Enhanced Cellular Uptake and Transport of Polyclonal Immunoglobulin G and Fab After Their Cationization

Abstract

Antibodies are poorly transported across cell membranes and biological barriers in vivo. Cationization of antibody molecules by the derivatization of surface carboxyl groups generating primary amino groups could represent a strategy for intracellular antibody delivery. Before cationization of polyclonal colchicine-specific IgG and Fab, using hexamethylenediamine the isoelectric point (αI) of native IgG and Fab (nIgG and nFab) was in the range of 5.9-9.0 and 8.7-9.3, respectively. The pI of cationized IgG and Fab (cIgG and cFab) were both higher at 8.7-10.3 and 9.5-11, respectively. The affinity and specificity of both IgG and Fab were not modified by cationization. When HL 60 cells were incubated with the native or cationized ¹²⁵I-BSA, -IgG and -Fab, the maximal cellular uptake of clgG and cFab was 3.2 and 2.4 times higher than that of nlgG and nFab at an extracellular concentration of 500ng/ml. Results also indicated that the uptake was dose- and temperature-dependent suggesting absorptive-mediated endocytosis of cationized antibodies by HL 60 cells. Confocal microscopy analysis indicated that the cationized antibodies were present in the plasma membranes and cytoplasm of HL 60 cells. Finally, a study with bovine arterial endothelial monolayer cells showed that the transport of cIgG and cFab through the monolayer cells was 3.3- and 4.3-fold higher for I-cIgG and ¹²⁵I-cFab than those of the corresponding native forms.     

Fab fragments of ovine antibody to colchicine enhance its clearance in the rat

Abstract

Context. Colchicine is an anti-inflammatory alkaloid used for the treatment of acute gout, but has a narrow therapeutic index. Colchicine overdoses are relatively rare, but have high mortality requiring rapid treatment. Objective. To evaluate the ability of a newly available ovine fragment antigen-binding (Fab) antibody to colchicine (ColchiFab^?) to protect rats against renal and other injury 24 h after colchicine ingestion. Materials and methods. Rats were gavaged with colchicine (5 mg/kg), then 2 h later injected intraperitoneally with 5 ml of sterile saline, or Fab anti-colchicine, a newly available ovine antibody to colchicine. Samples of blood were taken at 1, 2, 5 and 24 h after gavage, and urine was collected from 5 to 24 h after gavage. Concentrations of colchicine in tissue, blood and urine were measured by liquid chromatography/mass spectrometry, concentrations of Fab anti-colchicine, urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 or KIM-1 by enzyme-linked immunosorbent assay or ELISA, while concentrations of creatine kinase and creatinine (Cr) were measured enzymatically. Results. Colchicine equilibrated rapidly throughout the body and increased serum creatine kinase. Fab anti-colchicine also rapidly redistributed to the blood and remained at high concentrations over 24 h. Fab anti-colchicine caused a rapid 7.1-fold increase in serum colchicine level, followed by excretion of both colchicine and Fab anti-colchicine through the urine. This was associated with the accumulation of colchicine in the kidney, a reversal of colchicine-induced diarrhoea, and increasing urinary NGAL level; from 168 ± 48 to 477 ± 255 ng/mmol Cr [mean ± standard deviation or SD]. Discussion. Fab anti-colchicine greatly increased the clearance of colchicine, although increasing NGAL level suggested the presence of mild kidney damage. Conclusion. These data suggest clinical utility for Fab anti-colchicine in the treatment of colchicine overdose.     

Approach to the patients with inadequate response to colchicine in familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most common form of monogenic autoinflammatory conditions, and response to colchicine has been considered as one of its distinctive features among other hereditary periodic fever disorders. Prophylactic colchicine has been shown to be effective in the prevention of inflammatory attacks and development of amyloidosis. However, the highest tolerable doses of colchicine may not be adequate enough to manage these goals in approximately 5% of FMF patients. Inadequate response to colchicine in fully compliant FMF patients may be associated with genetic and/or environmental factors affecting disease severity and colchicine bioavailability. Clarification of the molecular pathogenic mechanisms of FMF has revealed that interleukin-1 beta (IL-1β) cytokine is the most likely target to attack, and several case reports and case series have already documented the efficacy and safety of available anti-IL-1 agents, such as anakinra, rilonacept, and canakinumab in those patients inadequately responding to colchicine. Characterization and early identification of those FMF patients with uncontrolled inflammatory activity have become more important after the availability of new treatment options for the prevention of disease-associated complications and permanent damages.     

