Quantitative studies on cell-mediated immunity in the pleural cavity of guinea-pigs

Coordinate cytokine gene expression in vivo following induction of tuberculous pleurisy in guinea pigs

Tuberculous pleurisy is a severe inflammatory response induced by Mycobacterium tuberculosis organisms that have escaped from lung granulomata into the pleural space during pulmonary infection. We have used the guinea pig model of tuberculous pleurisy to examine several aspects of the immune response to this antigen-specific inflammatory event. Pleurisy was induced by injection of heat-killed M. tuberculosis H37Rv directly into the pleural space of guinea pigs previously vaccinated with M. bovis BCG. Four animals were euthanized each day over a period of 9 days. Fluid in the pleural cavity was analyzed for transforming growth factor beta 1 (TGF-beta 1) and total interferon (IFN) protein levels. In addition, RNA was obtained from pleural cells and examined for TGF-beta 1, tumor necrosis factor alpha (TNF-alpha), IFN-gamma, and interleukin-8 (IL-8) expression by real-time PCR. Finally, pleural cells were examined for the ability to proliferate in response to concanavalin A and purified protein derivative (PPD) in vitro. In the pleural fluid, TGF-beta 1 protein concentrations increased over the course of the inflammatory response while IFN protein levels were not significantly altered. Expression of TGF-beta 1 mRNA peaked on days 3 and 4, and IFN-gamma mRNA expression peaked on day 3 and then returned to background levels. TNF-alpha mRNA expression was highest on days 2 to 4, and IL-8 mRNA levels remained elevated between days 2 and 5, peaking on day 3 before returning to background levels. PPD-induced proliferative responses were evident by day 3 and remained present throughout the study. Analysis of cytokine expression during tuberculous pleurisy may lead to a better understanding of the self-healing nature of this manifestation of tuberculosis.

Required early complement activation in contact sensitivity with generation of local C5-dependent chemotactic activity, and late T cell interferon gamma: a possible initiating role of B cells

Complement (C) is an important component of innate immunity, and was also shown recently to participate in induction of acquired B cell humoral immunity. In this study, we present evidence that C also participates in acquired T cell immunity. We found that C was involved in early events of the efferent elicitation phase of contact sensitivity (CS), and delayed-type hypersensitivity (DTH). Thus, CS and DTH were inhibited by administration of a C-blocker, soluble recombinant C receptor-1 (sCR1), when given 30 min before, but not 3 h after local antigen challenge. Among C components, local C5 were thought crucial to elicitation of CS, since local administration of anti-C5 monoclonal antibodies or locally injected C-depleting cobra venom factor also inhibited CS and DTH. These findings were consistent with our previous finding of the importance of C5 for CS elicitation, using congenitally C5-deficient mice. To dissect the mechanism of C dependence in CS, we demonstrated that locally increased early macrophage chemotactic activity (probably C5a) in evolving CS skin extracts, as well as late elaboration of IFN-gamma, were both inhibited by anti-C treatment. In addition, histological analysis showed that leukocyte recruitment into CS ear sites was similarly C-dependent. Furthermore, an initiating role of B cell-derived C-fixing immunoglobulin was suggested by demonstration of impaired CS responses in B cell-deficient mice. In summary, these results suggest that C was activated locally, perhaps via a B cell product, in an important early component of the stepwise events necessary to elicit CS, leading to local production of C5-dependent macrophage chemotactic activity and later IFN-gamma, and subsequently leading to cell infiltration, for development of T cell-dependent CS.

Eicosanoid release and early changes in two acute non specific inflammatory reactions. Major role of prostacyclin and leukotrienes

We have compared the early development (0-4h) of two acute non-specific inflammatory reactions induced by the intrapleural injection of isologous serum or a suspension of CaPP crystals. The intensity of the reactions was assessed in terms of the exudate volume, the number and ratio of pleural cells and different cell functions and secretions. The number of exudative cells elicited by isologous serum was higher than with CaPP but the PMN/Monocytes ratio was the same. The amount of protein in the serum-induced exudate was constant from 1 h to 4 h and was similar in the CaPP-induced pleural exudate at the latter time. The amount of complement increased similarly in the two models. The chemotactic potency of the exudates and cell supernatants following incubation showed similar values in the two models. Eicosanoid levels were higher in CaPP--than in isologous serum-induced exudates. Prostacyclin and peptidoleukotrienes were released in specially large amounts at the very outset of the inflammatory reactions.

