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1.
Clin Proteomics ; 21(1): 35, 2024 May 19.
Article in English | MEDLINE | ID: mdl-38764042

ABSTRACT

BACKGROUND: Currently, no effective measures are available to predict the curative efficacy of small-cell lung cancer (SCLC) chemotherapy. We expect to develop a method for effectively predicting the SCLC chemotherapy efficacy and prognosis in clinical practice in order to offer more pertinent therapeutic protocols for individual patients. METHODS: We adopted matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and ClinPro Tools system to detect serum samples from 154 SCLC patients with different curative efficacy of standard chemotherapy and analyze the different peptides/proteins of SCLC patients to discover predictive tumor markers related to chemotherapy efficacy. Ten peptide/protein peaks were significantly different in the two groups. RESULTS: A genetic algorithm model consisting of four peptides/proteins was developed from the training group to separate patients with different chemotherapy efficacies. Among them, three peptides/proteins (m/z 3323.35, 6649.03 and 6451.08) showed high expression in the disease progression group, whereas the peptide/protein at m/z 4283.18 was highly expressed in the disease response group. The classifier exhibited an accuracy of 91.4% (53/58) in the validation group. The survival analysis showed that the median progression-free survival (PFS) of 30 SCLC patients in disease response group was 9.0 months; in 28 cases in disease progression group, the median PFS was 3.0 months, a statistically significant difference (χ2 = 46.98, P < 0.001). The median overall survival (OS) of the two groups was 13.0 months and 7.0 months, a statistically significant difference (χ2 = 40.64, P < 0.001). CONCLUSIONS: These peptides/proteins may be used as potential biological markers for prediction of the curative efficacy and prognosis for SCLC patients treated with standard regimen chemotherapy.

2.
BMC Genomics ; 25(1): 42, 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38191283

ABSTRACT

Gene-edited mosquitoes lacking a gamma-interferon-inducible lysosomal thiol reductase-like protein, namely (mosGILTnull) have lower Plasmodium infection, which is linked to impaired ovarian development and immune activation. The transcriptome of mosGILTnull Anopheles gambiae was therefore compared to wild type (WT) mosquitoes by RNA-sequencing to delineate mosGILT-dependent pathways. Compared to WT mosquitoes, mosGILTnull A. gambiae demonstrated altered expression of genes related to oogenesis, 20-hydroxyecdysone synthesis, as well as immune-related genes. Serendipitously, the zero population growth gene, zpg, an essential regulator of germ cell development was found to be one of the most downregulated genes in mosGILTnull mosquitoes. These results provide a crucial missing link between two previous studies on the role of zpg and mosGILT in ovarian development. This study further demonstrates that mosGILT has the potential to serve as a target for the biological control of mosquito vectors and to influence the Plasmodium life cycle within the vector.


Subject(s)
Anopheles , Animals , Anopheles/genetics , Cell Differentiation , Immunity, Innate/genetics , Mosquito Vectors/genetics , Germ Cells
3.
Front Oncol ; 13: 1242460, 2023.
Article in English | MEDLINE | ID: mdl-37886174

ABSTRACT

Cancers of unknown primary (CUP) account for 2%-5% of all diagnosed cancers and are always characterized with fast-paced aggression, early metastasis, and unpredictable spread patterns Mediastinum metastasis with unknown primary origin is extremely rare and with a poor prognosis and short survival. There is no literature to refer to for its treatment. Here, we reported a case of squamous cell CUP in the mediastinum. A 50-year-old male patient was admitted after multi-line treatment of low differentiated squamous cell carcinoma in the mediastinum diagnosed 8 months before. In August 2019, the patient went to a local hospital for cough and dyspnea for 2 weeks. Then, he was diagnosed with squamous cell carcinoma of unknown primary origin with multiple lymph nodes metastasis. The patient was featured with programmed cell death-ligand 1 (PD-L1) expression strongly positive in 90% of tumor cells and the combined positive score of 90 and a tumor mutation burden of 1.79 MUts/Mb and microsatellite stable phenotype. The patient was treated with anti-programmed cell death-1 (PD-1) antibodies in combination with chemotherapy and responded to the treatment. The patient showed stable disease to multi-line immunotherapy for more than 7 months and finally got a clinical benefit of 2-year survival benefit. In conclusion, immunotherapy targeting PD-1/PD-L1 in combination with chemotherapy may play a crucial role in the later-line treatment and palliative care of CUP.

