Killing of rat pulmonary artery endothelial cells by activated polymorphonuclear leukocytes (PMNs), as measured at 4 hours, is catalase sensitive, iron dependent, and unaffected by addition of protease inhibitors. If the time course for exposure of endothelial cells to activated PMNs is extended to 18 hours, progressive injury occurs. Endothelial cell injury resulting at 18 hours is partially inhibited by catalase and partially inhibited by soybean trypsin inhibitor. Together, these two inhibitors function synergistically to protect the cells from injury. Exposure of endothelial cells to reagent H2O2 and purified proteolytic enzymes (trypsin, chymotrypsin, elastase, and cathepsin G) mimics the effects of activated PMNs: H2O2 alone is cytotoxic with maximal killing achieved by 4 hours; proteolytic enzymes produce cytotoxicity only at high concentrations and only after prolonged incubation (longer than 8 hours); and, in combination, H2O2 and proteolytic enzymes act synergistically. These data provide compelling evidence that PMN-mediated injury of endothelial cells involves interaction between oxygen products and proteases.

Bacteria and yeasts which are "opsonized" with cationic polyelectrolytes (poly-L-arginine, poly-L-histidine and arginine-rich histone) are avidly endocytosed by both "professional" and "non-professional" phagocytes. The cationized particles also strongly activate the respiratory burst in neutrophils and in macrophages leading to the generation of chemiluminescence, superoxide and hydrogen peroxide. On the other hand, lysine and ornithine-rich polymers are poor opsonic agents. Poly L-arginine is unique in its capacity to act synergistically with lectins, with chemotactic peptides and with cytochalasin B to generate large amounts of chemiluminescence and superoxide in human neutrophils. Unlike polyarginine, polyhistidine, in the absence of carrier particles, is one of the most potent stimulators of superoxide generations, known. Neutrophils treated with cetyltrimethylammonium bromide fail to generate superoxide, but generate strong luminol-dependent chemiluminescence which is totally inhibited by sodium azide and by thiourea. Neutrophils injured by cytolytic agents (saponin, digitonin, lysolecithin) lose their chemiluminescence and superoxide-generating capacities upon stimulation by a variety of ligands. These activities are however regained by the addition of NADPH. Lysolecithin can replace polyarginine in a "cocktail" also containing lectins and cytochalasin B, which strongly activate the respiratory burst. This suggests that polyarginine acts both as a cytolytic agent and as a ligand. Arginine and histidine-rich polyelectrolytes enhance the pathogenic effects of immune complexes in vivo (reversed Arthus phenomenon) presumably by "glueing" them to tissues. Polyhistidine complexed to catalase or to superoxide dismutase, markedly enhances their efficiency as antioxidants. On the other hand polyhistidine complexed to glucose oxidase markedly enhances injury to endothelial cells suggesting that the close association of the cationized enzyme with the plasma membrane facilitates the interaction of hydrogen peroxide with the targets. A variety of cationic agents (histone, polyarginine, polyhistidine, polymyxin B) and membrane-active agents (lysophosphatides, microbial hemolysins) act synergistically with glucose oxidase or with reagent hydrogen peroxide to kill target cells. The mechanisms by which arginine- and histidine-rich polyelectrolytes activate the respiratory burst in neutrophils might involve interaction with G-proteins, the activation of arachidonic acid metabolism and phospholipase A2, or the interaction with myeloperoxidase. Naturally-occurring cationic proteins might modulate several important functions of leukocytes and the course and outcome of the inflammatory process.

Treatment of Staphylococcus aureus in vitro with cationic agents results in the activation of their autolytic wall enzymes and in the degradation of their cell walls. Exposure of staphylococci either to hydrogen peroxide or the proteinases abolished the autolytic process. This effect was totally reversed by catalase and by proteinase inhibitors, respectively. It is suggested that the failure of neutrophils and macrophages to effectively degrade microbial cell wall components in inflammatory sites might be due to the inactivation of the autolytic wall enzymes of bacteria by hydrogen peroxide and by proteinases generated by the activated leukocytes. This might explain the prolonged chronic inflammatory sequelae seen following infections.

