Gut microbiota dysbiosis contributes to depression-like behaviors via hippocampal NLRP3-mediated neuroinflammation in a postpartum depression mouse model.

Postpartum depression (PPD) is a severe mental disorder that affects approximately 10---20% of women after childbirth. The precise mechanism underlying PPD pathogenesis remains elusive, thus limiting the development of therapeutics. Gut microbiota dysbiosis is considered to contribute to major depressive disorder. However, the associations between gut microbiota and PPD remain unanswered. Here, we established a mouse PPD model by sudden ovarian steroid withdrawal after hormone-simulated pseudopregnancy-human (HSP-H) in ovariectomy (OVX) mouse. Ovarian hormone withdrawal induced depression-like and anxiety-like behaviors and an altered gut microbiota composition. Fecal microbiota transplantation (FMT) from PPD mice to antibiotic cocktail-treated mice induced depression-like and anxiety-like behaviors and neuropathological changes in the hippocampus of the recipient mice. FMT from healthy mice to PPD mice attenuated the depression-like and anxiety-like behaviors as well as the inflammation mediated by the NOD-like receptor protein (NLRP)-3/caspase-1 signaling pathway both in the gut and the hippocampus, increased fecal short-chain fatty acids (SCFAs) levels and alleviated gut dysbiosis with increased SCFA-producing bacteria and reduced Akkermansia in the PPD mice. Also, downregulation of NLRP3 in the hippocampus mitigated depression-like behaviors in PPD mice and overexpression of NLRP3 in the hippocampal dentate gyrus induced depression-like behaviors in naïve female mice. Intriguingly, FMT from healthy mice failed to alleviate depression-like behaviors in PPD mice with NLRP3 overexpression in the hippocampus. Our results highlighted the NLRP3 inflammasome as a key component within the microbiota-gut-brain axis, suggesting that targeting the gut microbiota may be a therapeutic strategy for PPD.

Optimal Dose of Pituitrin in Laparoscopic Uterine Myomectomy: A Double-Blinded, Randomized Controlled Trial.

STUDY OBJECTIVE: To determine the optimal effective dose of pituitrin in laparoscopic myomectomy for uterine leiomyoma. DESIGN: Double-blinded, randomized controlled trial. SETTING: Tertiary women's hospital in China. PATIENTS: Total of 118 patients who underwent laparoscopic myomectomy. INTERVENTIONS: Patients randomly received 0, 2, 4, or 6 units of pituitrin injected into the myometrium surrounding the myoma. MEASUREMENTS AND MAIN RESULTS: Rate of satisfactory surgical condition, hemodynamic changes, total surgical time, and blood loss were recorded. The rates of satisfactory surgical conditions were 6.7%, 72.4%, 89.7%, and 93.3% in groups 0U, 2U, 4U, and 6U, respectively; they were higher in groups 2U, 4U, and 6U than those in group 0U, but there were no significant differences among the groups 2U, 4U, and 6U. The blood loss was higher in group 0U than that in groups 2U, 4U, and 6U (p < .01). Pituitrin was associated with a transient decrease in blood pressures and an increase in heart rate in a dose-dependent fashion, with more pronounced changes in groups 4U and 6U, and these groups also required a higher amount of vasoactive drug to correct hemodynamic changes (p < .05). CONCLUSION: Two units of pituitrin could provide a satisfactory surgical field with minimal hemodynamic changes for laparoscopic uterine myomectomy.

Photoplethysmography-derived approximate entropy and sample entropy as measures of analgesia depth during propofol-remifentanil anesthesia.

