Development and characterization of a continuous cell line, AFKM-On-H, from hemocytes of the European corn borer Ostrinia nubilalis (Hübner) (Lepidoptera, Pyralidae)

Development of two continuous hemocyte cell sublines in the Asian corn borer Ostrinia furnacalis and the identification of molecular markers for hemocytes

Granulocytes and plasmatocytes play important roles in clearing foreign objects in insects, but it is difficult to distinguish between them in immune reactions. Based on the hemocyte cell line SYSU-OfHe-C established at our lab, two cell sublines, SYSU-OfHe-C Granulocyte (Gr cells) and SYSU-OfHe-C Plasmatocyte (Pl cells), which possess the morphological characteristics of granulocytes and plasmatocytes, respectively, were established. Gr and Pl cells showed different behaviors in immune reactions, such as spreading, phagocytosis and encapsulation. Pl cells were easier to spread, but Gr cells tended to undergo aggregation, indicating that they may take different strategies to clear foreign objects. These results also suggested that granulocytes and plasmatocytes may express some different proteins. By comparing the gene expression in cells from the two sublines, 1662 differentially expressed genes were identified, and 13 out of 30 transmembrane proteins highly expressed in Pl cells (six) or Gr cells (seven) were further screened and confirmed by reverse-transcription polymerase chain reaction (PCR). Finally, three transmembrane genes specifically expressed in Pl cells and two transmembrane genes specifically expressed in Gr cells were screened out based on their expressions in immune reactions by quantitative PCR analysis. These genes may potentially be used as molecular markers to distinguish between granulocytes and plasmatocytes in Ostrinia furnacalis, and further to clarify the functions of immune hemocytes in cellular immune reaction such as encapsulation and so on.

Invertebrate Iridoviruses: A Glance over the Last Decade

Members of the family Iridoviridae (iridovirids) are large dsDNA viruses that infect both invertebrate and vertebrate ectotherms and whose symptoms range in severity from minor reductions in host fitness to systemic disease and large-scale mortality. Several characteristics have been useful for classifying iridoviruses; however, novel strains are continuously being discovered and, in many cases, reliable classification has been challenging. Further impeding classification, invertebrate iridoviruses (IIVs) can occasionally infect vertebrates; thus, host range is often not a useful criterion for classification. In this review, we discuss the current classification of iridovirids, focusing on genomic and structural features that distinguish vertebrate and invertebrate iridovirids and viral factors linked to host interactions in IIV6 (Invertebrate iridescent virus 6). In addition, we show for the first time how complete genome sequences of viral isolates can be leveraged to improve classification of new iridovirid isolates and resolve ambiguous relations. Improved classification of the iridoviruses may facilitate the identification of genus-specific virulence factors linked with diverse host phenotypes and host interactions.

Available Lepidopteran Insect Cell Lines

This chapter lists the known cell lines from Lepidoptera, largely based on previous compilations of insect cell lines published by W. Fred Hink. More than 320 lines from 65 species are listed. The official designation is given for each cell line as well as the species, tissue source, and, when known, the susceptibilities to baculoviruses.

A continuous cell line, SYSU-OfHe-C, from hemocytes of Ostrinia furnacalis possesses immune ability depending on the presence of larval plasma

A continuous cell line, SYSU-OfHe-C, from larval hemocytes of corn borer, Ostrinia furnacalis was established. With increasing passages, the cells grew increasingly faster, and approximately 45% of the cells were in division at passage 55. The culture was mainly composed of two types of cells, granulocytes and plasmatocytes, which showed different division and proliferation behaviors, but possessed similar phagocytic ability. Its spreading ability was significantly weaker than that of hemocytes from naïve larva; however, it could be promoted by larval plasma. Furthermore, its encapsulation ability was also promoted by larval plasma to form multilayer capsules on Sephadex A-25 beads. Finally, the expression of several immune-related genes was verified after provocation by microbes or Sephadex beads. These results indicated that the cell line possessed immune ability depending on the presence of plasma of naïve larvae and are beneficial to studies of insect cellular systems.