Cationic particles interact by electrostatic forces with membrane components of diverse cell types, including lymphocytes. Contact with cationized streptococci was shown to induce a murine T-cell hybridoma to transcribe lymphokine mRNA as well as secrete interleukin-2. This activation was accompanied by a rise in intracellular calcium. Cationized streptococci-induced activation of this T-cell hybridoma could be specifically inhibited by either chelating extracellular calcium or by treating with CD4 monoclonal antibody. These data indicate that the in vitro behaviour of T cells can be modulated by charged microbial particles; such interactions may have relevance for chronic inflammation associated with some bacterial infections.

We have observed an antiarthritic effect of combined chrysotherapy in adjuvant arthritis. Since superoxide radicals (O2-) are potent mediators of rheumatoid inflammation, we studied the combined effect of auranofin (AF) and injectable golds on luminol-dependent chemiluminescence (LDCL) and O2- generation by cytochrome-c reduction of activated leukocytes by different receptor-mediated stimuli: phorbol myristic acetate, 10(-6) M; f-Met-Leu-Phe, 10(-6) M; and poly-L-histidine, 10(-5) M. AF, 0.6 and 0.9 micrograms Au/ml, inhibited 34 and 58% of O2- generation, respectively; the addition to AF of 0.3 micrograms Au/ml of gold thiosulfate (GTS) increased this inhibition to 84 and 97% of the oxygen burst. Similar synergistic potentiation inhibition was obtained by LDCL. When the inhibition of O2- generation by the combined action of AF and GTS was compared with AF + gold sodium thiomalate (GTM), only GTS showed an activation on AF's inhibition of the oxygen burst of human leukocytes. The ligand thiosulfate in equimolar concentrations to GTS had a statistically significant (P less than 0.01) inhibitory effect on AF's blockade of O2- generation during the first 5 min of the interaction with the PMNs; thiomalate had no effect. Sequential pretreatment of PMNs with AF and GTS on O2- generation revealed that for synergism of combined gold action to take place, the cell membrane had to be subjected first to the action of oral gold or to the simultaneous combined action of oral and parenteral gold.(ABSTRACT TRUNCATED AT 250 WORDS)

In comparative clinical studies of auranofin (AF, oral gold) and parenteral gold in the treatment of rheumatoid arthritis, no difference in efficacy was detected. Since the pharmacologic profiles of these compounds are different, we studied their combined effect on adjuvant arthritis (AA). The effect of AF alone and combined with gold sodium thiomalate (GTM) or gold sodium thiosulfate (GTS) on the excretion of urinary hydroxyproline (UHP) and urinary calcium (UCa), and the articular index of arthritic rats was followed during five weeks of treatment. The excretion of UHP and UCa was significantly inhibited (P less than 0.005) in rats treated with AF combined with GTM or GTS as compared with animals treated with the individual gold compounds. However, the articular index only decreased significantly (P less than 0.02) in the group of rats treated with AF + GTS. The present studies open the possibility that combined treatment with oral and injectable gold provide a new approach for chrysotherapy with an increased antiarthritic potency.

Degradation of cell wall components of certain microbial species following phagocytosis by neutrophils and macrophages might involve the activation, by leucocyte cationic proteins, of the bacterial autolytic wall enzymes, leading to bacteriolysis. Lysozyme (a distinct cationic agent), which is the main muramidase present in leucocytes and in body fluids, might function not only as an enzyme but also as a potent activator of autolysis. Sulphated polyelectrolytes, proteolytic enzymes and oxygen radicals, which are released in inflammatory sites, might inactivate the autolytic wall enzymes, leading to the accumulation of peptidoglycan-polysaccharide complexes within macrophages. Activated macrophages are instrumental in initiating chronic inflammatory reactions. Undegraded microbial cell wall components also function as immunomodulators and as enhancers of non-specific resistance to infections and to malignancy.

