T cell syncytia induced by HIV release. T cell chemoattractants: demonstration with a newly developed single cell chemotaxis chamber

1998 ◽  
Vol 111 (1) ◽  
pp. 99-109 ◽  
Author(s):  
D.C. Shutt ◽  
L.M. Jenkins ◽  
E.J. Carolan ◽  
J. Stapleton ◽  
K.J. Daniels ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
T Cell ◽  
Molecular Mass ◽  
Conditioned Medium ◽  
Single Cells ◽  
High Molecular Mass ◽  
Molecular Masses ◽  
Mass Factor ◽  
Mass Activity ◽  
Cell Chemotaxis

A chemotaxis chamber has been developed to analyze both the velocity and the directionality of individual T cells in gradients of high molecular mass molecules over long periods of time. Employing this chamber, it is demonstrated that syncytia induced by HIV in SUP-T1 cell cultures release two T cell chemoattractants with approximate molecular masses of 30 and 120 kDa. Neither uninfected single cells nor polyethylene glycol-induced syncytia release detectable chemoattractant, suggesting that these chemoattractants are linked to HIV infection. Soluble gp120 functions as a T cell chemoattractant and the addition of anti-gp120 antibody to syncytium-conditioned medium blocks the high molecular mass chemoattractant activity but not the low molecular mass activity. The addition of anti-CD4 antibody to syncytium-conditioned medium also blocks the high molecular mass chemoattractant activity but not the low molecular mass activity. These results demonstrate that HIV-induced T cell syncytia release a low and a high molecular mass T cell chemoattractant, and suggest that the high molecular mass factor is gp120 and that it functions through the CD4 receptor.

scholarly journals Identification of two highly sialylated human tear-fluid DMBT1 isoforms: the major high-molecular-mass glycoproteins in human tears

2002 ◽  
Vol 366 (2) ◽  
pp. 511-520 ◽  
Author(s):  
Benjamin L. SCHULZ ◽  
David OXLEY ◽  
Nicolle H. PACKER ◽  
Niclas G. KARLSSON
Keyword(s):  
Molecular Mass ◽  
Peptide Mass Fingerprinting ◽  
High Molecular Mass ◽  
Tear Fluid ◽  
Protein Variant ◽  
Peptide Mass ◽  
Composite Gel ◽  
Molecular Masses ◽  
Protein Components ◽  
Sialyl Lea

Human open eye tear fluid was separated by low-percentage SDS/PAGE to detect high-molecular-mass protein components. Two bands were found with apparent molecular masses of 330 and 270kDa respectively. By peptide-mass fingerprinting after tryptic digestion, the proteins were found to be isoforms of the DMBT1 gene product, with over 30% of the predicted protein covered by the tryptic peptides. By using gradient SDS/agarose/polyacrylamide composite gel electrophoresis and staining for glycosylation, it was shown that the two isoforms were the major high-molecular-mass glycoproteins of >200kDa in human tear fluid. Western blotting showed that the proteins expressed sialyl-Lea. After the release of oligosaccharides by reductive β-elimination from protein blotted on to PVDF membrane, it was revealed by liquid chromatography-MS that the O-linked oligosaccharides were comprised mainly of highly sialylated oligosaccharides with up to 16 monosaccharide units. A majority of the oligosaccharides could be described by the formula dHex0→2NeuAc1→xHexxHexNAcx(-ol), x = 1–6, where Hex stands for hexose, dHex for deoxyhexose, HexNAc for N-acetylhexosamine and NeuAc for N-acetylneuraminate. The number of sialic acids in the formula is less than 5. Interpretation of collision-induced fragmentation tandem MS confirmed the presence of sialic acid and suggested the presence of previously undescribed structures carrying the sialyl-Lea epitopes. Small amounts of neutral and sulphated species were also present. This is the first time that O-linked oligosaccharides have been detected and described from protein variant of the DMBT1 gene.

Dynamic computed tomography with low- and high-molecular-mass contrast agents to assess microvascular permeability modifications in a model of liver fibrosis

2002 ◽  
Vol 103 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Roland MATERNE ◽  
Laurence ANNET ◽  
Stéphane DECHAMBRE ◽  
Christine SEMPOUX ◽  
Anne M. SMITH ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Contrast Agents ◽  
Molecular Mass ◽  
Hepatic Fibrosis ◽  
Mean Transit Time ◽  
Distribution Volume ◽  
High Molecular Mass ◽  
Permeability Changes ◽  
Molecular Masses ◽  
The Mean