4.
bioRxiv ; 2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37577703

ABSTRACT

Gene-edited mosquitoes lacking a g amma-interferon-inducible lysosomal thiol reductase-like protein, namely ( mosGILT null ) have lower Plasmodium infection, which is linked to impaired ovarian development and immune activation. The transcriptome of mosGILT null A. gambiae was therefore compared to wild type (WT) by RNA-sequencing to delineate mosGILT-dependent pathways. Compared to WT mosquitoes, mosGILT null A. gambiae demonstrated altered expression of genes related to oogenesis, 20-hydroxyecdysone synthesis, as well as immune-related genes. Serendipitously, the zero population growth gene, zpg , an essential regulator of germ cell development was found to be one of the most downregulated genes in mosGILT null mosquitoes. These results provide the crucial missing link between two previous studies on the role of zpg and mosGILT in ovarian development. This study further demonstrates that mosGILT has the potential to serve as a target for the biological control of mosquito vectors and to influence the Plasmodium life cycle within the vector.

5.
Proc Natl Acad Sci U S A ; 120(29): e2221118120, 2023 07 18.
Article in English | MEDLINE | ID: mdl-37428915

ABSTRACT

Proposed genetic approaches for reducing human malaria include population modification, which introduces genes into vector mosquitoes to reduce or prevent parasite transmission. We demonstrate the potential of Cas9/guide RNA (gRNA)-based gene-drive systems linked to dual antiparasite effector genes to spread rapidly through mosquito populations. Two strains have an autonomous gene-drive system coupled to dual anti-Plasmodium falciparum effector genes comprising single-chain variable fragment monoclonal antibodies targeting parasite ookinetes and sporozoites in the African malaria mosquitoes Anopheles gambiae (AgTP13) and Anopheles coluzzii (AcTP13). The gene-drive systems achieved full introduction within 3 to 6 mo after release in small cage trials. Life-table analyses revealed no fitness loads affecting AcTP13 gene-drive dynamics but AgTP13 males were less competitive than wild types. The effector molecules reduced significantly both parasite prevalence and infection intensities. These data supported transmission modeling of conceptual field releases in an island setting that shows meaningful epidemiological impacts at different sporozoite threshold levels (2.5 to 10 k) for human infection by reducing malaria incidence in optimal simulations by 50 to 90% within as few as 1 to 2 mo after a series of releases, and by ≥90% within 3 mo. Modeling outcomes for low sporozoite thresholds are sensitive to gene-drive system fitness loads, gametocytemia infection intensities during parasite challenges, and the formation of potentially drive-resistant genome target sites, extending the predicted times to achieve reduced incidence. TP13-based strains could be effective for malaria control strategies following validation of sporozoite transmission threshold numbers and testing field-derived parasite strains. These or similar strains are viable candidates for future field trials in a malaria-endemic region.


Subject(s)
Anopheles , Malaria, Falciparum , Malaria , Animals , Male , Humans , Anopheles/genetics , Anopheles/parasitology , Mosquito Vectors/genetics , Malaria/prevention & control , Plasmodium falciparum/genetics , Sporozoites , Malaria, Falciparum/parasitology
6.
Proc Natl Acad Sci U S A ; 120(11): e2213701120, 2023 03 14.
Article in English | MEDLINE | ID: mdl-36893279

ABSTRACT

While it has long been known that the transmission of mosquito-borne viruses depends on the establishment of persistent and nonlethal infections in the invertebrate host, specific roles for the insects' antiviral immune pathways in modulating the pathogenesis of viral infections is the subject of speculation and debate. Here, we show that a loss-of-function mutation in the Aedes aegypti Dicer-2 (Dcr-2) gene renders the insect acutely susceptible to a disease phenotype upon infection with pathogens in multiple virus families associated with important human diseases. Additional interrogation of the disease phenotype demonstrated that the virus-induced pathology is controlled through a canonical RNA interference (RNAi) pathway, which functions as a resistance mechanism. These results suggest comparatively modest contributions of proposed tolerance mechanisms to the fitness of A. aegypti infected with these pathogens. Similarly, the production of virus-derived piwi-interacting RNAs (vpiRNAs) was not sufficient to prevent the pathology associated with viral infections in Dcr-2 null mutants, also suggesting a less critical, or potentially secondary, role for vpiRNAs in antiviral immunity. These findings have important implications for understanding the ecological and evolutionary interactions occurring between A. aegypti and the pathogens they transmit to human and animal hosts.