Human neutrophils (PMNs) which have been incubated with lipoteichoic acid (LTA) from group A streptococci generated large amounts of superoxide (O2- chemiluminescence and hydrogen peroxide when challenged with anti-LTA antibodies. Cytochalasin B further enhanced O2- generation. The onset of O2- generation by the LTA-anti-LTA complexes was much faster than that induced by BSA-anti-BSA complexes. LTA-treated PMNs generated much less O2- when challenged with BSA complexes, suggesting that LTA might have blocked, nonspecifically, some of the Fc receptors on PMNs. PMNs treated with LTA-anti-LTA complexes further interacted with bystander nonsensitized PMNs resulting in enhanced O2- generation, suggesting that small numbers of LTA-sensitized PMNs might recruit additional PMNs to participate in the generation of toxic oxygen species. Protelolytic enzyme treatment of PMNs further enhanced the generation of O2- by PMNs treated with LTA-anti-LTA. Superoxide generation could also be induced when PMNs and anti-LTA antibodies interacted with target cells (fibroblasts, epithelial cells) pretreated with LTA. This effect was also further enhanced by pretreatment of the target cells with proteases. PMNs incubated with LTA released lysosomal enzymes following treatment with anti-LTA antibodies. The amounts of phosphatase, beta-glucoronidase, N-acetylglucosaminidase, mannosidase, and lysozyme release by LTA-anti-LTA complexes were much smaller than those released by antibody or histone-opsonized streptococci, suggesting that opsonized particles are more efficient lysosomal enzyme releasers. However, since the amounts of O2- generated by the LTA complexes equaled those generated by the opsonized particles, it is assumed that the signals for triggering a respiratory burst and lysosomal enzyme secretion might be different. Generation of O2- by LTA complexes was strongly inhibited by lipoxygenase inhibitors but not by cyclooxigenase inhibitors. Also phenylbutazone, trifluorperazine, and DASA markedly inhibited O2- generation induced by LTA complexes. These data suggest that bacterial products in the presence of antibody might have important biological effects on phagocytic cells and that these effects may be inimical to the host.

