Staphylococcus aureus lipid factors modulate melanoma cell clustering and invasion.

The microbiome can influence cancer development and progression. However, less is known about the role of the skin microbiota in melanoma. Here, we took advantage of a zebrafish melanoma model to probe the effects of Staphylococcus aureus on melanoma invasion.

Infection induced inflammation impairs wound healing through IL-1β signaling.

Wound healing is impaired by infection; however, how microbe-induced inflammation modulates tissue repair remains unclear. We took advantage of the optical transparency of zebrafish and a genetically tractable microbe, , to probe the role of infection and inflammation in wound healing. Infection with bacteria engineered to activate the inflammasome, Lm-Pyro, induced persistent inflammation and impaired healing despite low bacterial burden.

C-di-AMP accumulation disrupts glutathione metabolism and inhibits virulence program expression in .

Unlabelled: C-di-AMP is an essential second messenger in many bacteria but its levels must be regulated. Unregulated c-di-AMP accumulation attenuates the virulence of many bacterial pathogens, including those that do not require c-di-AMP for growth. However, the mechanisms by which c-di-AMP regulates bacterial pathogenesis remain poorly understood.

requires DHNA-dependent intracellular redox homeostasis facilitated by Ndh2 for survival and virulence.

is a remarkably well-adapted facultative intracellular pathogen that can thrive in a wide range of ecological niches. maximizes its ability to generate energy from diverse carbon sources using a respiro-fermentative metabolism that can function under both aerobic and anaerobic conditions. Cellular respiration maintains redox homeostasis by regenerating NAD while also generating a proton motive force.

Maintenance of heme homeostasis in through post-translational regulation of glutamyl-tRNA reductase.

is an important human pathogen responsible for a variety of infections including skin and soft tissue infections, endocarditis, and sepsis. The combination of increasing antibiotic resistance in this pathogen and the lack of an efficacious vaccine underscores the importance of understanding how maintains metabolic homeostasis in a variety of environments, particularly during infection. Within the host, must regulate cellular levels of the cofactor heme to support enzymatic activities without encountering heme toxicity.

Type I Interferon Signaling on Antigen-Presenting Cells Blunts Cell-Mediated Immunity toward Listeria monocytogenes.

Listeria monocytogenes is a facultative intracellular pathogen that has been used for decades to understand mechanisms of bacterial pathogenesis and both innate and adaptive immunity. L. monocytogenes is a potent activator of CD8 T-cell-mediated immunity, yet how the innate immune response to infection modulates CD8 T-cell responses is incompletely understood.

A tessellated lymphoid network provides whole-body T cell surveillance in zebrafish.

Homeostatic trafficking to lymph nodes allows T cells to efficiently survey the host for cognate antigen. Nonmammalian jawed vertebrates lack lymph nodes but maintain diverse T cell pools. Here, we exploit in vivo imaging of transparent zebrafish to investigate how T cells organize and survey for antigen in an animal devoid of lymph nodes.

Listeria monocytogenes GlmR Is an Accessory Uridyltransferase Essential for Cytosolic Survival and Virulence.

The cytosol of eukaryotic host cells is an intrinsically hostile environment for bacteria. Understanding how cytosolic pathogens adapt to and survive in the cytosol is critical to developing novel therapeutic interventions against these pathogens. The cytosolic pathogen Listeria monocytogenes requires (previously known as ), a gene of unknown function, for resistance to cell-wall stress, cytosolic survival, inflammasome avoidance, and, ultimately, virulence .

requires DHNA-dependent intracellular redox homeostasis facilitated by Ndh2 for survival and virulence.

is a remarkably well-adapted facultative intracellular pathogen that can thrive in a wide range of ecological niches. maximizes its ability to generate energy from diverse carbon sources using a respiro-fermentative metabolism that can function under both aerobic and anaerobic conditions. Cellular respiration maintains redox homeostasis by regenerating NAD while also generating a proton motive force (PMF).

A tessellated lymphoid network provides whole-body T cell surveillance in zebrafish.

Unlabelled: Homeostatic trafficking to lymph nodes allows T cells to efficiently survey the host for cognate antigen. Non-mammalian jawed vertebrates lack lymph nodes but maintain similarly diverse T cell pools. Here, we exploit imaging of transparent zebrafish to investigate how T cells organize and survey for antigen in an animal devoid of lymph nodes.

NAD(H)-loaded nanoparticles for efficient sepsis therapy via modulating immune and vascular homeostasis.

Sepsis is a life-threatening organ dysfunction responsible for nearly 270,000 deaths annually in the United States alone. Nicotinamide adenine dinucleotide (NAD), an immunomodulator, can potentially treat sepsis; however, clinical application of NAD is hindered by its inability to be directly taken up by cells. To address this challenge, a family of nanoparticles (NPs) loaded with either NAD or the reduced form of NAD (NADH), hereafter NAD(H)-loaded NPs, were engineered to enable direct cellular transport and replenishment of NAD(H).

requires cellular respiration for NAD regeneration and pathogenesis.

Cellular respiration is essential for multiple bacterial pathogens and a validated antibiotic target. In addition to driving oxidative phosphorylation, bacterial respiration has a variety of ancillary functions that obscure its contribution to pathogenesis. We find here that the intracellular pathogen encodes two respiratory pathways which are partially functionally redundant and indispensable for pathogenesis.

