The effects of immunological IgG binding to Staphylococcus aureus and IgG binding via protein A on the chemiluminescence (CL) response of human phagocytes were examined. The results obtained by enzyme immunoassay showed a clear correlation between the magnitude of the CL response and amount of IgG on protein A-deficient HL-87 strain. Despite no difference in protein A activity between 209P and Cowan I strains, the CL response to IgG-opsonized 209P cells was lower than that to Cowan I cells similarly opsonized. Moreover, the CL response to opsonized HL-87 cells was identical with that of opsonized Cowan I cells, which was a protein A-rich parent strain of the HL-87. The protein A activity of Cowan I cells was significantly decreased when the cells were treated with the Fc fraction of IgG before opsonization, but such a treatment did not change the phagocytic CL response. These results strongly suggest that IgG bound to protein A via its Fc portion has no effect on the phagocytic CL response and that IgG immunologically bound to S. aureus is responsible for the opsonization of the bacteria.

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Tumor necrosis factor-alpha (TNF-α)-inducing activity of several mycoplasmas including Mycoplasma pneumoniae, a causative agent in human respiratory infectious diseases, was investigated. Purified peritoneal macrophages from BALB/c mice markedly enhanced their cytotoxic activity to Meth A cells, when cultured with either viable or non-viable mycoplasmas. The supernatants of the macrophage culture with mycoplasmas, M. pneumoniae and Acholeplasma laidlawii, showed the potent cytotoxic activity to TNF-α-sensitive L cells but not to TNF-α-insensitive L cells. Addition of anti-TNF-α antiserum inhibited completely the cytotoxic activity of these supernatants, indicating that a major part of the cytotoxic activity might be due to TNF-α. Various other mycoplasmas, either glucose-or arginineutilizing species, as far as tested showed also the potent activity to produce TNF-α. These results strongly suggest the possibility that mycoplasmas possess the activity of TNF-α induction which might be responsible for a part of enhancement of cytotoxic activity of macrophages and resistance to infection with mycoplasmas in vivo.

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The relationship between formation of the Mg²⁺-induced hexagonal lattice structure by R-form lipopolysaccharides (LPS) and chemical structure of their R-cores was investigated using different kinds of R-form LPS from a series of mutants of Salmonella minnesota or S. typhimurium. The optimal experimental condition for formation of the hexagonal lattice structure was to suspend LPS preparations, from which cationic material was removed by electrodialysis, in 50mM tris (hydroxymethyl) aminomethane buffer at pH 8.5 containing 10mM MgCl₂. Under this experimental condition, Rb₁ LPS formed the hexagonal lattice structure with the lattice constant of 14.0±0.2nm. Ra LPS, which possesses the full length of R-core, also formed the hexagonal lattice structure but its lattice constant was larger (18.1± 0.2nm) than that of Rb₁ LPS (the lattice structure by Ra LPS was looser than that by Rb₁ LPS). All the other R-form LPS preparations tested, RcP⁺, RcP^-, Rd₁P^-, and Re LPS, whose R-cores are shorter than that of Rb₁ LPS, did not form the hexagonal lattice structure, but formed membranous structures showing various shapes which consisted of multiple bilayer structures. Failure to form the hexagonal lattice structure was the common feature of these kinds of R-form LPS irrespective of temperature at which the LPS suspensions in 10mM MgCl₂-50mM Tris buffer were incubated. From the results of the present study it was concluded that capability of R-form LPS to form the hexagonal lattice structure has a close correlation with the chemical structure of their R-cores.

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From 1983 to 1986, 1, 813 children in nursery schools in Ishigaki Island and 1, 228 children under 15 years old in the rural area in the Yaeyama District of Okinawa, Japan, were tested for anti-HTLV-I; 18 children (1.0%) in Ishigaki Island and 39 children (3.2%) in the rural area were positive. In order to survey when anti-HTLV-I developed in these children, their older serum samples were investigated retrospectively for 1 to 5 years. Two cases of seroconversion from anti-HTLV-I negative to positive were found between the age of 2 and 4, and there were no cases of seroconversion over 4 years old. Among the children who suffered maternal transmission of HTLV-I and developed anti-HTLV-I before the age of 15, about 80% of the children were considered to have anti-HTLV-I before the age of 2, and the remainder developed anti-HTLV-I before the age of 4.

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A new method for detection of varicella-zoster virus (VZV) DNA using field-inversion gel electrophoresis (FIGE) was devised. VZV-genomic DNA could be differentiated from the host cell DNA of human embryonic lung (HEL) fibroblasts infected with VZV under electrophoretic conditions allowing resolution of linear and double-stranded DNAs in the 49-230 kilobase pairs (Kb) range. The detection of VZV-genomic DNA from infected HEL cells was successful regardless of whether the VZV was a laboratory strain, live vaccine strain, or fresh isolate. Under the same electrophoretic conditions, DNA of VZV-infected HEL cells could be clearly differentiated from DNA obtained from HEL cells infected with herpes simplex virus type 1 (HSV-1), type 2 (HSV-2), or human cytomegalovirus (HCMV). Furthermore, VZV genomic DNA could be detected from as small a sample as 1.9×10⁴ VZV-infected HEL cells. Finally, we could detect VZV genomic DNA from 10 samples of vesicle tissue (blister lids, each about 1-4mm²) and one sample of vesicle fluid (about 5μl) obtained from patients diagnosed as having herpes-zoster. The results of this study indicate that FIGE is a simple and promising method for the detection of VZV from clinical materials as well as infected in vitro cultured cells.

