Expression of truncated Babesia microti apical membrane protein 1 and rhoptry neck protein 2 and evaluation of their protective efficacy

2017 ◽  
Vol 172 ◽  
pp. 5-11 ◽  
Author(s):  
Guanbo Wang ◽  
Artemis Efstratiou ◽  
Paul Franck Adjou Moumouni ◽  
Mingming Liu ◽  
Charoonluk Jirapattharasate ◽  
...  
2015 ◽  
Vol 83 (10) ◽  
pp. 3890-3901 ◽  
Author(s):  
Prasun Moitra ◽  
Hong Zheng ◽  
Vivek Anantharaman ◽  
Rajdeep Banerjee ◽  
Kazuyo Takeda ◽  
...  

The intraerythrocytic apicomplexanBabesia microti, the primary causative agent of human babesiosis, is a major public health concern in the United States and elsewhere. Apicomplexans utilize a multiprotein complex that includes a type I membrane protein called apical membrane antigen 1 (AMA1) to invade host cells. We have isolated the full-lengthB. microtiAMA1 (BmAMA1) gene and determined its nucleotide sequence, as well as the amino acid sequence of the AMA1 protein. This protein contains an N-terminal signal sequence, an extracellular region, a transmembrane region, and a short conserved cytoplasmic tail. It shows the same domain organization as the AMA1 orthologs from piroplasm, coccidian, and haemosporidian apicomplexans but differs from all other currently known piroplasmida, including otherBabesiaandTheileriaspecies, in lacking two conserved cysteines in highly variable domain III of the extracellular region. Minimal polymorphism was detected in BmAMA1 gene sequences of parasite isolates from six babesiosis patients from Nantucket. Immunofluorescence microscopy studies showed that BmAMA1 is localized on the cell surface and cytoplasm near the apical end of the parasite. Native BmAMA1 from parasite lysate and refolded recombinant BmAMA1 (rBmAMA1) expressed inEscherichia colireacted with a mouse anti-BmAMA1 antibody using Western blotting.In vitrobinding studies showed that both native BmAMA1 and rBmAMA1 bind to human red blood cells (RBCs). This binding is trypsin and chymotrypsin treatment sensitive but neuraminidase independent. Incubation ofB. microtiparasites in human RBCs with a mouse anti-BmAMA1 antibody inhibited parasite growth by 80% in a 24-h assay. Based on its antigenically conserved nature and potential role in RBC invasion, BmAMA1 should be evaluated as a vaccine candidate.


1996 ◽  
Vol 109 (6) ◽  
pp. 1215-1227 ◽  
Author(s):  
I. Hemery ◽  
A.M. Durand-Schneider ◽  
G. Feldmann ◽  
J.P. Vaerman ◽  
M. Maurice

In hepatocytes, newly synthesized apical plasma membrane proteins are first delivered to the basolateral surface and are supposed to reach the apical surface by transcytosis. The transcytotic pathway of apical membrane proteins and its relationship with other endosomal pathways has not been demonstrated morphologically. We compared the intracellular route of an apical plasma membrane protein, B10, with that of polymeric IgA (pIgA), which is transcytosed, transferrin (Tf) which is recycled, and asialoorosomucoid (ASOR) which is delivered to lysosomes. Ligands and anti-B10 monoclonal IgG were linked to fluorochromes or with peroxidase. The fate of each ligand was followed by confocal and electron microscopy in polarized primary monolayers of rat hepatocytes. When fluorescent anti-B10 IgG and fluorescent pIgA were simultaneously endocytosed for 15–30 minutes, they both uniformly labelled a juxtanuclear compartment. By 30–60 minutes, they reached the bile canaliculi. Tf and ASOR were also routed to the juxtanuclear area, but their fluorescence patterns were more punctate. Microtubule disruption prevented all ligands from reaching the juxtanuclear area. This area corresponded, at least partially, to the localization of the mannose 6-phosphate receptor, an endosomal marker. By electron microscopy, the juxtanuclear compartment was made up of anastomosing tubules connected to vacuoles, and was organized around the centrioles. B10 and pIgA were mainly found in the tubules, whereas ASOR was segregated inside the vacuolar elements and Tf within thinner, recycling tubules. In conclusion, transcytosis of the apical membrane protein B10 occurs inside tubules similar to those carrying pIgA, and involves passage via the pericentriolar area. In the pericentriolar area, the transcytotic tubules appear to maintain connections with other endosomal elements where sorting between recycled and degraded ligands occurs.


2019 ◽  
Vol 41 (9) ◽  
Author(s):  
Roberta Reis Soares ◽  
Clarissa F. Cunha ◽  
Raquel Ferraz‐Nogueira ◽  
Alessandro Marins‐dos‐Santos ◽  
Rodrigo Nunes Rodrigues‐da‐Silva ◽  
...  