The ability to monitor the physiological effect of the analgesic agent is of interest in clinical practice. Nonstationary changes would appear in photoplethysmography (PPG) during the analgesics-driven transition to analgesia. The present work studied the properties of nonlinear methods including approximate entropy (ApEn) and sample entropy (SampEn) derived from PPG responding to a nociceptive stimulus under various opioid concentrations. Forty patients with ASA I or II were randomized to receive one of the four possible remifentanil effect-compartment target concentrations (Ceremi) of 0, 1, 3, and 5 ng·ml-1 and a propofol effect-compartment target-controlled infusion to maintain the state entropy (SE) at 50 ± 10. Laryngeal mask airway (LMA) insertion was applied as a standard noxious stimulation. To optimize the performance of ApEn and SampEn, different coefficients were carefully evaluated. The monotonicity of ApEn and SampEn changing from low Ceremi to high Ceremi was assessed with prediction probabilities (PK). The result showed that low Ceremi (0 and 1 ng·ml-1) could be differentiated from high Ceremi (3 and 5 ng·ml-1) by ApEn and SampEn. Depending on the coefficient employed in algorithm: ApEn with k = 0.15 yielded the largest PK value (0.875) whereas SampEn gained its largest PK of 0.867 with k = 0.2. Thus, PPG-based ApEn and SampEn with appropriate k values have the potential to offer good quantification of analgesia depth under general anesthesia.

Generation and immunogenicity of virus-like particles based on mink enteritis virus capsid protein VP2 expressed in Sf9 cells.

Mink enteritis virus (MEV) is a parvovirus that causes acute enteritis in mink. The capsid protein VP2 of MEV is a major immunogenicity that is important for disease prevention. In this study, this protein was expressed in Spodoptera frugiperda 9 cells using a recombinant baculovirus system and was observed to self-assemble into virus-like particles (VLPs) with a high hemagglutination (HA) titer (1:216). A single-dose injection of VLPs (HA titer, 1:256) resulted in complete protection of mink against virulent MEV challenge for at least 180 days. These data suggest that these MEV VLPs could be used as a vaccine for the prevention of viral enteritis in mink.

A randomised dose-response study of prophylactic Methoxamine infusion for preventing spinal-induced hypotension during Cesarean delivery.

BACKGROUND: α-receptor agonists have been reported to be safe and effective for treating or preventing spinal-induced hypotension during cesarean delivery. As a pure α1 adrenergic agonist, methoxamine has potential advantages of reducing myocardial oxygen consumption and protecting the heart in obstetric patients compared to phenylephrine. The aim of this study was to determine the optimal prophylactic methoxamine infusion dose that would be effective for preventing spinal-induced hypotension in 50% (ED50) and 95% (ED95) of parturients. METHODS: Eighty parturients with a singleton pregnancy scheduled for elective cesarean delivery were randomly allocated to receive prophylactic methoxamine infusion at one of four different fixed-rates: 1 µg/kg/min (group M1), 2 µg/kg/min (group M2), 3 µg/kg/min (group M3), or 4 µg/kg/min (group M4). An adequate response was defined as absence of hypotension (maternal SBP < 80% of baseline or SBP < 90 mmHg). The values for ED50 and ED95 of prophylactic methoxamine infusion were determined by probit regression model. The outcomes of maternal hemodynamics and fetal status were compared among the groups. RESULTS: The calculated ED50 and ED95 (95% confidence interval) of prophylactic methoxamine infusion dose were 2.178 (95% CI 1.564 to 2.680) µg/kg/min and 4.821 (95% CI 3.951 to 7.017) µg/kg/min, respectively. The incidence of hypotension decreased with increasing methoxamine infusion dose (15/20, 11/20, 7/20 and 2/20 in group M1, M2, M3 and M4 respectively, P <  0.001). 1-min Apgar scores and umbilical arterial PaO2 were lower but umbilical arterial PaCO2 was higher in Group M1. No difference was found in the other incidence of adverse effects and neonatal outcomes among groups. CONCLUSIONS: Under the conditions of this study, when prophylactic methoxamine infusion was given at a fixed-rate based on body weight for preventing spinal-induced hypotension in obstetric patients, the values for ED50 and ED95 were 2.178 µg/kg/min and 4.821 µg/kg/min respectively. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), registry number of clinical trial: ChiCTR-1,800,018,988 , date of registration: October 20, 2018.

