scholarly journals Acquired granulocyte abnormality during drug allergic reactions: possible role of complement activation

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 3-8 ◽  
Author(s):  
TK Bowers ◽  
PR Craddock ◽  
HS Jacob
Keyword(s):  
Steroid Therapy ◽  
Complement Activation ◽  
Normal Serum ◽  
Heat Inactivation ◽  
Boyden Chamber ◽  
Systemic Lupus Erythematosis ◽  
Hemolytic Complement Activity

Abstract A profound defect in granulocyte chemotaxis was documented in an otherwise healthy 21-yr-old man who failed to localize granulocytes to an area of cellulitis during an allergic reaction to cephalothin. During the period of drug allergy, characterized by urticaria, eosinophilia, and profound hypocomplementemia, in vitro migration of the patient's granulocytes in the Boyden chamber was markedly impaired. Although devoid of hemolytic complement activity, the patient's serum possessed supranormal chemotactic activity, even following heat inactivation, suggesting the presence of chemotactically active complement split products. Chemotactic function improved concomitantly with steroid therapy and normalization of serum complement levels, and was entirely normal following clinical recovery and cessation of steroid therapy. The chemotactic abnormality noted in the patient's cells was reproduced in normal granulocytes by preincubation either with patient serum or with cobra venom-activated fresh (but not heated) normal serum, suggesting that in vivo exposure of granulocytes to activated complement was responsible for the patient's abnormal chemotactic response. This mechanism may contribute to the increased infection propensity noted in other conditions characterized by in vivo complement activation, such as rheumatoid arthritis and systemic lupus erythematosis.

scholarly journals Acquired granulocyte abnormality during drug allergic reactions: possible role of complement activation

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 3-8
Author(s):  
TK Bowers ◽  
PR Craddock ◽  
HS Jacob
Keyword(s):  
Steroid Therapy ◽  
Complement Activation ◽  
Normal Serum ◽  
Heat Inactivation ◽  
Boyden Chamber ◽  
Systemic Lupus Erythematosis ◽  
Hemolytic Complement Activity

A profound defect in granulocyte chemotaxis was documented in an otherwise healthy 21-yr-old man who failed to localize granulocytes to an area of cellulitis during an allergic reaction to cephalothin. During the period of drug allergy, characterized by urticaria, eosinophilia, and profound hypocomplementemia, in vitro migration of the patient's granulocytes in the Boyden chamber was markedly impaired. Although devoid of hemolytic complement activity, the patient's serum possessed supranormal chemotactic activity, even following heat inactivation, suggesting the presence of chemotactically active complement split products. Chemotactic function improved concomitantly with steroid therapy and normalization of serum complement levels, and was entirely normal following clinical recovery and cessation of steroid therapy. The chemotactic abnormality noted in the patient's cells was reproduced in normal granulocytes by preincubation either with patient serum or with cobra venom-activated fresh (but not heated) normal serum, suggesting that in vivo exposure of granulocytes to activated complement was responsible for the patient's abnormal chemotactic response. This mechanism may contribute to the increased infection propensity noted in other conditions characterized by in vivo complement activation, such as rheumatoid arthritis and systemic lupus erythematosis.

scholarly journals Blocking Jak/STAT signalling using tofacitinib inhibits angiogenesis in experimental arthritis

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Paola Di Benedetto ◽  
Piero Ruscitti ◽  
Onorina Berardicurti ◽  
Noemi Panzera ◽  
Nicolò Grazia ◽  
...  
Keyword(s):  
Serum Levels ◽  
Tube Formation ◽  
Boyden Chamber ◽  
Arthritis Score ◽  
Ethical Approval ◽  
Synovial Tissues ◽  
In Vivo Administration