Endogenous CRISPR-Cas Systems in Group I and Do Not Directly Target the Botulinum Neurotoxin Gene Cluster.

Most strains of proteolytic group I (G1 ) and some strains of possess genes encoding botulinum neurotoxin (BoNT), a potent neuroparalytic agent. Within G1 , conserved gene clusters of three major toxin serotypes (/A/B/F) can be found on conjugative plasmids and/or within chromosomal pathogenicity islands. CRISPR-Cas systems enable site-specific targeting of previously encountered mobile genetic elements (MGE) such as plasmids and bacteriophage through the creation of a spacer library complementary to protospacers within the MGEs.

In vivo fluorescence lifetime imaging of macrophage intracellular metabolism during wound responses in zebrafish.

The function of macrophages in vitro is linked to their metabolic rewiring. However, macrophage metabolism remains poorly characterized in situ. Here, we used two-photon intensity and lifetime imaging of autofluorescent metabolic coenzymes, nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD), to assess the metabolism of macrophages in the wound microenvironment.

PASTA kinase-dependent control of peptidoglycan synthesis via ReoM is required for cell wall stress responses, cytosolic survival, and virulence in Listeria monocytogenes.

Pathogenic bacteria rely on protein phosphorylation to adapt quickly to stress, including that imposed by the host during infection. Penicillin-binding protein and serine/threonine-associated (PASTA) kinases are signal transduction systems that sense cell wall integrity and modulate multiple facets of bacterial physiology in response to cell envelope stress. The PASTA kinase in the cytosolic pathogen Listeria monocytogenes, PrkA, is required for cell wall stress responses, cytosolic survival, and virulence, yet its substrates and downstream signaling pathways remain incompletely defined.

Phagocytes produce prostaglandin E2 in response to cytosolic Listeria monocytogenes.

Listeria monocytogenes is an intracellular bacterium that elicits robust CD8+ T-cell responses. Despite the ongoing development of L. monocytogenes-based platforms as cancer vaccines, our understanding of how L.

iNKT cells coordinate immune pathways to enable engraftment in nonconditioned hosts.

Invariant natural killer T (iNKT) cells are a conserved population of innate T lymphocytes that interact with key antigen-presenting cells to modulate adaptive T-cell responses in ways that can either promote protective immunity, or limit pathological immune activation. Understanding the immunological networks engaged by iNKT cells to mediate these opposing functions is a key pre-requisite to effectively using iNKT cells for therapeutic applications. Using a human umbilical cord blood xenotransplantation model, we show here that co-transplanted allogeneic CD4 iNKT cells interact with monocytes and T cells in the graft to coordinate pro-hematopoietic and immunoregulatory pathways.

Listeria monocytogenes MenI Encodes a DHNA-CoA Thioesterase Necessary for Menaquinone Biosynthesis, Cytosolic Survival, and Virulence.

is a Gram-positive, intracellular pathogen that is highly adapted to invade and replicate in the cytosol of eukaryotic cells. Intermediate metabolites in the menaquinone biosynthesis pathway are essential for the cytosolic survival and virulence of , independent of the production of menaquinone (MK) and aerobic respiration. Determining which specific intermediate metabolite(s) are essential for cytosolic survival and virulence has been hindered by the lack of an identified 1,4-dihydroxy-2-naphthoyl-coenzyme A (DHNA-CoA) thioesterase essential for converting DHNA-CoA to DHNA in the MK synthesis pathway.

Carbomer-based adjuvant elicits CD8 T-cell immunity by inducing a distinct metabolic state in cross-presenting dendritic cells.

There is a critical need for adjuvants that can safely elicit potent and durable T cell-based immunity to intracellular pathogens. Here, we report that parenteral vaccination with a carbomer-based adjuvant, Adjuplex (ADJ), stimulated robust CD8 T-cell responses to subunit antigens and afforded effective immunity against respiratory challenge with a virus and a systemic intracellular bacterial infection. Studies to understand the metabolic and molecular basis for ADJ's effect on antigen cross-presentation by dendritic cells (DCs) revealed several unique and distinctive mechanisms.

cancer vaccines: bridging innate and adaptive immunity.

Purpose Of The Review: Immunotherapy has emerged as a promising cancer treatment, however success in only select clinical indications underscores the need for novel approaches. Recently based vaccines have been developed to drive tumor specific T-cell responses. Here, we discuss recent preclinical studies using vaccines, innate immune pathways that influence T-cell priming, and new vaccine strategies in clinical trials.

Mutation of the Transcriptional Regulator YtoI Rescues Listeria monocytogenes Mutants Deficient in the Essential Shared Metabolite 1,4-Dihydroxy-2-Naphthoate (DHNA).

, a Gram-positive, facultative intracellular pathogen, survives and replicates in the cytosol of host cells. Synthesis of 1,4-dihydroxy-2-naphthoate (DHNA), an intermediate of menaquinone biosynthesis, is essential for cytosolic survival of independent from its role in respiration. Here, we demonstrate that DHNA is essential for virulence in a murine model of listeriosis due to both respiration-dependent and -independent functions.