The involvement of spinal annexin A10/NF-κB/MMP-9 pathway in the development of neuropathic pain in rats.

BACKGROUND: Neuropathic pain (NP) is a prevalent disease, which badly impairs the life quality of patients. The underlying mechanism of NP is still not fully understood. It has been reported that spinal Annexin A10 (ANXA10) contributes to NP. This study aims at exploring the underlying mechanisms of spinal ANXA10 in regulating NP in rats. METHODS: Spinal nerve ligation (SNL) was adopted to establish a NP model in rats. After SNL, paw withdrawal threshold and paw withdrawal latency were recorded to measure pain behaviors, RT-PCR was used to check the change of the expression of spinal ANXA10 mRNA, western blot analysis was used to detect the change of the protein level of ANXA10, nuclear factor kappa B (NF-κB), and maisrix metalloproteinase-9 (MMP-9) in the spinal cord. The levels of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukine-1ß (IL-1ß), and interleukine-6 (IL-6), were explored by ELISA kits. The effects of both knockdown of spinal ANXA10 and inhibition of NF-κB on pain behaviors and the expression of MMP-9 and proinflammatory cytokines were investigated. RESULTS: Our present findings highlighted that SNL caused pain hypersensitivity and increased the expression of spinal ANXA10/pNF-κB, TNF-α, IL-1ß, and IL-6 both in the early and late phase of NP in rats, while spinal MMP-9 was only slightly increased in the early phase of NP. Knockdown of ANXA10 at the spinal cord level suppressed the SNL-induced hyperalgesia and blocked the activation of NF-κB, TNF-α and IL-1ß both in the early and late phase of NP. Spinal ANXA10 knockdown could prevent the upregulation of spinal MMP-9 in the early phase and inhibit IL-6 expression in the late phase of SNL-induced NP. CONCLUSIONS: In conclusion, spinal ANXA10/NF-κB/MMP-9 pathway, along with the activation of proinflammatory cytokines, was involved in the SNL-induced NP. MMP-9 may act as the downstream target of ANXA10/NF-κB pathway in the development rather than the maintenance of NP.

Involvement of mGluR5 and TRPV1 in visceral nociception in a rat model of uterine cervical distension.

Metabotropic glutamate receptor 5 (mGluR5) and transient receptor potential vanilloid subtype 1 (TRPV1) have been shown to play critical roles in the transduction and modulation of cutaneous nociception in the central nervous system. However, little is known regarding the possible involvement of mGluR5 and TRPV1 in regulating visceral nociception from the uterine cervix. In this study, we used a rat model of uterine cervical distension to examine the effects of noxious stimuli to the uterine cervix on expression of spinal mGluR5 and TRPV1. Our findings included the following: (1) uterine cervical distension resulted in a stimulus-dependent increase in electromyographic, spinal c-Fos signal, and expression of mGluR5 and TRPV1 in the spinal cord; (2) intrathecal administration of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyri-dine significantly reduced the increased TRPV1 and c-Fos expression induced by uterine cervical distension; (3) the TRPV1 inhibitor SB-366791 inhibited increased spinal c-Fos expression but had no effect on the expression of mGluR5 in response to uterine cervical distension. Our findings indicate that the spinal mGluR5-TRPV1 pathway modulates nociceptive transmission in uterine cervical distension-induced pathological visceral pain.

Molecular identification of one event of Ds excision and re-insertion at two loci in rice genome.

