Transcriptome analyses reveal Litopenaeus vannamei hemocytes response to lipopolysaccharide.

Although vertebrate immunity has been well studied for the past decades, invertebrate immunity was much less explored. One possible reason was that in vitro culture system was not well established. In this study, Litopenaeus vannamei was applied as an invertebrate study model. Primary culture conditions for L. vannamei hemocytes were optimized to get relatively quiescent state cells. LPS was used as an immune stimulator and the responses of primary cultured hemocytes were transcriptomically analyzed. Our results showed that around 1,600 genes were upregulated and 800 genes were downregulated from LPS treated hemocytes. The altered genes could be classified into three categories: upregulated, downregulated, upregulated and then downregulated. Further qPCR validation showed that ubiquitin, ubiquitin-conjugating enzyme E2 C, ubiquitin-conjugating enzyme H1 and ubiquitin-conjugating enzyme H5b in ubiquitin-proteasome pathway were upregulated, cytochrome c oxidase 1, NADH dehydrogenase 1, Inosine-5'-monophosphate dehydrogenase 1b and phospholipid-transporting ATPase IA in mitochondria oxidation phosphorylation were downregulated. Our results showed that L. vannamei hemocyte inflammation responses share a lot of similarities with mammalian macrophage inflammation responses.