Seven polyinosinic•polycytidylic acid (poly I•poly C) preparations, ranging from 4.2 S to 21.2 S, prepared from various sizes of polyinosinate and polycytidylate, were examined for toxicity and interferon-inducing activity in mice. The increase in size of poly I•poly C was accompanied by increases both in the maximal amount of interferon produced and in the length of persistence of a high level of interferon in plasma. Toxicity of poly I•poly C was proportional to the molecular size within the range of 8 S to 16 S. The amount of interferon induced by 1/5 LD50 of poly I•poly C depended on the size of the inducer, being increasingly lower with progressively smaller sizes. Next, activities of poly I•poly C in culture cells were examined. The resistance-inducing activity of poly I•poly C in primary chick embryo cells (CEC) increased with the size of the inducer (4.2 S to 11.6 S), whereas the activity in L cells was not so markedly dependent upon its molecular size as in CEC. In the presence of calf serum during induction of resistance the activity was lowered. The activities of preparations with small molecular sizes were affected by calf serum more markedly than those of large molecular sizes. The interferon-inducing activity in RK13 was not appreciably influenced by the size of poly I•poly C, especially in the presence of DEAE-dextran, while the activity in L cells was markedly dependent upon the size of the inducer. These results suggest that the influence of the molecular size of poly I•poly C upon the resistance-inducing and interferon-inducing activities varies among different kinds of cells, and alters in the presence of serum or DEAE-dextran.
Strains of Neisseria gonorrhoeae were inoculated onto brain heart infusion (Difco) agar supplemented with penicillin and polyvinylpyrrolidone (PVP) as a stabilizer and cultivated in a candle extinction jar. L-form colonies became visible after a few days. They continued to grow and were viable for up to 38 days. The extent of inducibility of L forms of N. gonorrhoeae was examined semiquantitatively. It was found to be constant for each type and strain and to depend only slightly on the amount of penicillin added to the medium. None of the types of one strain produced L-form colonies. In another strain, avirulent types(T3, T4) showed more ability to produce L forms than virulent types (T1, T2) and no L forms were produced by the subtypes of T1 and T2-T1a and T2a. In a third strain, only T4 Produced L forms. Electron microscopic studies showed that the L forms consisted of a number of membranous vesicles and a variety of cell types such as those completely lacking cell walls and those with only remnants of cell walls. The results indicate the existence of subtypes of T1 and T2 of gonococci and the intrinsic inducibility of gonococcal types and strains to produce L forms.
The ultrastructure and component polysaccharides of the cell wall of Pythium debaryanum IFO-5919 were investigated. From results obtained by means of acid, alkali, Schweitzer reagent and β-1, 3-glucanase treatments and electron microscopy, it was concluded that 1) the acid-extracted fraction was a 1, 3-linked branched glucan, 2) the alkali-extracted fraction was a mixture of 1, 3-, 1, 6-, and 1, 3, 6-linked highly branched two glucans, 3) the Schweitzer reagent-extracted fraction was a β-1, 4-linked glucan, 4) the cell wall was constructed from two types of cullulosic microfibrils, as a frame and as a finer network, and amorphous β-1, 3-glucan including β-1, 6-linkage, 5) cellulosic microfibrils were covered by matrix material consisting of a mixture of amorphous β-1, 3-linked and β-1, 6-linked branching glucans.
Induction of antiviral activity and interferon by human placenta ribonucleic acid deaminated with sodium nitrite (NO2-RNA) was studied in vitro and in vivo. (1) Viral multiplication in diploid cells from human kidney (HK cells) was depressed by pretreatment with NO2-RNA, but not by pretreatment with the original placenta RNA. (2) NO2-RNA showed an interferon-inducing activity in rabbits and mice. (3) NO2-RNA sedimenting in 18 S and 28 S regions showed a higher antiviral activity than that sedimenting in 4 S region.
The activity of purified human Waldenstrom's IgM proteins to fix complement of human and guinea pig origins was compared at different temperatures using the polystyrene latex particle-adsorption method. It was shown that the interaction of the IgM proteins with complement differed depending on the source of complement and that a pronounced heterogeneity in complement-fixing activity was observed among the IgM proteins when tested with guinea pig complement. Thus, by the use of guinea pig complement, six human IgM proteins examined were classified roughly into two groups, one having a high and the other a low activity at 3 C as well as at 37 C. With human complement, five proteins showed a rather uniform activity at 37 C. However, there was one protein with no detectable activity, suggesting the presence of non-complement-fixing protein in the IgM class. All the six proteins showed no significant activity with human complement at 3 C. No antigenic difference has been found as yet in the Fc or Cμ2 region among these IgM proteins examined.
