Microbiology & Immunology - Research Publications
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ItemANTIGEN-SPECIFIC PRODUCTION OF IMMUNE INTERFERON BY T-CELL LINES(ROCKEFELLER UNIV PRESS, 1982)Continuous cultures of T cells reactive to the hapten 4-ethoxymethylene-2-phenyloxazolone were tested for interferon production after antigenic stimulation in vitro. Induction of interferon was antigen-specific and also restricted by the I region of the major histocompatibility complex. Kinetics of antigen induced interferon production were different from those reported for mitogen induced synthesis.
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ItemNo Preview AvailableCoronavirus-like particles in adults in Melbourne, Australia.(Wiley, 1989-12)Coronavirus-like particle(s) (CVLP) are faecal-derived pleomorphic membrane bound virus-like particles characterised by a fringe of club-shaped spikes that measure about 27 nm in length. The association of CVLP with a variety of social, clinical, and epidemiological factors was examined after a 69 month survey of faeces received for routine testing at an infectious diseases hospital. CVLP was found most commonly in three groups: first, intellectually retarded individuals who were usually inmates of institutions; second, recent overseas travellers who were either Indochinese refugees/immigrants or were overseas travellers who had usually visited developing communities for lengthy periods; and, third, male homosexuals who had a history of multiple sexual contacts and/or venereal disease. It was concluded that the excretion of CVLP had a strong association with unhygienic living or working conditions irrespective of any clinical symptoms the individual might show.
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ItemNo Preview AvailableVIRUSES AND VIRUS-LIKE PARTICLES IN THE FECES OF DOGS WITH AND WITHOUT DIARRHEA(AUSTRALIAN VETERINARY ASSN, 1984)Negative staining electron microscopy was used to identify viruses in 157 normal and 29 diarrhoeal faecal samples collected from 156 dogs admitted to an animal shelter during an 8 month period (March to October) in 1982. Seven distinct viral types were detected: 21-26 nm parvovirus-like particles, 28-31 nm astrovirus-like particles, a previously undescribed 34-35 nm "round" virus particle, coronavirus, coronavirus-like particles ( CVLP ), rotavirus and papova-like virus. Parvovirus-like particles alone were detected in 14 diarrhoeal and 50 normal faeces, astrovirus-like particles in 3 normal faeces, "round" viruses in 4 normal faeces, coronavirus in 2 diarrhoeal and 5 normal faeces, CVLP in one diarrhoeal and one normal faeces, rotavirus in 2 normal faeces, papova-like virus in one normal faeces, both parvovirus-like particles and coronavirus in 2 diarrhoeal and 2 normal faeces, parvovirus-like particles and rotavirus in one normal faeces and parvovirus-like and papova-like virus in one normal faeces. The significance of these findings in canine and human disease is discussed.
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ItemNo Preview AvailableVIRUS AND VIRUS-LIKE PARTICLES IN THE FECES OF CATS WITH AND WITHOUT DIARRHEA(WILEY, 1987-04)Negative staining electron microscopy was used to identify viruses in 166 normal and 62 diarrhoeal faecal samples from 208 cats admitted to an animal shelter during a 16-month period (March 1984 to June 1985). On the basis of size and shape 7 distinct viral types were detected: 24 nm parvovirus-like particles, 30 nm astrovirus, 30 nm picornavirus-like particles, reovirus, rotavirus, coronavirus and a 75 nm "togavirus-like" particle. The incidence of these particles in the 208 cats was 11%, 7%, 6%, 0.4%, 5%, 1% and 1% respectively. Virus isolation studies using 40 of the faecal samples succeeded in isolating reovirus 1 in 2 cases. Immune electron microscope studies demonstrated the presence of antibody in a human serum to cat astrovirus, but failed to clarify the identity of the parvovirus-like particles and picornavirus-like particles, other than showing that some of the parvovirus-like particles were not related to feline panleukopenia virus. It was found that parvovirus-like particles, astrovirus, picornavirus-like particles, reovirus and rotavirus could be excreted by cats with normal faeces as well as cats with diarrhoeal faeces. Parvovirus-like particles, astrovirus, picornavirus-like particles and rotavirus could be excreted in high concentration in normal faeces. There was no simple relationship between age and diarrhoea in the population of cats studied. Age was not a critical factor in the excretion of parvovirus-like particles, astrovirus, picornavirus-like particles and rotavirus. The incidence of diarrhoea was not clearly associated with the seasons.
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ItemPRECURSOR FREQUENCY-ANALYSIS OF LYMPHOKINE-SECRETING ALLOREACTIVE LYMPHOCYTES-T - DISSOCIATION OF SUBSETS PRODUCING INTERLEUKIN-2, MACROPHAGE-ACTIVATING FACTOR, AND GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR ON THE BASIS OF LYT-2 PHENOTYPE(ROCKEFELLER UNIV PRESS, 1982)The frequencies of precursors of C57BL/6 T lymphocytes that respond to DBA/2 alloantigens by secreting the lymphokines interleukin 2 (IL-2), macrophage-activating factor (MAF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been directly compared with cytolytic T lymphocyte precursor (CTL-P) frequencies in limiting dilution microcultures established from spleen cells positively or negatively selected on the basis of Lyt-2 phenotype. A clear dichotomy was observed between CTL-P, which were contained in the Lyt-2+ fraction, and precursors of IL-2-secreting cells, which were detected almost exclusively in the Lyt-2- population. In contrast, precursors of cells secreting MAF and GM-CSF were found in both populations: almost all responding cells from the Lyt-2- fraction produced both these factors, whereas the precursor frequency of MAF-secreting and GM-CSF-secreting cells was three- to fourfold lower in the Lyt-2+ population. These frequency data were consistent with quantitative differences observed in the average production of these lymphokines by Lyt-2+ and Lyt-2- populations.
