Single-cell sequencing of tumor-associated macrophages in a model.

Introduction: Tumor-associated macrophages may act to either limit or promote tumor growth, yet the molecular basis for either path is poorly characterized.

Methods: We use a larval model that expresses a dominant-active version of the Ras-oncogene (Ras) to study dysplastic growth during early tumor progression. We performed single-cell RNA-sequencing of macrophage-like hemocytes to characterize these cells in tumor- compared to wild-type larvae.

Chitinase-like proteins promoting tumorigenesis through disruption of cell polarity enlarged endosomal vesicles.

Introduction: Chitinase-like proteins (CLPs) are associated with tissue-remodeling and inflammation but also with several disorders, including fibrosis, atherosclerosis, allergies, and cancer. However, CLP's role in tumors is far from clear.

Methods: Here, we utilize and molecular genetics to investigate the function of CLPs (imaginal disc growth factors; Idgf's) in dysplastic salivary glands.

TRP channels, the missing link for Ca tuning by a unicellular eukaryotic parasite?

Sensing and responding to changes in the cellular environments are essential for the diverse family of Apicomplexan parasites, which undergo complex life cycles comprised of both extracellular and obligate intracellular stages. Despite evidence of paramount roles for Ca, the molecular players behind how parasites sense Ca and initiate Ca signaling cascades have remained enigmatic. In a recent publication, Marquez-Nogueras et al.

Anti-Fibrotic Activity of an Antimicrobial Peptide in a Drosophila Model.

Fibrotic lesions accompany several pathological conditions, including tumors. We show that expression of a dominant-active form of the Ras oncogene in Drosophila salivary glands (SGs) leads to redistribution of components of the basement membrane (BM) and fibrotic lesions. Similar to several types of mammalian fibrosis, the disturbed BM attracts clot components, including insect transglutaminase and phenoloxidase.

A Population Genomic Investigation of Immune Cell Diversity and Phagocytic Capacity in a Butterfly.

Insects rely on their innate immune system to successfully mediate complex interactions with their internal microbiota, as well as the microbes present in the environment. Given the variation in microbes across habitats, the challenges to respond to them are likely to result in local adaptations in the immune system. Here we focus upon phagocytosis, a mechanism by which pathogens and foreign particles are engulfed in order to be contained, killed, and processed.

Physiological Tradeoffs of Immune Response Differs by Infection Type in .

Understanding the tradeoffs that result from successful infection responses is central to understanding how life histories evolve. Gaining such insights, however, can be challenging, as they may be pathogen specific and confounded with experimental design. Here, we investigated whether infection from gram positive or negative bacteria results in different physiological tradeoffs, and whether these infections impact life history later in life (post-diapause development), in the butterfly .

Tissue-autonomous immune response regulates stress signaling during hypertrophy.

Postmitotic tissues are incapable of replacing damaged cells through proliferation, but need to rely on buffering mechanisms to prevent tissue disintegration. By constitutively activating the Ras/MAPK-pathway via -overexpression in the postmitotic salivary glands (SGs) of larvae, we overrode the glands adaptability to growth signals and induced hypertrophy. The accompanied loss of tissue integrity, recognition by cellular immunity, and cell death are all buffered by blocking stress signaling through a genuine tissue-autonomous immune response.

Special Issue: Insects, Nematodes, and Their Symbiotic Bacteria.

This special issue contains articles that add to the ever-expanding toolbox of insect pathogenic nematodes (entomopathogenic nematodes; EPNs) as well articles that provide new insights into the mutualistic interaction between EPNs and their hosts. The study of natural infection models such as EPNs allows detailed insight into micro- and macro-evolutionary dynamics of innate immune reactions, including known but also emerging branches of innate immunity. Additional new insights into the kinetics of EPN infections are gained by increased spatiotemporal resolution of advanced transcriptome studies and live imaging.

Differential Expression of Immune Genes between Two Closely Related Beetle Species with Different Immunocompetence following Attack by Asecodes parviclava.

Endoparasitoid wasps are important natural enemies of many insect species and are major selective forces on the host immune system. Despite increased interest in insect antiparasitoid immunity, there is sparse information on the evolutionary dynamics of biological pathways and gene regulation involved in host immune defense outside Drosophila species. We de novo assembled transcriptomes from two beetle species and used time-course differential expression analysis to investigate gene expression differences in closely related species Galerucella pusilla and G.

Responses against Entomopathogenic Nematodes: Focus on Hemolymph Clots.

Several insect innate immune mechanisms are activated in response to infection by entomopathogenic nematodes (EPNs). In this review, we focus on the coagulation of hemolymph, which acts to stop bleeding after injury and prevent access of pathogens to the body cavity. After providing a general overview of invertebrate coagulation systems, we discuss recent findings in which demonstrate that clots protect against EPN infections.