The maize Ac/Ds transposable elements are members of the hAT transposon superfamily, and have stable transpositional activity in transgenic rice plants. Ac/Ds transposable elements are considered to transpose via a conservative non-replicative "cut and paste" model, though their transposition mechanism is not completely understood. Previous studies have shown that Ds preferentially transposes to genetically linked sites after being excised from its original site in the presence of Ac-transposase. In this study, genomic sequences flanking Ds insertions from a Ds-tagged rice mutant and its rever- tant were determined by TAIL-PCR. The Ds insertion site, the excision footprint and the re-insertion sites in the mutant were identified using bioinformatics tool. The results showed that Ds element excised from its original insertion site on chromosome 3 by leaving an 8 bp footprint (CATCATGA), which resulted in exon changes in tagged gene. After the excision, Ds element was re-inserted into the coding sequences of two genes on chromosome 2 and chromosome 6, which encode a nicotianamine aminotransferase and a senescence-associated protein, respectively. The transposition behavior of Ds element in this study could not be fully explained by the "cut and paste" mechanism, while it is likely to transpose in a "cut and copy and paste" way.

Immunogenicity evaluation of a bivalent vaccine based on a recombinant rabies virus expressing gB protein of FHV-1 in mice and cats.

Feline viral rhinotracheitis (FVR) is caused by the feline herpesvirus-1 (FHV-1), which commonly results in upper respiratory symptoms, and can result in death in the kittens and weak cats. Rabies is an infectious disease with zoonotic characteristics highly relevant to public health and also poses a serious threat to cats. Vaccines are the most effective method to control the spread of both FHV-1 and RABV and have the advantage that they produce long-term specific immune responses. In this study, we constructed a bivalent vaccine against FHV-1 and rabies virus (RABV) simultaneously. The vaccine was constructed by cloning FHV-1 gB into a RABV based vector, and the recombinant RABV (SRV9-FHV-gB) expressing the FHV-1 gB protein was rescued. The growth characteristics of SRV9-FHV-gB were analyzed on NA and BSR cells. To assess the immunogenicity of the vaccine, mice and cats were immunized with SRV9-FHV-gB supplemented with Gel02 adjuvant. The SRV9-FHV-gB exhibited the same growth characteristics as the parent virus SRV9 in both BSR cells and NA cells. The safety of SRV9-FHV-gB was evaluated using 5-day-old and 14-day-old suckling mice. The results showed that mice infected with the SRV9-FHV-gB survived for longer than those in the SRV9 group. Mice immunized with inactivated SRV9-FHV-gB produced high titers of specific antibodies against FHV-1 and neutralizing antibodies against RABV. Cats that received three immunizations with SRV9-FHV-gB also produced neutralizing antibodies against both FHV-1 and RABV. This study represents the first time that a bivalent vaccine targeting FHV-1 and RABV has been constructed, laying the foundations and providing inspiration for the development of other multivalent vaccines.

Activation of GABAergic neurons in the dorsal raphe nucleus alleviates hyperalgesia induced by ovarian hormone withdrawal.

ABSTRACT: Menopausal and postmenopausal women, characterized by a significant reduction in ovarian hormones, have a high prevalence of chronic pain with great pain intensity. However, the underlying mechanism of hyperalgesia induced by ovarian hormone withdrawal remains poorly understood. Here, we report that decreases in the activity and excitability of GABAergic neurons in the dorsal raphe nucleus (DRN) are associated with hyperalgesia induced by ovariectomy in mice. Supplementation with 17ß-estradiol, but not progesterone, is sufficient to increase the mechanical pain threshold in ovariectomized (OVX) mice and the excitability of DRN GABAergic (DRNGABA) neurons. Moreover, activation of the DRNGABA neurons projecting to the lateral parabrachial nucleus was critical for alleviating hyperalgesia in OVX mice. These findings show the essential role of DRNGABA neurons and their modulation by estrogen in regulating hyperalgesia induced by ovarian hormone withdrawal, providing therapeutic basis for the treatment of chronic pain in physiological or surgical menopausal women.

Three in one: An effective and universal vaccine expressing heterologous tandem RBD trimer by rabies virus vector protects mice against SARS-CoV-2.

