Immunosuppression, nonspecific B-cell activation, and mitogenic activity associated with a high molecular weight component from Listeria monocytogenes

1982 ◽  
Vol 28 (12) ◽  
pp. 1373-1381 ◽  
Author(s):  
T. V. Otokunefor ◽  
S. B. Galsworthy

A high molecular weight component of a saline extract derived from Listeria monocytogenes contained amino acids, carbohydrates, and phosphorus. The same fraction was capable of promoting both the in vitro mitogenic and adjuvant activities and the in vivo immunosuppressive activity displayed by the crude extract. The material was mitogenic to B but not to T lymphocytes in vitro. Responses to sheep and horse erythrocytes as well as to lipopolysaccharide were suppressed. Immunosuppression was dose dependent and was present at 1, 2, or 3 days but absent 7 days after injection. Both primary and secondary responses to sheep erythrocytes were impaired.

2004 ◽  
Vol 24 (3) ◽  
pp. 997-1006 ◽  
Author(s):  
Eugene Varfolomeev ◽  
Frank Kischkel ◽  
Flavius Martin ◽  
Dhaya Seshasayee ◽  
Hua Wang ◽  
...  

ABSTRACT APRIL (a proliferation-inducing ligand) is a member of the tumor necrosis factor (TNF) superfamily. APRIL mRNA shows high levels of expression in tumors of different origin and a low level of expression in normal cells. APRIL shares two TNF receptor family members, TACI and BCMA, with another TNF homolog, BLyS/BAFF. BLyS is involved in regulation of B-cell activation and survival and also binds to a third receptor, BR3/BAFF-R, which is not shared with APRIL. Recombinant APRIL and BLyS induce accumulation of B cells in mice, while BLyS deficiency results in severe B-cell dysfunction. To investigate the physiological role of APRIL, we generated mice that are deficient in its encoding gene. APRIL−/− mice were viable and fertile and lacked any gross abnormality. Detailed histological analysis did not reveal any defects in major tissues and organs, including the primary and secondary immune organs. T- and B-cell development and in vitro function were normal as well, as were T-cell-dependent and -independent in vivo humoral responses to antigenic challenge. These data indicate that APRIL is dispensable in the mouse for proper development. Thus, BLyS may be capable of fulfilling APRIL's main functions.


1988 ◽  
Vol 2 (1) ◽  
pp. 7-11 ◽  
Author(s):  
T. Nagakura ◽  
T. Onda ◽  
Y. likura ◽  
T. Endo ◽  
H. Nagakura ◽  
...  

High molecular weight neutrophil chemotactic activity has been identified in resected human nasal polyps, inferior turbinates, and nasal secretions following antigen challenge. The estimated molecular weight, by gel filtration chromatography, was approximately 600,000. However, a heterogeneity of molecular weight in some patients was recognized. Our results suggest a possible role for high molecular weight-neutrophil chemotactic activity in the pathogenesis of hypersensitivity in the human nasal cavity.


Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 68 ◽  
Author(s):  
Silvia Tores de la Cruz ◽  
Amaia Iriondo-DeHond ◽  
Teresa Herrera ◽  
Yolanda Lopez-Tofiño ◽  
Carlos Galvez-Robleño ◽  
...  

Melanoidins present in coffee silverskin, the only by-product of the roasting process, are formed via the Maillard reaction. The exact structure, biological properties, and mechanism of action of coffee silverskin melanoidins, remain unknown. This research work aimed to contribute to this novel knowledge. To achieve this goal, melanoidins were obtained from an aqueous extract of Arabica coffee silverskin (WO2013004873A1) and was isolated through ultrafiltration (>10 kDa). The isolation protocol was optimized and the chemical composition of the high molecular weight fraction (>10 kDa) was evaluated, by analyzing the content of protein, caffeine, chlorogenic acid, and the total dietary fiber. In addition, the structural analysis was performed by infrared spectroscopy. Antioxidant properties were studied in vitro and the fiber effect was studied in vivo, in healthy male Wistar rats. Melanoidins were administered to animals in the drinking water at a dose of 1 g/kg. At the fourth week of treatment, gastrointestinal motility was evaluated through non-invasive radiographic means. In conclusion, the isolation process was effective in obtaining a high molecular weight fraction, composed mainly of dietary fiber, including melanoidins, with in vitro antioxidant capacity and in vivo dietary fiber effects.


