The effect of cortisone on the accumulation, activation, and necrosis of macrophages in tuberculous lesions

Rabbits were injected intramuscularly with cortisone acetate (2 mg/kg) on alternate days. Six days after the first injection these rabbits and controls were injected intradermally in multiple sites with BCG (the vaccine strain of tubercle bacillus). Periodically, over the next 2 months, the resulting lesions were measured and surgically biopsied, and the animals were tuberculin-tested. Macrophage activation in the BCG lesions was evaluated histochemically by staining for beta-galactosidase activity. Both BCG lesions (and tuberculin reactions) in the cortisone-treated group were considerably smaller than those in the control group. Cortisone was highly effective in reducing the number of infiltrating mononuclear cells (MN), the amount of caseous necrosis and ulceration, and the percent of NM that were beta-galactosidase-positive. The decreased activation and reduced number of macrophages readily explains the increased susceptibility to tuberculosis found amoung patients receiving glucocorticosteroids. In the BCG lesions, the local decrease in the number and function of leukocytes probably explains the decreased tissue necrosis. Such antiinflammatory effects of corticosteroids may offset, in selected antimicrobial-treated cases, the hormone's detrimental effect on host resistance to infectious agents.

Activation of alveolar macrophages exposed to lavage-procured immunoglobulin G obtained from normal rabbit lungs

Pulmonary washings from rabbits were freed of cells and added to the monolayers of homologous alveolar macrophages (AM). At 1 h after incubation with the pulmonary washings, many more cells adhered to glass, spread out, and showed enhanced Nitro Blue Tetrazolium reduction. The maximal effect of the pulmonary washings on AM activation was obtained 12 h after incubation. The AM activated by the pulmonary washings showed a higher capacity to inhibit the growth of intracellular BCG, and that capacity was correlated with the intensity of Nitro Blue Tetrazolium reduction by the AM. Gel filtration of the pulmonary washings through Sepharose 4B yielded five fractions. The factor that activated the AM functions was in fraction 4. When the immunoglobulin G in the fraction was removed by an immunoadsorbent column, AM activity was abolished. The effect of the immunoglobulin G was dose dependent, and minimal responses to 10(6) cells per ml were obtained at a protein concentration of 20 mug/ml. Lymphokines had no effect on AM activation with respect to the morphological alterations and Nitro Blue Tetrazolium reduction during the 24-h observation time. In summary, AM from normal rabbits were soon activated markedly by lavage-procured immunoglobulin G, but not by lymphokines.

Extracellular hydrolytic enzymes of rabbit dermal tuberculous lesions and tuberculin reactions collected in skin chambers

To evaluate extracellular hydrolytic enzymes in an in vivo system, plastic chambers were glued over rabbit dermal BCG lesions in various stages of development, after the central epithelium was removed with a scalpel. They were filled with tissue culture medium and left in place 2 days. The following enzymes in the fluid were assayed: collagenase (an enzyme secreted but not stored in macrophages); lysozyme (both secreted and stored); DNase and RNase (released on cell death and possibly regurgitated but not secreted); and, as a control, lactic dehydrogenase (released only on cell death). Tissue sections were prepared and studied histologically for the type of cell infiltrate, for beta-galactosidase (our marker enzyme for macrophage activation), and for necrosis. At 11 and 18 days of age the BCG lesions were largest and the number of activated macrophages in the chamber beds was highest. At this time the levels of the five enzymes assayed in the chamber fluids reached their peaks, tuberculin hypersensitivity was well developed, and the bacilli components would still be plentiful. In general, the chamber fluids from 11- and 18-day BCG lesions contained higher enzyme levels than chamber fluids from tuberculin reactions. Active collagenase was only detected in fluids from such BCG lesions. Evidently, the serum in the chamber fluids was sufficient to inhibit the lower amounts of collagenase probably released from smaller BCG lesions and tuberculin reactions (and from the 2-week polystyrene lesions that were also evaluated). These studies demonstrate that in chronic inflammatory reactions, both acid-acting and neutral-acting hydrolytic enzymes are released extracellularly. Tissue components would be hydrolyzed locally wherever the acid-acting hydrolytic enzymes encounter a drop in pH and wherever the concentration of neutral-acting hydrolytic enzymes exceeds the concentration of their inhibitors.

Enhancement of carrier-specific helper T cell function by the synthetic adjuvant, N-acetyl muramyl-L-alanyl-D-isoglutamine (MDP)

The adjuvant effect of a synthetic peptidoglycan, muramyl dipeptide (N-acetyl muramyl-L-alanyl-D-isoglutamine, MDP), was studied by using the anti-Tnp PFC and hemagglutinin responses of BALB/c mice to hapten-carrier conjugates. Administration of Tnp-OVA and MDP in saline to mice, followed 2 weeks later by a boost of Tnp-OVA in saline, led to significantly higher IgM and IgG anti-Tnp PFC and total anti-Tnp-hemagglutinin responses than those obtained in mice not treated with MDP in the initial immunization. A similar adjuvant effect by MDP on anti-hapten PFC responses was seen if mice were primed with KLH together with MDP and challenged with Tnp-KLH 2 weeks later. This apparent effect on carrier priming for helper function was confirmed and quantitated by double adoptive transfer experiments with graded numbers of spleen cells from KLH +/- MDP-primed mice and a fixed number of hapten-primed spleen cells from syngeneic Tnp-OVA immunized animals. These data suggest that at least one mode of action of the synthetic adjuvant MDP is via the enhanced stimulation of the helper T cell function.