GENERAL INTRODUCTION. The invasion of the tissues of a host by pathogenic microorganisms is usually followed by a series of sequential humoral and cellular events which include: the generation of chemotactic agents, the directional migration of leukocytes toward the invader, the opsonization of the agents by immunoglobulins and complement components, the intemalization of the agents within phagolysosomes. and eventually by the killing and biodegradation of the ingested agents. The perturbation of the leukocytes membranes by opsonized micro- organisms as well as by a variety of cytolytic agents generated by bacteria is also accompanied by a series of biochemical events which include an “oxygen burst" which culminates in the generation of oxygen radicals, some of which are directly involved in the killing of the ingested agents. Concomitantly with the activation of the oxygen metabolism, granulocytes (PMN)f and macrophages (MQ)f also generate chemiluminescence (CL) which is believed to be a natural consequence of the redox met mbrane perturbation due to phagocytosis. lt may involve the generation of a species of singlet oxygen and hydroxyl radicals or electronically excited carbonyl groups which relax with light emission. A relationship between CL and superoxide production has also been demonstrated by the reduction of CL which occurs following the addition of superoxide dismutase (SOD) to phagocytizing leukocytes. The CL signals which can be further amplified by luminol are also believed to be dependent upon myeloperoxidase (MPO)-catalyzed reactions and/or upon metabolism of arachidonic acid pathway(s). The luminol-de-pendent CL ( LDCL) reaction is currently employed to assess the opsonophagocytic properties of sera as we as for the evaluation of the membrane perturbation which is initiated, in leukocytes, by cytotoxic drugs, and by microbial toxins. ln addition to opsonized particles, a series of soluble ligands, i.e., chemotactic peptides, lectins, phorbol esters, calcium ionopohres, polyanethole sulfonate, and cationic polypeptides have all been shown to stimulate the oxygen burst and to generate CL in neutrophils, monocytes, and macrophages. Because of the relative ease and rapidity with which CL is measured in leukocytes, this method has also become a powerful tool to investigate host-and-parasite interrelationships and to assess defects in leukocyte functions (e.g. , chronic granulomatous disease of childhood (CGD) MPO deficiency, defects in complement components and in immunoglobulins, etc.). Recent studies from our laboratory have described a unique phenomenon which showed that a variety of microbial species can be very effectively “opsonized” by cationic proteins rich in arginine (e.g., histones. poly-L-arginine - PARG). Such opsonized microorganisms are readily internalized not only by "professional" phagocytes (PMNs and macrophages) but also by epithelial cells and by fibroblasts. We have postulated that perturbation of the mammalian cells by the highly-charged polyelectrolytes, coated upon particles, delivers a signal (through electrostatic interactions) to the cytoskeleton resulting in the invagination of the membrane and the formation of a phagocytic vacuole. This phenomenon mimics the cellular events that take place following the stimulation of the leukocyte membrane by antibody and complement-coated particles which function through the F and Cb receptors. Thus, the polycationic ligands may represent "archaic" antibodies capable of stimulating certain membrane sites probably nonspecifically (see Section A.l). Our studies further postulated that if leukocytes “recognize" cationic charges upon particles and respond to them by phagocytosis, such coated particles should also be able to trigger an “oxygen burst" in a fashion similar to that induced either by antibody-coated particles or by other membrane- active agents. Indeed, we have demonstrated tnat very intense LDCL and superoxide production ls triggered in blood leukocytes following stimulation with bacteria and zymosan particles which had been precoated with arginine rich histon PARG and paradoxically also by the anionic polyelectrolytes,.|iquoid. anddextransulfatc. The intensity of the CL signals obtained exceeded by many magnitudes those induced by antibody-coated particles. These findings further suggested that the stimulation of the leukocyte membrane, either simultaneously or sequentially by mixtures of different ligands, each recognizing a different membrane site, may perhaps culminate in a synergistic metabolic response. Such "multiple hits" may therefore generate large quantities of oxygen radicals and CL, presumably due to a more efficient activation of the membrane oxidase and a better assembly of the electron transport system leading to the generation of superoxide. We have chosen to examine agents like the chemotactic peptide F-Met-Leu-Phe (FMLP), a variety of lectins, calcium ionophore, PMA, liquoid, and poly ot-cationic peptides as probes for the stimulation of LDCL and superoxide production by human PMN. We have shown that whereas each ligand alone induced only a very moderate LDCL response in leukocytes, very intense CL signals were generated if the various ligands were employed as “cocktails, suggesting multiple mechanisms of activation of the oxygen metabolism in leukocytes (see also Reference 27). Since inflammatory exudates which accumulate following microbial proliferation in tissues are known to be rich in both cationic and anionic polyelectrolytes, we also postulated that some of these agents may coat either the surface of the leukocytes or the surface of the microorganisms, or both. and thus modulate mutual recognitions leading either to enhanced or depressed membrane perturbation. These changes may be monitored by CL and by the production of superoxide. The present report further expands our observations on the multiple roles played by polycationic and polyanionic agents and of "cocktails" of soluble ligands in the stimulation of the generation of LDCL and superoxide by human blood luekocytes and by mosue peritoneal macrophages, with an emphasis on the luekocyte-bacteria interactions in inflammation.

The mechanisms of biodegradation of microbial cell wall components is discussed. Employing Staphylococcus aureus as a model it is proposed that bacteriolysis following phagocytosis is mediated by the activation by leukocyte cationic proteins of the bacterial own autolytic wall enzymes. The role of lysozyme in bacteriolysis might not be due to its muramidase activity but to its cationic nature. A variety of sulfated polysaccharides, proteinases and oxygen radicals which might be present in inflamed tissues might inactivate the bacterial autolytic wall enzymes leading to the persistence of highly-phlogistic peptidoglycan-polysaccharide complexes within macrophages and to tissue damage.

