Volume 98, Issue 9 pp. 757-769
Original Article

Hemocyte-specific FREP13 abrogates the exogenous bacterial population in the hemolymph and promotes midgut endosymbionts in Anopheles stephensi

Charu Chauhan

Charu Chauhan

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, India

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Tanwee Das De

Tanwee Das De

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

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Seena Kumari

Seena Kumari

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, India

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Jyoti Rani

Jyoti Rani

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

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Punita Sharma

Punita Sharma

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

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Sanjay Tevatiya

Sanjay Tevatiya

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, India

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Kailash C Pandey

Kailash C Pandey

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

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Veena Pande

Veena Pande

Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, India

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Rajnikant Dixit

Corresponding Author

Rajnikant Dixit

Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi, 110077 India

Correspondence

Rajnikant Dixit, Laboratory of Host-Parasite Interaction Studies, ICMR-National Institute of Malaria Research, Dwarka, New Delhi 110077, India.

E-mail: [email protected]

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First published: 05 July 2020
Citations: 4

Abstract

The immune blood cells “hemocytes” of mosquitoes impart a highly selective immune response against various microorganisms/pathogens. Among several immune effectors, fibrinogen-related proteins (FREPs) have been recognized as key modulators of cellular immune responses; however, their physiological relevance has not been investigated in detail. Our ongoing comparative RNA-sequencing analysis identified a total of 13 FREPs originating from naïve sugar-fed, blood-fed, bacterial challenged and Plasmodium vivax–infected hemocytes in Anopheles stephensi. Transcriptional profiling of the selected seven FREP transcripts showed distinct responses against different pathophysiological conditions, where an exclusive induction of FREP12 after 10 days of P. vivax infection was observed. This represents a possible role of FREP12 in immunity against free circulating sporozoites and needs to be explored in the future. When challenged with live bacterial injection in the thorax, we observed a higher affinity of FREP13 and FREP65 toward Gram-negative and Gram-positive bacteria in the mosquito hemocytes, respectively. Furthermore, we observed increased bacterial survival and proliferation, which is likely compromised by the downregulation of TEP1, in FREP13 messenger RNA–depleted mosquito hemolymph. In contrast, after blood-feeding, we also noticed a significant delay of 24 h in the enrichment of gut endosymbionts in the FREP13-silenced mosquitoes. Taken together, we conclude that hemocyte-specific FREP13 carries the unique ability of tissue-specific regulation, having an antagonistic antibacterial role in the hemolymph, and an agonistic role against gut endosymbionts.

Conflict of Interest

The authors declare no conflicts of interest.

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