Data on Drosophila clots and hemocyte morphologies using GFP-tagged secretory proteins: Prophenoloxidase and transglutaminase.

Insect hemolymph coagulation: Kinetics of classically and non-classically secreted clotting factors Schmid et al., 2019. The linked article demonstrates the localization of two secretory proteins in Drosophila melanogaster, Prophenoloxidase (PPO2) and Transglutaminase-A (Tg) in hemocytes as well the clot with different tissue-specific drivers. Here we provide further data for the usefulness of the GFP-tagged version of the two crosslinking enzymes that are involved in clot hardening. The morphology of crystal cells is described using GFP-tagged PPO2 rather than with the use of antibodies in ex vivo hemolymph preparations. The use of the GFP-tagged proteins PPO2 and Tg is shown in additional contexts.

Insect hemolymph coagulation: Kinetics of classically and non-classically secreted clotting factors.

In most insects, hemolymph coagulation, which is analogous to mammalian blood clotting, involves close collaboration between humoral and cellular components. To gain insights into the secretion of cellular clotting factors, we created tagged versions of three different clotting factors. Our focus was on factors which are released in a non-classical manner and to characterize them in comparison to a protein that is classically released, namely Glutactin (Glt). Transglutaminase-A (Tg) and Prophenoloxidase 2 (PPO2), both of which lack signal peptide sequences, have been previously demonstrated to be released from plasmatocytes and crystal cells (CCs) respectively, the two hemocyte classes in naïve larvae. We found that at the molecular level, Tg secretion resembles the release of tissue transglutaminase in mammals. Specifically, Drosophila Tg is associated with vesicular membranes and remains membrane-bound after release, in contrast to Glt, which we found localizes to a different class of vesicles and is integrated into clot fibers. PPO2 on the other hand, is set free from CCs through cytolysis. We confirm that PPO2 is a central component of the cytosolic crystals and find that the distribution of PPO2 appears to vary across crystals and cells. We propose a tentative scheme for the secretory events during early and late hemolymph coagulation.

Human respiratory syncytial virus memphis 37 causes acute respiratory disease in perinatal lamb lung.

Respiratory syncytial virus (RSV) is the leading cause of hospitalization due to respiratory illness among infants and young children of industrialized countries. There is a lack of understanding of the severe disease mechanisms as well as limited treatment options, none of which are fully satisfactory. This is partly due to lack of a relevant animal model of perinatal RSV infection that mimics moderate to severe disease in infants. We and others have shown mild disease in perinatal lambs with either a bovine or a human A2 strain of RSV. The Memphis 37 clinical strain of human RSV has been used to produce mild to moderate upper respiratory disease in healthy adult volunteers. We hypothesized that the Memphis 37 strain of RSV would infect perinatal lambs and produce clinical disease similar to that in human infants. Perinatal (3- to 5-day-old) lambs were inoculated intranasally with 2 mL/nostril of 1×10(5) focus-forming units (FFU)/mL (n=2) or 2.1×10(8) FFU/mL (n=3) of RSV Memphis 37. Clinical signs, gross and histological lesions, and immune and inflammatory responses were assessed. Memphis 37 caused moderate to severe gross and histologic lesions along with increased mRNA expression of macrophage inflammatory protein. Clinically, four of the five infected lambs had a mild to severe increase in expiratory effort. Intranasally administered RSV strain Memphis 37 infects neonatal lambs with gross, histologic, and immune responses similar to those observed in human infants.