Abstract Objective During rheumatoid arthritis (RA), the angiogenic processes, occurring with pannus-formation, may be a therapeutic target. JAK/STAT-pathway may play a role and the aim of this work was to investigate the inhibiting role of a JAK-inhibitor, tofacitinib, on the angiogenic mechanisms occurring during RA. Methods After ethical approval, JAK-1, JAK-3, STAT-1, STAT-3 and VEGF expression was evaluated on RA-synovial-tissues. In vitro, endothelial cells (ECs), stimulated with 20 ng/ml of VEGF and/or 1 μM of tofacitinib, were assessed for tube formation, migration and proliferation, by Matrigel, Boyden chamber assay and ki67 gene-expression. In vivo, 32 mice received collagen (collagen-induced arthritis (CIA)) and 32 mice PBS (control). At day 19, CIA and controls mice were divided: 16 mice receiving vehicle and 16 mice receiving tofacitinib. At day 35, the arthritis score, the thickness of paw joints and the serum levels of VEGF and Ang-2 were evaluated. Results The expression of JAK-1, JAK-3, STAT-1, STAT-3 and VEGF in synovial tissue of RA-patients were significantly higher than healthy controls. In vitro, tofacitinib inhibited the ECs ability to form vessels, to proliferate and to migrate. In vivo, administration of tofacitinib prevented the increase of the arthritis score, the paw thickness, the synovial vessels and VEGF and Ang-2 serum-accumulation, when compared to CIA without tofacitinib. Conclusions We explored the anti-angiogenic role of tofacitinib, reporting its ability to inhibit in vitro the angiogenic mechanisms of ECs and in vivo the formation of new synovial vessels, occurring in CIA model. These findings suggest that the therapeutic effect of tofacitinib during RA may be also related to its anti-angiogenic activity.

scholarly journals The role of cytochrome P-450 in cholesterol biogenesis and catabolism

1972 ◽  
Vol 128 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Sandra D. Atkin ◽  
Eileen D. Palmer ◽  
P. D. English ◽  
B. Morgan ◽  
M. A. Cawthorne ◽  
...  
Keyword(s):  
Cholesterol Metabolism ◽  
Carbon Disulphide ◽  
Normal Serum ◽  
Liver Cholesterol ◽  
Drug Metabolizing Enzyme ◽  
Metabolizing Enzyme ◽  
Cytochrome P 450

1. Adjuvant-induced arthritis in rats is accompanied by a loss of activity of the drug-metabolizing enzyme system and a decrease in hepatic cytochrome P-450. 2. Arthritic rats have normal serum and liver cholesterol concentrations. 3. The rate of biogenesis of cholesterol in vivo and in vitro from either [14C]acetate or [14C]mevalonate in arthritic rats was the same as or greater than that found in control rats. 4. Treatment of rats with carbon disulphide (1ml/kg) resulted in a loss of drug-metabolizing-enzyme activity and increased cholesterol biogenesis. 5. The activity of cholesterol 7α-hydroxylase in adjuvant-induced arthritic rats did not differ significantly from that in control rats. 6. Rats fed with cholestyramine had an elevated hepatic cholesterol 7α-hydroxylase activity, but neither the concentration of cytochrome P-450 nor the activity of the drug-hydroxylating enzyme, aminopyrine demethylase, was affected. 7. The relationships between drug hydroxylation and cholesterol metabolism are discussed.

Variable association of complement activation by rituximab and paclitaxel in cancer patients in vivo and in their screening serum in vitro with clinical manifestations of hypersensitivity: a pilot study

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Gergely Tibor Kozma ◽  
Tamás Mészáros ◽  
Zsóka Weiszhár ◽  
Tamás Schneider ◽  
András Rosta ◽  
...  
Keyword(s):  
Pilot Study ◽  
Cancer Patients ◽  
Anticancer Drugs ◽  
Complement Activation ◽  
Clinical Manifestations ◽  
Hypersensitivity Reactions

AbstractTo explore the role of complement (C) activation in the hypersensitivity reactions (HSRs) to some anticancer drugs, as well as the use of the C activation biomarkers (C

scholarly journals PRP18, a protein required for the second reaction in pre-mRNA splicing.

1990 ◽  
Vol 10 (1) ◽  
pp. 324-332 ◽  
Author(s):  
U Vijayraghavan ◽  
J Abelson
Keyword(s):  
Micrococcal Nuclease ◽  
Heat Inactivation ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Exon 1 ◽  
In Vitro Splicing

We have investigated the role of a novel temperature-sensitive splicing mutation, prp18. We had previously demonstrated that an accumulation of the lariat intermediate of splicing occurred at the restrictive temperature in vivo. We have now used the yeast in vitro splicing system to show that extracts from this mutant strain are heat labile for the second reaction of splicing. The heat inactivation of prp18 extracts results from loss of activity of an exchangeable component. Inactivated prp18 extracts are complemented by heat-inactivated extracts from other mutants or by fractions from wild-type extracts. In heat-inactivated prp18 extracts, 40S splicing complexes containing lariat intermediate and exon 1 can assemble. The intermediates in this 40S complex can be chased to products by complementing extracts in the presence of ATP. Both complementation of extracts and chasing of the isolated prp18 spliceosomes takes place with micrococcal nuclease-treated extracts. Furthermore, the complementation profile with fractions of wild-type extracts indicates that the splicing defect results from a mutation in a previously designated factor required for the second step of splicing. The isolation of this mutant as temperature-sensitive lethal has also facilitated cloning of the wild-type allele by complementation.

