Morimasa Yoshioka

Protective Efficacy against Group B Streptococcal Infection in Neonatal Mice Delivered from Preimmunized Pregnants

Neonatal mice delivered from mothers preimmunized with heated or formalinized whole cell vaccines of type Ia, Ia/c and III/c group B streptococci were infected with each type of bacteria, and then serum antibodies of mothers and neonates who survived the experiments were measured by enzyme‐linked immunosorbent assay. The relationship between the protectivity in neonate mice and the antibody titers to the type specific polysaccharide antigens and the protein c antigen of their sera were examined.

Attachment of Mycoplasma pulmonis to Rat and Mouse Synovial Cells Cultured In Vitro

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.

Mycoplasma pulmonis Arthritis in Mice: Microbiological and Immunological Features

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.

Relationship between an 85 kDa Protein and the Protective Effects of Mycoplasma pneumoniae

In the immunoblot analysis, sera from patients infected with Mycoplasma pneumoniae reacted with the 168 kDa (P1) and the 85 kDa proteins of virulent strain FH‐P24 and P24‐S1 mutant strain but not with the 85 kDa protein of P24‐S11. Sera of hamsters and BALB/c mice, which had been immunized with live vaccines, were tested. In FH‐P24 immunized animals, 100% or 80%, and in P24‐S1, 40% of hamsters and 60% of BALB/c mice, developed antibodies against the 85 kDa protein, but antibodies were not detected in sera of P24‐S11 immunized animals. The correlation between the development of antibodies to 85 kDa protein in the sera of vaccinated animals and the effects of protection by living vaccines were suggested.

Immunogenicity and Protective Effect of Hemolysis Mutants of Mycoplasma pneumoniae

Two attenuated strains of Mycoplasma pneumoniae, P24‐S1 and P24‐S11, were tested for their ability as a live vaccine to confer on hamsters immune resistance against challenge infection with a virulent strain of M. pneumoniae, FH‐P24. Fifty percent protection was obtained by vaccination with the P24‐S1 strain administered once or twice. In contrast, only 10% of the animals were protected by the P24‐S11 vaccine even when it was given three times. Vaccination with the P24‐S1 strain resulted in higher humoral and cellular immune responses than the P24‐S11 did. These results suggest that the P24‐S1 strain has the primary qualities a vaccine which may be used for protection against human mycoplasmal infection.

Characterization and Pathogenicity of Hemolysis Mutants of Mycoplasma pneumoniae

Hemolysis mutants were produced by treating Mycoplasma pneumoniae FH‐P24 strain with N‐methyl‐N‐nitro‐nitrosoguanidine and were classified into three different groups. The first group of mutants, strains P24‐L1, L2, and L11, showed wide and clear hemolytic zones. Their attachment ability to erythrocytes of various animals and to hamster lung cells were the same as those of the parent strain. The second group, strain P24‐S1, showed non‐hemolysis and non‐hemadsorption, but retained the attachment ability to lung cells, although not to erythrocytes. The third group, strain P24‐S11, was non‐hemolytic, had completely lost the attaching ability, and did not proliferate in vivo. Strains in the first group produced significant microscopic pneumonic lesions in hamsters while strain P24‐S1 produced milder lung lesions. Strain P24‐S11 did not cause any lung lesions, and organisms were not recovered from the lungs of hamsters. The attachment of M. pneumoniae to respiratory epithelium as a cause of infection and the existence of a relationship between the hemolytic abilities of the organisms and histopathogenicity in the hamster lung tissue were further supported by the present data.

FRACTIONATION OF LIPID COMPONENTS ISOLATED FROM ENDOTOXIN AND THEIR CHEMICAL AND BIOLOGICAL PROPERTIES

Neutral, polar-I, and polar–II lipid fractions were separated, with organic solvents and silica gel column chromatography, from lipid material obtained by the acid hydrolysis of Salmonella typhosa, strain 0–901 endotoxins. The neutral lipids were mainly composed of fatty acids; the polar-I lipids of fatty acids and glucosamine, and the polar–II lipids of fatty acids, glucosamine, and phosphorylethanolamine. The lethal, pyrogenic, and interferon-inducing activities were found in polar–I and polar–II lipid fractions. The polar-II lipids were further fractionated by silica gel chromatography and 13 subfractions were obtained. Among these subfractions, the lethal activity was found in subfractions 1,2,3,4,5 and 7, being especially high in subfractions 2 and 3. The pyrogenic and interferon-inducing activities were in subfractions 1 through 5. Fatty acids, glucosamine and phosphorylethanolamine were in all subfractions. Contents of lauric acid, myristic acid and palmitic acid were comparably high in subfractions 1,2, and 3.