Subject(s)
Aedes , Flavivirus , Yellow Fever , Animals , Humans , RNA Interference , Yellow Fever/genetics , Flavivirus/genetics , Antiviral Agents , RNA, Small Interfering/genetics
8.
PLoS Pathog ; 19(1): e1010842, 2023 01.
Article in English | MEDLINE | ID: mdl-36656895

ABSTRACT

As a major insect vector of multiple arboviruses, Aedes aegypti poses a significant global health and economic burden. A number of genetic engineering tools have been exploited to understand its biology with the goal of reducing its impact. For example, current tools have focused on knocking-down RNA transcripts, inducing loss-of-function mutations, or expressing exogenous DNA. However, methods for transactivating endogenous genes have not been developed. To fill this void, here we developed a CRISPR activation (CRISPRa) system in Ae. aegypti to transactivate target gene expression. Gene expression is activated through pairing a catalytically-inactive ('dead') Cas9 (dCas9) with a highly-active tripartite activator, VP64-p65-Rta (VPR) and synthetic guide RNA (sgRNA) complementary to a user defined target-gene promoter region. As a proof of concept, we demonstrate that engineered Ae. aegypti mosquitoes harboring a binary CRISPRa system can be used to effectively overexpress two developmental genes, even-skipped (eve) and hedgehog (hh), resulting in observable morphological phenotypes. We also used this system to overexpress the positive transcriptional regulator of the Toll immune pathway known as AaRel1, which resulted in a significant suppression of dengue virus serotype 2 (DENV2) titers in the mosquito. This system provides a versatile tool for research pathways not previously possible in Ae. aegypti, such as programmed overexpression of endogenous genes, and may aid in gene characterization studies and the development of innovative vector control tools.


Subject(s)
Aedes , Animals , Humans , Hedgehog Proteins/metabolism , Mosquito Vectors/genetics , RNA/metabolism , Transcriptional Activation , CRISPR-Cas Systems
9.
Res Sq ; 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38196646

ABSTRACT

Vector control is a crucial strategy for malaria elimination by preventing infection and reducing disease transmission. Most gains have been achieved through insecticide-treated nets (ITNs) and indoor residual spraying (IRS), but the emergence of insecticide resistance among Anopheles mosquitoes calls for new tools to be applied. Here, we present the development of a highly effective murine monoclonal antibody, targeting the N-terminal region of the Plasmodium falciparum gametocyte antigen Pfs230, that can decrease the infection prevalence by > 50% when fed to Anopheles mosquitoes with gametocytes in an artificial membrane feeding system. We used a standard mouse immunization protocol followed by protein interaction and parasite-blocking validation at three distinct stages of the monoclonal antibody development pipeline: post-immunization, post-hybridoma generation, and final validation of the monoclonal antibody. We evaluated twenty antibodies identifying one (mAb 13G9) with high Pfs230-affinity and parasite-blocking activity. This 13G9 monoclonal antibody could potentially be developed into a transmission-blocking single-chain antibody for expression in transgenic mosquitoes.

10.
PLoS Biol ; 20(6): e3001668, 2022 06.
Article in English | MEDLINE | ID: mdl-35679279

ABSTRACT

The mosquito's innate immune system defends against a variety of pathogens, and the conserved siRNA pathway plays a central role in the control of viral infections. Here, we show that transgenic overexpression of Dicer2 (Dcr2) or R2d2 resulted in an accumulation of 21-nucleotide viral sequences that was accompanied by a significant suppression of dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) replication, thus indicating the broad-spectrum antiviral response mediated by the siRNA pathway that can be applied for the development of novel arbovirus control strategies. Interestingly, overexpression of Dcr2 or R2d2 regulated the mRNA abundance of a variety of antimicrobial immune genes, pointing to additional functions of DCR2 and R2D2 as well as cross-talk between the siRNA pathway and other immune pathways. Accordingly, transgenic overexpression of Dcr2 or R2d2 resulted in a lesser proliferation of the midgut microbiota and increased resistance to bacterial and fungal infections.


