Secretory Protein Biosynthesis in Snail Hemocytes: In vitro Modulation by Larval Schistosome Excretory-Secretory Products

1988 ◽  
Vol 74 (4) ◽  
pp. 538 ◽  
Author(s):  
Timothy P. Yoshino ◽  
Michael J. Lodes
Keyword(s):  
Protein Biosynthesis ◽  
Secretory Protein ◽  
Secretory Products

Characterization of excretory–secretory products from protoscoleces of Echinococcus granulosus and evaluation of their potential for immunodiagnosis of human cystic echinococcosis

Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 371-378 ◽  
Author(s):  
D. CARMENA ◽  
J. MARTÍNEZ ◽  
A. BENITO ◽  
J. A. GUISANTES
Keyword(s):  
Echinococcus Granulosus ◽  
Cystic Echinococcosis ◽  
Secretory Protein ◽  
Major Protein ◽  
Healthy Donors ◽  
Secretory Products ◽  
Protein Components ◽  
Human Cystic Echinococcosis

This study describes, for the first time, the characterization of excretory–secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, evaluating their usefulness in the immunodiagnosis of human cystic echinococcosis. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. This preparation contained over 20 major protein components which could be distinguished by 1-dimensional SDS–PAGE with apparent masses between 9 and 300 kDa. The culture of of protoscoleces from liver produced a greater variety of excretory–secretory protein components than those from lung. Determination of enzymatic activities of secreted proteins revealed the presence of phosphatases, lipases and glucosidases, but no proteases. These findings were compared to those obtained from somatic extracts of protoscoleces and hydatid cyst fluid products. Immunochemical characterization was performed by immunoblotting with sera from individuals infected by cystic echinococcosis (n=15), non-hydatidic parasitoses (n=19), various liver diseases (n=24), lung neoplasia (n=16), and healthy donors (n=18). Antigens with apparent masses of 89, 74, 47/50, 32, and 20 kDa showed specificity for immunodiagnosis of human hydatidosis. The 89 and 74 kDa components corresponded to antigens not yet described in E. granulosus, whereas proteins of 41–43 kDa and 91–95 kDa were recognized by the majority of the non-hydatid sera studied.

scholarly journals Characterization of the rat salivary-gland B1-immunoreactive proteins

1998 ◽  
Vol 330 (1) ◽  
pp. 437-444 ◽  
Author(s):  
Lily MIRELS ◽  
J. Abigail MIRANDA ◽  
D. William BALL
Keyword(s):  
Submandibular Gland ◽  
Protein A ◽  
Secretory Protein ◽  
Cdna Clones ◽  
Parotid Glands ◽  
Gene Encoding ◽  
Adult Rat ◽  
Related Clone ◽  
Secretory Products

The B1-immunoreactive proteins (B1-IPs) are major secretory products of rat submandibular gland acinar-cell progenitors, and are also produced by neonatal and adult rat sublingual and parotid glands. In order to characterize the B1-IPs, we have previously isolated cDNA clones encoding rat parotid secretory protein (PSP; the predominant parotid B1-IP) and the related clone ZZ3, which is developmentally regulated in the neonatal submandibular gland. The remainder of the B1-IPs were uncharacterized. This report demonstrates that all of the B1-IPs are derived from the PSP and ZZ3 transcripts. Molecular cloning and Western-blot analyses using PSP- and ZZ3-specific antisera show that, of the B1-IPs, only PSP and neonatal submandibular gland protein A (SMGA) are products of the Psp gene. This finding corrects our previous assertion that SMGA is derived from ZZ3. Neonatal submandibular gland proteins B1 and B2, as well as apparent Mr 26000-28000 and Mr 18000-20000 forms in submandibular, sublingual and parotid glands, are derived from the gene encoding ZZ3 by differential N-glycosylation and by proteolytic cleavage. The apparent Mr 18000-20000 proteolytic products are significant in secretion product collected in vitro, but rare in gland homogenate and submandibular/sublingual saliva. The gene encoding ZZ3 has been named Smgb. Psp and Smgb are regulated similarly in the developing submandibular gland, but differently in the sublingual and parotid glands. The expression pattern of Psp is conserved between rat and mouse. However, no evidence for proteins derived from an Smgb-like gene was observed in neonatal mouse submandibular or sublingual glands.

scholarly journals A rapid, parasite-dependent cellular response to Dirofilaria immitis in the Mongolian jird (Meriones unguiculatus)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Christopher C. Evans ◽  
Katherine M. Day ◽  
Yi Chu ◽  
Bridget Garner ◽  
Kaori Sakamoto ◽  
...  
Keyword(s):  
Cellular Response ◽  
Dirofilaria Immitis ◽  
Cell Attachment ◽  
Early Response ◽  
Meriones Unguiculatus ◽  
Filarial Parasite ◽  
Immune Mediated ◽  
Secretory Products ◽  
Species Specific

Abstract Background The Mongolian jird (Meriones unguiculatus) has long been recognized as a permissive host for the filarial parasite Brugia malayi; however, it is nonpermissive to another filarial parasite, canine heartworm (Dirofilaria immitis). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent. Methods Jird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry. Results In vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls (U(9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi, the results were similar (99.4% and 4.72% of D. immitis and B. malayi, respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U(11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U(9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry. Conclusions These results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity.

