Shuzo Kashiba

Enhanced Interleukin Production after Long-Term Administration of Erythromycin Stearate

The effects of erythromycin stearate (10 mg/kg/day) were studied on productions of interleukin (IL)-1 and -2 in mice after a long-term treatment. A 28-day treatment resulted in higher levels of IL-1 production by macrophages and of IL-2 production by splenocytes, while a 7-day treatment did not increase them. T-cell growth factor activity of IL-2 preparation prepared on day 28 of treatment as determined by HT-2 cell proliferation was reduced by about 40% in the presence of anti-murine IL-4 monoclonal antibodies, while control IL-2 activity was not reduced. Furthermore, a 28-day treatment with erythromycin stearate increased concanavalin A-induced blastogenesis of splenocytes significantly. These results suggest that long-term treatment with erythromycin stearate can stimulate host defense by increasing interleukin production.

Alterations of Host Resistance to Mouse Typhoid Infection by Sex Hormones

The effect on mouse typhoid infection of a 3‐day treatment of female virgin mice with 1 mg/day of female sex hormones (estrogen or progesterone), maintaining the same hormonal levels observed in pregnant mice for 30 days, was investigated in order to clarify the mechanisms of altered resistance during pregnancy. Estrogen‐exposed mice were more susceptible to the intraperitoneal challenge with Salmonella typhimurium as compared with the vehicle control mice, while progesterone treatment increased the survival times of mice. Estrogen exposure increased the number of peritoneal cells after treatment, but the inflammatory cellular response after infection was significantly suppressed. Although the estrogen‐treated and vehicle control mice had the same degrees of peritoneal cellular responses after infection, the death rates in the estrogen‐treated mice were higher than those in the vehicle control mice against challenge with 1 LD50 of S. typhimurium. On the other hand, progesterone treatment resulted in the marked influx of peritoneal cells after treatment was terminated, and also it induced a significant increase in the number of peritoneal cells after infection. Although survival times in the progesterone group were higher than those in other groups, all progesterone‐treated mice died after a challenge with 1,000 LD50 of S. typhimurium. These results suggest that progesterone enhances nonspecific resistance by increasing the influx of peritoneal cells after infection, while estrogen affects the acute inflammatory responses.

Opsonic effect of fibronectin on staphylococcal phagocytosis by human polymorphonuclear leukocytes: its relative inefficiency in post-phagocytic metabolic activities and in intracellular killing.

The binding of 125I‐labeled human plasma fibronectin (FN) to two strains of live Staphylococcus aureus (S. aureus) (a coagulase‐positive Cowan I and a coagulase‐negative Newman D2C) and the opsonic effect of FN on phagocytosis of these bacteria by human polymorphonuclear leukocytes (PMN) have been studied. 125I‐FN bound to a similar extent in both staphylococcal strains. The 125I‐FN‐binding was significantly inhibited by human fibrinogen as well as unlabeled FN. The FN‐binding was also reduced markedly by trypsinization of these bacteria, but the extent of its decrease did not correlate with their tryptic susceptibility of protein A and clumping factor. FN enhanced the uptake of these bacteria by PMN. However, its binding had no effect on superoxide anion (O2−) generation. The FN‐binding definitely stimulated staphylococcal ingestion and intracellular killing by PMN, but the extent of such promotion was dissimilar between these two strains of bacteria. These results suggest that post‐phagocytic metabolic activities as well as intracellular killing of these Staphylococci may also be greatly influenced by FN‐unrelated factors as are other bacteria having no FN‐receptors.

