Biomedical subjects
J L Maillard
Publications and source records attributed to J L Maillard.
Role of monocyte/macrophage derived matrix-metalloproteinases (gelatinases) in prolonged skin inflammation.
Neutral metalloproteinase activities in dermal extracellular space have been studied in several models of prolonged cutaneous inflammation in guinea pigs, by the following techniques: lysis of type I 14C-collagen fibrils, electrophoretic analysis of types I or IV collagen hydrolytic fragments and zymography. For 2-3 weeks, in parallel to mononuclear cell infiltration, collagenase activity was increased 3-4-fold. Constitutive gelatinases (67 and 72 kDa) augmented and larger molecular species emerged (92, 110 and 185 kDa), all of neutral metalloproteinase type. Guinea pig peritoneal monocytes/macrophages cultured with appropriate stimulation released large gelatinases in a similar set (92, 110, 210 kDa). These were purified from culture media by gelatin affinity and used in vivo as follows: (a) direct injection of monocyte/macrophage gelatinases; (b) injection of collagen I fragments (M(r) < 10,000) split off by gelatinases from preincubated (pH 5 and 38.5 degrees C) collagen I. In both instances, a mononuclear cell invasion of dermis occurred, indistinguishable from prolonged inflammation. These analogies suggest that monocyte/macrophage-derived metalloproteinases have an early and basic participation in the mechanism of prolonged inflammation.
Protection of vascular basement membrane and microcirculation from elastase-induced damage with a fluorinated beta-lactam derivative.
N-(2-chloromethylphenyl) 3,3-difluoroazetidin-2-one (AA 231-1), a specific suicide-type inhibitor of elastase which is known to suppress the lysis of chromogenic oligopeptides, elastin and elastic fibers, is effective also in preventing the degradation of the vascular basement membrane. The degradation of porcine glomerular basement membrane by purified human leukocyte elastase (HLE), was reduced in proportion of inhibitor dose (8.3 microM for 50% inhibition). It is noteworthy that there was no reduction of the inhibitory effect when the addition of AA 231-1 was delayed for 1 h after the addition of the enzyme to the substrate. In the guinea pig, reduction of the dermal microhemorrhage due to HLE was related to the dose of inhibitor and to its preincubation time with HLE before intradermal injection. The inflammatory hemorrhage associated with the Arthus skin reaction was moderately depressed by AA 231-1 in situ. A part of the vascular permeability induced by HLE also responded to the inhibitor. In spite of the tissular diffusion and the time-dependence parameters which restrict responsiveness of elastase to AA 231-1 in vivo this biochemical compound should be helpful in the study and possibly the cure of vascular injury related to elastase.
Biological evaluation of the inhibition of neutrophil elastase by a synthetic beta-lactam derivative.
A novel beta-lactam derivative, N-(2-chloromethylphenyl) 3,3-difluoroazetidin-2-one, which behaves as a time-dependent inactivator of leukocyte elastase, has been tested in biological models designed to detect its potential therapeutic value in the treatment of emphysema. Its effect on two types of leukocyte elastase, purified human leukocyte elastase and elastase freshly discharged upon stimulation of guinea pig polymorphonuclear neutrophils, was examined using three methods: the cleavage of a chromogenic peptide substrate, MeO-Suc-Ala-Ala-Pro-Val-NA, the lysis and solubilization of tritiated elastin and the microscopic examination of the damage to lung elastic network. The inhibitor was shown to be effective at preventing proteolysis due to leukocyte elastase. Besides its low cellular toxicity, no apparent hindrance of its efficiency was found in the above quasi in vivo environment. This suggests that this inhibitor may be of potential therapeutic value in elastase-related pathology.
Cellular transfer of autoimmune aspermogenic orchiepididymitis (AIAO) by the i.v. route in the guinea pig.
In this study, AIAO was adoptively transferred with a high proportion of success to syngeneic recipient guinea pigs. Donors of strains 2 and 13 were sensitized with a series of spermatozoal autoantigens (whole spermatozoa and three autoantigens isolated therefrom: S, P and T). Syngeneic (experimental) and allogeneic (control) recipients were all transferred by strictly i.v. injections of lymphoid cells. The damage observed in testis and epididymis (mainly in the latter) was identical to, but milder than, that seen in active forms of AIAO. The incidence and severity of the disease were dependent on: the type of inducing antigen, S, T, P in order of decreasing efficiency; the length of immunization in donors, with increasingly serious lesions as periods ranged from 1 to 4 weeks; the presence or not of a complementary treatment of recipients with bacterial adjuvant enhancing the disease. Other parameters were less important, such as the strain 2 or 13 specificities, the amount of immunogen or the addition of peritoneal cells to lymph node cells. Skin hypersensitivity was concomitantly transferred to a large majority of isogenic recipients. But the incidence and severity of the disease showed only a partial correlation with Arthus type or delayed type responses to autoantigens. Thus guinea pig AIAO, already known to be transferable by immune sera (mainly anti-P and also anti-T) may also be transferred in physiological conditions by sensitized lymphoid cells (mainly anti-S and also anti-T).
