A monoclonal antibody was produced to a Campylobacter-like organism (RMIT 32A) which was isolated from the terminal ileum of a pig with proliferative enteritis. Isotyping of the antibody revealed that it was an IgG_2a with kappa light chains. Immunoblots using the antibody against proteinase-K-treated whole cell lysates of RMIT 32A, a selection of Campylobacter species and other enteric bacteria showed that the antibody was specific for RMIT 32A and was directed against the lipopolysaccharide. This antibody can be used for the specific detection of RMIT 32A.

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Pili were detected using electron microscopy in clinical isolates of Shigella flexneri which had been continuously subcultivated in liquid media. Morphologically, the pili appeared as thin, flexible, cylindrical structures of up to 2-5μm in length and about 3-5nm in diameter. Two strains showed mannose-resistant (MR) hemagglutination to fresh fowl erythrocytes (type 4), and one to tannic acid-treated horse erythrocyte (type 3) pili. These pili are novel and different from the mannose-sensitive (MS) type 1 pili described by Duguid and Gillies.

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The serum antibody titers against oral streptococci were studied by enzyme-linked immunosorbent assay (ELISA) both in patients with Behçet's disease (BD) and control groups. The patients with BD showed significantly higher antibody titers to S. sanguis strains 113-20, 114-23, and 118-1 which were isolated from patients with BD, in comparison with control groups. Also, the reactions of high-titered sera to the crude cell wall and soluble (or membrane) fractions of the 113-20 strain were observed by western blot test. The sera of the patients with BD demonstrated strong bands of approximately 36kDa, 82kDa, and 87kDa in the crude cell wall fractions, and many bands of 80kDa to 150kDa in the membrane fractions, indicating that these proteins are the ones leading the high antibody titers to this bacterium in the sera of patients with BD.

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A simple method for the overproduction in Escherichia coli and purification of major core protein p24 of human immunodeficiency virus type 1 (HIV-1) was described. The gag-pol region encoding p24, p15, and protease was fused to 3' end of lacZ gene on plasmid. A LacZ-Gag fusion protein, the major primary product, is designed to be cleaved by the HIV-1 protease coexpressed through frameshifting. In fact, p24 and its immediate precursor, p25, were produced in the cells grown at 25C, but not at 37C. When the gag and pol frames were fused in-frame to express the protease without frameshifting, the main product, a LacZ-Gag-Pol fusion protein, was efficiently processed to give p24 exclusively both at 37C and 25C, suggesting more efficient expression of the protease. Recombinant p24 was purified to near homogeneity by a simple three-step procedure. The amino-terminal sequence of the recombinant p24 was the same as that of p24 deduced from nucleotide sequence, indicating that correct processing occurred in E. coli by the coexpressed protease. The method described here provides a means to obtain a large amount of highly pure p24, which is useful for crystallographic and functional studies, preparation of specific antibody, and diagnostic and prognostic uses.

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As the majority of human immunodeficiency virus (HIV) carriers are in asymptomatic stage for a long period of time, it is important to investigate the factors or surrogate markers for conversion from asymptomatic to symptomatic stage. Our study is designed to evaluate the relationship among virus isolation rate, anti-p17 antibody status and progression to AIDS. We studied anti-p17 antibody status along with virus isolation in 56 asymptomatic carriers and 46 AIDS cases. Progression to AIDS was markedly associated with high rate of virus isolation and loss of anti-p17 antibody. In order to know the meaning of loss of anti-p17 antibody during the clinical course, 15 anti-p17 antibody positive and 16 anti-p17 antibody negative cases were followed up prospectively for the development of AIDS. None of the anti-p17 antibody positive cases developed AIDS while 6 out of 16 anti-p17 negative cases developed AIDS during observation period (P<0.05). Progression to AIDS was associated with loss of anti-p17 antibody. Identification of cases losing anti-p17 antibody in peripheral blood during asymptomatic period may help high-risk group who are in need of chemoprophylaxis. Moreover, study of anti-p17 antibody may be helpful in designing vaccine in future if it works as a neutralizing antibody to HIV in vivo.

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Some SLID mice survived primary infection with herpes simplex virus 1 without the development of peripheral lesions but established coculture-positive ganglionic latency when a low dose of a wild-type strain was inoculated intracutaneously. The latency was also evidenced by the development of the fatal zosteriform skin lesions and the isolation of the virus during pregnancy. We consider that the viral entry into neurons without successive replication, rather than the arrest of the lyric infection within the cells, is an important mechanism in the establishment of latency.

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We recently reported that a unique B cell clone (B19-1^d), specific for a cross-reactive idiotype (CRI) on MOPC104E myeloma protein (M104E), enhances Igh-restricted CRI⁺ antibody production. In this paper, we report the nucleotide sequences of immunoglobulin heavy chain variable regions (V_H) of both M104E and B19-1^d-derived hybridoma (HB19) antibodies. The sequence data revealed that both belong to the J558 germ line V_H gene subfamily. Strikingly, not only the V_H region, but also the leader sequences of M104E and HB19 are very similar to each other at 88% (V_H) and 91% (leader) homology, but they use different D and J segments. The V_H region sequence similarity is highest among the germ line V_H gene sequences of the BALB/c J558 subfamily so far screened. Southern hybridization data, using 5'-noncoding regions of either M104E or HB19 genomic V_H gene clones as probes, revealed that both V_H genes are conserved in the M104E CRI producer strains of mice. Moreover, these probes show the restriction length polymorphism pattern of mouse V_H genes in various strains. That the HB19 V_H gene locates to the 5' upper arm of the M104E V_H gene on the chromosome was suggested by Southern blot hybridization. Immunoglobulin V_H gene restriction of idiotypic and antiidiotypic B-B cellular interaction is discussed from a molecular point of view.