Blood group H-active polysaccharide has been prepared from "smooth" strain Escherichia coli 2B-V by Freeman's method. α-Fucosidase derived from Bacillus fulminans caused the liberation of fucose from this polysaccharide, together with concomitant loss of blood group H activity. The results of quantitative microanalysis, borohydride reduction, the Morgan-Elson reaction and enzymic hydrolysis with β-galactosidase using isolated oligosaccharides obtained by partial acid hydrolysis indicated that the O-specific side chain of the polysaccharide has a pentasaccharide unit which is β-D-Gal-(1→3)-D-GalNAc-(1→)-D-GalNAc-Fuc with a D-glucose residue bound at some undetermined point on this structure. It was considered that terminal non-reducing fucose of the polysaccharide was liberated by partial acid hydrolysis.
The relationship between lymphocytes and macrophages in cellular immunity against tuberculous infection was studied by means of an in vitro cell culture system without addition of streptomycin. The peritoneal macrophages were obtained from normal mice or mice immunized with heat-killed tubercle bacilli in paraffin oil, boosted with live BCG and infected with H37Rv cells in vitro. The infected monolayers of macrophages were cultivated for 48 hr with immune lymphoid cells obtained from immunized mice. The intracellular growth of H37Rv cells 3, 5 and 7 days after infection was examined by counting tubercle bacilli within infected macrophages under a microscope. 1) The increase of bacilli within macrophages derived from immunized mice was slightly smaller than that in normal macrophages. 2) The addition of immune lymph node cells to the macrophage monolayers resulted in a marked decrease in the number of bacilli within both normal and "immune" macrophages. Conversely, normal lymph node cells exhibited an enhancing effect on the intracellular bacillary growth. 3) Immune lymph node cells showed a higher capacity to cause macrophages to suppress intracellular growth of bacilli than that of splenic lymphoid cells or thymocytes after addition to macrophage monolayers. 4) The treatment of lymphoid cells with inhibitors of protein synthesis, cycloheximide or streptovitacin A, resulted in a remarkable reduction of the ability of sensitized lymphocytes to cause macrophages to suppress multiplication of intracellular bacilli.
Enzyme(s) capable of decomposing N-acetylglucosaminyl ribitol teichoic acid prepared from the cell wall of Staphylococcus aureus FDA 209 P was obtained from the culture supernatant of a gramnegative, rod-shaped, spore-forming soil bacterium. Properties of the bacterium were very similar to those of Bacillus circulans.
A modified direct method of the macrophage migration inhibition test (MMIT) was attempted on a large number of patients with malignant or benign tumors. Results of the MMIT in almost all patients with benign tumors were negative except for those with hydatidiform moles, dermoid cysts and viral benign tumors such as verruca plana which were positive. The number of cases determined as false positives were exceptionally few. Conversely, about the half of the patients with malignant tumors were positive. The majority of negative cancer patients were confirmed pathologically to be advanced cases and, therefore, were postulated to have been immunologically unresponsive. The remaining false negative patients were diagnosed to be very early cases with their malignant foci too small to be effective antigenic stimuli. The MMIT was also performed postoperatively on some of the patients using autologous antigens, which had been preserved by freezing, for examination of changes in the per cent migration index. The results led the authors to conclude that postoperative repetitions of the test permitted them to tell that cancer cells had been completely eradicated or that a relapse might occur in the near future. Examinations of cross reactivity between tumor antigens revealed that such reactivity exists between cancer antigens and antigens originating in hydatidiform moles and that there is also a very strong cross reactivity between allogeneic cancer antigens regardless of differences in the organs of origin. This fact suggests that the present test is effective for the screening of preoperative patients with early cancer.
Strain differences in the antibody response to human IgG (HGG) were observed when aggregated HGG was injected intravenously. Lipopolysaccharide (LPS) administered subsequently markedly enhanced the antibody response to HGG in low responder C57BL/6 mice as compared with that in high responder DDD, C3H/He or (C57BL/6×DDD)F1 mice. Aggregate-free preparation of HGG at a dose of 0.5 mg induced immunological tolerance in all strains of mice tested. LPS injected subsequently converted tolerogenic, aggregate-free HGG into immunogen in DDD mice but not in C57BL/6 mice. To determine the correlation between adjuvanticity and mitogenicity of LPS, spleen cells from normal mice were cultured in the presence of LPS and 3H-thymidine uptake was measured. Spleen cells of DDD mice incorporated three times as much 3H-thymidine as those of C57BL/6 mice. There seems no strong correlation between both activities of LPS. The data obtained are discussed in terms of strain differences in the macrophage function for processing the antigen.