Single-cell analysis of mosquito hemocytes identifies signatures of immune cell sub-types and cell differentiation

  1. Hyeogsun Kwon
  2. Mubasher Mohammed
  3. Oscar Franzén
  4. Johan Ankarklev
  5. Ryan Smith  Is a corresponding author
  1. Iowa State university, United States
  2. Stockholm University, Sweden
  3. Karolinska Institutet, Sweden
  4. Iowa State University, United States

Abstract

Mosquito immune cells, known as hemocytes, are integral to cellular and humoral responses that limit pathogen survival and mediate immune priming. However, without reliable cell markers and genetic tools, studies of mosquito immune cells have been limited to morphological observations, leaving several aspects of their biology uncharacterized. Here, we use single-cell RNA sequencing (scRNA-seq) to characterize mosquito immune cells, demonstrating an increased complexity to previously defined prohemocyte, oenocytoid, and granulocyte subtypes. Through functional assays relying on phagocytosis, phagocyte depletion, and RNA-FISH experiments, we define markers to accurately distinguish immune cell subtypes and provide evidence for immune cell maturation and differentiation. In addition, gene-silencing experiments demonstrate the importance of lozenge in defining the mosquito oenocytoid cell fate. Together, our scRNA-seq analysis provides an important foundation for future studies of mosquito immune cell biology and a valuable resource for comparative invertebrate immunology.

Data availability

Data generated and analysed in this study are included in the manuscript and supporting files. In addition, data can be visualized and downloaded using the following server: https://alona.panglaodb.se/results.html?job=2c2r1NM5Zl2qcW44RSrjkHf3Oyv51y_5f09d74b770c9N/A

Article and author information

Author details

  1. Hyeogsun Kwon

    Entomology, Iowa State university, Ames, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4141-4061
  2. Mubasher Mohammed

    Molecular Biosciences, Stockholm University, Stockholm, Sweden
    Competing interests
    The authors declare that no competing interests exist.
  3. Oscar Franzén

    Integrated Cardio Metabolic Centre, Department of Medicine, Karolinska Institutet, Huddinge, Sweden
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7573-0812
  4. Johan Ankarklev

    Molecular Biosciences, Stockholm University, Stockholm, Sweden
    Competing interests
    The authors declare that no competing interests exist.
  5. Ryan Smith

    Entomology, Iowa State University, Ames, United States
    For correspondence
    smithr@iastate.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0245-2265

Funding

Swedish Society for Medical Research

  • Johan Ankarklev

Swedish Research Council

  • Johan Ankarklev

National Institute of Allergy and Infectious Diseases (R21AI144705)

  • Ryan Smith

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: The protocols and procedures used in this study were approved by the Animal Care and Use Committee at Iowa State University (IACUC-18-228).

Copyright

© 2021, Kwon 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.

Metrics

  • 4,092
    views
  • 601
    downloads
  • 50
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Hyeogsun Kwon
  2. Mubasher Mohammed
  3. Oscar Franzén
  4. Johan Ankarklev
  5. Ryan Smith
(2021)
Single-cell analysis of mosquito hemocytes identifies signatures of immune cell sub-types and cell differentiation
eLife 10:e66192.
https://doi.org/10.7554/eLife.66192

Share this article

https://doi.org/10.7554/eLife.66192

Further reading

    1. Genetics and Genomics
    2. Neuroscience
    Akanksha Bafna, Gareth Banks ... Patrick M Nolan
    Research Article

    The mammalian suprachiasmatic nucleus (SCN), situated in the ventral hypothalamus, directs daily cellular and physiological rhythms across the body. The SCN clockwork is a self-sustaining transcriptional-translational feedback loop (TTFL) that in turn coordinates the expression of clock-controlled genes (CCGs) directing circadian programmes of SCN cellular activity. In the mouse, the transcription factor, ZFHX3 (zinc finger homeobox-3), is necessary for the development of the SCN and influences circadian behaviour in the adult. The molecular mechanisms by which ZFHX3 affects the SCN at transcriptomic and genomic levels are, however, poorly defined. Here, we used chromatin immunoprecipitation sequencing to map the genomic localization of ZFHX3-binding sites in SCN chromatin. To test for function, we then conducted comprehensive RNA sequencing at six distinct times-of-day to compare the SCN transcriptional profiles of control and ZFHX3-conditional null mutants. We show that the genome-wide occupancy of ZFHX3 occurs predominantly around gene transcription start sites, co-localizing with known histone modifications, and preferentially partnering with clock transcription factors (CLOCK, BMAL1) to regulate clock gene(s) transcription. Correspondingly, we show that the conditional loss of ZFHX3 in the adult has a dramatic effect on the SCN transcriptome, including changes in the levels of transcripts encoding elements of numerous neuropeptide neurotransmitter systems while attenuating the daily oscillation of the clock TF Bmal1. Furthermore, various TTFL genes and CCGs exhibited altered circadian expression profiles, consistent with an advanced in daily behavioural rhythms under 12 h light–12 h dark conditions. Together, these findings reveal the extensive genome-wide regulation mediated by ZFHX3 in the central clock that orchestrates daily timekeeping in mammals.