Subject(s)
Aedes , Dengue Virus , Dengue , Zika Virus Infection , Zika Virus , Animals , Animals, Genetically Modified , Anti-Bacterial Agents/metabolism , Antifungal Agents , Dengue Virus/genetics , Humans , RNA, Double-Stranded/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Zika Virus/genetics
11.
PLoS Biol ; 20(1): e3001515, 2022 01.
Article in English | MEDLINE | ID: mdl-35025886

ABSTRACT

Anopheles gambiae melanization-based refractoriness to the human malaria parasite Plasmodium falciparum has rarely been observed in either laboratory or natural conditions, in contrast to the rodent model malaria parasite Plasmodium berghei that can become completely melanized by a TEP1 complement-like system-dependent mechanism. Multiple studies have shown that the rodent parasite evades this defense by recruiting the C-type lectins CTL4 and CTLMA2, while permissiveness to the human malaria parasite was not affected by partial depletion of these factors by RNAi silencing. Using CRISPR/Cas9-based CTL4 knockout, we show that A. gambiae can mount melanization-based refractoriness to the human malaria parasite, which is independent of the TEP1 complement-like system and the major anti-Plasmodium immune pathway Imd. Our study indicates a hierarchical specificity in the control of Plasmodium melanization and proves CTL4 as an essential host factor for P. falciparum transmission and one of the most potent mosquito-encoded malaria transmission-blocking targets.


Subject(s)
Anopheles/immunology , Lectins, C-Type/genetics , Plasmodium berghei/physiology , Plasmodium falciparum/physiology , Animals , Anopheles/genetics , Anopheles/parasitology , CRISPR-Cas Systems , Gene Knockout Techniques , Insect Proteins/genetics , Insect Proteins/metabolism , Lectins, C-Type/metabolism , Melanins/genetics , Melanins/immunology
12.
J Vis Exp ; (186)2022 08 11.
Article in English | MEDLINE | ID: mdl-37590506

Subject(s)
Biology , Culicidae , Animals
13.
Trends Parasitol ; 38(1): 54-66, 2022 01.
Article in English | MEDLINE | ID: mdl-34483052

ABSTRACT

Malaria is one of the deadliest diseases. Because of the ineffectiveness of current malaria-control methods, several novel mosquito vector-based control strategies have been proposed to supplement existing control strategies. Mosquito transgenesis and gene drive have emerged as promising tools for preventing the spread of malaria by either suppressing mosquito populations by self-destructing mosquitoes or replacing mosquito populations with disease-refractory populations. Here we review the development of mosquito transgenesis and its application for malaria control, highlighting the transgenic expression of antiparasitic effector genes, inactivation of host factor genes, and manipulation of miRNAs and lncRNAs. Overall, from a malaria-control perspective, mosquito transgenesis is not envisioned as a stand-alone approach; rather, its use is proposed as a complement to existing vector-control strategies.


Subject(s)
Anopheles , Malaria , Animals , Anopheles/physiology , Gene Transfer Techniques , Malaria/parasitology , Mosquito Control , Mosquito Vectors/genetics
14.
mBio ; 12(6): e0309121, 2021 12 21.
Article in English | MEDLINE | ID: mdl-34903042