The rapid emergence of Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2) variants, coupled with severe immune evasion and imprinting, has jeopardized the vaccine efficacy, necessitating urgent development of broad protective vaccines. Here, we propose a strategy employing recombinant rabies viruses (RABV) to create a universal SARS-CoV-2 vaccine expressing heterologous tandem receptor-binding domain (RBD) trimer from the SARS-CoV-2 Prototype, Delta, and Omicron strains (SRV-PDO). The results of mouse immunization indicated that SRV-PDO effectively induced cellular and humoral immune responses, and demonstrated higher immunogenicity and broader SARS-CoV-2 neutralization compared to the recombinant RABVs that only expressed RBD monomers. Moreover, SRV-PDO exhibited full protection against SARS-CoV-2 in the challenge assay. This study demonstrates that recombinant RABV expressing tandem RBD-heterotrimer as a multivalent immunogen could elicit a broad-spectrum immune response and potent protection against SARS-CoV-2, making it a promising candidate for future human or veterinary vaccines and offering a novel perspective in other vaccine design.

Distinguishing preeclampsia using the falling scaled slope (FSS) --- a novel photoplethysmographic morphological parameter.

BACKGROUND: Preeclampsia (PE) presence could lead to hemodynamic changes. Previous research suggested that morphological parameters based on photoplethysmographic pulse waves (PPGW) could help diagnose PE. AIM: To investigate the performance of a novel PPGPW-based parameter, falling scaled slope (FSS), in distinguishing PE. To investigate the advantages of the machine learning algorithm over the conventional statistical methods in the analysis. METHODS: Eighty-one pieces of PPGPW data were acquired for the study (PE, n = 44; normotensive, n = 37). The FSS values were calculated and used to construct a PE classifier using the K-nearest neighbors (KNN) algorithm. A predicted PE state varying from 0 to 1 was also calculated. The classifier's performance in distinguishing PE was evaluated using the ROC and AUC. A comparison was conducted with previously published PPGPW-based models. RESULT: Compared to the previous PPGPW-based parameters, FSS showed a better performance in distinguishing PE with an AUC value of 0.924, the best threshold of 0.498 could predict PE with a sensitivity of 84.1% and a specificity of 89.2%. As for the analysis method, training a classifier using the KNN algorithm had an advantage over the conventional statistical methods with the AUC values of 0.878 and 0.749, respectively. CONCLUSION: The result indicated that FSS might be an effective tool for identifying PE. Moreover, the machine learning algorithm could further help the data analysis and improve performance. [Figure: see text].

Comparison of the ED50 of prophylactic butorphanol in preventing morphine-induced pruritus with or without palonosetron: a prospective, double-blinded, randomized dose-response trial using an up-down sequential allocation method.

BACKGROUND: Butorphanol has been used to reduce the incidence and severity of neuraxial morphine-induced pruritus. Palonosetron is a commonly used antiemetic for the prevention of postoperative nausea and vomiting. The aim of our study was to compare the effective dose in 50% of subjects (ED50) of intravenous butorphanol infusion with or without a single intravenous bolus of palonosetron for preventing pruritus induced by epidural administration of morphine. METHODS: A total of 120 parturients were randomly assigned to receive an intravenous bolus injection of palonosetron plus continuous infusion of butorphanol (Group P + B) or an intravenous bolus of saline plus continuous infusion of butorphanol (Group B) after epidural administration of morphine. The antipruritic effect was graded as satisfactory (numerical rating scale (NRS) of pruritus ≤3) or unsatisfactory (NRS >3) within 48 h after morphine treatment. The first patient in each group received butorphanol infusion at a rate of 4 µg/kg/h. The infusion dose for each subsequent patient in the corresponding group was increased by 0.2 µg/kg/h after an unsatisfactory response or decreased by 0.2 µg/kg/h after a satisfactory response. The ED50 was calculated for each group and compared using up-down sequential analysis. RESULTS: The ED50 (mean [95% confidence interval (CI)]) of the dose of intravenous butorphanol infusion for preventing moderate to severe pruritus was lower in Group P + B (3.29 µg/kg/min [3.25-3.34 µg/kg/min]) than in Group B (3.57 µg/kg/min [3.47-3.67 µg/kg/min]) (p < 0.05). CONCLUSIONS: Under the conditions of the present study, a prophylactic use of 0.25 mg palonosetron reduced the ED50 of prophylactic infusion of butorphanol by approximately 8% to achieve a satisfactory antipruritic effect after epidural morphine for post-caesarean analgesia.

