scholarly journals Fish type I and type II interferons: composition, receptor usage, production and function

2019 ◽  
Vol 12 (2) ◽  
pp. 773-804 ◽  
Author(s):  
Zhen Gan ◽  
Shan Nan Chen ◽  
Bei Huang ◽  
Jun Zou ◽  
Pin Nie
Keyword(s):  
Type I ◽  
Type Ii ◽  
Receptor Usage ◽  
And Function

scholarly journals Mutants of Type II Heat-Labile Enterotoxin LT-IIa with Altered Ganglioside-Binding Activities and Diminished Toxicity Are Potent Mucosal Adjuvants

2006 ◽  
Vol 75 (2) ◽  
pp. 621-633 ◽  
Author(s):  
Hesham F. Nawar ◽  
Sergio Arce ◽  
Michael W. Russell ◽  
Terry D. Connell
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Binding Activity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Type Ii ◽  
Heat Labile ◽  
Enhanced Expression ◽  
Adhesin Protein ◽  
And Function

ABSTRACT The structure and function LT-IIa, a type II heat-labile enterotoxin of Escherichia coli, are closely related to the structures and functions of cholera toxin and LT-I, the type I heat-labile enterotoxins of Vibrio cholerae and enterotoxigenic Escherichia coli, respectively. While LT-IIa is a potent systemic and mucosal adjuvant, recent studies demonstrated that mutant LT-IIa(T34I), which exhibits no detectable binding activity as determined by an enzyme-linked immunosorbent assay, with gangliosides GD1b, GD1a, and GM1 is a very poor adjuvant. To evaluate whether other mutant LT-IIa enterotoxins that also exhibit diminished ganglioside-binding activities have greater adjuvant activities, BALB/c mice were immunized by the intranasal route with the surface adhesin protein AgI/II of Streptococcus mutans alone or in combination with LT-IIa, LT-IIa(T14S), LT-IIa(T14I), or LT-IIa(T14D). All three mutant enterotoxins potentiated strong mucosal immune responses that were equivalent to the response promulgated by wt LT-IIa. All three mutant enterotoxins augmented the systemic immune responses that correlated with their ganglioside-binding activities. Only LT-IIa and LT-IIa(T14S), however, enhanced expression of major histocompatibility complex class II and the costimulatory molecules CD40, CD80, and CD86 on splenic dendritic cells. LT-IIa(T14I) and LT-IIa(T14D) had extremely diminished toxicities in a mouse Y1 adrenal cell bioassay and reduced abilities to induce the accumulation of intracellular cyclic AMP in a macrophage cell line.

scholarly journals Biosynthesis of Polyketides in Streptomyces

2019 ◽  
Vol 7 (5) ◽  
pp. 124 ◽  
Author(s):  
Chandra Risdian ◽  
Tjandrawati Mozef ◽  
Joachim Wink
Keyword(s):  
Secondary Metabolites ◽  
Structure And Function ◽  
Polyketide Synthases ◽  
Type I ◽  
Type Ii ◽  
Filamentous Form ◽  
Gram Positive Bacteria ◽  
Wide Range ◽  
Different Types ◽  
And Function

Polyketides are a large group of secondary metabolites that have notable variety in their structure and function. Polyketides exhibit a wide range of bioactivities such as antibacterial, antifungal, anticancer, antiviral, immune-suppressing, anti-cholesterol, and anti-inflammatory activity. Naturally, they are found in bacteria, fungi, plants, protists, insects, mollusks, and sponges. Streptomyces is a genus of Gram-positive bacteria that has a filamentous form like fungi. This genus is best known as one of the polyketides producers. Some examples of polyketides produced by Streptomyces are rapamycin, oleandomycin, actinorhodin, daunorubicin, and caprazamycin. Biosynthesis of polyketides involves a group of enzyme activities called polyketide synthases (PKSs). There are three types of PKSs (type I, type II, and type III) in Streptomyces responsible for producing polyketides. This paper focuses on the biosynthesis of polyketides in Streptomyces with three structurally-different types of PKSs.

scholarly journals Influence of ovarian cancer type I and type II microenvironment on the phenotype and function of monocyte-derived dendritic cells

2017 ◽  
Vol 19 (12) ◽  
pp. 1489-1497 ◽  
Author(s):  
J. Surówka ◽  
I. Wertel ◽  
K. Okła ◽  
W. Bednarek ◽  
R. Tarkowski ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dendritic Cells ◽  
Type I ◽  
Cancer Type ◽  
Type Ii ◽  
And Function

Three Types of Hereditary Antiterombin III Deficiency

1979 ◽  
Author(s):  
I. Nagy ◽  
H. Losonczy
Keyword(s):  
Antithrombin Iii ◽  
Clinical Signs ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Basic Activity ◽  
At Iii ◽  
And Function

