Expression Of Cellular Immunity Research Articles

2 実験的ラット舌癌発生過程における細胞性免疫反応の発現 (第477回大阪歯科学会例会)

2 実験的ラット舌癌発生過程における細胞性免疫反応の発現 (第477回大阪歯科学会例会)

Expression of cellular immunity during experimental carcinogenesis in the rat tongue

Expression of cellular immunity during experimental carcinogenesis in the rat tongue

Evolution of lesion formation, parasitic load, immune response, and reservoir potential in C57BL/6 mice following high- and low-dose challenge with Leishmania major.

A model of cutaneous leishmaniasis using 10(2) Leishmania major metacyclic promastigotes inoculated into the footpads of genetically resistant C57BL/6 mice was studied in order to more accurately reproduce the evolution of lesion formation and the kinetics of parasite growth and immune response as they might occur in naturally exposed reservoirs and in human hosts. In contrast to the more conventional experimental model employing 10(6) metacyclic promastigotes, in which the rapid development of footpad lesions was associated with an increasing number of amastigotes in the site, the low-dose model revealed a remarkably "silent" phase of parasite growth, lasting approximately 6 weeks, during which peak parasitic loads were established in the absence of any overt pathology. Footpad swelling was observed after 6 weeks, coincident with the onset of parasite clearance and with production of high levels of interleukin-12 (IL-12) and gamma interferon (IFN-gamma) in draining lymph nodes. Low-dose challenge of IL-12- and IFN-gamma-depleted or -deficient mice provided strong evidence that the induction or expression of cellular immunity is essentially absent during the first 6 to 8 weeks of intracellular growth, since the concentration of amastigotes in the site was not enhanced compared to that for wild-type animals during this time. By monitoring the ability of infected mice to transmit parasites to vector sand flies, it was observed that following low-dose challenge, footpads without apparent lesions provided an efficient source of parasites for exposed flies and that the low-dose challenge actually extended the duration of parasite transmissibility during the course of infection.

Analysis of Mycobacterium tuberculosis-derived substance which induces interleukin-12 production from macrophages

Protection of hosts against tuberculosis depends on expression of cellular immunity. To express cellular immunity, interleukin 12 (IL-12) has been shown to play an important role. Although Mycobacterium tuberculosis is known to induce IL-12 from macrophages (M phi s), the mechanism for the induction is still unclear. To understand the mechanisms of IL-12 induction from M phi s by M. tuberculosis, the IL -12-inducing ability of substances derived from M. tuberculosis was investigated in vitro. Production of IL-12 in culture medium of M phi s was measured by ELISA system using specific antibodies. Live M. tuberculosis H37Rv induced slightly higher IL-12 production than live M. tuberculosis H37Ra upon stimulation of human or mouse alveolar macrophages (hAM phi s or mAM phi s). Heat-killed M. tuberculosis failed to induce IL-12 production of alveolar macrophages (AM phi). The responses of hAM phi s and mAM phi s to M. tuberculosis were remarkably different. mAM phi s produced five times larger amount of IL-12, compared with that from hAM phi s. Human peripheral blood mononuclear cells (PBMC) obtained by the density gradient centrifugation were also used for induction of IL-12 production. Although production levels of IL-12 from PBMC stimulated with M. tuberculosis were below the detectable level, addition of interferon-gamma (IFN-gamma) or neutralizing antibody against IL-10 augmented the production of IL-12 from PBMC, suggesting that IFN-gamma and IL-10 regulate the production of IL-12 from M phi positively and negatively, respectively. To characterize the physicochemical properties of IL-12-inducing molecules, M. tuberculosis H37Rv was disrupted by pressing with 1,000 bar and centrifuged and separated into cytosol and cell wall fraction. The culture filtrate was also examined on IL-12-inducing activity. Among the three subjects examined, cytosol was found to induce the highest production of IL-12 from mAM phi s 1 day after the stimulation. Addition of IFN-gamma to the cytosol fraction markedly increased the production of IL-12 from mAM phi s. The molecular weight of IL-12-inducing substance was shown to be more than 30kDa by fractionating with molecular filters. Treatment of 30kDa-fraction with IL-12-inducing activity by proteinase K completely abolished the activity. Furthermore, approximately 90% of IL-12-inducing activity of 30kDa-fraction was lost by proteinase K treatment even in the presence of IFN-gamma. These results indicate that the major component of IL-12-inducing activity is a protein. The identification of this IL-12-inducing active substance may provide a new therapeutic tool for tuberculosis.

Immunological Aspects of Sarcoidosis: Review

Summary1. Sarcoidosis is characterized by granuloma formation in many tissues. The origin of the granuloma formation remains unknown.2. The Kveim reaction (intradermic injection of a suspension prepared from sarcoid tissue) is a reliable aid in the diagnosis of sarcoidosis when a validated suspension is used. The reaction seems to be the expression of a specific lymphocyte response to an antigen of the suspension.3. The number of circulating lymphocytes is decreased in the active forms.4. Many parameters of T-cell function point to a decreased cellular immunity (impaired delayed hypersensitivity skin reactions, low E-rosette, impaired antigenic and mitogenic stimulation).5. Antilymphocytic factors can be demonstrated in sarcoidosis serum and are perhaps responsible for the depression of T-cell function.6. Other findings suggest a concomittant T-cell stimulation (atypical lymphocytes, increased spontaneous DNA formation and MIF production, Kveim reaction as an expression of cellular immunity).7. The level ...

B型肝炎における肝細胞壊死

B型肝炎における肝細胞壊死

Cellular immunity with special reference to monocytes of mice immunized with live vaccine of Salmonella enteritidis.

The mice which had been immunized with highly virulent live S. enteritidis acquired a strong immunity against the bacilli and could perfectly survive a challenge with intravenous injection of a highly virulent strain S. enteritidis 116-54 in a dose of 1, 000×MLD. The sera of the mice contained O and H antibodies but no demonstrable factor to prevent death due to infection. However, large mononuclear cells from liver, subcutaneous tissue and peritoneal cavity of the immunized mice exhibited an immune activity. The cells could suppress intracellular proliferation of phagocytized highly virulent bacilli and finally digested them without addition of exogenous immune sera. The activity was regarded as an expression of cellular immunity. It could be established only after contact with live bacilli. The supernatant fluid of the culture of the immunized cells or the cellular fraction which was sedimented at 100, 000g contained a transfer agent which could transfer cellular immunity. The transfer agent was inactivated by RNase but resisted DNase or trypsin treatment. An antibody reacting to live S. enteritidis 116-54 was demonstrated in the immunized cells, even after absorption with formalin treated bacilli which contained O and H antigens. This antibody, defined as the cellular antibody, could suppress the growth of S. enteritidis 116-54 in vitro in collaboration with complement and lysozyme.