Divergent modulation of pain and anxiety by GABAergic neurons in the ventrolateral periaqueductal gray and dorsal raphe.

The ventrolateral periaqueductal gray (vlPAG) collaborates with the dorsal raphe (DR) in pain regulation and emotional response. However, the roles of vlPAG and DR γ-aminobutyric acid (GABA)-ergic neurons in regulating nociception and anxiety are contradictory and poorly understood. Here, we observed that pharmacogenetic co-activation of vlPAG and DR GABAergic (vlPAG-DRGABA+) neurons enhanced sensitivity to mechanical stimulation and promoted anxiety-like behavior in naïve mice. Simultaneous inhibition of vlPAG-DRGABA+ neurons showed adaptive anti-nociception and anti-anxiety effects on mice with inflammatory pain. Notably, vlPAGGABA+ and DRGABA+ neurons exhibited opposing effects on the sensitivity to mechanical stimulation in both naïve state and inflammatory pain. In contrast to the role of vlPAGGABA+ neurons in pain processing, chemogenetic inhibition and chronic ablation of DRGABA+ neurons remarkably promoted nociception while selectively activating DRGABA+ neurons ameliorated inflammatory pain. Additionally, utilizing optogenetic technology, we observed that the pronociceptive effect arising from DRGABA+ neuronal inhibition was reversed by the systemic administration of morphine. Our results collectively provide new insights into the modulation of pain and anxiety by specific midbrain GABAergic subpopulations, which may provide a basis for cell type-targeted or subregion-targeted therapies for pain management.

A bacterium-like particle vaccine displaying protective feline herpesvirus 1 antigens can induce an immune response in mice and cats.

Feline herpesvirus 1 (FHV-1) is a highly transmissible virus that mainly causes ocular and upper respiratory infections in cats and seriously threatens the health of domestic cats and captive or wild cats (such as tigers, cheetahs, and lions). Vaccination is crucial to reduce the incidence rate and mortality of cats infected with FHV-1. In this study, three bacterium-like particles (BLPs) displaying the gB, gC, and gD proteins of FHV-1 were constructed based on a gram-positive enhancer matrix-protein anchor (GEM-PA) surface display system. Indirect immunofluorescence assay, western blot, and electron microscopy results showed that gB, gC or gD protein of FHV-1 was successfully displayed on the surface of GEM particles. Additionally, we designed one more BLPs, designated gB&gC&gD-GEM, which consisted of a mixture of gB-GEM, gC-GEM, and gD-GEM at a protein content ratio of 1:1:1. Mice were immunized with the four BLPs mixed with Gel02 adjuvant, and the results indicated that neutralizing antibody level in the gB&gC&gD-GEM group was superior than those in the other groups. Moreover, gB&gC&gD-GEM significantly increased the secretion of cytokines, as well as the activation and maturation of B cells. It also boosted the production of central memory T cells among CD4 + and CD8 + T cells. Moreover, gB&gC&gD-GEM mixed with Gel02 adjuvant provoked an antibody response in cats. In conclusion, the BLPs vaccine prepared from gB&gC&gD-GEM induced specific humoral and cellular immune responses to FHV-1 and be used as a potential vaccine candidate for the control of FHV-1 infection in cats.

A recombinant rabies virus chimera expressing the DC-targeting molecular MAB2560 shows enhanced vaccine immunogenicity through activation of dendritic cells.

