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Hixson B, Huot L, Morejon B, Yang X, Nagy P, Michel K, Buchon N. The transcriptional response in mosquitoes distinguishes between fungi and bacteria but not Gram types. BMC Genomics 2024; 25:353. [PMID: 38594632 PMCID: PMC11003161 DOI: 10.1186/s12864-024-10153-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/22/2024] [Indexed: 04/11/2024] Open
Abstract
Mosquitoes are prolific vectors of human pathogens, therefore a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster, is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae (s.l.) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti, however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.
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Affiliation(s)
- Bretta Hixson
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Louise Huot
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Bianca Morejon
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Xiaowei Yang
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
- Current address: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute for Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Peter Nagy
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Nicolas Buchon
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA.
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2
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Rosenthal PJ, Asua V, Bailey JA, Conrad MD, Ishengoma DS, Kamya MR, Rasmussen C, Tadesse FG, Uwimana A, Fidock DA. The emergence of artemisinin partial resistance in Africa: how do we respond? THE LANCET. INFECTIOUS DISEASES 2024:S1473-3099(24)00141-5. [PMID: 38552654 DOI: 10.1016/s1473-3099(24)00141-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 04/21/2024]
Abstract
Malaria remains one of the most important infectious diseases in the world, with the greatest burden in sub-Saharan Africa, primarily from Plasmodium falciparum infection. The treatment and control of malaria is challenged by resistance to most available drugs, but partial resistance to artemisinins (ART-R), the most important class for the treatment of malaria, was until recently confined to southeast Asia. This situation has changed, with the emergence of ART-R in multiple countries in eastern Africa. ART-R is mediated primarily by single point mutations in the P falciparum kelch13 protein, with several mutations present in African parasites that are now validated resistance mediators based on clinical and laboratory criteria. Major priorities at present are the expansion of genomic surveillance for ART-R mutations across the continent, more frequent testing of the efficacies of artemisinin-based regimens against uncomplicated and severe malaria in trials, more regular assessment of ex-vivo antimalarial drug susceptibilities, consideration of changes in treatment policy to deter the spread of ART-R, and accelerated development of new antimalarial regimens to overcome the impacts of ART-R. The emergence of ART-R in Africa is an urgent concern, and it is essential that we increase efforts to characterise its spread and mitigate its impact.
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Affiliation(s)
- Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA, USA.
| | - Victor Asua
- Infectious Diseases Research Collaboration, Kampala, Uganda; University of Tübingen, Tübingen, Germany
| | - Jeffrey A Bailey
- Center for Computational Molecular Biology, Brown University, Providence, RI, USA; Departments of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Melissa D Conrad
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania; Department of Biochemistry, Kampala International University in Tanzania, Dar es Salaam, Tanzania; School of Public Health, Harvard University, Boston, MA, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda; Department of Medicine, Makerere University, Kampala, Uganda
| | | | - Fitsum G Tadesse
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia; London School of Hygiene and Tropical Medicine, London, UK
| | - Aline Uwimana
- Rwanda Biomedical Center, Kigali, Rwanda; Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - David A Fidock
- Department of Microbiology and Immunology and Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
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3
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Stewart ATM, Mysore K, Njoroge TM, Winter N, Feng RS, Singh S, James LD, Singkhaimuk P, Sun L, Mohammed A, Oxley JD, Duckham C, Ponlawat A, Severson DW, Duman-Scheel M. Demonstration of RNAi Yeast Insecticide Activity in Semi-Field Larvicide and Attractive Targeted Sugar Bait Trials Conducted on Aedes and Culex Mosquitoes. INSECTS 2023; 14:950. [PMID: 38132622 PMCID: PMC10743515 DOI: 10.3390/insects14120950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/04/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023]
Abstract
Eco-friendly new mosquito control innovations are critical for the ongoing success of global mosquito control programs. In this study, Sh.463_56.10R, a robust RNA interference (RNAi) yeast insecticide strain that is suitable for scaled fermentation, was evaluated under semi-field conditions. Inactivated and dried Sh.463_56.10R yeast induced significant mortality of field strain Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus larvae in semi-field larvicide trials conducted outdoors in St. Augustine, Trinidad, where 100% of the larvae were dead within 24 h. The yeast was also stably suspended in commercial bait and deployed as an active ingredient in miniature attractive targeted sugar bait (ATSB) station sachets. The yeast ATSB induced high levels of Aedes and Culex mosquito morbidity in semi-field trials conducted in Trinidad, West Indies, as well as in Bangkok, Thailand, in which the consumption of the yeast resulted in adult female mosquito death within 48 h, faster than what was observed in laboratory trials. These findings support the pursuit of large-scale field trials to further evaluate the Sh.463_56.10R insecticide, a member of a promising new class of species-specific RNAi insecticides that could help combat insecticide resistance and support effective mosquito control programs worldwide.