1989 ◽  
Vol 256 (6) ◽  
pp. G1070-G1081 ◽  
Author(s):  
T. Urushidani ◽  
D. K. Hanzel ◽  
J. G. Forte

When isolated rabbit gastric glands were stimulated with histamine plus isobutylmethylxanthine, a redistribution of H+-K+-ATPase, from microsomes to a low-speed pellet, occurred in association with the phosphorylation of an 80-kDa protein (80K) in the apical membrane-rich fraction purified from the low-speed pellet. Histamine alone or dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP), but not carbachol, also stimulated both the redistribution of H+-K+-ATPase and phosphorylation of 80K. Under stimulated conditions, 80K copurified in the apical membrane fraction along with H+-K+-ATPase and actin; whereas purified microsomes from resting stomach were highly enriched in H+-K+-ATPase but contained neither 80K nor actin. Treatment of the apical membranes with detergents, salts, sonication, and so on, led us to conclude that 80K is a membrane protein, unlike actin; however, the mode of association of 80K with membrane differed from H+-K+-ATPase, an integral membrane protein. Isoelectric focusing and peptide mapping revealed that 80K consists of six isomers of slightly differing pI, with 32P occurring only in the three most acidic isomers and exclusively on serine residues. Moreover, stimulation elicited a shift in the amount of 80K isomers, from basic to acidic, as well as phosphorylation. We conclude that 80K is an apical membrane protein in the parietal cell and an important substrate for cAMP-dependent, but not calcium-dependent, pathway of acid secretion.


1991 ◽  
Vol 261 (1) ◽  
pp. C143-C153 ◽  
Author(s):  
H. W. Harris ◽  
M. L. Zeidel ◽  
C. Hosselet

Antidiuretic hormone (ADH) stimulation of toad bladder granular cells rapidly increases the osmotic water permeability (Pf) of their apical membranes by insertion of highly selective water channels. Before ADH stimulation, these water channels are stored in large cytoplasmic vesicles called aggrephores. ADH causes aggrephores to fuse with the apical membrane. Termination of ADH stimulation results in prompt endocytosis of water channel-containing membranes via retrieval of these specialized regions of apical membrane. Protein components of the ADH water channel contained within these retrieved vesicles would be expected to be integral membrane protein(s) that span the vesicle's lipid bilayer to create narrow aqueous channels. Our previous work has identified proteins of 55 (actually a 55/53-kDa doublet), 17, 15, and 7 kDa as candidate ADH water channel components. We now have investigated these candidate ADH water channel proteins in purified retrieved vesicles. These vesicles do not contain a functional proton pump as assayed by Western blots of purified vesicle protein probed with anti-H(+)-ATPase antisera. Approximately 60% of vesicle protein is accounted for by three protein bands of 55, 53, and 46 kDa. Smaller contributions to vesicle protein are made by the 17- and 15-kDa proteins. Triton X-114-partitioning analysis shows that the 55, 53, 46, and 17 kDa are integral membrane proteins. Vectorial labeling analysis with two membrane-impermeant reagents shows that the 55-, 53-, and 46-kDa protein species span the lipid bilayer of these vesicles. Thus the 55-, 53-, and 46-kDa proteins possess characteristics expected for ADH water channel components. These data show that the 55- and 53- and perhaps the 46-, 17-, and 15-kDa proteins are likely components of aqueous transmembrane pores that constitute ADH water channels contained within these vesicles.


1995 ◽  
Vol 269 (3) ◽  
pp. C797-C801 ◽  
Author(s):  
N. Franki ◽  
F. Macaluso ◽  
W. Schubert ◽  
L. Gunther ◽  
R. M. Hays

Antidiuretic hormone (arginine vasopressin) induces a cyclic process of docking, fusion, and endocytosis of water channel-containing vesicles in the collecting duct. There is now evidence that docking and endocytosis are mediated by an array of proteins associated with vesicles and target membranes. In recent studies, we have shown that cellubrevin, a member of the vesicle-associated membrane protein family, as well as other docking proteins, are expressed in the rat inner medullary collecting duct. We now show by immunogold electron microscopy that cellubrevin is present on vesicles containing water channels, that it is associated with both coated and uncoated vesicles, and that it is present on the apical membrane. Cellubrevin, therefore, is in a position to mediate one or more steps in arginine vasopressin-induced water channel cycling.


2017 ◽  
Vol 113 ◽  
pp. 152-159 ◽  
Author(s):  
Xiaoqian Tang ◽  
Hongye Wang ◽  
Fuguo Liu ◽  
Xiuzhen Sheng ◽  
Jing Xing ◽  
...  

2004 ◽  
Vol 72 (11) ◽  
pp. 6511-6518 ◽  
Author(s):  
Clíona A. O'Dwyer ◽  
Karen Reddin ◽  
Denis Martin ◽  
Stephen C. Taylor ◽  
Andrew R. Gorringe ◽  
...  

ABSTRACT Commensal neisseriae share with Neisseria meningitidis (meningococcus) a tendency towards overproduction of the bacterial outer envelope, leading to the formation and release during growth of outer membrane vesicles (OMVs). OMVs from both meningococci and commensal neisseriae have shown promise as vaccines to protect against meningococcal disease. We report here the successful expression at high levels of heterologous proteins in commensal neisseriae and the display, in its native conformation, of one meningococcal outer membrane protein vaccine candidate, NspA, in OMVs prepared from such a recombinant Neisseria flavescens strain. These NspA-containing OMVs conferred protection against otherwise lethal intraperitoneal challenge of mice with N. meningitidis serogroup B, and sera raised against them mediated opsonophagocytosis of meningococcal strains expressing this antigen. This development promises to facilitate the design of novel vaccines containing membrane protein antigens that are otherwise difficult to present in native conformation that provide cross-protective efficacy in the prevention of meningococcal disease.


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