A new method of eliciting delayed hypersensitivity in the mouse abdominal cavity

A new method of determining delayed hypersensitivity quantitatively was investigated in mice. Mice were sensitized with 150 micrograms of ferritin and, 3 weeks later, antigen challenge was performed by implanting a sponge containing antigen in the abdominal cavity. Cells accumulated in the sponge markedly increased in number for 24-72 h after the challenge; mononuclear cells predominated by 48 h. When sensitized lymphocytes were transferred passively to a normal recipient, marked cell accumulation in the sponge was found 48 h after the challenge. Immunological specificity was confirmed in animals sensitized to antigen and receiving passive transfer of sensitized cells. Strain differences in this reaction were observed. Cortisone (20 mg/kg for 6 days before challenge) significantly decreased cell accumulation. Delayed hypersensitivity was also elicited in the ear of sensitized animals. Extracts of sponges removed from antigen-challenged mice had macrophage chemotactic activity.

Lotifazole (F 1686), a non-steroidal anti-inflammatory agent with an unusual pharmacological spectrum

Lotifazole (F 1686) - 4-phenyl-2-(2',2',2-trichloroethoxycarboxamido) thiazole - has a range of anti-inflammatory activities in animals that differs from the activities of classic non-steroidal drugs. It reduces carrageenin-induced oedema in rats, UV-induced erythema in guinea pigs, and Arthus pleurisies in rats only at high doses. It does not affect Freund's-adjuvant polyarthritis, and it only slightly affects passive skin anaphylaxis in rats and anaphylactic shock in guinea pigs. Lotifazole does not greatly inhibit prostaglandin synthesis. However, at low doses and after various conditions of treatment, F 1686 reduces PPD- and Bordetella- pertussis-induced delayed-hypersensitivity pleurisy in guinea pigs and rats, respectively, and contact hypersensitivity reactions to picryl chloride and oxazolone in mice. Its action on the two models of delayed-hypersensitivity pleurisy is reflected in a decrease of the pleural exudate and of the number of mononuclear cells in the focus of inflammation. At active doses, Lotifazole does not cause changes in the differential leukocyte count in normal animals. It appears, furthermore, to be a T-lymphocyte stimulant.

Cyclic adenosine 3', 5'-monophosphate and the mechanism of action of three common anti-inflammatory drugs

1 The effects of indomethacin, dexamethasone and colchicine on cyclic adenosine 3', 5'-monophosphate (cyclic AMP) concentration in leucocytes during a crystal-induced pleurisy in rats were studied. 2 Each of the drugs significantly increased leucocyte cyclic AMP content within 3 h of the injection of crystals. 3 By 6 h, leucocyte cyclic AMP levels returning toward control levels and could not be sustained at the higher level by an additional administration of the respective anti-inflammatory drug.

Delayed hypersensitivity reactions in guinea-pigs using cotton pellets; demonstration of macrophage migration inhibition activity in the cell free exudate

Subcutaneous implantation of cotton pellets containing PPD into CFA sensitised guinea-pigs produced a reaction of having many characteristics of the delayed hypersensitivity (DH) reaction, together with less conspicuous features of a non-immunological response. The time course of the cellular response in the reaction showed a slow onset, attaining maximum levels between 18 and 24 hr. Mononuclear cells dominated the reaction from 18 to 48 hr. In animals treated with ALS the reaction diminished to the level of a non-immunological reaction. The model made it possible to detect macrophage migration inhibition factor (MIF) activity in the skin exudates. From 6--48 hr high molecular weight antigen-dependent MIF activity was found associated with immunoglobulin. At 18 hr, two types of low molecular weight MIF activity were demonstrated. One was antigen-dependent and the other was antigen-independent. Treatment of sensitised guinea-pigs with ALS abolished the appearance of these factors, suggesting that they might be related to cell-mediated immunity. At 48 hr, the low molecular weight antigen-dependent MIF activity was still evident whereas the low molecular weight antigen-independent activity was not detected. High molecular weight antigen-independent MIF activity was also found at 18 hr. No MIF activity was demonstrated in any of the control exudates.

Protease inhibitors reduce the reverse passive Arthus reaction

Trasylol, ovomucoid, tranexamic acid and soybean inhibitor decrease the vascular permeability as measured by extravasation of 131I-albumin when injected with the antibody at induction of a reverse passive Arthus reaction in the rat skin. Trasylol given systemically also had a suppressive effect, similar to phenylbutazone. When the reaction was induced in the pleural cavity, both Trasylol and tranexamic acid reduced the influx of leucocytes.