Heparinoids and related negatively-charged substances caused suppression of the penicillin-induced bacteriolysis of staphylococci and a higher viability rate. Furthermore, the penicillin-induced release of cell wall material was reduced by these substances. The main reason for this suppression of bacteriolysis was an inhibition of the activity of cell wall autolytic enzymes while the penicillin-specific perturbations of wall morphogenesis were not affected.

Murine tumor cells were induced to phagocytize either Candida albicans or group A streptococcal cells. The presence of microbial particles within the tumor cell cytoplasm had no effect on in vitro tumor cell growth. However, when Candida albicans-infected tumor cells were injected into syngeneic mice, they formed tumors that grew faster, invaded the surrounding normal tissue more rapidly and metastasized more rapidly than control tumor cells. Tumor cells infected with group A streptococcal particles did not grow faster or show increased malignant behavior. These data indicate that the in vivo behavior of malignant tumor cells can be modulated by microbial particles, which are often present in the microenvironment of the growing tumor.

Poly-L-histidine (PHSTD) of molecular weight 26,000 induced the generation of large amounts of superoxide (O2-) and hydrogen peroxide (H2O2) in human neutrophils (PMNs). Despite its low solubility at neutral pH, PHSTD was bound very rapidly to the PMN surfaces. Maximal generation of O2- took place with 4-5 X 10(-6) M of PHSTD, starting after a lag of about 25 sec and proceeding for 15-17 min at a rate of 150 nmol/10(7) PMNs/min, suggesting that this polycation is one of the most potent stimulators of O2- generation known, PHSTD was found to be non-toxic for PMNs even at millimolar concentrations. Generation of O2- by PHSTD depended on extracellular calcium; it was inhibited by calcium channel blockers and by trifluoperazine, and it triggered a sharp rise in intracellular calcium as determined by the Quin 2 fluorescence technique. The generation of both O2- and H2O2 by PHSTD was partially inhibited by cytochalasin B or (CYB, CYE). On the other hand, CYB markedly enhanced the generation of both O2- and H2O2 following stimulation of PMNs either by PHSTD, polyarginine, histone, or by antibody-opsonized group A streptococci. Electron microscopic analysis and NBT reduction tests revealed that both PHSTD and PHSTD-opsonized streptococci were avidly phagocytosed by PMNs. Since CYB totally inhibited internalization of both PHSTD and the PHSTD-opsonized streptococci, it was suggested that these agents stimulated oxygen radical generation mainly on the leukocyte surfaces. Complexes (CX) formed between PHSTD and polyanethole sulfonate (a strong polyanion) or between histone and the polyanion mimicked immune CX in their ability to trigger the generation of large amounts of O2- which were inhibited by CYB. Generation of O2- and chemiluminescence either by PHSTD or by PHSTD-opsonized streptococci were markedly inhibited by poly-L-glutamate, suggesting that PHSTD acted as a cationic agent which interacted via electrostatic forces with some negatively charged sites in the leukocyte membrane. Generation of H2O2 by PHSTD was also markedly inhibited by deoxyglucose, KCN, DASA, as well as by the lipoxygenase inhibitors nordihydroguaiaretic acid, phenidone, and propylgallate. On the other hand, cyclooxygenase inhibitors such as aspirin, indomethacin, and piroxicam were inactive, suggesting that arachidonic acid metabolism via lipoxygenase pathway might have been involved in the activation by PHSTD of the NADPH oxidase in PMNs.(ABSTRACT TRUNCATED AT 400 WORDS)

