performed for the patients with initial AVF dysfunction. RESULTS: Compared with the CG, the patients in the RG after the nursing intervention had statistically lower AVF dysfunction rates, notably lower SAS and SDS scores, remarkably higher total compliance rates and ESCA scores, and a dramatically lower total incidence of complications. AVF dysfunction occurred in 26 of 196 patients (13.4%) during the follow-up, with an increased risk of AVF loss in patients over 60 years old, lower blood pressure, higher hemoglobin concentrations, lower treatment compliance, self-care inability, and routine nursing interventions. After the nursing, the WHOQOL-BREF and nursing satisfaction scores in the RG were noticeably higher than they were in the CG. CONCLUSION: Autologous AVF dysfunction is the result of multiple risk factors, and personalized nursing can reduce the incidence of complications, improve patients' treatment compliance and self-care abilities, and ameliorate their quality of life.

Wolbachia Utilizes lncRNAs to Activate the Anti-Dengue Toll Pathway and Balance Reactive Oxygen Species Stress in Aedes aegypti Through a Competitive Endogenous RNA Network.

Long non-coding RNAs (lncRNA), a class of RNA molecules without protein coding potential, are more than 200 nucleotides in length and widely present in a variety of species. Although increasing progress in regard to the determination of lncRNA function has been made in vertebrates, Aedes aegypti lncRNAs were only identified recently and the functions of few lncRNAs have been annotated so far. Herein, the genome-wide alteration of the lncRNA expression profile trigged by Wolbachia wAlbB infection was investigated by comparing A. aegypti Aag2 cells and W-Aag2 cells infected with Wolbachia wAlbB. Based on lncRNA sequencing, 3035 differentially expressed lncRNAs (DE lncRNAs) in total were identified upon Wolbachia infection, which were further validated by quantitative PCR. The constructed co-expression network of DE lncRNAs and mRNAs revealed that Wolbachia-induced DE lncRNAs were highly enriched in the oxidative phosphorylation pathway via trans-activity, according to the KEGG pathway enrichment analyses. In addition, the established competitive endogenous RNA (ceRNA) network identifies the DE lncRNAs enriched in cellular oxidant detoxification based on GO enrichment analysis. Furthermore, silencing of aae-lnc-7598, the significantly up-regulated lncRNA with the highest fold change induced by Wolbachia, caused a significant reduction of antioxidant catalase 1B (CAT1B) gene expression as well as the enhancement of mitochondrial reactive oxygen species (ROS) production in living cells. These findings indicate that Wolbachia manipulates lncRNA to balance intracellular ROS stress and ensure its endosymbiosis in host A. aegypti. Notably, the function assay demonstrated that aae-lnc-0165 suppressed by Wolbachia could induce expression of the REL1 gene, the key regulator of downstream Toll pathway, through the sequence-specific binding of aae-miR-980-5p, which contributes to the activation of Toll pathway. Moreover, the depletion of aae-lnc-0165 caused the suppression of mitochondrial ROS levels in living cells. Our data reveal that Wolbachia activates the anti-dengue Toll pathway through a lncRNA-ceRNA pattern. Taken together, our finding suggested that Wolbachia utilizes lncRNAs to activate host anti-dengue Toll pathway via a ceRNA network. Moreover, Wolbachia employs lncRNAs to ensure ROS homeostasis for ROS-based anti-dengue defense through either trans-regulation or the ceRNA network. This study identifies novel potential molecular biomarkers for prevention and control of epidemic dengue.

Effect of continuous positive airway pressure on gastroesophageal reflux in patients with obstructive sleep apnea: a meta-analysis.