The authors detected in the last seven years 15 patients with hereditary antithrombin III/AT III/ abnormality. All of them had typical clinical signs of recurrent arterious and venous thromboembolie. The abnormality inherited as an autosomal trait. Three types of the abnormality could be observed. In Type I both quantity and function of AT III were extremely decreased. In type II AT III is normal in quantity but abnormal in function. In Type III AT III is quantitatively normal and also its function seems normal as far as its basic activity is concerned /activity measured in absence of heparin/, but its abnormality becomes manifest in the presence of heparin in vitro/and also in vivo/. 5 of the patients belonged to Type I, 4 to Type II and 6 to Type III. In 60 examined family members of the 15 patients an abnormal AT III could be observed in 44, clinical signs in 23.The examination of AT III activity in the presence of a given amount of heparin ia of great importance in recognition of the different types of antithrombin III abnormalities.

Neuromuscular Organization of the Human Upper Esophageal Sphincter

1998 ◽  
Vol 107 (5) ◽  
pp. 370-377 ◽  
Author(s):  
Liancai Mu ◽  
Ira Sanders
Keyword(s):  
Upper Esophageal Sphincter ◽  
Muscle Fiber Types ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Pharyngeal Plexus ◽  
Motor End Plate ◽  
Horizontal Part ◽  
Esophageal Sphincter ◽  
And Function

The upper esophageal sphincter (UES) is a key component of swallowing, and yet, its anatomy and function are still incompletely understood. The UES is a functional entity that is composed of three muscles: the cricopharyngeal (CP) muscle, the inferior pharyngeal constrictor (IPC) muscle, and the upper esophageal (UE) muscle. This study compared the anatomy of the three muscles of the UES in nine human autopsy specimens. The variables examined included the pattern of motor end plates (acetylcholinesterase stain), the proportion of fast- and slow-twitch muscle fibers (myofibrillar adenosinetriphosphatase), and the details of their nerve supply (Sihler's stain). The results demonstrated that each variable is different in the three muscles. For example, the IPC muscle is innervated by the pharyngeal plexus, the CP muscle by both the pharyngeal plexus and the recurrent laryngeal nerve (RLN), and the UE muscle by the RLN. The IPC and CP muscles showed distinct motor end plate bands, while the horizontal part of the CP muscle also contained small and randomly scattered end plates. This latter pattern was present throughout the UE muscle. Analysis of the muscle fiber types of the UES revealed a type I (slow) predominance (89%) in the CP and UE muscles and a type II (fast) predominance (62%) in the IPC muscle. However, the IPC muscle is composed of two layers: a fast, thick, outer layer (90% type II) and a slow, thin, inner layer (85% type I). The implications of these findings for the diagnosis and treatment of UES dysfunction will be discussed.

Dimeric/oligomeric DNA methyltransferases: an unfinished story

2009 ◽  
Vol 390 (9) ◽  
Author(s):  
Ernst G. Malygin ◽  
Alexey A. Evdokimov ◽  
Stanley Hattman
Keyword(s):  
Experimental Data ◽  
Dna Methyltransferases ◽  
Structure And Function ◽  
Type I ◽  
Type Ii ◽  
Kinetic Characteristics ◽  
Biological Substrate ◽  
Oligomeric Dna ◽  
And Function

Abstract DNA methyltransferases (MTases) are enzymes that carry out post-replicative sequence-specific modifications. The initial experimental data on the structure and kinetic characteristics of the EcoRI MTase led to the paradigm that type II systems comprise dimeric endonucleases and monomeric MTases. In retrospect, this was logical because, while the biological substrate of the restriction endonuclease is two-fold symmetrical, the in vivo substrate for the MTase is generally hemi-methylated and, hence, inherently asymmetric. Thus, the paradigm was extended to include all DNA MTases except the more complex bifunctional type I and type III enzymes. Nevertheless, a gradual enlightenment grew over the last decade that has changed the accepted view on the structure of DNA MTases. These results necessitate a more complex view of the structure and function of these important enzymes.

scholarly journals Sites of vulnerability on ricin B chain revealed through epitope mapping of toxin-neutralizing monoclonal antibodies

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0236538
Author(s):  
David J. Vance ◽  
Amanda Y. Poon ◽  
Nicholas J. Mantis
Keyword(s):  
Monoclonal Antibodies ◽  
Mammalian Cells ◽  
Type I ◽  
Dependent Manner ◽  
Type Ii ◽  
Single Chain ◽  
Carbohydrate Recognition Domains ◽  
And Function ◽  
Golgi Network ◽  
Dose Dependent