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ItemINHIBITION OF AUTOIMMUNE NEUROPATHOLOGICAL PROCESS BY TREATMENT WITH AN IRON-CHELATING AGENT(ROCKEFELLER UNIV PRESS, 1984)Lewis rats that are primed with guinea pig spinal cord homogenized in complete Freund's adjuvant (GPSCH-CFA) develop overt symptoms of experimental allergic encephalomyelitis (EAE). Treatment with the iron-chelating agent, desferrioxamine B mesylate (DFOM), at various times before the onset of EAE, dramatically suppressed both the severity and duration of disease. When DFOM was administered to rats soon after the development of neurological signs, a rapid recovery occurred, though mild, transient symptoms could be seen approximately 1 wk after withdrawal of the drug. Treatment with DFOM was always accompanied by a diminution of T cell responsiveness on the part of the delayed-type hypersensitivity/helper subset and, on histological examination, an absence of inflammatory cells from lesions. Iron is believed to influence both the migration and function of immune effector cells. It can also act as a catalyst in the formation of free radicals, which are highly toxic agents causing tissue damage in sites of inflammation. The mechanisms underlying the effect of DFOM on the severity of EAE, and the possible implications for treatment of multiple sclerosis are discussed.
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ItemSPECIES-RESTRICTED INTERACTIONS BETWEEN CD8 AND THE ALPHA-3 DOMAIN OF CLASS-I INFLUENCE THE MAGNITUDE OF THE XENOGENEIC RESPONSE(ROCKEFELLER UNIV PRESS, 1989-10-01)As compared with the vigorous T cell response normally observed against allogeneic MHC molecules, T cells recognize xenogeneic MHC molecules poorly. To define structural features of the MHC molecule important for such species-specific recognition, HLA-A2(A2)-specific murine CTL were examined for their recognition of transfected cell lines expressing the class I molecules A2 or A2/H-2Kb(A2/Kb). A2/Kb is a chimeric molecule consisting of the alpha 1 and alpha 2 domains of A2 and the alpha 3, transmembrane, and cytoplasmic regions of Kb. The majority of CTL clones showed enhanced recognition of transfected cell lines expressing this chimeric molecule. Enhanced recognition was shown to correlate with sensitivity of the CTL clones to inhibition by anti-CD8 antibody. These results suggested that CD8 may interact with class I in a species-specific manner, and that suboptimal CD8 interaction with the alpha 3 domain of xenogeneic molecules may be an important contribution to poor xenoreactivity. This conclusion was supported by the capacity of A2/Kb, but not A2 human cell transfectants, to induce a primary in vitro CTL xenoresponse specific for A2.
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ItemT-CELLS THAT ENCOUNTER VIRUS IN THE COMPLETE ABSENCE OF A PARTICULAR H-2-ANTIGEN ARE NONRESPONSIVE WHEN STIMULATED AGAIN IN THE CONTEXT OF THAT H-2-ANTIGEN(ROCKEFELLER UNIV PRESS, 1980)Immunologically naive BALB/c (H-2d) and C57BL/6J (B6) (H-2b) T-cell populations can, after filtration to remove alloreactive precursor lymphocytes, be induced to respond to vaccinia virus presented in the context of H-2Kk when stimulated in an appropriate recipient. Exposure to vaccinia virus 6 wk previously completely abrogated the capacity of BALB/c T cells to interact with H-2Kk-vaccinia virus. This is also true for negatively selected B6 thoracic duct lymphocytes taken at 14 or 18 d, but not at 6 wk after immunization: the discrepancy is thought to reflect the progressive emergence of new T cells in the latter group. No evidence could be found for the operation of suppression, and the results are considered to indicate that T cells that interact with virus in the absence of the relevant H-2 antigen are tolerized. Whereas stimulation to effector function is H-2 restricted, induction of immune paralysis may be unrestricted. The capacity of T-cell populations to respond to virus presented in the context of allogeneic H-2 determinants thus depends upon previous antigenic experience.
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ItemPHENOTYPIC ANALYSIS OF THE INFLAMMATORY EXUDATE IN MURINE LYMPHOCYTIC CHORIOMENINGITIS(ROCKEFELLER UNIV PRESS, 1987-06-01)The massive inflammation of the cerebrospinal fluid (CSF) which occurs in adult mice injected with lymphocytic choriomeningitis virus (LCMV) has been analyzed by flow microfluorometry (FMF). The great majority of the T cells detected by direct examination of freshly obtained CSF were found to be Lyt-2+, with an almost total absence of L3T4+ lymphocytes. The Lyt-2/L3T4 ratio of lymphocytes in blood was within normal limits. Predominance of the Lyt-2+ subset was confirmed by culturing the CSF cells after mitogenic stimulation. In addition, the T lymphocytes in CSF of cyclophosphamide-suppressed, virus-infected recipients that had been injected 4 d previously with LCMV-immune spleen cells were almost entirely donor Lyt-2+ cells, while the nonlymphoid elements were exclusively of host origin. However this pattern of donor and host T cell distribution was reversed when the LCMV-infected recipients were not immunosuppressed. The frequency of LCMV-specific CTL precursors in CSF taken immediately before the development of symptoms was as low as 1:3,000 cells. Thus most of the T lymphocytes extravasating into the CSF of mice with LCM are passive participants recruited as a consequence of the function of relatively few LCMV-specific effector T cells. The dominance of the Lyt-2+ T cell subset in the CSF of mice with LCM is intriguing.