BACKGROUND: Rabies, caused by the rabies virus (RABV), is an ancient and neglected zoonotic disease posing a large public health threat to humans and animals in developing countries. Immunization of animals with a rabies vaccine is the most effective way to control the epidemic and the occurrence of the disease in humans. Therefore, the development of cost-effective and efficient rabies vaccines is urgently needed. The activation of dendritic cells (DCs) is known to play an important role in improving the host immune response induced by rabies vaccines. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we constructed a recombinant virus, rCVS11-MAB2560, based on the reverse genetic system of the RABV CVS11 strain. The MAB2560 protein (a DC-targeting molecular) was chimeric expressed on the surface of the viral particles to help target and activate the DCs when this virus was used as inactivated vaccine. Our results demonstrated that inactivated rCVS11-MAB2560 was able to promote the recruitment and/or proliferation of DC cells, T cells and B cells in mice, and induce good immune memory after two immunizations. Moreover, the inactivated recombinant virus rCVS11-MAB2560 could produce higher levels of virus-neutralizing antibodies (VNAs) in both mice and dogs more quickly than rCVS11 post immunization. CONCLUSIONS/SIGNIFICANCE: In summary, the recombinant virus rCVS11-MAB2560 chimeric-expressing the molecular adjuvant MAB2560 can stimulate high levels of humoral and cellular immune responses in vivo and can be used as an effective inactivated rabies vaccine candidate.

An inactivated recombinant rabies virus chimerically expressed RBD induces humoral and cellular immunity against SARS-CoV-2 and RABV.

Many studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect various animals and transmit among animals, and even to humans, posing a threat to humans and animals. There is an urgent need to develop inexpensive and efficient animal vaccines to prevent and control coronavirus disease 2019 (COVID-19) in animals. Rabies virus (RABV) is another important zoonotic pathogen that infects almost all warm-blooded animals and poses a great public health threat. The present study constructed two recombinant chimeric viruses expressing the S1 and RBD proteins of the SARS-CoV-2 Wuhan01 strain based on a reverse genetic system of the RABV SRV9 strain and evaluated their immunogenicity in mice, cats and dogs. The results showed that both inactivated recombinant viruses induced durable neutralizing antibodies against SARS-CoV-2 and RABV and a strong cellular immune response in mice. Notably, inactivated SRV-nCoV-RBD induced earlier antibody production than SRV-nCoV-S1, which was maintained at high levels for longer periods. Inactivated SRV-nCoV-RBD induced neutralizing antibodies against both SARS-CoV-2 and RABV in cats and dogs, with a relatively broad-spectrum cross-neutralization capability against the SARS-CoV-2 pseudoviruses including Alpha, Beta, Gamma, Delta, and Omicron, showing potential to be used as a safe bivalent vaccine candidate against COVID-19 and rabies in animals.

Spatiotemporal Dynamics of Wetland in Dongting Lake Based on Multi-Source Satellite Observation Data during Last Two Decades.

Monitoring the dynamics of wetland resources has practical value for wetland protection, restoration and sustainable utilization. Dongting Lake wetland reserves are well known for both their intra-annual and inter-annual dynamic changes due to the effects of natural or human factors. However, most wetland monitoring research has failed to consider the seasonal wetlands, which is the most fragile wetland type, requiring more attention. In this study, we used multi-source time series remote sensing data to monitor three Dongting Lake wetland reserves between 2000 and 2020, and the seasonal wetlands were separated from permanent wetlands. Multispectral and indices time series were generated at 30 m resolution using a two-month composition strategy; the optimal features were then selected using the extension of the Jeffries-Matusita distance (JBh) and random forest (RF) importance score; yearly wetland maps were identified using the optimal features and the RF classifier. Results showed that (1) the yearly wetland maps had good accuracy, and the overall accuracy and kappa coefficients of all wetland maps from 2000 to 2020 were above 89.6% and 0.86, respectively. Optimal features selected by JBh can improve both computational efficiency and classification accuracy. (2) The acreage of seasonal wetlands varies greatly among multiple years due to inter-annual differences in precipitation and evaporation. (3) Although the total wetland area of the three Dongting Lake wetland reserves remained relatively stable between 2000 and 2020, the acreage of the natural wetland types still decreased by 197.0 km2, and the change from natural wetland to human-made wetland (paddy field) contributed the most to this decrease. From the perspective of the ecological community, the human-made wetland has lower ecological function value than natural wetlands, so the balance between economic development and ecological protection in the three Dongting Lake wetland reserves requires further evaluation. The outcomes of this study could improve the understanding of the trends and driving mechanisms of wetland dynamics, which has important scientific significance and application value for the protection and restoration of Dongting Lake wetland reserves.

