中国恒河猴(Macaca mulatta)外周血CD4+CD25+T淋巴细胞的研究

目的:研究中国恒河猴外周血中CD4 CD25 T淋巴细胞亚群及其分布频率。方法:利用流式细胞术对50只中国恒河猴外周血CD4 CD25 T淋巴细胞进行了分析。结果:发现所有被检测的恒河猴个体中均存在明显的CD4 CD25 T淋巴细胞亚群;CD4 CD25 T淋巴细胞大约占CD4 T淋巴细胞的9.1%(变化范围为2.6%～18.1%);其中CD4 CD25highT淋巴细胞约占2.5%(0.3%～5.5%)。对不同年龄和性别个体中CD4 CD25 T淋巴细胞频率的初步分析未发现统计学上有年龄或性别差异。结论:中国恒河猴可用于与CD4 CD25 T细胞相关的人类疾病的研究中。     

Development and selection of γδ T cells

Summary:  Two main lineages of T cells develop in the thymus: those that express the αβ T-cell receptor (TCR) and those that express the γδ TCR. Whereas the development, selection, and peripheral localization of newly differentiated αβ T cells are understood in some detail, these processes are less well characterized in γδ T cells. This review describes research carried out in this laboratory and others, which addresses several key aspects of γδ T-cell development, including the decision of precursor cells to differentiate into the γδ versus αβ lineage, the ordered differentiation over the course of ontogeny of functional γδ T-cell subsets expressing distinct TCR structures, programming of ordered Vγ gene rearrangement in the thymus, including a molecular switch that ensures appropriate Vγ rearrangements at the appropriate stage of development, positive selection in the thymus of γδ T cells destined for the epidermis, and the acquisition by developing γδ T cells of cues that determine their correct localization in the periphery. This research suggests a coordination of molecularly programmed events and cellular selection, which enables specialization of the thymus for production of distinct T-cell subsets at different stages of development.     

Probiotics in infancy induce protective immune profiles that are characteristic for chronic low-grade inflammation

Background Probiotics are widely studied both in the treatment and prevention of allergic diseases, but their mode of action is poorly known. Objective Our aim was to examine the effect of probiotic bacteria on in vivo cytokine, antibody, and inflammatory responses in allergy‐prone infants. Methods In a randomized double‐blind study, probiotic bacteria or placebo were given for 1 month before delivery to mothers and for 6 months to infants with a family history of allergy. Plasma samples were analysed for C‐reactive protein (CRP), total IgA and IgE, food‐specific IgA, IgG, and IgE, IL‐2, IL‐4, IL‐6, IL‐10, TNF‐α, and IFN‐γ. We analysed the associations of immunological and inflammatory parameters at age 6 months with probiotic treatment and allergic phenotype at 2 years. Results Infants receiving probiotic bacteria had higher plasma levels of CRP (P=0.008), total IgA (P=0.016), total IgE (P=0.047), and IL‐10 (P=0.002) than infants in the placebo group. Increased plasma CRP level at age 6 months was associated with a decreased risk of eczema [odds ratio (OR) 0.41 [95% confidence interval (CI) 0.17–0.99], P=0.046], and with a decreased risk of allergic disease [OR 0.38 (95% CI 0.16–0.87), P=0.023] at age 2 years, when adjusted with probiotic use. Conclusion The association of CRP with a decreased risk of eczema at 2 years of age in allergy‐prone children supports the view that chronic, low‐grade inflammation protects from eczema. Probiotic‐induced low‐grade inflammation was characterized by elevation of IgE, IgA, and IL‐10, the changes typically observed in helminth infection‐associated induction of regulatory mechanisms. The findings emphasize the role of chronic microbial exposure as an immune modulator protecting from allergy.     