PURPOSE: Gastroesophageal reflux disease (GERD) often occurs in patients with obstructive sleep apnea (OSA). Although continuous positive airway pressure (CPAP) is considered to be the preferred treatment for OSA, the effect of CPAP therapy on reflux events remains controversial. In this study, we utilized meta-analysis to investigate whether or not CPAP treatment reduces the incidence of reflux. METHODS: Two independent reviewers obtained the data sources from the database of PubMed, Elsevier, Cochrane library, and CNKI using search terms, and then filtered the target articles based on the inclusion and exclusion criteria. RevMan (version 5.3) and STATA (version 12.0) were used for data synthesis. The effect of CPAP treatment on GERD was studied by calculating the weighted mean difference (WMD) and standard deviation (SD) before and after CPAP treatment. RESULTS: Ten studies involving a total of 272 participants were included in this study. The results showed that the total of WMD before and after CPAP was - 17.68 (95% CI - 30.67 to - 4.69) for percentage time pH < 4, - 24.66 (95% CI - 36.15 to - 13.18) for the longest reflux duration, - 27.53 (95% CI - 49.53 to - 5.52) for number of reflux events, - 49.76 (95% CI - 60.18 to - 39.35) for DeMeester score, - 1.85 (95% CI - 3.00 to - 0.71) for reflux diseases questionnaire (RDQ) score, and - 8.95 (95% CI - 16.00 to - 1.89) for reflux symptom index (RSI). The subgroup analysis demonstrated that the improvement of reflux symptoms was more obvious with the extension of treatment time. CONCLUSIONS: This meta-analysis showed that CPAP treatment significantly reduces the incidence of reflux events in patients with OSA.

The whole mitochondrial genome of Sarcophaga kanoi (Diptera: Sarcophagidae).

Sarcophaga kanoi Park, 1962, a widely distributed flesh fly in Southeast Asia, is important in forensic entomology. Notably, its mitochondrial genome could provide the unique and accurate molecular information in species identification which facilitate forensic practices in estimation of postmortem interval especially in putrefied cadaver cases. Thus, we sequenced and characterized the whole mitochondrial genome (mitogenome) of S. kanoi for the first time, which was collected from Southern China in this study. The 15,319 bp mitogenome contained 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and a putative control region. The total nucleotide composition of this circular genome was 39.7% for A, 9.3% for G, 14.2% for C, and 36.8% for T. To better understand the genetic relationship, the phylogenetic analysis was constructed according to the 13 PCGs sequence of S. kanoi and other 11 species. The phylogenetic tree showed that the S. kanoi was placed in a sub-clade with S. similis. Our study updated the new genetic information for dipteran mitogenomes, which could broaden the background knowledge for forensic entomology, molecular genetics and developmental biology. It has the potential application on the species identification using genetic markers.

The complete mitochondrial genome of Sarcophaga scopariiformis (Diptera: Sarcophagidae).

Sarcophaga scopariiformis (Diptera: Sarcophagidae), a potential vector of pathogens as well as one of the important flesh fly specie in forensic entomology. We have firstly sequenced and assembled the whole mitogenome of S. scopariiformis in this study. The circular mitogenome is 15,325 bp in length, consisting of A (39.3%), G (9.4%), T (36.8%), and C (14.5%). It showed in a typical mitochondrial genome similar to other sarcophagids species, which is composed of 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and a non-coding AT-rich region. Moreover, the phylogenetic analysis based on 13 PCGs has been conducted. The topological structure of the phylogenetic tree clearly indicated that S. scopariiformis was more closed to the species of Sarcophaga peregrina in genetic distance, compared to the other sarcophagids species. This study provided a useful data reference for genetic structure and phylogenetic analysis of Sarcophagidae.

Incompatible and sterile insect techniques combined eliminate mosquitoes.

The radiation-based sterile insect technique (SIT) has successfully suppressed field populations of several insect pest species, but its effect on mosquito vector control has been limited. The related incompatible insect technique (IIT)-which uses sterilization caused by the maternally inherited endosymbiotic bacteria Wolbachia-is a promising alternative, but can be undermined by accidental release of females infected with the same Wolbachia strain as the released males. Here we show that combining incompatible and sterile insect techniques (IIT-SIT) enables near elimination of field populations of the world's most invasive mosquito species, Aedes albopictus. Millions of factory-reared adult males with an artificial triple-Wolbachia infection were released, with prior pupal irradiation of the released mosquitoes to prevent unintentionally released triply infected females from successfully reproducing in the field. This successful field trial demonstrates the feasibility of area-wide application of combined IIT-SIT for mosquito vector control.

