The success of Mycobacterium species as pathogens depends on their ability to maintain an infection inside the phagocytic vacuole macrophage. Although bacteria are reported modulate maturation intracellular vacuoles, nature such modifications is unknown. In this study, vacuoles formed around avium failed acidify below pH 6.3 6.5. Immunoelectron microscopy infected macrophages and immunoblotting isolated phagosomes showed that acquire lysosomal membrane protein LAMP-1, but not vesicular...

Alveolar macrophages have been shown to bind glycoproteins and synthetic glycoconjugates (neoglycorpoteins) that mannose, N-acetylglucosamine, or glucose in the exposed, nonreducing position. Galactose-terminal are not bound. Binding of radiolabeled ligands cells is nearly completely impaired by presence an excess yeast mannan. temperature sensitive proceeds optimally at pH 7.0. Prior treatment with trypsin severely decreases their capacity ligands. An inhibition assay has developed, using...

Chloroquine-resistant Plasmodium falciparum accumulate significantly less chloroquine than susceptible parasites, and this is thought to be the basis of their resistance. However, reason for lower accumulation was unknown. The resistant parasite has now been found release 40 50 times more rapidly parasite, although initial rates are same. Verapamil two other calcium channel blockers, as well vinblastine daunomycin, each slowed increased by (but not susceptible) falciparum. These results...

The BCL-2 family of proteins is composed both pro- and antiapoptotic regulators, although its most critical biochemical functions remain uncertain. structural similarity between the BCL-X L monomer several ion-pore-forming bacterial toxins has prompted electrophysiologic studies. Both BAX insert into KCl-loaded vesicles in a pH-dependent fashion demonstrate macroscopic ion efflux. Release maximum at ≈pH 4.0 for proteins; however, demonstrates broader pH range activity. purified also planar...

Endolysosomes can be damaged by diverse materials. Terminally compartments are degraded lysophagy, but pathways that repair salvageable organelles poorly understood. Here we found the endosomal sorting complex required for transport (ESCRT) machinery, known to mediate budding and fission on endolysosomes, also plays an essential role in their repair. ESCRTs were rapidly recruited acutely injured endolysosomes through a pathway requiring calcium ESCRT-activating factors was independent of...

We review the characteristics of osteoblast differentiation and bone matrix synthesis. Bone in air breathing vertebrates is a specialized tissue that developmentally replaces simpler solid tissues, usually cartilage. living organ bounded by layer osteoblasts that, because transport compartmentalization requirements, produce exclusively as an organized tight epithelium. With growth, are reorganized incorporated into cells, osteocytes, which communicate with each other surface epithelium cell...

Mycobacterium avium (MAC) organisms multiply in phagosomes that have restricted fusigenicity with lysosomes, do not acidify due to a paucity of vacuolar proton-ATPases, yet remain accessible recycling endosomes. During the course mycobacterial infections, IFN-gamma-mediated activation host and bystander macrophages is key mechanism regulation bacterial growth. Here we demonstrate keeping earlier studies, cytokine leads decrease MAC viability, demonstrable by esterase staining fluorescein...

The in vivo application of cytolytic peptides for cancer therapeutics is hampered by toxicity, nonspecificity, and degradation. We previously developed a specific strategy to synthesize nanoscale delivery vehicle incorporating the nonspecific amphipathic peptide melittin into outer lipid monolayer perfluorocarbon nanoparticle. Here, we have demonstrated that favorable pharmacokinetics this nanocarrier allows accumulation murine tumors dramatic reduction tumor growth without any apparent...

Bisphosphonates are useful in treatment of disorders with increased osteoclastic activity, but the mechanism by which bisphosphonates act is unknown. We used cultures chicken osteoclasts to address this issue, and found that 1-hydroxyethylidenediphosphonic acid (EHDP), dichloromethylidenediphosphonic (Cl2MDP), or 3-amino-1-hydroxypropylidene-1,1-diphosphonic (APD) all cause direct dose-dependent suppression activity. Effects mediated bone-bound drugs, 50% reduction bone degradation occurring...

Entamoeba histolytica adheres to human colonic mucus, epithelial cells, and other target cells via a galactose (Gal) or N-acetyl-D-galactosamine (GalNAc) inhibitable surface lectin. Blockade of this adherence lectin with Gal GalNAc in vitro prevents amebic killing cells. We have identified purified the by two methods: affinity columns derivatized monomers terminal glycoproteins, immunoblots prepared monoclonal antibodies that inhibit adherence. By both methods was as 170-kD secreted...