scholarly journals 1202. Subinhibitory Concentrations of Omadacycline Inhibit Staphylococcus aureus Hemolytic Activity in Vitro

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S622-S623
Author(s):  
Alisa W Serio ◽  
S Ken Tanaka ◽  
Kelly Wright ◽  
Lynne Garrity-Ryan
Keyword(s):  
Staphylococcus Aureus ◽  
Protein Synthesis ◽  
Virulence Factors ◽  
Hemolytic Activity ◽  
Protein Biosynthesis ◽  
The United States ◽  
Aureus Strain ◽  
Protein Synthesis Inhibitors ◽  
Subinhibitory Concentrations

Abstract Background In animal models of Staphylococcus aureus infection, α-hemolysin has been shown to be a key virulence factor. Treatment of S. aureus with subinhibitory levels of protein synthesis inhibitors can decrease α-hemolysin expression. Omadacycline, a novel aminomethylcycline antibiotic in the tetracycline class of bacterial protein biosynthesis inhibitors, is approved in the United States for treatment of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI) in adults. This study was performed to determine the durability of inhibition and effect of subinhibitory concentrations of omadacycline on S. aureus hemolytic activity. Methods All experiments used the methicillin-sensitive S. aureus strain Wood 46 (ATCC 10832), a laboratory strain known to secrete high levels of α-hemolysin. Minimum inhibitory concentrations (MICs) of omadacycline and comparator antibiotics (tetracycline, cephalothin, clindamycin, vancomycin, linezolid) were determined. Growth of S. aureus with all antibiotics was determined and the percentage of hemolysis assayed. “Washout” experiments were performed with omadacycline only. Results S. aureus cultures treated with 1/2 or 1/4 the MIC of omadacycline for 4 hours showed hemolysis units/108 CFU of 47% and 59% of vehicle-treated cultures, respectively (Fig. 1A, 1B). In washout experiments, treatment with as little as 1/4 the MIC of omadacycline for 1 hour decreased the hemolysis units/108 CFU by 60% for 4 hours following removal of the drug (Table 1). Figure 1 Table 1 Conclusion Omadacycline inhibited S. aureus hemolytic activity in vitro at subinhibitory concentrations and inhibition was maintained for ≥ 4 hours after removal of extracellular drug (Fig. 2). The suppression of virulence factors throughout the approved omadacycline dosing interval, in addition to the in vitro potency of omadacycline, may contribute to the efficacy of omadacycline for ABSSSI and CABP due to virulent S. aureus. This finding may apply to other organisms and other virulence factors that require new protein synthesis to establish disease. Figure 2 Disclosures Alisa W. Serio, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) S. Ken Tanaka, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) Kelly Wright, PharmD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) Lynne Garrity-Ryan, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder)

scholarly journals The site of the inhibitory action of salicylate on protein biosynthesis in vitro

1970 ◽  
Vol 117 (3) ◽  
pp. 68P-68P ◽  
Author(s):  
Mary Burleigh ◽  
M. J. H. Smith
Keyword(s):  
Inhibitory Action ◽  
Protein Biosynthesis

scholarly journals Sorting and storage during secretory granule biogenesis: looking backward and looking forward

1998 ◽  
Vol 332 (3) ◽  
pp. 593-610 ◽  
Author(s):  
Peter ARVAN ◽  
David CASTLE
Keyword(s):  
Secretory Pathway ◽  
Molecular Mechanisms ◽  
Secretory Granules ◽  
Secretory Proteins ◽  
Membrane Composition ◽  
Granule Formation ◽  
Granule Membrane ◽  
Regulated Secretory Pathway ◽  
Secretory Products

Secretory granules are specialized intracellular organelles that serve as a storage pool for selected secretory products. The exocytosis of secretory granules is markedly amplified under physiologically stimulated conditions. While granules have been recognized as post-Golgi carriers for almost 40 years, the molecular mechanisms involved in their formation from the trans-Golgi network are only beginning to be defined. This review summarizes and evaluates current information about how secretory proteins are thought to be sorted for the regulated secretory pathway and how these activities are positioned with respect to other post-Golgi sorting events that must occur in parallel. In the first half of the review, the emerging role of immature secretory granules in protein sorting is highlighted. The second half of the review summarizes what is known about the composition of granule membranes. The numerous similarities and relatively limited differences identified between granule membranes and other vesicular carriers that convey products to and from the plasmalemma, serve as a basis for examining how granule membrane composition might be established and how its unique functions interface with general post-Golgi membrane traffic. Studies of granule formation in vitro offer additional new insights, but also important challenges for future efforts to understand how regulated secretory pathways are constructed and maintained.

Secretory products of multiple sclerosis B cells are cytotoxic to oligodendroglia in vitro

2012 ◽  
Vol 246 (1-2) ◽  
pp. 85-95 ◽  
Author(s):  
Robert P. Lisak ◽  
Joyce A. Benjamins ◽  
Liljana Nedelkoska ◽  
Jennifer L. Barger ◽  
Samia Ragheb ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
Secretory Products
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