Presence of Common Antigenic Epitope in Outer Surface Protein (Osp) A and OspB of Japanese Isolates Identified as Borrelia garinii

Japanese Borrelia strains FujiP2, AP83, NT24, NT29 and HT2 which had a 31-kilodalton protein non-reactive with monoclonal antibody (MAb) H5332 to outer surface protein A (OspA) were identified as B. garinii by the DNA hybridization method. MAb P3134 raised to strain NT24 reacted with OspA and the OspB-ranging protein of these isolates and cross-reacted with the OspB-ranging protein of some other isolates. Since the reactive protein was extracted by the Triton X-114 phase partitioning method, the MAb recognized the common epitope present in OspA and OspB. To our knowledge, this is the first report of an MAb reactive to both OspA and OspB.     

Studies of peptide antibiotics. XLIV. Syntheses and biological activities of gramicidin S analogs containing delta-hydroxy-L-norvaline or glycine

The antibiotic gramicidin S (GS) has the structure of cyclo (-L-Val1-L-Orn2-L-Leu3-D-Phe4-L-Pro5-L-Val1'-L-Orn2'-L-Leu3'-D-Phe4'-L-Pro5'-) and is basic in character. Five GS analogs including [Gly1,1']-GS and the neutral [L-Hnv2,2']-GS (Hnv represents delta-hydroxynorvaline) were synthesized by the solid-phase method to evaluate the role of L-Val1,1' and L-Orn2,2' residues in GS. The hybrid analogs [( Gly1]-GS and [L-Hnv2]-GS) and [D-Tyr4,4']-GS showed high antibacterial activities, whereas [Gly1,1']-GS and [L-Hnv2,2']-GS possessed no activity. Inhibitory effects by these analogs for the adsorption of 14C-labeled GS on cells of bacteria sensitive to GS were determined. The structure-activity relationship of GS is discussed on the basis of the results on these GS analogs.     

Localization and ultrastructure of pulmonary dendritic cells during delayed-type hypersensitivity reactions in mice

Dendritic cells (DCs) are widely distributed in the airways and can serve as potent antigen-presenting cells. To clarify their involvement in the cell-mediated immune responses of the lung, we immunohistochemically investigated their distribution and kinetics during pulmonary delayed-type hypersensitivity (DTH) reactions induced in sensitized mice by intratracheal instillation of hapten. Cellular infiltrate appeared around the bronchiole and its accompanying blood vessel at 12 h after elicitation and progressively expanded by 48 h. As quantitated by computer-assisted morphometry, I-A(+) DCs and CD4(+) Th cells significantly increased in number around the bronchiole to a maximum at 24 h, whereas F4/80(+) macrophages were predominantly accumulated around the accompanying vessel with a peak at 48 h. Serial-section analysis revealed that DCs were colocalized with Th cells in the inflamed peribronchiolar tissue. Immunoelectron microscopy demonstrated that DCs found inside and around the capillaries and venules of peribronchiolar interstitium displayed round forms, indicating their emigration from here, while those situated far from the microvessels were elongated, often in close apposition to the lymphocytes. Mitosis of DCs was rarely seen. The present results suggest that peribronchiolar accumulation of DCs resulting from accelerated influx of blood-borne immature DCs and the interaction with T cells at the application site may play inducing roles in the development of pulmonary DTH reactions by enhancing the recruitment of macrophages.     

Localization of the Trypanosoma cruzi-specific Mr 25,000 antigen by immune electron microscopy using monoclonal antibodies

Two monoclonal antibodies reacted with the Trypanosoma cruzi-specific antigen of an apparent Mr 25,000 from all developmental forms (Tachibana et al. 1986). This T. cruzi-specific antigen was found at the plasma membrane by immunoperoxidase electron microscopy using the monoclonal antibodies TCF48 and TCF87. The TCF48 and TCF87-treated cells showed stain deposits at the plasma membrane clearly distinguishable from those in cells treated with a monoclonal antibody against a surface antigen. This suggests that the epitope(s) of the Mr 25,000 antigen is located on the inner surface or in the matrix of the plasma membrane. TCF48 and TCF87 also reacted with an antigen on the microtubules of the axoneme, but not with the subpellicular microtubules. These results suggest that the T. cruzi-specific Mr 25,000 antigen is common to both the plasma membrane and axoneme but it is not located at the subpellicular microtubules. Its identity and that of the surface antigen, Gp25 (Scharfstein et al. 1983) as well as its role in the pathogenicity of the parasite are discussed.