Clinical evaluation of pivmecillinam in intractable urinary-tract infections with complications. A comparative study with amoxicillin by a randomized double-blind technique

A comparative study was made by the double-blind technique in order to make clear the usefulness of pivmecillinam in the treatment of intractable complicated urinary-tract infections using amoxicillin as a reference drug. Pivmecillinam was given in dosage of 400 mg (potency) per day which was one-fifth the dose of amoxicillin 2,000 mg (potency) per day. In global judgement, pivmecillinam was found superior to amoxicillin. It showed a "significant" superiority over amoxicillin for the treatment of, among others, the urinary-tract infections after prostatectomy, which are intractable diseases. When evaluated by symptoms, pivmecillinam improved bacteriuria "significantly" better than amoxicillin. When seen by causative organisms, the pivmecillinam treatment was "significantly" superior to the amoxicillin treatment against E. coli infections. Pivmecillinam was active against amoxicillin-resistant E. coli. Incidence of adverse reactions was less frequent with pivmecillinam than with amoxicillin. These results indicate that pivmecillinam is a drug of high usefulness for the treatment of intractable complicated urinary-tract infections when evaluated using amoxicillin as a reference drug.

Histochemical studies relating the activation of macrophages to the intracellular destruction of tubercle bacilli

Dermal tuberculous lesions, both primary and those of reinfection, were produced in rabbits with 14C-labeled BCG and biopsied once at various times. Macrophage activation was evaluated by the indolyl histochemical test for beta-galatosidase, the number of bacilli in macrophages by acid-fast staining, and the breakdown of bacilli by autoradiography. After the rabbits became tuberculin positive, the stongly activated macrophage population contained a) fewer parasitized cell, b) fewer bacilli in each parasitized cell, and c) more "free" 14C-label (not associated with intact bacilli) than the weakly activated macrophage population. These results suggest that the more highly activated macrophages had destroyed many of the bacilli that they once contained and that their power to do so was enhanced by immunologic mechanisms.

Immunogenicity of lysozyme derivatives lipid-conjugated to various degrees in mice treated with and without cyclophosphamide: dissociation of delayed-type hypersensitivity and helper function

Lysozyme and a series of its lipid-conjugated derivatives without adjuvant were examined in mice for their abilities to induce delayed-type hypersensitivity (DTH), helper T-cell activity, and antibody formation. In addition, the effect of cyclophosphamide (CY) on the immune responses was assessed in mice immunized with these lysozyme derivatives. Precipitated lysozyme without lipid conjugation was a good inducer of both antibody and DTH responses. Lipid conjugation to lysozyme to intermediate degrees readily caused the failure only in inducing the antibody response. As lysozyme was lipid-conjugated more heavily, DTH response was also reduced and finally abolished. In contrast, the helper activity was little affected by any degree of lipid conjugation. These results indicate that the helper T-cell activity was dissociated from the both DTH response and the antibody production. CY pretreatment extensively enhanced DTH response induced by such lipid-conjugated derivatives that failed to induce antibody response. Furthermore, CY pretreatment in doses in a wide range enhanced not only DTH response but also antibody formation. It is, therefore, concluded that the enhancement of DTH response by CY does not necessarily entail suppression of antibody formation.

Different effects of phytohemagglutinin-activated lymphocytes and their culture supernatants on macrophage function

When rabbit peritoneal exudate cells were incubated for 24 and 48 h with phytohemagglutinin-activated lymphocytes or their culture supernatants, two times as many cells remained adherent to culture slides as in the controls. More spreading cells were found among the adherent cells in the stimulated cultures. Eighty percent of spreading cells that were induced by supernatants were negative or faintly positive for beta-galactosidase. On the other hand, half of the spreading cells induced by activated lymphocytes were positive (1+ to 4+) for beta-lymphocytes and their supernatants. Under similar conditions, unstimulated peritoneal cells showed less marked activation. These findings show that macrophages can appear morphologically activated and yet not be enzymatically activated by lymphokines. Possible mechanisms of direct interaction of activated lymphocytes and macrophages are discussed.

Cell-mediated and humoral immunity in mice: cross reaction between lysozyme and S-carboxymethylated lysozyme studied by a modified footpad test

The mouse sensitized by subcutaneous (sc) injection of lysozyme in emulsion of Freund's complete adjuvant (FCA) was shown by a modified footpad test to develop three kinds of hypersensitivities. Injecting lysozyme in 2.5-mul emulsion of Freund's incomplete adjuvant (FIA) into the footpad elicited strong footpad swelling in 30 min (anaphylactic reaction), in 3 hr (Arthus-type reaction) and in 24 hr (delayed-type hypersensitivity; DTH). The mice showing anaphylactic reaction in the footpad test manifested severe active systemic anaphylaxis, and the sera of these animals showed high IgG1 antibody titers with only sparingly detectable or no IgE antibody titers. In the sensitizing system with the use of FCA, the antigenicity of S-carboxymethylated lysozyme (CM-lysozyme) devoid of the three-dimensional conformation of lysozyme was compared with that of the native molecule. CM-lysozyme and lysozyme completely cross-reacted to each other in DTH, but not at all in the anaphylactic or Arthus-type reaction or in IgG1 antibody production. CM-lysozyme was shown also to have the ability to bestow immunological memory for the induction of humoral immunity against lysozyme; intravenous (iv) injection of lysozyme in saline or sc injection of CM-lysozyme-FCA alone failed to induce immediate hypersensitivities and IgG1 antibody production against lysozyme, but pre-sensitization by sc injection of CM-lysozyme-FCA enabled the animal to induce these responses to significant levels when iv injection of lysozyme in saline was given as a booster.