ABSTRACT

Malaria is caused when Plasmodium sporozoites are injected along with saliva by an anopheline mosquito into the dermis of a vertebrate host. Arthropod saliva has pleiotropic effects that can influence local host responses, pathogen transmission, and exacerbation of the disease. A mass spectrometry screen identified mosquito salivary proteins that are associated with Plasmodium sporozoites during saliva secretions. In this study, we demonstrate that one of these salivary antigens, Anopheles gambiae sporozoite-associated protein (AgSAP), interacts directly with Plasmodium falciparum and Plasmodium berghei sporozoites. AgSAP binds to heparan sulfate and inhibits local inflammatory responses in the skin. The silencing of AgSAP in mosquitoes reduces their ability to effectively transmit sporozoites to mice. Moreover, immunization with AgSAP decreases the Plasmodium burden in mice that are bitten by Plasmodium-infected mosquitoes. These data suggest that AgSAP facilitates early Plasmodium infection in the vertebrate host and serves as a target for the prevention of malaria. IMPORTANCE Malaria is a vector-borne disease caused by Plasmodium sporozoites. When an anopheline mosquito bites its host, it releases Plasmodium sporozoites as well as saliva components. Mosquito proteins have the potential to serve as antigens to prevent or influence malaria without directly targeting the pathogen. This may help set a new paradigm for vaccine development. In this study, we have elucidated the role of a novel salivary antigen, named Anopheles gambiae sporozoite-associated protein (AgSAP). The results presented here show that AgSAP interacts with Plasmodium falciparum and Plasmodium berghei sporozoites and modulates local inflammatory responses in the skin. Furthermore, our results show that AgSAP is a novel mosquito salivary antigen that influences the early stages of Plasmodium infection in the vertebrate host. Individuals living in countries where malaria is endemic generate antibodies against AgSAP, which indicates that AgSAP can serve as a biomarker for disease prevalence and epidemiological analysis.


Subject(s)
Anopheles/immunology , Insect Proteins/immunology , Malaria/parasitology , Mosquito Vectors/immunology , Plasmodium berghei/physiology , Plasmodium falciparum/physiology , Salivary Proteins and Peptides/immunology , Animals , Anopheles/genetics , Anopheles/parasitology , Female , Humans , Insect Proteins/genetics , Malaria/immunology , Malaria/transmission , Mice , Mice, Inbred C57BL , Mosquito Vectors/genetics , Mosquito Vectors/parasitology , Plasmodium berghei/genetics , Plasmodium falciparum/genetics , Salivary Proteins and Peptides/genetics , Sporozoites/genetics , Sporozoites/physiology
15.
Sci Rep ; 11(1): 22578, 2021 11 19.
Article in English | MEDLINE | ID: mdl-34799605

ABSTRACT

Anopheline mosquitoes are the sole vectors for the Plasmodium pathogens responsible for malaria, which is among the oldest and most devastating of human diseases. The continuing global impact of malaria reflects the evolutionary success of a complex vector-pathogen relationship that accordingly has been the long-term focus of both debate and study. An open question in the biology of malaria transmission is the impact of naturally occurring low-level Plasmodium infections of the vector on the mosquito's health and longevity as well as critical behaviors such as host-preference/seeking. To begin to answer this, we have completed a comparative RNAseq-based transcriptome profile study examining the effect of biologically salient, salivary gland transmission-stage Plasmodium infection on the molecular physiology of Anopheles gambiae s.s. head, sensory appendages, and salivary glands. When compared with their uninfected counterparts, Plasmodium infected mosquitoes exhibit increased transcript abundance of genes associated with olfactory acuity as well as a range of synergistic processes that align with increased fitness based on both anti-aging and reproductive advantages. Taken together, these data argue against the long-held paradigm that malaria infection is pathogenic for anophelines and, instead suggests there are biological and evolutionary advantages for the mosquito that drive the preservation of its high vectorial capacity.


Subject(s)
Anopheles/genetics , Gene Expression Profiling , Malaria, Falciparum/genetics , Mosquito Vectors/genetics , Plasmodium falciparum/pathogenicity , Transcriptome , Aging/genetics , Aging/metabolism , Animals , Anopheles/metabolism , Anopheles/parasitology , Evolution, Molecular , Genetic Fitness , Host-Parasite Interactions , Malaria, Falciparum/parasitology , Mosquito Vectors/metabolism , Mosquito Vectors/parasitology , Odorants , RNA-Seq , Receptors, Odorant/genetics , Receptors, Odorant/metabolism , Smell/genetics
16.
PLoS Biol ; 19(5): e3001182, 2021 05.
Article in English | MEDLINE | ID: mdl-33979323