Immunogenic Dialyzable Factor Derived from a Ribosomal Fraction of Salmonella typhimurium

The preparation, properties, and immunogenicity of the dialyzable factor from a ribosomal fraction of Salmonella typhimurium are described. The ribosomal fraction was purified to eliminate O‐antigenic components, by affinity chromatography (Sepharose‐anti‐O antibody conjugates used as immunoadsorbent). The dialyzable factor was obtained in the concentrated dialysate of the purified ribosomal fraction which was alternately frozen in dry‐ice acetone and thawed in an 80 C water bath, for a total of five or six cycles. When this preparation was tested for its ability to protect mice against challenge with 1,000 LD50 of the homologous bacteria, it afforded 100% protection at a dose equivalent to 5.0 μg of RNA. The protection conferred by this factor was mainly cell mediated but immune serum enhanced this immunity despite the fact that no antibodies were detected in it. The protective activity of this factor was sensitive to RNase digestion but resistant to proteolytic enzymes. Ion exchange chromatography of this factor with DEAE‐Sephadex A‐25 (in 7 M Urea‐0.02 M Tris‐HCl buffer, pH 7.5) resulted in a single A260 peak which was found to be immunogenic. Chemical analysis of this peak after it was concentrated and desalted revealed that this immunogenic fraction was composed mainly of mixed nucleotides. The data indicate that protective immunity conferred by a ribosomal vaccine is associated with RNA but may not require the intact RNA molecule.

Hepatic lesions in experimental Campylobacter jejuni infection of mice.

Mice orally infected with Campylobacter jejuni developed focal infiltrative necrotic lesions in the liver, as determined by both histology and liver function tests. The initial histopathological feature was a focal infiltrative lesion in the parenchyma and portal triads. Foci of infiltrative lesions became necrotic between days 30 and 60 post-inoculation (p.i.). During this period, portal infiltrates increased in severity. From month 4 p.i., focal areas of infiltrative necrosis in the liver parenchyma became extensive. Study of liver function demonstrated mild elevations of transaminases, alkaline phosphatase and lactic dehydrogenase, and also the presence of hypoalbuminaemia. Although histopathological changes of the liver became gradually more marked after day 30 p.i., liver functions of infected mice were most affected at 2 months p.i. The capacity of C. jejuni to induce hepatic lesions seemed to be related to that of organisms to persist in the gall bladder; there was no correlation between biliary carriage in infected mice and positive faecal culture.

Effects of Mouse Testicular Extract on Immunocompetent Cells

ABSTRACT: We investigated mouse testicular extract (TE) to clarify its biological functions in reproductive immunity. TE, at concentrations of 50–300 μg/ml, enhanced macrophage activities of spreading, glucose consumption, and cytostasis against a susceptible tumor cell line. On the other hand, TE inhibited concanavalin A (Con A)‐induced T‐cell blastogenesis in the dose range of 10–600 μg/ml. To elucidate the origin of TE, W/Wvmice, which genetically lack germ cells, were used. TE obtained from W/Wv mice enhanced the spreadability of macrophages and inhibited Con A‐induced blastogenesis of T cells. The enhancement of macrophage spreading was only achieved by the interstitial fluid (IF), while the suppression of Con A‐induced T‐cell responses was detected in seminiferous tubule fluid (STF) as well as in IF. TE did not affect listerial antigen‐specific responses of lymphocytes in vitro. These results suggest that TE has the capacity to regulate the biological responses associated with reproduction.

Immunogenic dialyzable factor derived from a ribosomal fraction of Salmonella typhimurium. II. Isolation and characterization of the protective moiety in the dialyzable factor.

An immunogenic dialyzable factor was obtained by dialysis of the freeze‐thawed ribosomal fraction derived from a smooth virulent strain (LT2) of Salmonella typhimurium. Ion exchange chromatography of the dialyzable factor on Dowex 1‐X2 (Cl– form) demonstrated the presence of four peaks and the fourth peak eluted with 0.4 m NaCl in 0.005 n HCl was found to be necessary for protection. This effective peak was not obtained by chromatography of nonprotective dialyzable factors such as an RNase digest. Dowex chromatography of the dialyzable factors isolated from rough mutants of strain LT2 revealed that the dialyzable factor of strain SL1004 whose live vaccine is capable of inducing protective immunity contained fairly large amounts of peak IV. DEAE‐cellulose for two‐dimensional thin layer chromatography was used to identify the composition of the dialyzable factor and peak IV. Eight spots were located under ultraviolet light and seven spots were characterized by their absorption ratios. In peak IV, four nucleotides were located and identified by comparison with a map of the original dialyzable factor. The data show that the effective components of the dialyzable factor are mixed nucleotides and may be unique to ribonucleic acids of strains of S. typhimurium in which live vaccines are capable of affording mouse protection.