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Affiliation(s)
- Akilah T. M. Stewart
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA; (A.T.M.S.); (K.M.); (T.M.N.); (L.S.); (D.W.S.)
- Eck Institute for Global Health, The University of Notre Dame, Notre Dame, IN 46556, USA
| | - Keshava Mysore
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA; (A.T.M.S.); (K.M.); (T.M.N.); (L.S.); (D.W.S.)
- Eck Institute for Global Health, The University of Notre Dame, Notre Dame, IN 46556, USA
| | - Teresia M. Njoroge
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA; (A.T.M.S.); (K.M.); (T.M.N.); (L.S.); (D.W.S.)
- Eck Institute for Global Health, The University of Notre Dame, Notre Dame, IN 46556, USA
| | - Nikhella Winter
- Department of Life Sciences, Faculty of Science & Technology, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago; (N.W.); (R.S.F.); (S.S.); (L.D.J.); (A.M.)
| | - Rachel Shui Feng
- Department of Life Sciences, Faculty of Science & Technology, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago; (N.W.); (R.S.F.); (S.S.); (L.D.J.); (A.M.)
| | - Satish Singh
- Department of Life Sciences, Faculty of Science & Technology, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago; (N.W.); (R.S.F.); (S.S.); (L.D.J.); (A.M.)
| | - Lester D. James
- Department of Life Sciences, Faculty of Science & Technology, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago; (N.W.); (R.S.F.); (S.S.); (L.D.J.); (A.M.)
| | - Preeraya Singkhaimuk
- Department of Entomology, US Army Medical Directorate–Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok 10400, Thailand; (P.S.); (A.P.)
| | - Longhua Sun
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA; (A.T.M.S.); (K.M.); (T.M.N.); (L.S.); (D.W.S.)
- Eck Institute for Global Health, The University of Notre Dame, Notre Dame, IN 46556, USA
| | - Azad Mohammed
- Department of Life Sciences, Faculty of Science & Technology, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago; (N.W.); (R.S.F.); (S.S.); (L.D.J.); (A.M.)
| | - James D. Oxley
- Southwest Research Institute, San Antonio, TX 78238, USA;
| | | | - Alongkot Ponlawat
- Department of Entomology, US Army Medical Directorate–Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok 10400, Thailand; (P.S.); (A.P.)
| | - David W. Severson
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA; (A.T.M.S.); (K.M.); (T.M.N.); (L.S.); (D.W.S.)
- Eck Institute for Global Health, The University of Notre Dame, Notre Dame, IN 46556, USA
- Department of Life Sciences, Faculty of Science & Technology, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago; (N.W.); (R.S.F.); (S.S.); (L.D.J.); (A.M.)
- Department of Biological Sciences, College of Science, The University of Notre Dame, Notre Dame, IN 46556, USA
| | - Molly Duman-Scheel
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA; (A.T.M.S.); (K.M.); (T.M.N.); (L.S.); (D.W.S.)
- Eck Institute for Global Health, The University of Notre Dame, Notre Dame, IN 46556, USA
- Department of Biological Sciences, College of Science, The University of Notre Dame, Notre Dame, IN 46556, USA
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Zheng R, Wang Q, Wu R, Paradkar PN, Hoffmann AA, Wang GH. Holobiont perspectives on tripartite interactions among microbiota, mosquitoes, and pathogens. THE ISME JOURNAL 2023; 17:1143-1152. [PMID: 37231184 PMCID: PMC10356850 DOI: 10.1038/s41396-023-01436-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 04/18/2023] [Accepted: 05/16/2023] [Indexed: 05/27/2023]
Abstract
Mosquito-borne diseases like dengue and malaria cause a significant global health burden. Unfortunately, current insecticides and environmental control strategies aimed at the vectors of these diseases are only moderately effective in decreasing disease burden. Understanding and manipulating the interaction between the mosquito holobiont (i.e., mosquitoes and their resident microbiota) and the pathogens transmitted by these mosquitoes to humans and animals could help in developing new disease control strategies. Different microorganisms found in the mosquito's microbiota affect traits related to mosquito survival, development, and reproduction. Here, we review the physiological effects of essential microbes on their mosquito hosts; the interactions between the mosquito holobiont and mosquito-borne pathogen (MBP) infections, including microbiota-induced host immune activation and Wolbachia-mediated pathogen blocking (PB); and the effects of environmental factors and host regulation on the composition of the microbiota. Finally, we briefly overview future directions in holobiont studies, and how these may lead to new effective control strategies against mosquitoes and their transmitted diseases.
