Particle uptake driven phagocytosis in macrophages and neutrophils enhances bacterial clearance.

Humans are exposed to numerous synthetic foreign particles in the form of drug delivery systems and diagnostic agents. Specialized immune cells (phagocytes) clear these particles by phagocytosing and attempting to degrade them. The process of recognition and internalization of the particles may trigger changes in the function of phagocytes.

Intramacrophage ROS Primes the Innate Immune System via JAK/STAT and Toll Activation.

Tissue injury is one of the most severe environmental perturbations for a living organism. When damage occurs in adult Drosophila, there is a local response of the injured tissue and a coordinated action across different tissues to help the organism overcome the deleterious effect of an injury. We show a change in the transcriptome of hemocytes at the site of tissue injury, with pronounced activation of the Toll signaling pathway.

Remote Control of Intestinal Stem Cell Activity by Haemocytes in Drosophila.

The JAK/STAT pathway is a key signaling pathway in the regulation of development and immunity in metazoans. In contrast to the multiple combinatorial JAK/STAT pathways in mammals, only one canonical JAK/STAT pathway exists in Drosophila. It is activated by three secreted proteins of the Unpaired family (Upd): Upd1, Upd2 and Upd3.

Gut physiology mediates a trade-off between adaptation to malnutrition and susceptibility to food-borne pathogens.

The animal gut plays a central role in tackling two common ecological challenges, nutrient shortage and food-borne parasites, the former by efficient digestion and nutrient absorption, the latter by acting as an immune organ and a barrier. It remains unknown whether these functions can be independently optimised by evolution, or whether they interfere with each other. We report that Drosophila melanogaster populations adapted during 160 generations of experimental evolution to chronic larval malnutrition became more susceptible to intestinal infection with the opportunistic bacterial pathogen Pseudomonas entomophila.

The Drosophila MAPK p38c regulates oxidative stress and lipid homeostasis in the intestine.

The p38 mitogen-activated protein (MAP) kinase signaling cassette has been implicated in stress and immunity in evolutionarily diverse species. In response to a wide variety of physical, chemical and biological stresses p38 kinases phosphorylate various substrates, transcription factors of the ATF family and other protein kinases, regulating cellular adaptation to stress. The Drosophila genome encodes three p38 kinases named p38a, p38b and p38c.

Autocrine and paracrine unpaired signaling regulate intestinal stem cell maintenance and division.

The Janus kinase (JAK) signal transducer and activator of transcription (STAT) pathway is involved in the regulation of intestinal stem cell (ISC) activity to ensure a continuous renewal of the adult Drosophila midgut. Three ligands, Unpaired 1, Unpaired 2 and Unpaired 3 (Upd1, Upd2 and Upd3, respectively) are known to activate the JAK/STAT pathway in Drosophila. Using newly generated upd mutants and cell-specific RNAi, we showed that Upd1 is required throughout the fly life to maintain basal turnover of the midgut epithelium by controlling ISC maintenance in an autocrine manner.

Infection-induced host translational blockage inhibits immune responses and epithelial renewal in the Drosophila gut.

Typically, immune responses control the pathogen, while repair and stress pathways limit damage caused by pathogenesis. The relative contribution of damage to the outcome of pathogenesis and the mechanistic links between the immune and repair pathways are poorly understood. Here, we analyze how the entomopathogenic bacterium Pseudomonas entomophila induces irreversible damage to the Drosophila gut.

Invasive and indigenous microbiota impact intestinal stem cell activity through multiple pathways in Drosophila.

Gut homeostasis is controlled by both immune and developmental mechanisms, and its disruption can lead to inflammatory disorders or cancerous lesions of the intestine. While the impact of bacteria on the mucosal immune system is beginning to be precisely understood, little is known about the effects of bacteria on gut epithelium renewal. Here, we addressed how both infectious and indigenous bacteria modulate stem cell activity in Drosophila.

Heat shock factor gene family in rice: genomic organization and transcript expression profiling in response to high temperature, low temperature and oxidative stresses.

Binding of heat shock factors (HSFs) with heat shock element sequence is critical for the transcriptional induction of heat shock genes. Rice genome sequence shows 26 OsHsf genes out of which 25 possess various important domains noted in HSFs i.e.