Many fundamental advances in the field of innate immunity have been made through studying the immune system of the fruit fly, Drosophila melanogaster. Their simplified physiology has allowed for the identification and dissection of conserved immune receptors and signaling pathways, which have resulted in numerous medical advances and contributed greatly to the overall progress of the immunity field. The value of studying invertebrate immunity has been recognized by many, with a variety of researchers exploring this topic in model systems ranging from aphids to grasshoppers. One project in the Bosco Lab is expanding the investigation of the immune system to other closely related fruit fly species, we are not only shedding light on the evolution of the immune system, but also hope to discover novel immune processes.
Through this investigation, we have begun to characterize a poorly described immune cell termed a nematocyte. These cells are generated in response to an immune challenge, such as infection of a parasite. We have shown that, upon immune induction, nematocytes develop long projectiles, and create an organized meshwork of cells analogous to a cell ‘web’. The effectiveness of these cells as a part of the immune response is dependent on the creation of this multi-cellular structure. However, the type of attachments between cells in these structures cannot be determined using standard light microscopy and remains an open question in our research.
With the generous support of the Alumni Research Award we have been able to explore the ultrastructure of these cells using transmission electron microscopy (TEM). This imaging technique has provided a high-resolution view of the internal subcellular structures and organization of these cells that is enhancing our understanding and characterization of this immune response. In addition, this experiment has allowed us to begin uncovering the larger scale arrangement of these multicellular immune structures. As we further analyze these images we expect to uncover data that will continue to inform our view of how individual blood cells are able to organize into a larger structure and bring insight into the cellular coordination of this immune response.