scholarly journals Von Willebrand Factor Activates the Alternative Complement Pathway In Vivo in a Mouse Model of Complement Thrombotic Microangiopathy

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 29-30
Author(s):  
Paula M Jacobi ◽  
Sarah E Sartain
Keyword(s):  
Endothelial Cells ◽  
Platelet Count ◽  
Mouse Model ◽  
Complement Activation ◽  
Complement Components ◽  
Von Willebrand ◽  
Willebrand Factor

Introduction Thrombotic microangiopathy (TMA) is a group of disorders presenting with microvascular thrombosis, microangiopathic hemolytic anemia, thrombocytopenia, and microvascular endothelial injury ultimately leading to end organ damage. Atypical hemolytic uremic syndrome (aHUS) and bone marrow transplantation-associated TMA (TA-TMA) are two types of TMA known as "complement TMA," as they are associated with dysfunction of the alternative complement pathway (AP), part of the innate immune system. Complement TMA episodes are frequently initiated during inflammation, and the role of inflammation in these TMAs may be in part related to the finding that the inflammatory cytokine TNF up-regulates complement components, down-regulates complement regulators, and causes AP activation in human glomerular microvascular endothelial cells (GMVECs) in vitro. However, the precise mechanism of AP activation in complement TMA is poorly understood. It has been demonstrated that von Willebrand factor (VWF) serves as a surface for AP activation in vitro. Inflammatory cytokines are stimulatory to endothelial cells, leading to excessive VWF secretion; in fact, patients with inflammatory disorders such as complement TMA demonstrate elevated plasma VWF levels, and this abundance of VWF may lead to excessive AP activation. We hypothesized that in complement TMA, VWF released from endothelial cells during inflammation activates the AP. The objective was to investigate whether VWF-mediated AP activation is initiating episodes of complement TMA in vivo in a complement TMA mouse model. Methods A mouse model of complement TMA was developed. To provoke complement TMA, wild-type (WT) C57BL/6J mice (purchased from Jackson Laboratories) were injected intraperitoneally with 5 mg/kg of the inflammatory endotoxin lipopolysaccharide (LPS). Twenty-four hours after injection of either LPS or saline (control), markers of complement TMA-lactate dehydrogenase (LDH), creatinine, platelet count, and complement activation by a rabbit erythrocyte (ER) lysis assay-were measured. ER specifically activate the AP in mammalian plasma in the presence of Mg/EGTA, and the resulting lysis is an indicator of the extent to which complement components have been consumed in vivo: low ER lysis in vitro indicates high complement activation in vivo. To assess the role of VWF in AP activation in vivo, VWF-/- mice (purchased from Jackson Laboratories on a C57BL/6J background) were injected with 5 mg/kg LPS to induce complement TMA. Twenty-four hours after injection, plasma ER lysis was measured and compared to ER lysis in LPS-injected WT C57BL/6J mice. Other markers of complement TMA, including LDH, creatinine, and platelet count, were also measured in both LPS-injected VWF-/- and WT C57BL/6J mice. Results Compared to saline-injected WT C57BL/6J mice, the LPS-injected mice demonstrated significantly: A) higher LDH (hemolysis); B) higher creatinine (renal dysfunction); C) lower platelet count; and D) lower ER lysis (increased AP activation) (Fig. 1). These results confirm the establishment of a complement TMA murine model. Furthermore, LPS-injected VWF-/- mice demonstrated significantly higher ER lysis values than the LPS-injected WT C57BL/6J mice, indicating less AP activation (Fig 2). Because VWF-/- mice do not produce any VWF, these data suggest that VWF contributes to AP activation in vivo in complement TMA. Finally, the LPS-injected VWF-/- mice had less severe TMA as demonstrated by lower LDH levels, lower creatinine levels, and higher platelet counts compared to the LPS-injected WT C57BL/6J mice (Fig. 3). The LPS-injected VWF-/- mice still had a mild degree of AP activation and TMA compared to saline-injected WT C57BL/6J mice, implying that there are complex mechanisms of AP activation in complement TMA that rely heavily on VWF. Conclusions In this study we demonstrated that VWF was important in complement activation and provocation of TMA in a complement TMA murine model. These data are the first step toward a better understanding of VWF's role in complement TMA and may lead to the development of therapeutics that inhibit inflammation, VWF release, or VWF-complement binding to curb AP activation in aHUS and TA-TMA, thereby preventing devastating outcomes. Further study is necessary to delineate the precise mechanisms of VWF-mediated AP activation and TMA development so that these treatment modalities may be explored. Disclosures No relevant conflicts of interest to declare.

