High-resolution imaging of protein secretion at the single-cell level using plasmon-enhanced FluoroDOT assay.

Secreted proteins mediate essential physiological processes. With conventional assays, it is challenging to map the spatial distribution of proteins secreted by single cells, to study cell-to-cell heterogeneity in secretion, or to detect proteins of low abundance or incipient secretion. Here, we introduce the "FluoroDOT assay," which uses an ultrabright nanoparticle plasmonic-fluor that enables high-resolution imaging of protein secretion.

Virologic Efficacy of Casirivimab and Imdevimab COVID-19 Antibody Combination in Outpatients With SARS-CoV-2 Infection: A Phase 2 Dose-Ranging Randomized Clinical Trial.

Importance: The monoclonal antibody combination of casirivimab and imdevimab reduced viral load, hospitalization, or death when administered as a 1200-mg or greater intravenous (IV) dose in a phase 3 COVID-19 outpatient study. Subcutaneous (SC) and/or lower IV doses should increase accessibility and/or drug supplies for patients.

Objective: To assess the virologic efficacy of casirivimab and imdevimab across different IV and SC doses compared with placebo.

Consequence of enhanced LC3-trafficking for a live, attenuated M. tuberculosis vaccine.

Development of a new vaccine against tuberculosis is urgently needed. Recent work has demonstrated that two related LC3-associated trafficking pathways, autophagy and LC3-associated phagocytosis (LAP), enhance antigen presentation and might play a role in vaccine efficacy. Mycobacterium tuberculosis inhibits both LC3-trafficking pathways.

Mycobacterium tuberculosis EsxH inhibits ESCRT-dependent CD4 T-cell activation.

Mycobacterium tuberculosis (Mtb) establishes a persistent infection, despite inducing antigen-specific T-cell responses. Although T cells arrive at the site of infection, they do not provide sterilizing immunity. The molecular basis of how Mtb impairs T-cell function is not clear.

Role of Metal-Dependent Regulation of ESX-3 Secretion in Intracellular Survival of Mycobacterium tuberculosis.

More people die every year from Mycobacterium tuberculosis infection than from infection by any other bacterial pathogen. Type VII secretion systems (T7SS) are used by both environmental and pathogenic mycobacteria to secrete proteins across their complex cell envelope. In the nonpathogen Mycobacterium smegmatis, the ESX-1 T7SS plays a role in conjugation, and the ESX-3 T7SS is involved in metal homeostasis.

Mycobacterium tuberculosis induces the miR-33 locus to reprogram autophagy and host lipid metabolism.

Mycobacterium tuberculosis (Mtb) survives in macrophages by evading delivery to the lysosome and promoting the accumulation of lipid bodies, which serve as a bacterial source of nutrients. We found that by inducing the microRNA (miRNA) miR-33 and its passenger strand miR-33*, Mtb inhibited integrated pathways involved in autophagy, lysosomal function and fatty acid oxidation to support bacterial replication. Silencing of miR-33 and miR-33* by genetic or pharmacological means promoted autophagy flux through derepression of key autophagy effectors (such as ATG5, ATG12, LC3B and LAMP1) and AMPK-dependent activation of the transcription factors FOXO3 and TFEB, which enhanced lipid catabolism and Mtb xenophagy.

Ubiquilin 1 Promotes IFN-γ-Induced Xenophagy of Mycobacterium tuberculosis.

The success of Mycobacterium tuberculosis (Mtb) as a pathogen rests upon its ability to grow intracellularly in macrophages. Interferon-gamma (IFN-γ) is critical in host defense against Mtb and stimulates macrophage clearance of Mtb through an autophagy pathway. Here we show that the host protein ubiquilin 1 (UBQLN1) promotes IFN-γ-mediated autophagic clearance of Mtb.

Ca2+ Signaling but Not Store-Operated Ca2+ Entry Is Required for the Function of Macrophages and Dendritic Cells.

Store-operated Ca(2+) entry (SOCE) through Ca(2+) release-activated Ca(2+) (CRAC) channels is essential for immunity to infection. CRAC channels are formed by ORAI1 proteins in the plasma membrane and activated by stromal interaction molecule (STIM)1 and STIM2 in the endoplasmic reticulum. Mutations in ORAI1 and STIM1 genes that abolish SOCE cause severe immunodeficiency with recurrent infections due to impaired T cell function.

Effect of Caenorhabditis elegans age and genotype on horizontal gene transfer in intestinal bacteria.

Horizontal gene transfer (HGT) between bacteria occurs in the intestinal tract of their animal hosts and facilitates both virulence and antibiotic resistance. A model in which both the pathogen and the host are genetically tractable facilitates developing insight into mechanistic processes enabling or restricting the transfer of antibiotic resistance genes. Here we develop an in vivo experimental system to study HGT in bacteria using Caenorhabditis elegans as a model host.

Control of intestinal bacterial proliferation in regulation of lifespan in Caenorhabditis elegans.

Background: A powerful approach to understanding complex processes such as aging is to use model organisms amenable to genetic manipulation, and to seek relevant phenotypes to measure. Caenorhabditis elegans is particularly suited to studies of aging, since numerous single-gene mutations have been identified that affect its lifespan; it possesses an innate immune system employing evolutionarily conserved signaling pathways affecting longevity. As worms age, bacteria accumulate in the intestinal tract.

Competition and resilience between founder and introduced bacteria in the Caenorhabditis elegans gut.

The microbial communities that reside within the intestinal tract in vertebrates are complex and dynamic. In this report, we establish the utility of Caenorhabditis elegans as a model system for identifying the factors that contribute to bacterial persistence and for host control of gut luminal populations. We found that for N2 worms grown on mixed lawns of bacteria, Salmonella enterica serovar Typhimurium substantially outcompeted Escherichia coli, even when E.

[Development of a protocol of pyrosequencing for determination of the polymorphism at position -31 of the interleukin-1beta gene in the study of risk of development of stomach cancer].

Background: Single nucleotide polymorphism association studies among cases and controls have been widely used for genetic analysis. The pyrosequencing method is based on indirect luminometric quantification of the pyrophosphate that is released as a result of nucleotide incorporation onto an amplified template. It has the advantages of accuracy, flexibility, automatization and speed when compared with PCR-RFLP method.

Immune responses to Helicobacter pylori colonization: mechanisms and clinical outcomes.

Helicobacter pylori colonizes the stomachs of half of the world's population and usually persists in the gastric mucosa of human hosts for decades or life. Although most H. pylori-positive people are asymptomatic, the presence of H.

Human lymphocyte antigen DR7 protects against proliferative retinopathy with type II diabetes mellitus.

Background: This study was undertaken in order to analyze the genetic incidence of human lymphocyte antigen diabetic retinopathy (HLA-DR) and its influence in proliferative diabetic retinopathy (PDR).

Methods: We designed a case-control study in which 127 mestizo Mexican patients with DM II and diabetic retinopathy were studied. DNA was extracted and HLA-DR regions were amplified using PCR.