2001 ◽  
Vol 127 (3) ◽  
pp. 1243-1255 ◽  
Author(s):  
Yong-Woo Kim ◽  
Dae-Sup Park ◽  
Seung-Cheol Park ◽  
Sung Hee Kim ◽  
Gang-Won Cheong ◽  
...  

1998 ◽  
Vol 95 (16) ◽  
pp. 9319-9324 ◽  
Author(s):  
Frank S. Lee ◽  
Robert T. Peters ◽  
Luan C. Dang ◽  
Tom Maniatis

A critical step in the signal-induced activation of the transcription factor NF-κB is the site-specific phosphorylation of its inhibitor, IκB, that targets the latter for degradation by the ubiquitin–proteasome pathway. We have previously shown that mitogen-activated protein kinase/ERK kinase kinase 1 (MEKK1) can induce both this site-specific phosphorylation of IκBα at Ser-32 and Ser-36 in vivo and the activity of a high molecular weight IκB kinase complex in vitro. Subsequently, others have identified two proteins, IκB kinase α (IKK-α) and IκB kinase β (IKK-β), that are present in a tumor necrosis factor α-inducible, high molecular weight IκB kinase complex. These kinases are believed to directly phosphorylate IκB based on the examination of the kinase activities of IKK immunoprecipitates, but more rigorous proof of this has yet to be demonstrated. We show herein that recombinant IKK-α and IKK-β can, in fact, directly phosphorylate IκBα at Ser-32 and Ser-36, as well as homologous residues in IκBβ in vitro, and thus are bona fide IκB kinases. We also show that MEKK1 can induce the activation of both IKK-α and IKK-β in vivo. Finally, we show that IKK-α is present in the MEKK1-inducible, high molecular weight IκB kinase complex and treatment of this complex with MEKK1 induces phosphorylation of IKK-α in vitro. We conclude that IKK-α and IKK-β can mediate the NF-κB-inducing activity of MEKK1.


1974 ◽  
Vol 62 (2) ◽  
pp. 355-361 ◽  
Author(s):  
JENNIFER M. DEHNEL ◽  
P. D. McCONAGHEY ◽  
M. J. O. FRANCIS

SUMMARY Plasma somatomedin is the intermediary through which growth hormone (GH) exerts its effects on the growing skeleton. Somatomedin activity may be produced in vitro by perfusion of the liver and kidneys of rats with Waymouth's medium containing GH. The relationship between the activity of plasma somatomedin and somatomedin of hepatic and renal origin has yet to be clarified. Somatomedin from plasma can be separated into active fractions of both high and low molecular weight. Similarly, ultrafiltration of medium containing somatomedin of hepatic origin indicates the existence of two active fractions, one of high molecular weight (greater than 50000) and one of low molecular weight (less than 1000). The latter can be attributed to the release of amino acids, such as serine and glutamine, by the perfused tissue. The high molecular weight fraction is believed to represent GH-dependent somatomedin. Fractions that inhibit production of cartilage matrix are present in liver perfusates as well as in plasma. These results provide further evidence that the liver is a source of GH-dependent somatomedin in vivo. Furthermore, cartilage growth may be controlled not only by the GH-stimulated release of somatomedin by the liver, but also by its release of acid-labile somatomedin inhibitors.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2578-2578
Author(s):  
Mrinmoy Sanyal ◽  
Rosemary Fernandez ◽  
Shoshana Levy

Abstract CD81 is a component of the CD19/CD21 coreceptor complex in B cells. This tetraspanin molecule was previously shown to enable membrane reorganization in B cells responding to complement-bound antigens. Here we stimulated B cells via their B cell receptor (BCR) and demonstrate that Cd81−/− B cells fluxed higher intracellular free calcium ion along with increased phosphorylation of PLCγ2 and Syk. The stimulated Cd81−/− B cells also proliferated faster and secreted higher amounts of antibodies. Moreover, activation of the TLR4 pathway in Cd81−/− B cells induced increased proliferation and antibody secretion. Furthermore, Cd81−/− mice mounted a significantly higher immune response to T-cell independent antigens than their wildtype counterparts. Finally, analysis of Cd81−/− B cells that were generated by bone marrow transplantation into Rag1−/− mice confirmed a cell intrinsic hyperactive phenotype. Taken together, these results indicate that CD81 plays a negative role in B cell activation in vitro and in vivo.


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