Release of a lymphokine-like plasminogen activator by stimulated B lymphocytes.
This report extends to the guinea pig the discovery of a lymphocyte plasminogen activator (LPA) previously described in the mouse. In the guinea pig, we have identified enzymatic activity similar to that in the mouse, but which has two distinct components: first, as in the mouse, a membrane-bound molecule present even in the quiescent lymphocyte (mLPA), and second, a previously unreported soluble molecule appearing in the culture medium after appropriate cell stimulation (sLPA). This sLPA, like most known lymphokines, was released by in vitro recall of sensitized lymphocytes by the antigen and by direct contact with a mitogen. There was a parallel evolution in the culture for sLPA and for some other well-known lymphokines (LT, LIF), and their detection thresholds were of the same order. A possible activation of plasminogen (Pg) by macrophages contaminating the lymphocyte cultures was carefully rule out. sLPA was produced by lymph node lymphocytes as well as by blood lymphocytes, but not by spleen cells, thymocytes, or peritoneal lymphocytes. A study of the kinetics of the release of sLPA, together with that of metabolic modifiers, suggested that an intracellular synthesis precedes the secretion of the molecule. Data obtained from the use of B- and T-enriched subpopulations or B- or T-dependent antigens and mitogens point to the B lymphocytes as the major, if not exclusive, source of sLPA. The choice of synthetic chromogenic substrates S 2251, S 2444, and S 2288 in some experiments led us to confirm most of the above properties of sLPA with still greater precision and reliability.
Plasminogen activation by normal B lymphocytes, a function associated with the cell membrane.
When purified murine plasminogen was added to cultures of mouse spleen B cells, active plasmin progressively appeared in the supernatants. This reaction, resulting from the specific cleavage of the plasminogen by lymphocyte plasminogen activator (LPA), was measured in a fibrinolysis assay using 125I-fibrinogen. T cells were totally ineffective; under certain conditions, they could even antagonize the B cell action. Of the various B populations studied, i.e., obtained from spleen, lymph nodes, or blood of various mouse strains, all expressed the same property of plasminogen activation, which concerned mainly medium-sized B cells. Since only slight activities were detected in extracellular or intracellular compartments, a membrane-associated proteolytic enzyme may be responsible for plasminogen activation. Submitted to a series of group-specific antiproteases, the lymphocyte plasminogen activator essentially behaved as a serine-protease, with sensitivity to diisopropyl fluorophosphate, phenyl methyl sulfonyl fluoride, and nitro phenyl guanidino benzoate. The fast renewal of the enzyme in the membrane was also demonstrated by different techniques, using modifiers of cell physiology, like cycloheximide and dexamethasone, or following the reexpression of the enzyme by the cell kinetically.
Adjuvants and in vitro antibody production.
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Non-hemorrhagic arthus reaction and its independence from circulating antibodies and complement.
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Interaction between 'sensitized lymphocytes' and antigen in vitro. V. Vascular permeability induced by skin-reactive factor.
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Elicitation of arthus reactions in guinea pigs by homologous gamma 1 and gamma 2 immunoglobulins.
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[Decomplementization by a factor extracted from cobra venom. Effect on several immune reactions of the guinea pig and rat].
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Proceedings: "In vitro" production of pharmacological agents resulting from the interaction between sensitized lymphocytes and tuberculin.
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Regulatory mast cells. I Suppressive action of their products on an in vitro primary immune reaction.
Products of mast cell degranulation, as well as histamine and serotonin, were added to a Mishell and Dutton preparation for in vitro primary immunisation (induction of IgM antibody formation) to sheep or horse red blood cells. Degranulation products were either obatined beforehand by reacting passively sensitised mast cells with the corresponding antigen (unrelated to or identical with the in vitro immunising antigen) or liberated into the culture medium where mast cells actively sensitised to the in vitro immunising antigen had been added. A 46 to 72 % reduction of direct (IgM) plaque forming cells was observed in all cases. This reduction was prevented by anti-histamine. The responsible mediators were active in the 0 to 24 hour period after antigen introduction. The anaphylactic degranulating antibodies triggering this inhibitory activity were found to be thermolabile in one experiment. An in vivo-induced mast cell degranulation led to a reduced formation of plaque forming cells. The enhancing and immunoregulatory activity of anaphylactic mouse antibodies is therefore tentatively and at least partially attributed to their capacity to degranulate mast cells after contact with the antigen.