Complement is not involved in monocrotaline pyrrole-induced pulmonary injury

1988 ◽  
Vol 254 (2) ◽  
pp. H258-H264
Author(s):  
L. H. Bruner ◽  
K. J. Johnson ◽  
G. O. Till ◽  
R. A. Roth
Keyword(s):  
Lung Injury ◽  
Complement Activation ◽  
Pulmonary Injury ◽  
Serum Complement ◽  
Rat Serum ◽  
Complement Activity ◽  
Hemolytic Complement Activity ◽  
Monocrotaline Pyrrole

Monocrotaline pyrrole (MCTP) causes pulmonary vascular injury, pulmonary hypertension, and right ventricular hypertrophy in rats. The mechanisms by which MCTP causes lung injury are not known. After treatment with a moderate dose of MCTP, several days pass before major lung injury is detected, thus suggesting that the damage is caused indirectly. Since activation of the complement system can cause lung injury, it was of interest to test whether complement activation may be important in lung injury due to MCTP. Accordingly, rats were given a single dose of MCTP (3.5 mg/kg iv), and serum hemolytic complement activity was measured at several times after rats were treated. Neutrophil aggregometry also was used to determine whether complement activation products could be detected in serum after MCTP was given in vivo. The effect of complement depletion on MCTP-induced pulmonary injury was tested by cotreating rats with purified cobra venom factor and MCTP. MCTP treatment did not cause detectable complement activation in vivo, and complement depletion did not protect rats from lung injury. The direct effect of MCTP on serum complement also was tested by exposing fresh rat serum to MCTP in vitro and measuring serum complement activity. MCTP decreased serum hemolytic complement activity in vitro, but it did not interfere with subsequent zymosan-induced activation of complement. These results suggest that complement does not play a role in the development of major lung injury that occurs several days after treatment of rats with MCTP.

THU0073 THE ANTI-ANGIOGENIC ROLE OF TOFACITINIB DURING EXPERIMENTAL MODEL OF ARTHRITIS.

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 249-250
Author(s):  
P. Cipriani ◽  
P. DI Benedetto ◽  
P. Ruscitti ◽  
O. Berardicurti ◽  
V. Liakouli ◽  
...  
Keyword(s):  
Experimental Model ◽  
Inflammatory Cells ◽  
Serum Levels ◽  
Boyden Chamber ◽  
Research Support ◽  
Synovial Tissues ◽  
Research Grant

Background:During rheumatoid arthritis (RA), a chronic autoimmune disease, the loop existing between inflammation and angiogenesis, characterised by new vessels formation associated with the increased recruitment of inflammatory cells, via the abnormal neo-angiogenesis in the synovial tissues, is considered an early important pathogenic mechanism.Tofacitinib, a potent and selective JAK inhibitor, showed a good profile of safety and efficacy in RA patients, slowing the radiographic progression of the disease. In the last years, many works confirmed that some pro-angiogenic genes are targets of STATs family, and among them, vascular endothelial growth factors (VEGF), a potent pro-angiogenic molecule, may promote the new vessels formation via JAK/STAT pathways.Objectives:The aim of this work was to investigate the inhibiting role of tofacitinib, on the angiogenic mechanisms occurring during experimental model of arthritis.Methods:Healthy control (HC) ECs were stimulated with VEGF and/or tofacitinib and assessed for tube formation and migration, by matrigel and Boyden chamber assay. Furthermore, after ethical approval the experimental model of arthritis was obtained, stimulating 32 mice with collagen (CIA) and 32 mice with PBS (control). At day-19, CIA and controls mice were divided in 16 mice receiving vehicle and 16 mice receiving tofacitinib. At day-35, the mice were scarified and the thickness of paw joints, the synovial vessels and the serum levels of VEGF and Ang-2 were evaluatedResults:In vitro, after tofacitinib-treatment, HC-ECs lose their ability to form vessels and to migrate.In vivo, tofacitinib significantly prevented the increase of paw thickness induced by the collagen administration and reduced the vessel density in synovial tissues of joints, when compared to CIA that did not received tofacitinib. Furthermore, the serum levels of VEGF and Ang-2 were higher in CIA mice, than in control mice. The administration of tofacitinib was able to prevent the VEGF and Ang-2 accumulation in CIA mice.Conclusion:During the last decade, the biological analogies between solid tumors and synovial pannus, and the encouraging results of anti-angiogenic treatments in oncology, lead to increasing interest for angiogenesis as a possible therapeutic target in RA. The present study demonstrated the anti-angiogenic efficacy of tofacitinib, opening a new perspective application for this molecule and improving our therapeutic skill to control the clinical evolution of RA.References:[1]Leblond A et al. Autoimmun Rev 2017;16:594-601.[2]Fleischmann R et al. N Engl J Med 2012;367:495-507.[3]Marrelli A, Autoimmun Rev 2011;10:595-8.Disclosure of Interests:Paola Cipriani Grant/research support from: Actelion, Pfizer, Speakers bureau: Actelion, Pfizer, Paola Di Benedetto Grant/research support from: Paola Di Benedetto received grant from Dompè outside this work., Piero Ruscitti Grant/research support from: Piero Ruscitti received grant from Pfizer outside this work., Speakers bureau: Piero Ruscitti received speaker honoraria BMS, MSD, Ely Lilly, SOBI outside this work, Onorina Berardicurti: None declared, Vasiliki Liakouli Grant/research support from: Vasiliki Liakouli received grant from Pfizer outside this work., Speakers bureau: Vasiliki Liakouli received speaker honoraria from Sanofi Genzyme outside this work., Francesco Carubbi Speakers bureau: Francesco Carubbi received speaker honoraria from Abbvie and Celgene outside this work., Noemi Panzera: None declared, Nicolò Grazia: None declared, Mauro Di Vito Nolfi: None declared, Barbara Di Francesco: None declared, Antonio Maurizi: None declared, Nadia Rucci: None declared, Anna Teti: None declared, Francesca Zazzeroni: None declared, Edoardo Alesse: None declared, Roberto Giacomelli Grant/research support from: Roberto Giacomelli received research grant from Pfizer.This study was supported by an unconditioned Research grant from Pfizer., Speakers bureau: Roberto Giacomelli received speaker honoraria from Abbvie, Roche, Actelion, BMS, MSD, Ely Lilly, SOBI and Pfizer outside this work.