Molecular identification of the magnesium transport gene family in Brassica napus.

Magnesium (Mg2+) is an essential element for plant growth. Its transport and homeostasis in plants is mainly maintained by the MRS2/MGT of Mg2+ transporters. Little is known about the MRS2/MGT gene family in Brassica napus L. (B. napus), one of the most important oil grains. In our present study, we identified 36 putative MRS2/MGT genes (BnMGTs) from B. napus and investigated their phylogeny, expression pattern and function. These BnMGT genes were sorted into five distinguished groups by the phylogenetic analysis, and they were clearly homologous with the MRS2/MGT genes in Arabidopsis and rice. Complementation assays using the Salmonella typhimurium mutant MM281 demonstrated that the BnMGT genes were capable of mediating Mg2+ uptake and transport, with varied affinities to Mg2+. The expression pattern analysis showed that the expression of BnMGTs were tissue-specific and varied in different tissues. This work provides the molecular basis to discover the function of BnMGT gene family in plant growth and development.

The bacterium Wolbachia exploits host innate immunity to establish a symbiotic relationship with the dengue vector mosquito Aedes aegypti.

A host's immune system plays a central role in shaping the composition of the microbiota and, in return, resident microbes influence immune responses. Symbiotic associations of the maternally transmitted bacterium Wolbachia occur with a wide range of arthropods. It is, however, absent from the dengue and Zika vector mosquito Aedes aegypti in nature. When Wolbachia is artificially forced to form symbiosis with this new mosquito host, it boosts the basal immune response and enhances the mosquito's resistance to pathogens, including dengue, Zika virus and malaria parasites. The mechanisms involved in establishing a symbiotic relationship between Wolbachia and A. aegypti, and the long-term outcomes of this interaction, are not well understood. Here, we have demonstrated that both the immune deficiency (IMD) and Toll pathways are activated by the Wolbachia strain wAlbB upon its introduction into A. aegypti. Silencing the Toll and IMD pathways via RNA interference reduces the wAlbB load. Notably, wAlbB induces peptidoglycan recognition protein (PGRP)-LE expression in the carcass of A. aegypti, and its silencing results in a reduction of symbiont load. Using transgenic mosquitoes with stage-specific induction of the IMD and Toll pathways, we have shown that elevated wAlbB infection in these mosquitoes is maintained via maternal transmission. These results indicate that host innate immunity is utilized to establish and promote host-microbial symbiosis. Our results will facilitate a long-term projection of the stability of the Wolbachia-A. aegypti mosquito system that is being developed to control dengue and Zika virus transmission to humans.

The Maternally Inheritable Wolbachia wAlbB Induces Refractoriness to Plasmodium berghei in Anopheles stephensi.

The endosymbiont Wolbachia wAlbB induces refractoriness to Plasmodium falciparum in Anopheles stephensi, the primary mosquito vector of human malaria in the Middle East and South Asia. However, it remains unknown whether such refractoriness can be extended to other malaria species. In particular, it was reported that under very specific conditions, wAlbB can enhance Plasmodium infection in some hosts. Here, we measured the impact of wAlbB on the rodent malaria parasite Plasmodium berghei in A. stephensi by comparing the load of oocysts and sporozoites in midguts and salivary glands, respectively, between wAlbB-infected and -uninfected mosquitoes. To investigate whether wAlbB modulated mosquito immune defense against parasites, we compared the expression of the immune genes, which were previously reported to involve in antimalarial response, in both midguts and the remaining carcass tissues of mosquitoes. The stable association of wAlbB with A. stephensi resulted in reduction of parasites by more than half at the oocyst stage, and up to 91.8% at the sporzoite stage. The anti-plasmodium immune genes, including TEP1, LRIM1, Toll pathway gene Rel1 and the effector Defensin 1, were induced by wAlbB in different mosquito body tissues. These findings suggest that immune priming is a potential cause of wAlbB-mediated antimalarial response in A. stephensi. More importantly, no evidence was found for any enhancement of Plasmodium infection in A. stephensi stably infected with wAlbB. We discuss these findings with possible implementations of Wolbachia for malaria control in disease endemic areas.