Some properties of he nolysin produced by Vibrio vulnificus were investigated. The hemolysin was heat labile, and the hemolytic activity was inhibited by adding cholesterol or divalent cations. Cholesterol inhibited the temperature-independent hemolysin-binding step, suggesting that cholesterol made up the binding site. of the cell membrane, whereas the divalent cations inhibited the temperature-dependent membrane-degradation step. However, the V. vulnificus hemolysin was stable to oxygen and sulfhydryl reagents and was not inactivated by antiserum against streptolysin O, suggesting that the V. vulnificus hemolysin differs from oxygen-labile hemolysins which bind to cholesterol. The V. vulnificus hemolysin seems to be one of the exceptional cholesterol-binding hemolysins.

View full abstract

A sensitive enzyme-linked immunosorbent assay (ELISA) with rough-surfaced glass beads used as the solid phase was developed for detection of IgG, IgM, and IgA antibodies to Haemophilus influenzae type b capsular polysaccharide (HITB-CP). A successful method for indirect coating of glass bead surfaces with HITB-CP, and parameters affecting the specificity and sensitivity of the assay are described. This ELISA system proved to be 100 times as sensitive as the standard indirect fluorescent-antibody assay. The assay was applied to the measurement of antibodies to HITB-CP in serum and nasal secretions and proved to be a useful tool in the evaluation of immunological response to HITB infection.

View full abstract

The attachment of Mycoplasma pulmonis m53 organisms to mouse and rat synovial cells was examined by using the organisms and the synovial cells treated in various ways. M. pulmonis treated with trypsin attached to the synovial cells, but the organisms treated with pronase, formaldehyde, glutaraldehyde, or heat did not. These findings suggest that the sites for binding M. pulmonis to the mouse and rat synovial cells are of polypeptide nature. Treatment of M. pulmonis with sialic acid and treatment of the synovial cell sheets with neuraminidase did not affect the attachment. The synovial cell surface for receptors M. pulmonis organisms would be different from those on respiratory cells or erythrocytes for M. pneumoniae or M. gallisepticum. Even nonviable organisms and M. pulmonis membranes attached to the mouse or rat synovial cells. The nature of the receptor of mouse synovial cells would be different from that of rat cells, since rat cells were affected by treatment with formaldehyde or glutaraldehyde, but mouse cells were not.

View full abstract

A wall-active, amphophilic antibiotic aculeacin A significantly but incompletely inhibited in vitro the activity of β-(1, 3)glucan synthase prepared from highly susceptible yeasts Saccharomyces cerevisiae and Candida albicans. In contrast, comparable cell-free preparations from S. cerevisiae active in chitin synthase or mannan synthase were insensitive to the antibiotic, suggesting selectivity of its action in synthesis of the yeast cell wall.
An electron microscopic study of the effects of aculeacin A at 0.31μg/ml, the optimally active concentration, on osmotically stabilized C. albicans cells revealed morphological alterations in both cell walls and cell membranes. Deformation in contour and derangement of the layered structure of the cell wall were prominent. In addition, massive fibrous material of β-glucan-like microfibrils was occasionally extruded from the cell surface. Accompanying this effect on the cytology of the cell wall, ultrastructural and functional impairment of the cell membrane was demonstrated by transmission and freeze-fracture electron microscopic techniques.
These data suggest that aculeacin A affects synthesis of the yeast cell wall through not only selective blockage of β-(1, 3)glucan synthase, as a result of a primary interaction with the cell membrane, but also inhibition of the fabrication of β-glucan or other wall components into well-organized cell walls.

View full abstract

During chronic infection of mice with mouse cytomegalovirus (MCMV), the virus was isolated from various tissues by cocultivation with allogeneic mouse embryonic fibroblasts (MEF). Infectious virus was recovered from over 15% of the pancreases, salivary glands, kidneys, lacrimal glands, and spleens. When activated macrophages were obtained by intraperitoneal injection of peptone into mice infected 3 months earlier, they harbored MCMV.
Macrophages or lymphocytes were infected with MCMV in vitro and injected into normal mice intravenously. The peritoneal cavities of these mice were then stimulated by peptone injection 3 months after the transfer, and peritoneal or splenic macrophages and lymphocytes were cocultured with allogeneic MEF. MCMV was recovered from the peritoneal and splenic macrophages and not from the lymphocytes.

View full abstract

The formation of varicella-zoster (V-Z) virus-associated antigens was studied in V-Z virus-infected Vero cells by means of indirect immunofluorescence. Early antigen (EA) was first detected inside V-Z virus-infected Vero cells 4 to 6hr after infection, whereas surface membrane antigen (SMA) was expressed on the outer surface of infected cells 2 to 3hr later than EA, and intranuclear late antigen (LA) was detected several hours later than SMA antigen. EA expression was not inhibited by cytosine arabinoside (Ara-C) treatment, whereas LA formation was completely blocked by Ara-C. The presence of two components of SMA early SMA (ESMA) and late SMA (LSMA), was suggested by this difference in susceptibility to Ara-C. The formation of all viral antigens, EA, SMA, and LA, was blocked by inhibitors of RNA and protein synthesis.

View full abstract

Mycoplasma pulmonis m53 was inoculated intraarticularly in the bilateral hind footpads and bilateral knee joints of BALB/c mice. Mycoplasmas were recovered from the affected joints over 20 weeks accompanying acute or subacute inflammation. Intensive deposition of immunoglobulins, a complement (C3) and mycoplasma cell antigens occurred in synovial and adjacent connective tissues. The histopathologically intact kidneys, brain, and lungs showed deposition of IgG and the complement on the endothelial cells of blood vessels. An IgG-rheumatoid factor like substance (RFLS) was detected in the serum of the mice by an enzyme-linked immunoabsorbent assay. Persistence of mycoplasma cells and immune complexes in the articular tissues might cause the prolongation of inflammatory responses in murine mycoplasmal arthritis.

View full abstract

Sequential production of interferon (IFN)-α/β and IFN-γ in the circulation of mice which had been previously infected with viable Listeria monocytogenes was induced by injection of lipopolysaccharide (LPS) derived from Salmonella typhimurium. IFN-α/β production occurred 2hr after injection of LPS, thereafter IFN-γ appeared and the maximum titer was demonstrated at 6hr. At that time, almost all of the IFN was IFN-γ. IFN-γ production in response to LPS was observed from the 5th through the 11th day after infection with Listeria, but it was not demonstrated in either mice infected with lower doses of viable Listeria or mice immunized with heat-killed bacteria. IFN-α/β production was not drastically affected by treatment with hydrocortisone, cyclophosphamide, carrageenan, anti-thymocyte serum, or anti-asialo GM1 antibody, whereas IFN-γ production was suppressed by administration of all those agents. Noteworthily, IFN-α/β, but not IFN-γ, was produced even 6hr after stimulation with LPS in cyclophosphamide- or antithymocyte serum-treated mice. IFN-γ induction by LPS was markedly suppressed in mice in which IFN-α/β produced by Listeria infection itself had been depleted by treatment with anti-mouse IFN-α/β antibody, but it was not inhibited in mice when IFN-α/β induced not by Listeria infection but by LPS had been depleted by treatment with anti-mouse IFN-α/β antibody.

View full abstract