Considerable attention has been focused on the role of electrostatic charge in the pathogenesis of immune complex-mediated tissue injury. The authors have examined the ability of cationic (histone, polyhistidine, polyarginine) and anionic (polyanetholsulfonate) polyelectrolytes to modulate acute immune complex-mediated tissue injury. Tissue injury elicited in rats by the reversed dermal Arthus reaction was increased 26-43% by addition of polyelectrolytes to antibody prior to its intradermal injection. Kinetic studies using 111In-labeled neutrophils indicated that the enhanced tissue injury was not the result of increased influx of neutrophils. Infusion of polyethylene glycol-conjugated superoxide dismutase prior to induction of the Arthus reaction resulted in 40-68% suppression of tissue injury. Concomitant in vitro functional studies (enzyme secretion, O-2 and H2O2 generation, and chemiluminescence) of rat neutrophils demonstrated that addition of polyelectrolytes to preformed immune complexes (IgG-bovine serum albumin) resulted in marked increases in O-2, H2O2, and chemiluminescence, but no increases in enzyme secretion, compared with neutrophils stimulated with immune complexes alone. The cationic polyelectrolytes did not alter the capacity of preformed immune complexes to activate complement in vitro. These studies suggest that both cationic and anionic polyelectrolytes can increase the pathogenic potential of immune complexes and that this modulation is, at least in part, mediated by enhanced generation of toxic oxygen-derived metabolites by neutrophils.

Voluminous literature exists today on the involvement of cationic polyelectrolytes (CPs) in host and parasite interrelationships. It has been shown that CPs of neutrophil (1-14), eosinophil (15, 16), macrophage (17), and platelet (18) origins function as distinct microbicidal agents. These probably constitute a "secondary" defense line supplementary to the main oxygen-dependent microbicidal systems of "professional" phagocytes. CPs have, however, also been implicated as modulators of blood clotting (19) and fibrinolysis (20), as a permeability-enhancing factors (21-23), in mast cell degranulation and in histamine release (24), as pyrogenic agents (25), as enhancers of complementmediated lysis (26), as modulators of PMN adherence (27-29) and chemotaxis (30-34), and as modulators of endocytosis (35-45) to list only several of the properties ascribed to these agents. Since the effects of CPs probably involve the interaction, through electrostatic forces, with negatively charged sites on target cells (36), it is plausible that the complex polyelectrolytic milieu found in infectious and inflammatory sites might function to modulate and regulate several important interactions of the host with invaders (46-48). Although CPs are primarily recognized for their distinct killing properties (10-13), recent studies have suggested that CPs might also be involved in a variety of additional biological, biochemical, and immunopathological phenomena which are seldom discussed in the general context of host and parasite interrelationships. The present review deals primarily with the possible involvement of CPs (1) in endocytosis and in cell adherence, (2) as activators of the respiratory burst in "professional" phagocytes, (3) as activators of the autolytic wall enzymes in certain microbial species and its relation to bacteriolysis and to the pathogenesis of chronic inflammation induced by bacterial cell walls, and (4) as agents capable of modulating the pathogenicity of immune complexes. It was felt that a discussion of these "other" properties of CPs is timely as it may shed a new light on the role of surface charge in cell-to-cell interactions as seen in inflammatory and infectious sites.

Introduction Cationic polyelectrolytes play important roles in many biological systems. Histones [20] and cationic proteins of lysosomal origin [8, 18, 24, 25, 28, 33, 36, 37], both rich in arginine, and synthetic poly a-amino acids [3, 4, 5, 6, 23, 30] have been shown to be bactericidal and cytotoxic to a variety of bacteria and mammalian cells. In addition, these compounds modulate blood coagulation [30] and fibrinolysis [10]; agglutinate bacteria and mammalian cells [30]; modulate chemotaxis [16]; enhance adherence of mammalian cells to surfaces [26]; function as opsonins for phagocytosis by both "professional" and "nonprofessional" cells [3,5,6,17,27,28,34]; activate autolytic cell wall enzymes of Staphylococci [15]; and block Fe receptors for IgG upon certain group A Streptococci [14]. More recent studies have shown that histone-opsonized bacteria induced intense Iuminot- dependent chemiluminescence (LDCL) in human polymorphonuclear leukocytes (PMNs) and mouse peritoneal macrophages [In Furthermore, poly-i.-arginine collaborated with mixtures of lectins, calcium ionophore and the chemotactic peptide formyl-methionyl-Ieucyl-phenylalanine to induce synergistic LDCL and superoxide production in human PMNs [12,13]. Thus, arginine-rich polyelectrolytes appear to participate in many cellular functions related to host defenses against infection, presumably by mechanisms involving electrostatic interactions and ligand- receptor coupling phenomena. The objective of this present study was to investigate the possibility that arginine- rich polycations might facilitate the introduction of a variety of agents into eukaryotic cells. For this purpose, we have studied phagocytosis by Entamoeba histolytica of Candida albicans, and by Acanthamoeba palestinensis of Mycobacterium marinum.