ABSTRACT

Melanin, a black-brown pigment found throughout all kingdoms of life, has diverse biological functions including UV protection, thermoregulation, oxidant scavenging, arthropod immunity, and microbial virulence. Given melanin's broad roles in the biosphere, particularly in insect immune defenses, it is important to understand how exposure to ubiquitous environmental contaminants affects melanization. Glyphosate-the most widely used herbicide globally-inhibits melanin production, which could have wide-ranging implications in the health of many organisms, including insects. Here, we demonstrate that glyphosate has deleterious effects on insect health in 2 evolutionary distant species, Galleria mellonella (Lepidoptera: Pyralidae) and Anopheles gambiae (Diptera: Culicidae), suggesting a broad effect in insects. Glyphosate reduced survival of G. mellonella caterpillars following infection with the fungus Cryptococcus neoformans and decreased the size of melanized nodules formed in hemolymph, which normally help eliminate infection. Glyphosate also increased the burden of the malaria-causing parasite Plasmodium falciparum in A. gambiae mosquitoes, altered uninfected mosquito survival, and perturbed the microbial composition of adult mosquito midguts. Our results show that glyphosate's mechanism of melanin inhibition involves antioxidant synergy and disruption of the reaction oxidation-reduction balance. Overall, these findings suggest that glyphosate's environmental accumulation could render insects more susceptible to microbial pathogens due to melanin inhibition, immune impairment, and perturbations in microbiota composition, potentially contributing to declines in insect populations.


Subject(s)
Anopheles/drug effects , Glycine/analogs & derivatives , Melanins/metabolism , Moths/drug effects , Animals , Anopheles/immunology , Cryptococcus neoformans/pathogenicity , Diptera/drug effects , Diptera/immunology , Glycine/metabolism , Glycine/pharmacology , Immunity, Innate/drug effects , Immunity, Innate/immunology , Infections/immunology , Infections/metabolism , Infections/physiopathology , Insecta/drug effects , Insecta/immunology , Lepidoptera/drug effects , Lepidoptera/immunology , Moths/immunology , Plasmodium falciparum/pathogenicity , Virulence , Glyphosate
17.
Parasit Vectors ; 13(1): 489, 2020 Sep 24.
Article in English | MEDLINE | ID: mdl-32972453

ABSTRACT

BACKGROUND: Surveillance of mosquito infection status is critical for planning and deployment of proper mosquito control initiatives. Point-of-care (POC) detection assays are necessary for monitoring the infection prevalence and geographical range of viruses in mosquito vector populations. We therefore assessed the novel real-time PCR (qPCR) bCUBE (Hyris, London, UK) molecular diagnostic system as a tool for virus detection. METHODS: Aedes aegypti Rps17 was used to validate and determine correlation coefficient for the novel bCUBE qPCR system to a laboratory standard StepOnePlus real-time PCR system (Applied Biosystems, Waltham, MA, USA). Experimentally infected Ae. aegypti were quantified for Zika (ZIKV) and dengue virus serotype 2 (DENV2) viral genomic RNA. Infection prevalence was compared to plaque assay. RESULTS: We developed and validated a novel qPCR system for the detection of ZIKV and DENV2 using the real-time qPCR system bCUBE. With bCUBE-based qRT-PCR, viral genomic RNA could be detected in individually infected Ae. aegypti mosquitoes and in pools of 5, 10 or 15 mosquitoes. CONCLUSIONS: The portable qPCR bCUBE diagnostic system is capable of detecting Zika and dengue virus in mosquitoes and therefore has potential as a practical field-deployable diagnostic test for vector-borne disease surveillance programmes.


Subject(s)
Aedes/virology , Dengue Virus/genetics , Mosquito Vectors/virology , Real-Time Polymerase Chain Reaction/methods , Zika Virus/genetics , Animals , Dengue Virus/classification , Dengue Virus/isolation & purification , Female , Mosquito Control , Point-of-Care Testing , Zika Virus/classification , Zika Virus/isolation & purification
18.
Sci Adv ; 6(20): eaay5898, 2020 05.
Article in English | MEDLINE | ID: mdl-32426491

ABSTRACT

The malaria parasite's complex journey through the Anopheles mosquito vector provides multiple opportunities for targeting Plasmodium with recombinant effectors at different developmental stages and different host tissues. We have designed and expressed transgenes that efficiently suppress Plasmodium infection by targeting the parasite with multiple independent endogenous and exogenous effectors at multiple infection stages to potentiate suppression and minimize the probability for development of resistance to develop. We have also addressed the fitness impact of transgene expression on the mosquito. We show that highly potent suppression can be achieved by targeting both pre-oocyst stages by transgenically overexpressing either the endogenous immune deficiency immune pathway transcription factor Rel2 or a polycistronic mRNA encoding multiple antiparasitic effectors and simultaneously targeting the sporozoite stages with an anti-sporozoite single-chain antibody fused to the antiparasitic protein Scorpine. Expression of the selected endogenous effector systems appears to pose a lower fitness cost than does the use of foreign genes.