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Peripheral blood lymphocytes obtained from HTLV-II-infected persons (n=13) and cultured in the absence of exogenous stimulator demonstrated augmented spontaneous proliferation (17, 672±5, 498cpm) when compared with cells from healthy donors (1, 921±1, 306cpm). Removal of non-T population did not abrogate the proliferative response of patients' PBMC, suggesting that the proliferation is not related to the autologous mixed lymphocyte reaction. Addition of recombinant inter-leukin-2 (rIL-2; 0.1U/ml) to spontaneously proliferating cultures from HTLV-II-infected persons resulted in a 3-to 4-fold increase in proliferation (61, 985±16, 003); in contrast, PBMC from controls demonstrated 38- to 42-fold increase in their proliferative capacity in response to rIL-2 (77, 256±13, 044). Antibodies to both IL-2 receptor and HLA-DR were able to inhibit the spontaneous proliferation of PBMC from HTLV-II-infected persons in a dose-dependent manner. Furthermore, addition of cyclosporin A, which preferentially blocks accumulation of IL-2 mRNA, also inhibited spontaneous proliferation in a dose-dependent manner. These observations suggest that the spontaneous proliferation of HTLV-II-infected PBMC is at least in part an HLA-DR-driven, IL-2-dependent event, which is not analogous to the AMLR.

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This paper describes the finding of monoclonal antibody (MoAb) more reactive to cell-surface α-fetoprotein (AFP) than to free AFP by using a simple in vitro system. Twelve mouse MoAbs, ten IgG₁, one IgG_2a. and one IgG_2b, against human AFP from hepatocellular carcinoma were obtained by the cell fusion technique. Each hybridoma supernatant was assayed by enzyme-linked immunosorbent assay (ELISA) to solid-phase AFP. The assay results showed that two MoAbs, 67D and 80G, were most reactive to AFP. 80G had a higher affinity constant than 67D, while the both reactions were similarly difficult to inhibit by free AFP in ELISA. 67D and 80G reacted with AFP on the surface of ethanol-fixed cells from the human hepatoma cell line HuH-7 and this reaction was also difficult to inhibit by free AFP in Cell ELISA. Furthermore, Western blot analysis showed that 67D and 80G were more reactive to membrane-bound AFP than other antibodies. These findings first suggest that there could be anti-AFP MoAbs preferably binding to cell-surface AFP rather than to serum AFP.

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We examined the effects of gamma-interferon (γ-IFN) and the new immunosuppressant FK506 on resting B cell proliferation of New Zealand black/white F₁ hybrid (B/W F₁) mice, an animal model of human systemic lupus erythematosus (SLE). γ-IFN and FK506 inhibited in a dose-dependent manner both B cell proliferation and autoantibody production of resting B cells respectively. There was a synergistic interaction between γ-IFN and FK506 in their inhibition and they did not exhibit cell cytotoxicity. This in vitro synergism of γ-IFN and FK506 may have clinical application in that low doses of γ-IFN and FK506 combinations may be effective to correct polyclonal B cell activation of patients with SLE.

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Virulence of R. equi ATCC 33701 was compared by the intraperitoneal (i.p.) and intravenous (i.v.) routes in mice. Strain ATCC 33701 was more virulent by the i.v. than the i.p. route. The LD₅₀ of strain ATCC 33701 by either route correlated with the initial number of bacteria in the liver and spleen at day 0.

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Sera from 420 military personnel serving in Sabah and Sarawk, Malaysia, were tested for antibodies to Pseudomonas pseudomallei exotoxin and whole cell antigens by enzyme-linked immunosorbent assay procedure (ELISA). Data showed that 54.4% of serum samples were positive for antibodies to P. pseudomallei exotoxin and 65.7% were positive for antibodies to the whole cell antigens. Samples gave much lower titers for anti-exotoxin antibodies compared to titers against crude whole cell antigens. The incidence of antibody to exotoxin was highest in the age groups ranging from 26 to 32 years, where the positive rates were higher than 40% and 30% for military personnel serving in Sarawak and Sabah, respectively.

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The existence of molecular transactivations between EBV and HIV-1, as well as reactivations of EBV latent infections in AIDS patients, have been recently documented. In order to shed more light on the putative association between EBV and HIV, and its role in the evolution to AIDS, we have determined simultaneously p24 protein and EBV DNA in culture supernatants of peripheral blood mononuclear cells from 47 individuals suspected of having HIV infection. The results of the in vitro assays were correlated with the clinical stage of the individuals and their serologic status to EBV. Statistical analysis showed a concordance between HIV infection and in vitro detection of EBV DNA (P<0.002); particularly, a strong correlation between the presence of EBV DNA and p24 in culture was observed (P<0.001). These results are consistent with the occurrence of viral interactions, manifested in vitro. However, in our series, the appearance of EBV DNA in culture was not concomitant with an elevation of anti-VCA IgG titers, anti-EA titers or the development of symptomatology, suggestive of a reactivation of a latent EBV infection or a progression of HIV infection, Therefore we conclude that, although interaction between both viruses may take place at the molecular level, there is no clear evidence of the repercussion that this event may have on the clinical course of HIV infection.

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