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61.
Protective cytotoxic T lymphocyte responses against paramyxoviruses induced by epitope-based DNA vaccines: involvement of IFN-gamma 总被引:1,自引:0,他引:1
Hsu SC; Obeid OE; Collins M; Iqbal M; Chargelegue D; Steward MW 《International immunology》1998,10(10):1441-1447
Plasmid DNA vectors have been constructed with minigenes encoding a single
cytotoxic T lymphocyte (CTL) epitope from either the M2 protein of
respiratory syncytial virus (RSV) or from the nucleoprotein of measles
virus (MV) with or without a signal sequence (also called secretory or
leader sequence). Following intradermal immunization, plasmids in which the
CTL epitopes were expressed in-frame with the signal sequence were more
effective at inducing peptide- and virus- specific CTL responses than
plasmids expressing CTL epitopes without the signal sequence. This
immunization resulted in protection against MV-induced encephalitis and a
significant reduction in viral load following RSV challenge. The reduction
of viral load following RSV challenge was abrogated by prior injection with
anti-IFN-gamma antibodies. These results highlight the ability of
epitope-based DNA immunization to induce protective immune responses to
well-defined epitopes and indicate the potential of this approach for the
development of vaccines against infectious diseases.
相似文献
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The CD28 antigen has been recently demonstrated to be a costimulatory molecule and is expressed by almost all thymic and peripheral T cell receptor (TcR) αδ+ and γλ+ cells in the mouse system. We show here that expression of CD28 is heterogeneous among murine intestinal intraepithelial lymphocytes (IEL). Whereas some TcR αβ-expressing IEL subsets such as CD4+8? and CD4?8α+β+ cells express CD28 at the same levels as their phenotypic counterparts in lymph node, other subsets of TcR αβ cells (including CD4?8α+β? and CD4+8αβ+β cells) as well as TcR γλ+ IEL fail to express CD28. Parallel experiments using aged BALB/c-nu/nu mice indicated that CD28 expression patterns among IEL are quite similar to those of normal BALB/c mice. Furthermore, forward light scatter analysis showed that CD28? cells are considerably larger than CD28+ cells in the gut, although cycling cells were rare in both subsets. Finally CD28? cells in the gut did not proliferate or produce IL-2 upon stimulation by anti-CD3 monoclonal antibodies (mAb) and phorbol 12-myristate 13-acetate, whereas CD28+ cells in the gut and lymph nodes responded to these stimuli. The response of the CD28+ cells was enhanced by anti-CD28 mAb. These results suggest that CD28? IEL (CD4-8α+β? cells, and some CD4+8α+β?cells) may follow a different developmental pathway from that of CD28+ IEL in a thymus-independent environment, and that expression of CD28 correlates with responsiveness of the cells to triggering via the TcR-CD3 complex. 相似文献
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Strategies for molecular characterisation of methicillin- and gentamicin-resistant Staphylococcus aureus in a Canadian nosocomial outbreak 总被引:1,自引:0,他引:1
Sixteen methicillin-resistant Staphylococcus aureus (MRSA) isolates, from a single nosocomial outbreak, were tested for molecular and phenotypic relationships. Two of the 16 outbreak strains were gentamicin resistant (Gmr) and the plasmids that they carried were characterised by reverse field electrophoresis, restriction endonuclease analysis and gene hybridisation. The gentamicin-resistant (Gmr) strains harboured two plasmids, a Gmr plasmid of 36.5 kb and a cryptic plasmid of 25.4 kb, whereas the other 14 isolates contained only the cryptic plasmid. Gentamicin resistance was encoded by a 2.5-kb HindIII fragment of the 32.8-kb plasmid and is similar to the 2.5-kb HindIII fragment also described for S. aureus Gmr plasmids from Australia and the USA. The Gmr plasmid was non-conjugal and was cured by ethidium bromide at a frequency of 4%. Two MRSA strains isolated subsequently from the same hospital were also Gmr and had identical plasmid and restriction endonuclease profiles to the two Gmr strains studied initially. Two other S. aureus isolates from the original carrier detected in this study and from his son were methicillin and gentamicin susceptible and had novel profiles. Since large plasmids show anomalous migration in agarose gels, more definitive analyses than simple plasmid identification should be considered when studying nosocomial outbreaks. 相似文献
67.
Waanders Gary A.; Lussow Alexander R.; MacDonald H. Robson 《International immunology》1993,5(1):55-61
Reactivity of murine T cells with viral or bacterial superantigensis clearly correlated with the expression of TCR Vßdomains. Thus, T cells responding to the minor lymphocyte stimulatorylocus (Mls-1a) or staphylococcal enterotoxin B (SEB) expresspredominantly TCR Vß6 or Vß8.2 respectively.We have investigated the involvement of the other major variableelement of the TCR, the V domain, in these superantigen responses.Using a panel of anti-TCR V mAbs, It is demonstrated that theTCR V repertoire among superantigen stimulated Vß6+or Vß8.2+ blasts (responding to Mls-1a or SEB respectivelyin vitro) is altered in comparison with anti-CD3 stimulatedcells expressing the same V domains. Furthermore, the TCR Vrepertoire is strongly skewed in TCR Vß8.2 transgenicmice that have undergone extensive peripheral clonal deletionafter SEB injection. These data imply that the V domain influencessuperantigen recognition by sthe TCR. 相似文献
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We present a 16-month-old boy with developmental delay, minor anomalies, small penis, and lymphedema of the upper limbs. Routine cytogenetic analysis suspected a duplication of 5q. Fluorescent in situ hybridization (FISH) with a cosmid probe (MCC at the 5q22 APC region) showed tandemly duplicated fluorescent signals on one of chromosomes 5, whereas FISH with three YAC probes (TYAC12 at 5q35, HTY3182 at 5q34, and TYAC139 at 5q31) did not give duplicated signals. These findings indicate a duplication of 5q22 band in one chromosome 5. The boy we describe here is the first case of a pure partial duplication of 5q to be proven by FISH techniques. A review of previously reported cases of putative partial 5q duplication showed no consistent phenotype. 相似文献
70.