Inverted Vδ1/Vδ2 ratio within the T cell receptor (TCR)-γδ T cell population in peripheral blood of heart transplant recipients

We investigated the levels of TCR-γδ T cells and their subpopulations Vδ1 and Vδ2 in the peripheral blood lymphocytes (PBL) of 28 heart transplant (HTx) patients. Patients (n = 10) receiving cyclosporin A (CsA) for treatment of a nephrotic syndrome (NS) and 10 healthy individuals served as controls. There was no difference in levels of TCR-γδ T cells between the different groups. However, an elevated proportion of Vδ1⁺γδ T cells was found in the PBL of HTx patients, especially when these cells were present in their graft-infiltrating lymphocyte (GIL) cultures. Vδ1⁺γδ T cells of HTx patients showed normal expression of CD45RO and lacked the activation markers CD25 and HLA-DR. After expanding in IL-2-containing medium, PBL cultures of HTx patients more often were dominated by Vδ1 cells than PBL cultures of controls, in which Vδ2 cells were predominantly grown. The aberrant composition of the TCR-γδ population in HTx patients was not a result of immunosuppressive medication, since the proportion Vδ1⁺γδ T cells was normal in the PBL of the NS patients receiving a similar dose of CsA. It is postulated that long-term antigenic stimulation by the graft, at low level, might be responsible for the altered composition of the γδ pool in the HTx patients. Since no donor HLA-specific γδ T cells have been detected, other ligands, such as heat shock proteins, may be involved.     

Immunohistochemical profile of primary sclerosing Iipogranuloma of the scrotum: Report of five cases

Five cases of primary sclerosing scrotal lipogranuloma were examined histologically and immunohistochemically. Every case lacked a history of injection or trauma, and revealed Common histologicat features; a typical granuloma composed of epithelioid cells and multinucleated giant cells, and inflammatory infiltrates of eosinophils, lymphocytes and macrophageimonocytes in the interstitium. lmmunahistochemistry disclosed the epithelioid cells and multinuclaated giant cells of the granuloma to be monocytetr in nature, as bath types of cells were positive for lyso-yme, α-1-antltrypin, α-1-antichymotrypsin, and KP-1. In the interstitium, KP-1 positive monocytes, L-26 positive B lymphocytes, UCHL-1 positive T lymphocytes and 5–100 protein positive Langerhans-like cells were frequently found. 5100 protein positive cells could not be detected in the granuloma. Primary sclerosing lipogranuloma of the scrotum, therefore, is a peculiar inflammation characterized by granulomas consisting of monocytes and marked tissue eosinophilia of unknown etiology.     

Induction of lymphokine-activated killer cells with low-dose interleukin 2 and interferon-γ in oral cancer patients

Lymphokine-activated killer (LAK) cells were induced with low-dose recombinant interleukin 2 (rIL-2) and recombinant interferon- (IFN-) in 28 oral carcinoma patients. The patients received daily intravenous injections of rIL-2 (1.2×10⁵ U/m²) and rIFN- (7.0×10⁴ U/m²), and both natural killer (NK) and LAK activities were periodically examined. A significant increase in CD16⁺CD57⁺ and CD16⁺CD57^– NK subsets was observed after the induction. An increase in the T-cell population was also found, with a significant increase in CD3⁺HLA-DR⁺, CD8⁺Leu8^–, and CD4⁺Leu8^– cells. Significant increases in NK activity, from the original level of 32.0±13.7 to 49.9±15.2%, and LAK activity, from 4.8±3.5 to 11.0±6.1%, at Day 7 were observed. Both activities were maintained at high levels during the cytokine injections, but greater enhancement of the killing activities could not be obtained subsequently. When NK and LAK activities were investigated in each subpopulation of CD3^– and CD16^– cells, no remarkable cytotoxic activity could be observed before induction in any subset without NK activity in CD3^– cells (31.1±14.3%). At Day 7, NK activity of CD16^– cells increased up to 21.4±14.9%, accompanied by an increase in CD3^–-cell activity (54.5±20.6%). LAK activities of both subsets were also enhanced, with activity at Day 7 of 6.5±5.6 and 9.4±6.6% in CD16^– and CD3^– cells, respectively. These increased activities were maintained at the same level during the induction. Phorbol myristate acetate-induced polymorphonuclear leukocyte (PMNL) O ₂ ^– generation was significantly increased, from the original 81.1±28.1 to 95.6±34.9 pmol/min/10⁴ cells, after 1 week of treatment. Protein kinase C activity in the cytosol decreased, and the activity in the membrane fraction conversely increased. No remarkable adverse effects except for mild fever were observed. Together with LAK induction ability and PMNL enhancement, with scarce toxicity, a combination of low-dose rIL-2 and rIFN- is thought to be useful in cancer treatments.     