Interstitial collagen formation and transformation of the fenestrated hepatic sinusoids into continuous capillaries are major ultrastructural changes that occur in liver cirrhosis and fibrosis. These modifications lead to progressive restriction of blood–liver exchanges. The purpose of our study was to evaluate the permeability changes in a model of hepatic fibrosis by using dynamic computed tomography (CT) enhanced with contrast agents of different molecular masses. Dynamic single-section CT of the liver was performed after intravenous bolus administration of a low-molecular-mass contrast agent (iobitridol) and an experimental high-molecular-mass agent (P840) in normal control rabbits and in rabbits with hepatic fibrosis. Hepatic, aortic and portal venous time–density curves were fitted with a dual-input one-compartmental model to calculate the hepatic mean transit time and distribution volume of the contrast agents. In the rabbits with liver fibrosis, the mean transit time of the high-molecular-mass agent was shorter than that of the low-molecular-mass agent (10.0±1.8s and 12.0±1.2s respectively; P<0.05). The distribution volume accessible to the high-molecular-mass agent was also smaller (22.2±4.8% compared with 32.0±6.7%; P<0.01). In the normal rabbits, the mean transit times of the high- and low-molecular-mass agents did not differ significantly, and nor did their distribution volumes. Our results demonstrate decreased sinusoidal permeability for the high-molecular-mass agent P840 in a model of hepatic fibrosis. Non-invasive assessment of permeability changes in liver fibrosis can be performed with dynamic CT and contrast agents of different molecular masses.

scholarly journals Gross Variability in the Detection of Prolactin in Sera Containing Big Big Prolactin (Macroprolactin) by Commercial Immunoassays

2002 ◽  
Vol 87 (12) ◽  
pp. 5410-5415 ◽  
Author(s):  
Thomas P. Smith ◽  
Abdulwahab M. Suliman ◽  
Michael N. Fahie-Wilson ◽  
T. Joseph McKenna
Keyword(s):  
Clinical Practice ◽  
Polyethylene Glycol ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Reading Methods ◽  
Clinical Laboratories ◽  
Secondary Screening ◽  
Mass Form ◽  
Frequent Presence

Abstract A high molecular mass form of prolactin (PRL), macroprolactin, accumulates in the sera of some subjects. Although macroprolactin exhibits limited bioactivity in vivo, it retains immunoreactivity. We examined the frequency of macroprolactinemia in clinical practice and the ability of immunoassay systems to distinguish between macroprolactin and monomeric PRL. Of 300 hyperprolactinemic sera identified, 71 normalized following treatment of sera with polyethylene glycol, indicating that 24% of hyperprolactinemia could be accounted for by macroprolactin. Ten of these macroprolactinemic sera were circulated to 18 clinical laboratories. Two sets of PRL measurements of the 10 untreated sera were obtained from each of the nine most commonly used immunoassay systems. Across the nine assay systems, differences in the PRL estimates ranged from 2.3- to 7.8-fold. Elecsys users reported the highest PRL levels. Somewhat lower values were reported for DELFIA systems followed by Immuno-1, AxSYM, and Architect assays. The Immulite 2000 assay generated PRL levels equivalent to approximately 50% of those reported by the high-reading methods. The lowest PRL levels were reported by Access, ACS:180, and Centaur systems. To avoid confusion caused by the frequent presence of macroprolactin accounting for hyperprolactinemia, secondary screening for the presence of macroprolactin is recommended.

HIV-induced T-cell syncytia release a two component T-helper cell chemoattractant composed of Nef and Tat

1999 ◽  
Vol 112 (22) ◽  
pp. 3931-3941
Author(s):  
D.C. Shutt ◽  
D.R. Soll
Keyword(s):  
T Cell ◽  
Molecular Mass ◽  
T Helper Cells ◽  
Chemotactic Activity ◽  
T Helper ◽  
Concentration Gradients ◽  
Cd4 Receptor ◽  
Helper Cells ◽  
Lower Molecular Mass ◽  
Mass Activity

Using a newly developed gradient chamber to provide independent measurements of chemokinesis (stimulated motility) and chemotaxis (stimulated motility up a concentration gradient) of individual T-helper cells, it was recently demonstrated that HIV-induced T-cell syncytia release two distinct chemotactic activities that are separable by their rates of diffusion. The molecular masses of the two chemoattractant activities were estimated to be 30 and 120 kDa. The higher molecular mass activity was demonstrated to be the viral glycoprotein gp120. In an attempt to identify the lower molecular mass activity, chemotaxis and chemokinesis of T-helper cells were analyzed in individual concentration gradients of the virally encoded proteins Rev, p24, Tat and Nef. None functioned alone as a chemoattractant, but both Tat and Nef alone functioned as chemokinetic stimulants. When Tat and Nef were used together to generate parallel gradients, they stimulated chemotaxis. Antibody to either Tat or Nef neutralized the lower molecular mass chemotactic activity released by syncytia. The addition of antibody to the CD4 receptor or the addition of soluble CD4 inhibited high molecular mass chemotactic activity but not the low molecular mass chemotactic activity in HIV-induced syncytium-conditioned medium, demonstrating that the former but not the latter activity is mediated through the CD4 receptor. These results identify the combination of Nef and Tat as the lower molecular mass T cell chemoattractant released by HIV-induced syncytia, and provide the first evidence suggesting that parallel concentration gradients of two proteins are necessary for chemotaxis.