The asexual erythrocytic stage of the malarial parasite ingests and degrades hemoglobin its host red cell. To study this process, we labeled cytoplasm uninfected cells with fluorescein-dextran, infected those trophozoite- schizont-rich cultures Plasmodium falciparum, harvested them 110-120 h later in trophozoite stage. After lysis cell digitonin, only fluorescence remaining was small (0.5-0.9 micron) vesicles similar to parasite's food vacuole. As measured by spectrofluorimetry, pH these...

H+ countertransport.We have previously shown (Rothenberg, P.,

Receptor-mediated endocytosis of rat preputial beta-glucuronidase and the glycoconjugate mannose-BSA by alveolar macrophages is inhibited chloroquine ammonium chloride. We have previously reported that these drugs cause a loss cell surface binding activity they do not inhibit internalization receptor ligand complexes when incubated with cells at 37 degrees C. In this report we more clearly delineate intracellular site weak base inhibition recycling mechanism inhibition. From our analysis...

Glycoproteins having mannose and/or N-acetylglucosamine in the terminal non-reducing position [Stockert, Morell & Scheinberg (1976) Biochem. Biophys. Res. Commun. 68, 988–993], and various lysosomal enzymes [Stahl, Schlesinger, Rodman Doebber Nature (London) 264, 86–8] are rapidly cleared from plasma by liver after intravenous administration. A cell-separation technique was used to determine cellular localization of 125I-labelled beta-glucuronidase, ribonuclease B, agalacto-orosomucoid...

The phagolysosome is perhaps the most effective antimicrobial site within macrophages due both to its acidity and variety of hydrolytic enzymes. Few species pathogens survive multiply in these vesicles. However, one strategy for microbial survival would be induce a higher pH organelles, thus interfering with activity many lysosomal Altering intravesicular milieu might also profoundly influence antigen processing, drug delivery, activity. Here we report first example an organism proliferating...

Wolfram syndrome is an autosomal recessive neuro-degenerative disorder associated with juvenile onset non-autoimmune diabetes mellitus and progressive optic atrophy. The disease has been attributed to mutations in the WFS1 gene, which codes for a protein predicted possess 9–10 transmembrane segments. Little known concerning function of (wolframin). Endoglycosidase H digestion, immunocytochemistry, subcellular fractionation studies all indicated that wolframin localized endoplasmic reticulum...

Bone resorption by osteoclasts requires massive transcellular acid transport, which is accomplished the parallel action of a V-type proton pump and chloride channel in osteoclast ruffled border. We have studied molecular basis for appearance transport as avian bone marrow mononuclear cells acquire resorptive phenotype <i>in vitro</i>. demonstrate critical role regulated expression border become competent to resorb bone. Molecular characterization shows that it related renal microsomal...

125I-Labeled L-fucose-albumin complex and rat preputial beta-glucuronidase are rapidly cleared from plasma after intravenous infusion. L-Fucose-albumin retards the clearance of whereas D-fucose-albumin is inactive. In vitro, 125I-labeled taken up into or rabbit alveolar macrophages by receptor-mediated pinocytosis. Uptake (37 degrees C) time-dependent, saturable with increasing ligand concentration (Kuptake = 4.4 X 10(-8) M), requires Ca2+. poorly up. Binding (4 Ca2+ dependent. uptake fully...

Binding studies with cells that had been permeabilized saponin indicate alveolar macrophages have an intracellular pool of mannose-specific binding sites which is about 4-fold greater than the cell surface pool. Monensin, a carboxylic ionophore mediates proton movement across membranes, has no effect on ligand to but blocks receptor-mediated uptake 125I-labelled beta-glucuronidase. Inhibition was concentration- and time-dependent. Internalization receptor-bound ligand, after warming 37...

Like many physiological ligands, several viruses and toxins enter mammalian cells through receptor-mediated endocytosis. Once internalized, the nucleic acids of toxic subunit diphtheria toxin gain access to cytosol host cell an acidic intracellular compartment. In this report, we present evidence that one class mutants Chinese hamster ovary (CHO)-K1 cells, which is "cross-resistant" Pseudomonas exotoxin A, toxin, animal viruses, has a defect in acidification endosome. Cells were allowed...