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Affiliation(s)
- Ronger Zheng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qiqi Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Runbiao Wu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Prasad N Paradkar
- CSIRO Health and Biosecurity, Australian Centre for Disease Preparedness, Geelong, VIC, Australia
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Guan-Hong Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
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Biabi MFAB, Fogang B, Essangui E, Maloba F, Donkeu C, Keumoe R, Cheteug G, Magoudjou N, Slam C, Kemleu S, Efange N, Perraut R, Nsango SE, Eboumbou Moukoko CE, Assam JPA, Etoa FX, Lamb T, Ayong L. High Prevalence of Polyclonal Plasmodium falciparum Infections and Association with Poor IgG Antibody Responses in a Hyper-Endemic Area in Cameroon. Trop Med Infect Dis 2023; 8:390. [PMID: 37624328 PMCID: PMC10459087 DOI: 10.3390/tropicalmed8080390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 08/26/2023] Open
Abstract
Malaria remains a major public health problem worldwide, with eradication efforts thwarted by drug and insecticide resistance and the lack of a broadly effective malaria vaccine. In continuously exposed communities, polyclonal infections are thought to reduce the risk of severe disease and promote the establishment of asymptomatic infections. We sought to investigate the relationship between the complexity of P. falciparum infection and underlying host adaptive immune responses in an area with a high prevalence of asymptomatic parasitaemia in Cameroon. A cross-sectional study of 353 individuals aged 2 to 86 years (median age = 16 years) was conducted in five villages in the Centre Region of Cameroon. Plasmodium falciparum infection was detected by multiplex nested PCR in 316 samples, of which 278 were successfully genotyped. Of these, 60.1% (167/278) were polyclonal infections, the majority (80.2%) of which were from asymptomatic carriers. Host-parasite factors associated with polyclonal infection in the study population included peripheral blood parasite density, participant age and village of residence. The number of parasite clones per infected sample increased significantly with parasite density (r = 0.3912, p < 0.0001) but decreased with participant age (r = -0.4860, p < 0.0001). Parasitaemia and the number of clones per sample correlated negatively with total plasma levels of IgG antibodies to three highly reactive P. falciparum antigens (MSP-1p19, MSP-3 and EBA175) and two soluble antigen extracts (merozoite and mixed stage antigens). Surprisingly, we observed no association between the frequency of polyclonal infection and susceptibility to clinical disease as assessed by the recent occurrence of malarial symptoms or duration since the previous fever episode. Overall, the data indicate that in areas with the high perennial transmission of P. falciparum, parasite polyclonality is dependent on underlying host antibody responses, with the majority of polyclonal infections occurring in persons with low levels of protective anti-plasmodial antibodies.
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Affiliation(s)
- Marie Florence A Bite Biabi
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Douala, Douala BP 2701, Cameroon
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon
| | - Franklin Maloba
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Rodrigue Keumoe
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Medical Laboratory Sciences, Faculty of Science, University of Buea, Buea BP 63, Cameroon
| | - Nina Magoudjou
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Celine Slam
- Department of Pathology, School of Medicine, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA;
| | - Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
| | - Noella Efange
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Buea, Buea BP 63, Cameroon
| | - Ronald Perraut
- Centre Pasteur du Cameroun Annex, Garoua BP 921, Cameroon;
| | - Sandrine Eveline Nsango
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon
| | - Jean Paul Assam Assam
- Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon; (J.P.A.A.); (F.-X.E.)
| | - François-Xavier Etoa
- Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon; (J.P.A.A.); (F.-X.E.)
| | - Tracey Lamb
- Department of Pathology, School of Medicine, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA;
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
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6
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Hixson B, Huot L, Morejon B, Yang X, Nagy P, Michel K, Buchon N. The transcriptional response in mosquitoes distinguishes between fungi and bacteria but not Gram types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550663. [PMID: 37546902 PMCID: PMC10402080 DOI: 10.1101/2023.07.26.550663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Mosquitoes are prolific vectors of human pathogens; a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster , is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae ( s.l. ) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti , however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.
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