scholarly journals PRP18, a protein required for the second reaction in pre-mRNA splicing

1990 ◽  
Vol 10 (1) ◽  
pp. 324-332 ◽  
Author(s):  
U Vijayraghavan ◽  
J Abelson
Keyword(s):  
Micrococcal Nuclease ◽  
Heat Inactivation ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Exon 1 ◽  
In Vitro Splicing

We have investigated the role of a novel temperature-sensitive splicing mutation, prp18. We had previously demonstrated that an accumulation of the lariat intermediate of splicing occurred at the restrictive temperature in vivo. We have now used the yeast in vitro splicing system to show that extracts from this mutant strain are heat labile for the second reaction of splicing. The heat inactivation of prp18 extracts results from loss of activity of an exchangeable component. Inactivated prp18 extracts are complemented by heat-inactivated extracts from other mutants or by fractions from wild-type extracts. In heat-inactivated prp18 extracts, 40S splicing complexes containing lariat intermediate and exon 1 can assemble. The intermediates in this 40S complex can be chased to products by complementing extracts in the presence of ATP. Both complementation of extracts and chasing of the isolated prp18 spliceosomes takes place with micrococcal nuclease-treated extracts. Furthermore, the complementation profile with fractions of wild-type extracts indicates that the splicing defect results from a mutation in a previously designated factor required for the second step of splicing. The isolation of this mutant as temperature-sensitive lethal has also facilitated cloning of the wild-type allele by complementation.

scholarly journals THE ROLE OF OPSONINS IN NON-SPECIFIC IMMUNITY

1960 ◽  
Vol 111 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Derrick Rowley
Keyword(s):  
Normal Serum ◽  
Phagocytic Cells ◽  
E Coli ◽  
Specific Immunity ◽  
Viable Bacteria ◽  
Bacterial Lipopolysaccharides ◽  
Transport Of Bacteria

A study of the recoveries of radioactivity, and of viable bacteria following injection of P32-labelled E. coli into the mouse peritoneum, has indicated that the rapid decrease in viable bacteria which occurs is largely due to peritoneal events, and not to the transport of bacteria elsewhere. The serum from mice given lipopolysaccharides 48 hours previously, when used to pretreat bacteria before intraperitoneal injection, was found to stimulate phagocytosis to a greater extent than did pretreatment with normal serum. In addition, macrophages themselves were found to be affected by contact with lipopolysaccharides, either in vivo or in vitro in such a way as to promote their phagocytic abilities. It is suggested that the provocation of non-specific immunity by bacterial lipopolysaccharides involves two facets at least; firstly, an increase in the opsonic capacity of the serum, and secondly an increase in the inherent capacity of phagocytic cells to perform this function.

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