Immunoreactivity of hypothalamo-neurohypophysial neurons which secrete corticotropin-releasing hormone (CRH) and vasopressin (Vp): immunocytochemical evidence for a correlation with their functional state in colchicine-treated rats

Summary The specific immunoreactivity of neurons containing corticotropin-releasing hormone (CRH) or vasopressin (Vp) was studied both centrally, in the parvocellular division of the paraventricular nucleus, and distally, in the external median eminence. Control rats were compared with adrenalectomized rats and with animals supplemented with corticosterone or dexamethasone, either without additional treatment, or 24, and 48 h after an intraventricular injection of colchicine. In all groups of animals, colchicine induced a progressive and parallel decrease in both CRH and Vp immunoreactivity within the axons of the external median eminence. A semi-quantitative estimation of this axonal immunostaining showed that the decrease was clearly correlated with the axons' releasing activity according to the different functional states of the adrenocorticotropic system. Increased rates of hormonal release induced by adrenalectomy could be seen in the accelerated depletion of axonal immunoreactivity whereas corticosteroid supplementation had the opposite effect. Correspondingly, the progressive intensification of the CRH and Vp immunoreactivity within the perikarya following colchicine treatment was further markedly enhanced in adrenalectomized rats and diminished after corticosteroid supplementation. Taken together, these data suggest that in these neurons, perikaryal hormone synthesis may be closely related to the releasing activity of the axon terminals. They further point to appropriate colchicine treatment as useful tool for evaluating the functional state of CRH and Vp neurons of the parvocellular paraventricular nucleus under various experimental conditions.     

Lichenoid drug eruption induced by colchicine: case report

Lichenoid drug eruption (LDE) is a common cutaneous side effect of drugs including antimalarials, antihypertensives, nonsteroids, anti-inflammatory drugs and diuretics. The physiopathologic relationship between colchicine treatment and LDE is unclear. There is very little documentation of LDE induced by colchicine in the literature. In this report, we present a case that developed LDE on the abdomen and the legs during the colchicine treatment.     

NMDA receptor is involved in neuroinflammation in intracerebroventricular colchicine-injected rats

The neurodegeneration in intracerebroventricular (icv) colchicine injected (ICIR) rats is linked with neuroinflammation. Glutamate excitotoxicity through NMDA receptors is involved with the neuroinflammation in some animal models of Alzheimer Disease (AD), but it has not been explored in ICIR rats. The aim of this study was to investigate the role of NMDA receptors (by blocking it's activity with memantine) in colchicine-induced neuroinflammation and neurodegeneration and impacts on peripheral immune parameters in ICIR rats. Levels of inflammatory markers (IL-1β, TNFα, ROS, nitrite) in the hippocampus and serum, histopathology of the hippocampus and select peripheral immune parameters were measured 14 and 21-days after icv colchicine injection in rats. These parameters were also measured in rats that received daily per os administration of memantine (20?mg/kg) in both study durations. Neuroinflammation in the hippocampus of ICIR rats was associated with neurodegeneration (chromatolysis, plaque formation), along with changes in inflammatory markers in the serum and alterations in peripheral immune parameters (phagocytic activity of WBC and splenic PMN, cytotoxic activity/leukocyte adhesion inhibition by splenic MNC). Administration of memantine to ICIR rats resulted in mitigation of colchicine-induced inflammation in the hippocampus, inflammatory markers in the serum and neurodegeneration and also led to recovery of the measured immune endpoints; most of these effects were greater with the longer duration of study. Phagocytic activity of WBC and splenic PMN cells appeared to correlate with levels of the measured central inflammatory markers. It appears from the results that neuroinflammation might be linked with the NMDA receptor activity in ICIR rats and that this receptor is involved in the process of progressive neuroinflammation and neurodegeneration in the hippocampus of ICIR and potentially in immunomodulation in these same hosts.     

口服脂肪乳剂对二甲基亚硝胺肝损伤大鼠的干预作用

用二甲基亚硝胺染毒制作的肝损伤大鼠实验模型 ,采用脂肪乳剂灌服给药进行防治性处理。结果发现 :具有营养作用的脂肪乳剂对大鼠体重和肝脾重量的增加、肝纤维化的改善等均优于具有抗炎和抗纤维化作用的秋水仙碱 (P <0 .0 1)。