Synthesis and Characterization of High-Molecular Mass Polyethylene Glycol-Conjugated Oligonucleotides

1997 ◽  
Vol 8 (6) ◽  
pp. 793-797 ◽  
Author(s):  
Gian Maria Bonora ◽  
Eugenia Ivanova ◽  
Valentina Zarytova ◽  
Barbara Burcovich ◽  
Francesco Maria Veronese
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Synthesis And Characterization

scholarly journals Prolactin and macroprolactin: a case report of hyperprolactinaemia highlighting the interpretation of discrepant results

2003 ◽  
Vol 40 (3) ◽  
pp. 298-300 ◽  
Author(s):  
AAA Ismail ◽  
PL Walker ◽  
MN Fahie-Wilson ◽  
N Jassam ◽  
JH Barth
Keyword(s):  
Case Report ◽  
Polyethylene Glycol ◽  
Molecular Mass ◽  
High Molecular Mass

Immunoassay methods for prolactin detect macroprolactin (i.e. high molecular mass complexes of prolactin) to various degrees. Therefore it is generally assumed that the widely differing results by methods that measure both moieties to a differing extent are due to the presence of macroprolactin. We present a case which challenges such an assumption and suggest that precipitation by polyethylene glycol is the most reliable screen for identifying macroprolactin (and/or interfering antibodies if present).

Assessment of macroprolactinemia inpatients with prolactinoma

2017 ◽  
Vol 43 (1) ◽  
pp. 71-75
Author(s):  
Sema Ciftci Dogansen ◽  
Gulsah Yenidunya Yalin ◽  
Sema Yarman
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Mass ◽  
Clinical Features ◽  
Prolactin Level ◽  
High Molecular Mass ◽  
Benign Condition ◽  
Significant Difference ◽  
Negative Findings ◽  
The Mean ◽  
Polyethylene Glycol Precipitation

AbstractPurpose:Macroprolactin, the high-molecular mass prolactin isoform, is considered to be an inactive product with extrapituitary origin. Although macroprolactinemia is considered a benign condition, there is evidence of overlapping clinical features among patients with hyperprolactinemia. Data on the prevalence of macroprolactinemia in prolactinomas is also quite limited. The aim of this study was to assess the prevalence of macroprolactinemia in our patients with prolactinoma.Methods:The study included patients with macroprolactinoma (n=50) and microprolactinoma (n=16). Prolactin level was measured with an electrochemiluminescent immunoassay, and macroprolactinemia was defined as the percentage of prolactin recovery <40% after the polyethylene glycol precipitation.Results:Macroprolactinemia was not detected in our patients with prolactinoma (the percentage of PRL recovery range; 55%–96%). The mean percentage of prolactin recovery was similar in patients with macroprolactinoma and microprolactinoma (67.7%±8.0% and 70%±9.4%, respectively, p=0.96).Conclusion:Macroprolactinemia is generally associated with negative findings on pituitary imaging. Although the monomeric prolactin is dominant, rarely macroprolactin may also be present in prolactinomas. We did not detect presence of macroprolactin in any of the patients and there was no statistically significant difference between micro- and macroprolactinomas in terms of prolactin recovery.

scholarly journals Poly(Aspartic Acid) Degradation by aSphingomonas sp. Isolated from Freshwater

1999 ◽  
Vol 65 (9) ◽  
pp. 4268-4270 ◽  
Author(s):  
Kenji Tabata ◽  
Ken-Ichi Kasuya ◽  
Hideki Abe ◽  
Kozue Masuda ◽  
Yoshiharu Doi
Keyword(s):  
Molecular Mass ◽  
River Water ◽  
Aspartic Acid ◽  
Cell Extract ◽  
High Molecular Mass ◽  
Acid Degradation ◽  
Degrading Bacterium ◽  
Molecular Masses ◽  
Bacterium Strain

ABSTRACT A poly(aspartic acid) degrading bacterium (strain KT-1 [JCM10459]) was isolated from river water and identified as a member of the genus Sphingomonas. The isolate degraded only poly(aspartic acid)s of low molecular masses (<5 kDa), while the cell extract hydrolyzed high-molecular-mass poly(aspartic acid)s of 5 to 150 kDa to yield aspartic acid monomer.

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