Ricin toxin’s B subunit (RTB) is a multifunctional galactose (Gal)-/N-acetylgalactosamine (GalNac)-specific lectin that promotes uptake and intracellular trafficking of ricin’s ribosome-inactivating subunit (RTA) into mammalian cells. Structurally, RTB consists of two globular domains (RTB-D1, RTB-D2), each divided into three homologous sub-domains (α, β, γ). The two carbohydrate recognition domains (CRDs) are situated on opposite sides of RTB (sub-domains 1α and 2γ) and function non-cooperatively. Previous studies have revealed two distinct classes of toxin-neutralizing, anti-RTB monoclonal antibodies (mAbs). Type I mAbs, exemplified by SylH3, inhibit (~90%) toxin attachment to cell surfaces, while type II mAbs, epitomized by 24B11, interfere with intracellular toxin transport between the plasma membrane and the trans-Golgi network (TGN). Localizing the epitopes recognized by these two classes of mAbs has proven difficult, in part because of RTB’s duplicative structure. To circumvent this problem, RTB-D1 and RTB-D2 were expressed as pIII fusion proteins on the surface of filamentous phage M13 and subsequently used as “bait” in mAb capture assays. We found that SylH3 captured RTB-D1 (but not RTB-D2) in a dose-dependent manner, while 24B11 captured RTB-D2 (but not RTB-D1) in a dose-dependent manner. We confirmed these domain assignments by competition studies with an additional 8 RTB-specific mAbs along with a dozen a single chain antibodies (VHHs). Collectively, these results demonstrate that type I and type II mAbs segregate on the basis of domain specificity and suggest that RTB’s two domains may contribute to distinct steps in the intoxication pathway.

scholarly journals Distinct CD1d docking strategies exhibited by diverse Type II NKT cell receptors

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Catarina F. Almeida ◽  
Srinivasan Sundararaj ◽  
Jérôme Le Nours ◽  
T. Praveena ◽  
Benjamin Cao ◽  
...  
Keyword(s):  
Nkt Cells ◽  
Type I ◽  
Type Ii ◽  
Nkt Cell ◽  
Lipid Antigens ◽  
Microbial Antigen ◽  
Health And Disease ◽  
Lipid Antigen ◽  
And Function ◽  
Antigen Presenting

AbstractType I and type II natural killer T (NKT) cells are restricted to the lipid antigen-presenting molecule CD1d. While we have an understanding of the antigen reactivity and function of type I NKT cells, our knowledge of type II NKT cells in health and disease remains unclear. Here we describe a population of type II NKT cells that recognise and respond to the microbial antigen, α-glucuronosyl-diacylglycerol (α-GlcADAG) presented by CD1d, but not the prototypical type I NKT cell agonist, α-galactosylceramide. Surprisingly, the crystal structure of a type II NKT TCR-CD1d-α-GlcADAG complex reveals a CD1d F’-pocket-docking mode that contrasts sharply with the previously determined A’-roof positioning of a sulfatide-reactive type II NKT TCR. Our data also suggest that diverse type II NKT TCRs directed against distinct microbial or mammalian lipid antigens adopt multiple recognition strategies on CD1d, thereby maximising the potential for type II NKT cells to detect different lipid antigens.

scholarly journals Alphavirus-Induced Membrane Rearrangements during Replication, Assembly, and Budding

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 984
Author(s):  
Zeinab Elmasri ◽  
Benjamin L. Nasal ◽  
Joyce Jose
Keyword(s):  
Current Knowledge ◽  
Rna Replication ◽  
Type I ◽  
Type Ii ◽  
Fatal Disease ◽  
Structural Modifications ◽  
Host Interactions ◽  
Infected Cells ◽  
Membrane Type ◽  
And Function

Alphaviruses are arthropod-borne viruses mainly transmitted by hematophagous insects that cause moderate to fatal disease in humans and other animals. Currently, there are no approved vaccines or antivirals to mitigate alphavirus infections. In this review, we summarize the current knowledge of alphavirus-induced structures and their functions in infected cells. Throughout their lifecycle, alphaviruses induce several structural modifications, including replication spherules, type I and type II cytopathic vacuoles, and filopodial extensions. Type I cytopathic vacuoles are replication-induced structures containing replication spherules that are sites of RNA replication on the endosomal and lysosomal limiting membrane. Type II cytopathic vacuoles are assembly induced structures that originate from the Golgi apparatus. Filopodial extensions are induced at the plasma membrane and are involved in budding and cell-to-cell transport of virions. This review provides an overview of the viral and host factors involved in the biogenesis and function of these virus-induced structures. Understanding virus–host interactions in infected cells will lead to the identification of new targets for antiviral discovery.

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