Separate transfer of mouse protection and delayed-type hypersensitivity with Salmonella typhimurium transfer factor

Delayed-type hypersensitivity (DTH) induced with Salmonella typhimurium transfer factor (TF) contributed to an increase in mean survival days of mice challenged with homologous organisms and afforded only a low level of host protection as determined by survival rate, compared with that obtained by active immunization. TF of other enteric bacteria could transfer DTH which is cross-reactive to salmonella antigen but did not afford host protection. Although TF of Listeria monocytogenes did not transfer the cross-reactive DTH, it could confer the significant increase in mean survival days against the lethal challenge with S. typhimurium. Listerial ribosomal vaccine conferred the high level of mouse protection without inducing DTH to salmonella antigen. The resistance generated upon active immunization with listerial ribosomal vaccine could be enhanced by the injection of S. typhimurium TF to the same level as that obtained after immunization with homologous ribosomal vaccine. Among salmonella TF, there could be no cross-reactive immunity between S. typhimurium and S. choleraesuis, although the cross-reactive DTH was observed. The DTH transfer ability of TF was sensitive to Pronase which could not affect the ability to transfer host immunity, but RNase could abolish the ability to transfer host immunity without impairing DTH transfer activity. These results suggest that in mouse typhoid infection, DTH is not associated with host protection as determined by survival rate.

Biological Functions of Mouse Seminal Vesicle Fluid I. Suppression of Blastogenic Responses of Lymphocytes

The effect of mouse seminal vesicle fluid (SVF) on blastogenic response of splenocytes to mitogens was investigated. SVF significantly suppressed blastogenic response of splenocytes to concanavalin A and phytohemagglutinin in a dose-dependent manner, but blastogenic response to lipopolysaccharide was suppressed only at low, although significant, levels, even at high concentrations of SVF. Extensive dialysis did not reduce the capacity of SVF to inhibit blastogenesis of splenocytes. For elucidation of the mechanisms of suppression of blastogenic response, interleukin-2 (IL-2)-dependent cells were cultured in the presence of IL-2 and various concentrations of SVF. The presence of SVF did not inhibit the proliferative response of IL-2-dependent cells to IL-2. These results suggest that the suppression of blastogenic response of T lymphocytes to mitogens in seminal plasma is caused by an undialyzable component (or components) derived from seminal vesicle and is attributable to the alteration of receptors for mitogens or of IL-2 receptors that are expressed on stimulation by mitogens.

経気管吸引法 (TTA) にてムコイド型緑膿菌を検出した呼吸器感染症の臨床的検討

We performed a clinical study of 20 cases (33 episodes) of respiratory infections due to mucoid Pseudomonas aeruginosa by transtracheal aspiration (TTA) in the recent 10 years. There was only one pneumonia without underlying chronic lower respiratory infection (CLRTI) case positive for mucoid P. aeruginosa and others were all CLRTI among 33 TTA trials. In contrast, nonmucoid P. aeruginosa was recovered from 9 cases of respiratory infections without underlying CLRTI among 46 TTA trials. Monomicrobial infection of mucoid P. aeruginosa was 69.7%, and polymicrobial infection containing mucoid P. aeruginosa was 30.3%, and Haemophilus influenzae was the most frequent microorganism recovered with mucoid P. aeruginosa. The recovery rate of mucoid P. aeruginosa among P. aeruginosa-colonized cases was 56.3% in diffuse panbronchiolitis, and that was 42.9% and 40.0% in bronchiectasis and chronic bronchitis, respectively. Mortality due to pneumonia with nonmucoid P. aeruginosa was 46.1%, but there was no fatal pneumonia case with mucoid P. aeruginosa. In CLRTI, laboratory data were not remarkably different between mucoid and non-mocoid P. aeruginosa-colonized cases. Thus, these results suggest that mucoid P. aeruginosa is a more important organism in persistent infections in the lower respiratory tract compared with nonmucoid P. aeruginosa, and further investigations is required on the mechanism and clinical role of this infection.