Serotonin modulates insect hemocyte phagocytosis via two different serotonin receptors

  1. Yixiang Qi
  2. Jia Huang  Is a corresponding author
  3. Meng-qi Li
  4. Ya-su Wu
  5. Ren-ying Xia
  6. Gong-yin Ye
  1. Zhejiang University, China

Abstract

Serotonin (5-HT) modulates both neural and immune responses in vertebrates, but its role in insect immunity remains uncertain. We report that hemocytes in the caterpillar, Pieris rapae are able to synthesize 5-HT following activation by lipopolysaccharide. The inhibition of a serotonin-generating enzyme with either pharmacological blockade or RNAi knock-down impaired hemocyte phagocytosis. Biochemical and functional experiments showed that naive hemocytes primarily express 5-HT1B and 5-HT2B receptors. The blockade of 5-HT1B significantly reduced phagocytic ability, however the blockade of 5-HT2B increased hemocyte phagocytosis. The 5-HT1B-null Drosophila melanogaster mutants showed higher mortality than controls when infected with bacteria, due to their decreased phagocytotic ability. Flies expressing 5-HT1B or 5-HT2B RNAi in hemocytes also showed similar sensitivity to infection. Combined, these data demonstrate that 5-HT mediates hemocyte phagocytosis through 5-HT1B and 5-HT2B receptors and serotonergic signaling performs critical modulatory functions in immune systems of animals separated by 500 million years of evolution.

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Author details

  1. Yixiang Qi

    State Key Laboratory of Rice Biology and Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  2. Jia Huang

    State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
    For correspondence
    huangj@zju.edu.cn
    Competing interests
    The authors declare that no competing interests exist.
  3. Meng-qi Li

    State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  4. Ya-su Wu

    State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  5. Ren-ying Xia

    State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.
  6. Gong-yin Ye

    State Key Laboratory of Rice Biology, Key Laboratory of Agricultural Entomology of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Utpal Banerjee, University of California, Los Angeles, United States

Publication history

  1. Received: October 10, 2015
  2. Accepted: March 10, 2016
  3. Accepted Manuscript published: March 14, 2016 (version 1)
  4. Version of Record published: April 4, 2016 (version 2)

Copyright

© 2016, Qi et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Yixiang Qi
  2. Jia Huang
  3. Meng-qi Li
  4. Ya-su Wu
  5. Ren-ying Xia
  6. Gong-yin Ye
(2016)
Serotonin modulates insect hemocyte phagocytosis via two different serotonin receptors
eLife 5:e12241.
https://doi.org/10.7554/eLife.12241

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