Pertussis vaccine pleurisy: a model of delayed hypersensitivity

Male Wistar rats have been sensitized to Bordetella pertussis using a mixture of Freund's incomplete adjuvant and pertussis organisms. Intrapleural challenge 12 days later with pertussis produced a marked delayed inflammatory response, maximal at 48 hours and dominated by influx of mononuclear cells. Dosing with D-penicillamine (25 mg/kg) and levamisole (5 mg/kg) at the time of challenge produced a significant enhancement of the reaction. A long period of dosing with either drug, or treatment with indomethacin (3 mg/kg), suppressed the response. The relevance of this to the testing and mode of action of antirheumatic drugs is discussed.

Studies on mechanisms of immobilization of mononuclear cells in the delayed hypersensitivity (DH) reaction

Migration inhibitory (MI) activity in exudates, and 'migration' and 'inhibition of migration' of exudate cells was investigated in the delayed hypersensitivity (DH) reaction induced by intrapleural injection of PPD into complete Freund's adjuvant(CFA)-sensitized guinea-pigs. During the initial reaction (6-hour), two types of antigen-dependent MI activity were detected in serum and cell free exudate. One was a high molecular weight material associated with immunoglobulin, and the other was a low molecular weight material and appeared to be so-called antigen-dependent migration inhibitory factor (MIF). As the reaction progressed (i.e. 12-24-hour), two types of antigen-independent MI activity were revealed in exudate, but not in serum. One of these was a high molecular weight material, and the other was a low molecular weight material and thought to be so-called antigen-independent MIF. Similar experiments were performed on the reversed passive Arthus (RPA) reaction in the pleural cavity of guinea-pigs. A high molecular weight substance having MI activity was detected in 6-hour cell free exudate and was found to be antigen-independent. So-called MIF was not found in this reaction. Migration of unseparated exudate cells from the 18-hour DH reaction was less extensive than that of 6-hour unseparated cells. Addition of antigen caused further inhibition, the effect on 18-hour exudate cells being more pronounced. These results were further examined, using mononuclear cells separated on a Ficoll-Isopaque gradient. The migration area of the mononuclear cells was reduced as the DH reaction progressed. Mononuclear cells from the DH reaction gave a smaller migration area throughout the reaction in comparison with blood mononuclear cells. The migration area of the RPA exudate mononuclear cells was also reduced as the reaction progressed. However 6-hour RPA exudate mononuclear cells gave a larger migration area than blood mononuclear cells. The migration of mononuclear cells from DH exudate was inhibited by addition of antigen. A greater degree of inhibition of migration was induced by addition of antigen to mononuclear cells from 18- and 24-hour exudate cells in comparison with 6- and 12-hour exudates. The migration of mononuclear cells from normal blood (i.e. unsensitized animals) and RPA exudate (6- and 18-hour) was unaffected by addition of antigen. Similar results were obtained for blood of complete Freund's adjuvant sensitized animals from 0- to 18-hour. Adherent (A) and nonadherent (NA) mononuclear cells from 18-hour DH exudate were separated through a glass bead column. The migration of adherent cells from 6-hour exudates was not significantly inhibited whereas that of 18-hour mononuclear cells was markedly inhibited. The effect on migration of each mononuclear cell fraction was detected by mixing with peritoneal exudate cells (used as indicator cells). The effect of the A cells from 18-hour mononuclear cell exudates on peritoneal exudate cells was strong, whereas that of 6-hour exudates was less marked...

Anti-inflammatory models in animals

The pleural cavity of rats and guinea-pigs has been utilized to study the inflammatory response to immediate hypersensitivity, delayed hypersensitivity, calcium pyrophosphate and carrageenan. The mediators will be described and their possible interaction with cyclic AMP. Finally the effect of some anti-inflammatory agents on these models will be discussed.

Pharmacological mediators of various immunological and non-immunological inflammatory reactions produced in the pleural cavity

Intrapleural exudates have been produced in rats and guinea-pigs using calcium pyrophosphate, cell mediated immunity, reversed passive Arthus reaction and carrageenan. The intracellular concentration of various pharmacological mediators has been measured at different times during the evolution of these inflammatory responses. These have been correlated with volume of exudate and cellular migration. The significance of these findings has been discussed and the possible application to the search for new anti-inflammatory agents and their use in diagnostic procedures.

A model for the quantitative study of Arthus (immunologic) hypersensitivity in rats

A model of reverse passive Arthus (RPA) reaction in the pleural cavity of rats is described. The time course of development of exudate and migration of cells has been examined. It has been found to be complement dependent and dominated by polymorphonuclear cells. The reaction reaches a peak around 6 hours after challenge. Cyclic AMP levels have been measured both intracellularly and extracellularly and have been found to persist at high levels after the waning of the reaction.