High-Resolution Infection Kinetics of Entomopathogenic Nematodes Entering .

Entomopathogenic nematodes (EPNs) have been a useful model for studying wound healing in insects due to their natural mechanism of entering an insect host either through the cuticle or an orifice. While many experiments have shed light on nematode and host behavior, as well as the host immune response, details regarding early nematode entry and proliferative events have been limited. Using high-resolution microscopy, we provide data on the early infection kinetics of and its symbiotic bacteria, .

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 , Prophenoloxidase (PPO2) and Transglutaminase-A (Tg) in hemocytes as well the clot with different tissue-specific drivers.

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).

Corrigendum: Characterization of Reproductive Dormancy in Male .

[This corrects the article on p. 572 in vol. 7, PMID: 27932997.

The Immune Phenotype of Three Leukemia Models.

Many leukemia patients suffer from dysregulation of their immune system, making them more susceptible to infections and leading to general weakening (cachexia). Both adaptive and innate immunity are affected. The fruit fly has an innate immune system, including cells of the myeloid lineage (hemocytes).

Geographic variation and trade-offs in parasitoid virulence.

Host-parasitoid systems are characterized by a continuous development of new defence strategies in hosts and counter-defence mechanisms in parasitoids. This co-evolutionary arms race makes host-parasitoid systems excellent for understanding trade-offs in host use caused by evolutionary changes in host immune responses and parasitoid virulence. However, knowledge obtained from natural host-parasitoid systems on such trade-offs is still limited.

Multi-target Chromogenic Whole-mount In Situ Hybridization for Comparing Gene Expression Domains in Drosophila Embryos.

To analyze gene regulatory networks active during embryonic development and organogenesis it is essential to precisely define how the different genes are expressed in spatial relation to each other in situ. Multi-target chromogenic whole-mount in situ hybridization (MC-WISH) greatly facilitates the instant comparison of gene expression patterns, as it allows distinctive visualization of different mRNA species in contrasting colors in the same sample specimen. This provides the possibility to relate gene expression domains topographically to each other with high accuracy and to define unique and overlapping expression sites.

Slowed aging during reproductive dormancy is reflected in genome-wide transcriptome changes in Drosophila melanogaster.

Background: In models extensively used in studies of aging and extended lifespan, such as C. elegans and Drosophila, adult senescence is regulated by gene networks that are likely to be similar to ones that underlie lifespan extension during dormancy. These include the evolutionarily conserved insulin/IGF, TOR and germ line-signaling pathways.

The Drosophila Chitinase-Like Protein IDGF3 Is Involved in Protection against Nematodes and in Wound Healing.

Chitinase-like proteins (CLPs) of the 18 glycosyl hydrolase family retain structural similarity to chitinases but lack enzymatic activity. Although CLPs are upregulated in several human disorders that affect regenerative and inflammatory processes, very little is known about their normal physiological function. We show that an insect CLP (Drosophila imaginal disc growth factor 3, IDGF3) plays an immune-protective role during entomopathogenic nematode (EPN) infections.

Apoptosis in Hemocytes Induces a Shift in Effector Mechanisms in the Drosophila Immune System and Leads to a Pro-Inflammatory State.

Apart from their role in cellular immunity via phagocytosis and encapsulation, Drosophila hemocytes release soluble factors such as antimicrobial peptides, and cytokines to induce humoral responses. In addition, they participate in coagulation and wounding, and in development. To assess their role during infection with entomopathogenic nematodes, we depleted plasmatocytes and crystal cells, the two classes of hemocytes present in naïve larvae by expressing proapoptotic proteins in order to produce hemocyte-free (Hml-apo, originally called Hemoless) larvae.

The sleeping beauty: how reproductive diapause affects hormone signaling, metabolism, immune response and somatic maintenance in Drosophila melanogaster.

Some organisms can adapt to seasonal and other environmental challenges by entering a state of dormancy, diapause. Thus, insects exposed to decreased temperature and short photoperiod enter a state of arrested development, lowered metabolism, and increased stress resistance. Drosophila melanogaster females can enter a shallow reproductive diapause in the adult stage, which drastically reduces organismal senescence, but little is known about the physiology and endocrinology associated with this dormancy, and the genes involved in its regulation.

Differences in cellular immune competence explain parasitoid resistance for two coleopteran species.

The immune defence of an organism is evolving continuously, causing counteradaptations in interacting species, which in turn affect other ecological and evolutionary processes. Until recently comparative studies of species interactions and immunity, combining information from both ecological and immunological fields, have been rare. The cellular immune defense in insects, mainly mediated by circulating hemocytes, has been studied primarily in Lepidoptera and Diptera, whereas corresponding information about coleopteran species is still scarce.