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The profile of generation and characteristics of immunosuppressive macrophages (Mφs), which suppress the ConA-mitogenic response of spleen cells (SPCs), in host CBA/JN mice during the course of Mycobacterium avium complex (MAC) and M. tuberculosis (MT) infections were investigated. In both infections, a marked reduction in ConA mitogenic response of splenic T cells was seen around 2 weeks after infection, and this was accompanied by generation of potent immunosuppressive Mφs in the SPCs of infected mice. The suppressive activity was much stronger in MT-infected mice than in MAC-infected ones. In both infections, the large part of the suppressive Mφs exhibited suppressor activity that depended on the arachidonic acid cascade, particularly mediated by prostaglandins (PGs), and the remainder showed the suppressor action independent from PGs. The unique finding of this study is that the generation of IL-2 reactive T cell populations in SPCs in response to ConA signal was markedly inhibited by the MAC- and MT-induced immunosuppressive Mφs, whereas the suppressive Mφs failed to reduce the IL-2-producing ability of splenic T cells. In any case, the present results indicate a close similarity in immunosuppressive Mφs induced by MAC and MT infections.

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This paper reports the nature of abnormally expressed Forssman (F) antigen in the lymph node cells of MRL/MpJ-1pr/1pr, autoimmune mice, and also reports its autoantibody in sera. By acetylation study of the F antigen with [¹⁴C] acetic anhydride, we concluded that the F antigen was not a glycolipid but a glycoprotein. Several bands of F-active glycoproteins were identified on a nitrocellulose sheet after purification by an anti-F antibody affinity column. Hemolysis of SRBC by some sera from MRL/MpJ/1pr/1pr was inhibited by purified F glycoprotein and also by F glycolipid. The antibody in the serum, however, seemed to be more specific for F glycoproteins than F glycolipid, but the opposite was the case for rabbit anti-F glycolipid antibody. No significant difference of the SRBC hemolysis levels was observed between the sera from MRL/MpJ-1pr/1pr and its congenic MRL/MpJ-+/+ mice.

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The effect of actinomycin D (ACT-D) on human neutrophil chemotaxis, chemiluminescence (CL), superoxide (O₂^-) production, phagocytic uptake, and intracellular bacterial killing has been examined. The viability of the ACT-D-treated neutrophils was 98%, even at a concentration of 10μg/ml for 4hr. Using fMLP as the chemotactic factor, depressed chemotaxis was demonstrated following ACT-D (1-10μg/ml) pretreatment of neutrophils as compared with the non-treated controls. Similar ACT-D pretreatment produced the depressed responses in phorbol myristate acetate-induced CL and superoxide production by neutrophils. Moreover, using heat-inactivated human serum as an opsonin for Salmonella enteritidis (NCTC 6676), there was a significant difference in intracellular killing (P<0.01) but no difference in phagocytic uptake between ACT-D-treated and non-treated neutrophils. These studies indicate that ACT-D profoundly impairs both intracellular bacterial killing by human neutrophil through an effect on respiratory burst activity and directed cell migration of human neutrophils.

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Peritoneal exudate macrophages from mice, rats, and guinea pigs were assessed using six different parameters of macrophage activation to determine whether the cells were stimulated under similar experimental conditions. Peritoneal exudate macrophages from mice, irrespective of strain, were far less responsive to a variety of in vitro stimulatory effects of N-acetylmuramyl-L-alanyl-D-isoglutamine than those from rats or guinea pigs, while no significant differences were noted with the reactivity to stimulation by endotoxic lipopolysaccharide. We conclude that macrophage activation by MDP in vitro is species dependent.

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The effects of B subunit of cholera toxin (CTB) on delayed-type hypersensitivity (DTH) response to influenza vaccine derived from influenza virus A/PR/8/34 (PR-8, H1N1) virus were investigated in B10 mice that were immunized intranasally with both influenza vaccine and CTB. The result showed [1] that intranasal inoculation of this combination augmented DTH response to influenza vaccine, which reached its peak 6 days after inoculation, and also induced accelerated DTH response upon a second inoculation of influenza vaccine alone 4 weeks later, [2] that the cross-reactive DTH response to PR-8 vaccine was elicited by the injection of the different influenza A-type virus vaccine into the footpad of the vaccinated mice, but was not by influenza B-type virus vaccine, [3] that the DTH-mediating T cells were detected selectively in the lungs of mice that received the nasal inoculation of the vaccine and CTB together, but that subcutaneous inoculation of this combination failed to induce DTH-mediating T cells in the lungs. These results, together with the previous papers (Tamura et al, Vaccine 7: 257-262; 314-320, 1989), suggest that CTB could augment both humoral and DTH responses against influenza vaccine in the respiratory mucosal tract.

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