In vivo effects of monoclonal antibody to ICAM-1 (CD54) in nonhuman primates with renal allografts

These studies test whether allograft rejection can be blocked by interference with leukocyte adhesion, using a murine IgG2a mAb (R6.5) reactive with monkey ICAM-1 (CD54). In 16 Cynomolgus renal allograft recipients, R6.5 was administered prophylactically as the sole immunosuppressive agent for 12 days (0.01 to 2 mg/kg/day). Survival in 14 recipients with technically successful grafts was significantly prolonged (24.2 +/- 2.4 vs 9.2 +/- 0.6 days for controls; p less than 0.001). Intercellular adhesion molecule-1 (CD54) (ICAM-1) was expressed on vascular endothelium in the kidney and other organs in the monkey in a pattern similar to that in humans. During cellular rejection in controls, ICAM-1 expression increased on endothelial cells, infiltrating mononuclear leukocytes and tubular cells. Biopsies during R6.5 administration showed decreased T cell infiltration (CD2, CD8, CD4) compared with controls and decreased arterial endothelial inflammation. No changes occurred in circulating T cells, aside from variable coating with mIgG. In six of eight other recipients R6.5 administration (0.5 to 2 mg/kg/day for 10 days) reversed preexisting rejection that resulted from taper of Cyclosporine to subtherapeutic levels. Responding grafts showed decreased edema and hemorrhage but no consistent change in the infiltrate. At 1 h after the first dose, mouse IgG deposited primarily on the graft vascular endothelium without any change in the inflammatory infiltrate. Mouse IgG also deposited on the endothelium of normal organs without eliciting an inflammatory response and was cleared from the endothelium within 4 days. Inasmuch as the principal site of binding was the vascular endothelium, we hypothesize that the antibody blocks adhesion to graft ICAM-1 molecules on the vessels. Anti-ICAM-1 also binds to recipient cells and may interfere with Ag presentation and/or T cell interactions. Whatever the mechanism(s), these studies indicate that an anti-ICAM-1 antibody inhibits T cell mediated injury in vivo, and that ICAM-1 is a critical molecule in the pathogenesis of allograft rejection.     

Leukocyte inhibitory factor activates human neutrophils and macrophages to release leukotriene B4 and thromboxanes

Recent evidence has proved that cytokines can stimulate the production of 5-lipoxygenase products. Leukotriene B4 (LTB4) is a major mediator of leukocyte activation in acute inflammatory reactions, which produce chemotaxis, lysosomal enzyme release, and cell aggregation. Leukocyte inhibitory factor (LIF) also causes biological responses related to inflammation, i.e., LIF directly induces specific granule secretion by polymorphonuclears (PMNs) and potentiates many formyl-methionyl-leucyl-phenylalanine (FMLPs) mediated responses. Since arachidonic acid products are important mediators of inflammation, we have studied the effects of LIF on the arachidonic acid cascade products LTB4 and thromboxane A2 (TxA2). Resuspended at a final concentration of greater than 95% polymorphonuclear PMNs were isolated and tested with some cytokines on the release of LTB4 and TxA2. Peripheral blood mononuclear cells were isolated and seeded in Petri dishes and incubated for 60 min. Adherent macrophages were used for the cytokine stimulation study. Both types of leukocytes were treated with LIF, interleukin 6 (IL 6), and granulocyte-monocyte colony stimulating factor (GM-CSF) at different concentrations, and test agents A23187 and FMLP. Radioimmunoassay for LTB4 and TxB2 was determined by the resulting supernatants. Treatment of PMNs and macrophages with LIF at different concentrations proved to generate significant increases in LTB4 and TxA2 production. This was compared with IL 6 and GM-CSF, which had no effects. In these experiments, TxA2 generations could not be attributed to platelet contamination of PMN suspensions. The quantity of platelet contamination was not sufficient to influence how much TxB2 was produced. The similarities of LIF to other arachidonate stimulating cytokines suggest a similar mode of action in producing hematologic changes typical of tissue injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of vitamin on 2-deoxy-d-glucose uptake in human fibroblast cultures

Summary 2-Deoxy-d-glucose (2-DOG) uptake was tested in human fibroblast cultures in the presence and absence of vitamin E. Addition of 10 μg/ml vitamin E to the culture medium significantly reduced this uptake for 2-DOG concentrations of 0.005, to 10 mmol/liter (P≤0.01). The decrease of 2-DOG uptake was inversely proportional to the rise in 2-DOG concentration (P≤0.01). The presence of vitamin E reduced by 71% the average cellular level of lipid peroxides (expressed as thiobarbituric acid reactive substances) and caused a small but significant decrease in the cholesterol concentration (P≤0.01). These last results might explain the decrease in 2-DOG uptake observed in the presence of vitamin E.     

