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Switching between humoral and cellular immune responses in Drosophila is guided by the cytokine GBP.

ABSTRACT: Insects combat infection through carefully measured cellular (for example, phagocytosis) and humoral (for example, secretion of antimicrobial peptides (AMPs)) innate immune responses. Little is known concerning how these different defense mechanisms are coordinated. Here, we use insect plasmatocytes and hemocyte-like Drosophila S2 cells to characterize mechanisms of immunity that operate in the haemocoel. We demonstrate that a Drosophila cytokine, growth-blocking peptides (GBP), acts through the phospholipase C (PLC)/Ca(2+) signalling cascade to mediate the secretion of Pvf, a ligand for platelet-derived growth factor- and vascular endothelial growth factor-receptor (Pvr) homologue. Activated Pvr recruits extracellular signal-regulated protein kinase to inhibit humoral immune responses, while stimulating cell 'spreading', an initiating event in cellular immunity. The double-stranded RNA (dsRNA)-targeted knockdown of either Pvf2 or Pvr inhibits GBP-mediated cell spreading and activates AMP expression. Conversely, Pvf2 overexpression enhances cell spreading but inhibits AMP expression. Thus, we describe mechanisms to initiate immune programs that are either humoral or cellular in nature, but not both; such immunophysiological polarization may minimize homeostatic imbalance during infection.

SUBMITTER: Tsuzuki S

PROVIDER: S-EPMC5755975 | biostudies-literature | 2014 Aug

REPOSITORIES: biostudies-literature

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Switching between humoral and cellular immune responses in Drosophila is guided by the cytokine GBP.

Tsuzuki Seiji S Matsumoto Hitoshi H Furihata Shunsuke S Ryuda Masasuke M Tanaka Hirotoshi H Sung Eui Jae EJ Bird Gary S GS Zhou Yixing Y Shears Stephen B SB Hayakawa Yoichi Y

Nature communications 20140818

Insects combat infection through carefully measured cellular (for example, phagocytosis) and humoral (for example, secretion of antimicrobial peptides (AMPs)) innate immune responses. Little is known concerning how these different defense mechanisms are coordinated. Here, we use insect plasmatocytes and hemocyte-like Drosophila S2 cells to characterize mechanisms of immunity that operate in the haemocoel. We demonstrate that a Drosophila cytokine, growth-blocking peptides (GBP), acts through the ...[more]

PMID: 25130174

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Switching between humoral and cellular immune responses in Drosophila is guided by the cytokine GBP.

Publications

Switching between humoral and cellular immune responses in Drosophila is guided by the cytokine GBP.

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