Subject(s)
Anopheles , Malaria , Plasmodium , Animals , Animals, Genetically Modified , Anopheles/genetics , Antiparasitic Agents , Malaria/genetics , Mosquito Vectors/genetics , Plasmodium falciparum/genetics
19.
PLoS Pathog ; 16(4): e1008453, 2020 04.
Article in English | MEDLINE | ID: mdl-32330198

ABSTRACT

Malaria, caused by the protozoan parasite Plasmodium and transmitted by Anopheles mosquitoes, represents a major threat to human health. Plasmodium's infection cycle in the Anopheles vector is critical for transmission of the parasite between humans. The midgut-stage bottleneck of infection is largely imposed by the mosquito's innate immune system. microRNAs (miRNAs, small noncoding RNAs that bind to target RNAs to regulate gene expression) are also involved in regulating immunity and the anti-Plasmodium defense in mosquitoes. Here, we characterized the mosquito's miRNA responses to Plasmodium infection using an improved crosslinking and immunoprecipitation (CLIP) method, termed covalent ligation of endogenous Argonaute-bound RNAs (CLEAR)-CLIP. Three candidate miRNAs' influence on P. falciparum infection and midgut microbiota was studied through transgenically expressed miRNA sponges (miR-SPs) in midgut and fat body tissues. MiR-SPs mediated conditional depletion of aga-miR-14 or aga-miR-305, but not aga-miR-8, increased mosquito resistance to both P. falciparum and P. berghei infection, and enhanced the mosquitoes' antibacterial defenses. Transcriptome analysis revealed that depletion of aga-miR-14 or aga-miR-305 resulted in an increased expression of multiple immunity-related and anti-Plasmodium genes in mosquito midguts. The overall fitness cost of conditionally expressed miR-SPs was low, with only one of eight fitness parameters being adversely affected. Taken together, our results demonstrate that targeting mosquito miRNA by conditional expression of miR-SPs may have potential for the development of malaria control through genetically engineered mosquitoes.


Subject(s)
Anopheles/immunology , Malaria, Falciparum/parasitology , MicroRNAs/immunology , Mosquito Vectors/immunology , Plasmodium berghei/physiology , Plasmodium falciparum/physiology , Animals , Anopheles/genetics , Anopheles/parasitology , Female , MicroRNAs/genetics , Mosquito Vectors/genetics , Mosquito Vectors/parasitology , Plasmodium berghei/genetics , Plasmodium berghei/immunology , Plasmodium falciparum/genetics , Plasmodium falciparum/immunology
20.
Microorganisms ; 8(2)2020 Feb 17.
Article in English | MEDLINE | ID: mdl-32079354

ABSTRACT

As a novel and safe sanitizer, polyhexamethylene guanidine hydrochloride (PHMG) has been used to inhibit the spoilage of agricultural products caused by fungi. However, little is known about its antibacterial effects on vegetables. In this study, we evaluated the disinfection efficacy of PHMG on ready-to-eat lettuce. PHMG (150-200 mg/L) treatment for 5 min was optimal for lettuce disinfection. Compared to several household sanitizers (vinegar: 1% acetic acid; kettle descaler: 1% citric acid; "84" disinfectant: 200 mg/L sodium hypochlorite), PHMG showed the greatest reductions in Escherichia coli O157:H7, Listeria monocytogenes, aerobic mesophilic counts, aerobic psychrotrophic counts and molds and yeasts. Quality analysis of color (as determined by L*, a* and b*) and determination of electrolyte leakage indicated that PHMG did not cause any additional quality loss as compared to other household sanitizers. These results provide a reference for the application of PHMG as a vegetable sanitizer at the ready-to-eat stage.

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