GEM-PA-Based Subunit Vaccines of Crimean Congo Hemorrhagic Fever Induces Systemic Immune Responses in Mice.

The Crimean Congo Hemorrhagic Fever Virus (CCHFV) is a tick-borne bunyavirus of the Narovirus genus, which is the causative agent of Crimean Congo Hemorrhagic Fever (CCHF). CCHF is endemic in Africa, the Middle East, Eastern Europe and Asia, with a high case-fatality rate of up to 50% in humans. Currently, there are no approved vaccines or effective therapies available for CCHF. The GEM-PA is a safe, versatile and effective carrier system, which offers a cost-efficient, high-throughput platform for recovery and purification of subunit proteins for vaccines. In the present study, based on a GEM-PA surface display system, a GEM-PA based vaccine expressing three subunit vaccine candidates (G-GP, including G-eGN, G-eGC and G-NAb) of CCHFV was developed, displaying the ectodomains of the structural glycoproteins eGN, eGC and NAb, respectively. According to the immunological assays including indirect-ELISA, a micro-neutralization test of pseudo-virus and ELISpot, 5 µg GPBLP3 combined with Montanide ISA 201VG plus Poly (I:C) adjuvant (A-G-GP-5 µg) elicited GP-specific humoral and cellular immunity in BALB/c mice after three vaccinations via subcutaneous injection (s.c.). The consistent data between IgG subtype and cytokine detection, ELISpot and cytokine detection indicated balanced Th1 and Th2 responses, of which G-eGN vaccines could elicit a stronger T-cell response post-vaccination, respectively. Moreover, all three vaccine candidates elicited high TNF-α, IL-6, and IL-10 cytokine levels in the supernatant of stimulated splenocytes in vitro. However, the neutralizing antibody (nAb) was only detected in A-G-eGC and A-G-eGC vaccination groups with the highest neutralizing titer of 128, suggesting that G-eGC could elicit a stronger humoral immune response. In conclusion, the GEM-PA surface display system could provide an efficient and convenient purification method for CCHFV subunit antigens, and the G-GP subunit vaccine candidates will be promising against CCHFV infections with excellent immunogenicity.

A bacterium-like particle vaccine displaying Zika virus prM-E induces systemic immune responses in mice.

The emergence of Zika virus (ZIKV) infection, which is unexpectedly associated with congenital defects, has prompted the development of safe and effective vaccines. The Gram-positive enhancer matrix-protein anchor (GEM-PA) display system has emerged as a versatile and highly effective platform for delivering target proteins in vaccines. In this study, we developed a bacterium-like particle vaccine, ZI-△-PA-GEM, based on the GEM-PA system. The fusion protein ZI-△-PA, which contains the prM-E-△TM protein of ZIKV (with a stem-transmembrane region deletion) and the protein anchor PA3, was expressed. The fusion protein was successfully displayed on the GEM surface to form ZI-△-PA-GEM. Moreover, the intramuscular immunization of BALB/c mice with ZI-△-PA-GEM combined with ISA 201 VG and poly(I:C) adjuvants induced durable ZIKV-specific IgG and protective neutralizing antibody responses. Potent B-cell/DC activation was also stimulated early after immunization. Notable, splenocyte proliferation, the secretion of multiple cytokines, T/B-cell activation and central memory T-cell responses were elicited. These data indicate that ZI-△-PA-GEM is a promising bacterium-like particle vaccine candidate for ZIKV.