Assessment of chemical carcinogen-induced transforming activity using BALB/c-3T3 cells

Summary The BALB/c-3T3 cell transformation assay evaluates the morphologic transforming potential of test chemicals using cultured mammalian cells as targets. The assay is semiquantitative and employs a contact-inhibited clone of cells derived from the original BALB/c-3T3 mouse cell line. Transforming activity, or a focus, is recognized as a dense layer of morphologically altered cells superimposed on a monolayer of the normal cell phenotype. The induction of transforming activity in a standard assay has been reported to correlate well with the carcinogenicity of many test chemicals in rodent bioassay; however, the standard assay does not detect carcinogens of all chemical classes. This report describes an operational protocol for the standard BALB/c-3T3 cell transformation assay. In addition, it provides assay acceptance criteria and a discussion of a method to evaluate transforming activity data.     

Identification of neurons with acetylcholinesterase and NADPH-diaphorase activities in the centrifugal visual system of the chick

The isthmo-optic nuclei (ION) and ectopic neurons, which constitute the centrifugal visual system (CVS), are thought to be cholinoceptive and nitrergic. However, it is not clear which neurons express these markers, namely the ones that project to the retina rather than in neurons that only participate in a local circuit. Therefore, to characterize the neurochemical patterns of the centrifugal visual system in the post-hatched chick, retinopetal cells of the isthmo-optic nuclei and the ectopic region were identified via immunolabeling for cholera toxin, a neuronal tracer, which has been injected in the ocular globe. Then, double labeled with acetylcholinesterase histochemistry to reveal cholinergic synapses, or NADPH-diaphorase histochemistry as a nitrergic marker. Briefly, acetylcholinesterase activity was present mainly in cholera toxin labeled cell bodies of the isthmo-optic nucleus and the ectopic region indicating that retinal projecting neurons of centrifugal visual system comprise a cholinoceptive pathway. On the other hand, NADPH-diaphorase histochemistry was present in the neuropile and sparse cell bodies inside of the isthmo-optic nucleus and in ectopic neurons which were not cholera toxin positive suggesting their role in an intrinsic circuit of the centrifugal visual system. These data support the idea that these two neurochemical systems are present in distinct neuronal populations in the centrifugal visual system.     

Mast cells at the host-pathogen interface: host-protection versus immune evasion in leishmaniasis

Infection of a susceptible host with Leishmania, a protozoan parasite, causes the disease leishmaniasis, which is characterized by neutrophil, eosinophil, macrophage, lymphocyte and mast cell infiltration into the infected tissue followed by parasite growth. Although the roles played by other cells in leishmaniasis are known, the role of mast cells remains to be ascertained. Here, we demonstrate that Leishmania regulates mast cell infiltration to the site of infection, mast cell production and mast cell function resulting in differential growth of the parasite in resistant (C57BL/6 or CBA/T6T6) and susceptible (BALB/c) macrophages. An interleukin-3-dependent augmentation in mast cell committed progenitors is observed in BALB/c but not in C57BL/6 mice during Leishmania infection. The mast cell supernatants inhibit IFN-gamma-dependent restriction of Leishmania growth in macrophages in BALB/c mice whereas the reverse phenomenon occurs in C57BL/6 mice. Our data reveals a different facet of host-pathogen interaction.