Introduction. Although a voluminous literature exists today which describes, in great detail, the role played by "professional" phagocytes and by serum components in the killing of pathogenic bacteria in vitro and in vivo (l-7) very surprisingly, however, little is actually known about the fate and mode of disposal of microorganisms once they had been rendered non-viable by the defence systems of the host. It is expected that the rich arsenal of lysosomal hydro- lases, including the key muralytic enzyme lysozyme (LYZ), present in leukocytes and in body fluids might be adequate to biodegrade the complex structures of the microbial cells. Paradoxically, however, the majority of bacteria are highly refractory to LYZ action. There is also some confusion in the literature concerning the distinction between bactericidal and bacteriolytic processes. It is conceivable that while a major degradation of microbial cell walls may be followed by a bactericidal reaction, the mere killing of bacteria either by oxygen radicals (2) or by complement-dependent cytlytic antibodies (7) may not necessarily be accompanied by a significant cell wall degradation. Many experimental models, with laboratory animals, have distinctly shown the persistence, for very long periods, of non-viable bacteria and of undergraded microbial cell wall components, within macrophages, in chronic inflammatory sites (8-l8). Thus, one should categorically differentiate between bactericidal and bacteriolytic phenomena. It is apparent, therefore, that mammalian tissues fail, for still not/fully known reasons, to biodegrade and eliminate microbial cell wall components. Peptidoglycan (PPG)-polysaccharide (PS) complexes derived from microbial cell walls possess distinct pathobiological and and pathophysiological properties (19-21). These include the capacity to activate the complement cascade and to generate chemotactic agents, to induce fever, to activate the respiratory burst in leukocytes and to modulate the immune responses (19-24), to mention only a few of the plethora of functions ascribed to PPG. These properties may also explain the very complex interrelationships which exist between the parasite and the host during microbial infections and the possible reasons for the development of certain post-infectious sequelae, which involve the prolonged persistence of bacterial cell wall components in tissues (10-15).

Liquoid (polyanethole sulfonate) was neither capable of influencing the growth nor the viability of staphylococci. But liquoid induced a suppression of the activity of different autolytic wall systems of normally growing staphylococci, i.e., autolysins which participate in cross wall separation as well as autolysins which are responsible for cell wall turnover. Additionally, the lysostaphin-induced wall disintegration of staphylococci was inhibited by liquoid. However, no indication could be found for a direct inhibition of lytic wall enzymes by liquoid; rather an interaction of liquoid with the target structure for the autolytic wall enzymes, the cell wall itself, was postulated. On the basis of the experimental data with the teichoic acid- mutant S. aureus 52A5 the sites of wall teichoic acid were supposed to be an important target for the binding of liquoid to the staphylococcal cell wall.

Summary. Viable Staphylococcus aureus (strain Oxford beta lactamase negative) which had been cultivated either in the absence or presence of penicillin G (subinhibitory concentrations) were injected into the knee joint of adult rats. Tissue sections taken five days following the injections and analyzed by an electron microscope revealed the persistence of apparently intact cell walls within macrophages at the inflammatory sites. The data suggest that even under penicillin effect the macrophages were capable only of digesting the bacterial cytoplasmic constituents (plasmolysis) but failed to degrade the bacterial peptidoglycan. The possible role played by anionic polyelectrolytes, which accumulate at the inflammatory sites, in the inhibition of cell wall degradation by leukocytes in 1/it/0 and the role played by leukocyte factors in the activation of the bacterial own autolytic wall enzymes will be discussed.