Candida albicans stress mannoproteins expression in superficial and systemic candidiasis

The presence of heat shock mannoproteins (HSMPs) reactive with sIgA was demonstrated in several C. albicans strains. The subculture of the C. albicans isolated from mucosal surfaces on Sabouraud's dextrose agar at 25 °C switched off the HSMP expression. A re-expression of the HSMPs was obtained in the same medium by shifting the temperature of incubation to 37 °C. However, expression of HSMPs in two strains isolated from deep infections was maintained during several subcultures on Sabouraud's dextrose agar at 25 °C. A glycoprotein of 200 kDa seemed to be the main HSMP reacting with vaginal sIgA. The data presented in this study suggest that factors other than temperature can influence the expression of C. albicans HSMPs and therefore these antigens should be referred as stress mannoproteins.Abbreviations HSMPs heat shock mannoproteins - MAb monoclonal antibody - sIgA secretory IgA     

Periodic fluctuations in proliferation of SV-40 transformed human skin fibroblast lines with prolonged lifespan

A human fibroblastic cell line transformed by the SV40-T antigen sequence and continuously cultured for 7 months displayed large periodic variations in cell proliferation. This contrasted with other characteristics of this cell line that remained constant: mosaic cell shape, absence of cell contact inhibition, and predominance of a hypodiploid population. Similar fluctuations in proliferative capacity were also found during the long-term growth of a transformed but nonimmortalized human fibroblastic line prior to senescence, and in the established hamster fibroblastic Nil cell line. This growth pattern suggests a recurrent stimulation of growth in these three transformed cell lines. The proliferation pattern from cultured transformed cells may thus be complex and requires further investigation. These variations presumably influence major cell functions. This observation has important implications for the analysis of data from such cell lines.Abbreviations I-SF immortalized human skin fibroblasts - T-SF transformed human skin fibroblasts - FBS fetal bovine serum     

Overview of a quality assurance/quality control compliance program consistent with FDA regulations and policies for somatic cell and gene therapies: a four year experience

Somatic cell and gene therapy involve the application of biological technologies to an individual patient through the use of living cells which provide a therapeutic benefit (Aliski, 1991). Various forms of cellular and gene therapies are being developed and evaluated in an increasing number of clinical trials for congential and acquired disorders. The potential and progress of these therapeutic applications have resulted in an increasing effort by the Food and Drug Administration (FDA) to develop the regulatory framework under which these therapeutic approaches would insure safety and efficacy, the primary mandate of the FDA.Over five years ago Cellcor began to define the parameters, specifications, and conditions relevant to a Quality Assurance/Quality Control (QA/QC) program that has evolved to insure safety and maximize the efficacy of applications of the company'sex vivo technology, autolymphocyte therapy. Autolymphocyte therapy is an outpatient form of somatic cell immunotherapy based upon the infusion of T cells that have been activatedex vivo using a combination of previously generated autologous cytokines and an anti-CD3 monoclonal antibody.We have been able to demonstrate the feasibility for the safe, controlled, and consistent preparation and delivery of a cellular therapy by application of relevant GMP regulations. This presentation reviews aspects of this program and chronicles our experience which at present amounts to over 4400 infusions for over 700 patients. This program provides a high degree of assurance that a cellular therapy program can be carried out in a multisite mode involving hundreds of patients through the strict adherence to cGMP as set forth in existing regulations. It would be prudent that developers of cellular andex vivo gene therapies establish a similar cell processing and QA/QC infrastructure at an early developmental stage to optimize safety and reproducibility and facilitate regulatory review.     

Different signal transduction by epidermal growth factor may be responsible for the difference in modulation of amino acid transport between fetal and adult hepatocytes

[1-¹⁴C]-2-aminoisobutyric acid (AIB) uptake and signal transduction pattern after epidermal growth factor (EGF) stimulation were examined in freshly isolated hepatocytes from 20-day-old fetuses and 3-month-old rats. EGF induced a transient increase of AIB transport after 10 min only in adult animals; the observed unresponsiveness of fetal liver is not dependent on a lack of EGF receptors which are present though to a lesser extent on the plasma membrane in this period. As far as the production of the second messengers, inositol trisphosphate (IP₃) and calcium, is concerned, substantial differences were found: EGF increased IP₃ production in adult hepatocytes, whereas it had no effect in fetal ones. Moreover, the addition of EGF induced a calcium transient in hepatocytes from adult animals, while there was no increase in fetal cells. The lack of EGF effect on amino acid transport in fetal cells could be due to its inability to produce both IP₃ and calcium transients, suggesting that this transduction pathway is not activated during fetal life.     

Trophic exchange in Pardosa hortensis (Lycosidae, Araneae)

Young Pardosa hortensis not only need their mother's help to leave their cocoon once developed (about 20 days), as they are unable to open it by themselves, but also during the period they are carried around in the cocoon. Using radioactive markers, indirect evidence revealed that the mother periodically opens the cocoon to feed her young and reseals it with fresh silk. Water is probably the main component in trophic exchange.