The Sepharose was incubated with the hemocyte lysate overnight at 4C. of the most important species in aquaculture, is affected worldwide by diseases, notably those caused by white spot syndrome virus (WSSV). WSSV has resulted in large economic losses of the shrimp aquaculture industry. Therefore, the control of this virus is important to ensure the long-term survival of shrimp aquaculture. Due to the extreme virulence of WSSV, preventing and inhibiting the spread of the virus is very difficult. It is well known that the disease resistance of shrimp, as an invertebrate, is entirely dependent on the innate immune system, including cellular and humoral responses . The innate immune system is the first line of inducible NCT-503 host defense against bacterial, fungal and viral pathogens . Although most of shrimp die because of the WSSV infection, some of the WSSV-infected shrimp survive, indicating that shrimp possess immune factors responsible for the shrimp resistance against the virus invasion. As reported, some DNAJC15 shrimp proteins, such as PmAV, hemocyanin, Ran and Rab6, take great effects on the antiviral immunity NCT-503 of shrimp [3C6]. The Toll, immune deficiency (IMD) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways are the primary signaling pathways that regulate the immune response of invertebrates against the virus infection in shrimp . In recent years, small interfering RNAs (siRNAs) and microRNAs (miRNAs) have been found to mediate the antiviral defense in shrimp [8C11]. The siRNAs and miRNAs function by targeting the host and/or virus genes. Up to date, however, the immune factors involved in shrimp defenses against the virus invasion have not intensively investigated. As well known, cytokines play important roles in the animal immune defenses against pathogenic infection [12, 13]. Generally, cytokines are polypeptides or proteins with low molecular masses that are secreted by activated immunocytes or matrix cells. Cytokines have enormous impacts on the development of the immune system, the host defense and tumor immunobiology . In vertebrates, the innate immune cells, including macrophages and NCT-503 dendritic cells, express Toll-like receptors (TLRs), which bind to conserved sequences expressed by microorganisms . Upon recognition of their ligands on microorganisms, TLRs induce the expression of a variety of host defense genes, including antimicrobial peptides, inflammatory cytokines and chemokines and other effectors against the invading pathogens. The intracellular signaling pathway activated by TLRs is conserved from to mammals . For viral infections, virus-associated molecules, such as genomic DNA or RNA, produced in infected cells can be recognized by the host pattern-recognition receptors (PRRs) expressed in innate immune cells . After recognition of viral components, PRRs initiate effective antiviral responses in the host, including the production of a variety of cytokines and the induction of inflammatory and adaptive immune responses . Particularly, type I interferon is the key cytokines produced by hosts against the virus infection, which mediate the induction of both the innate immune response and the adaptive immune response to viruses [18,19]. At present, the roles of cytokines in the immunity of vertebrates have been well documented. In invertebrates, several studies have shown that cytokines are present and have various roles, such as the cytokine TNF in the Toll pathways of fruitfly and penaeidin of shrimp [20, 21]. However, the information on the effects of cytokines in the innate immunity of invertebrates is limited. In this investigation, the cytokines of shrimp were characterized to elucidate the roles of cytokines in the invertebrate immune response against viral infection. The results showed.