重组跨膜型人CD55分子在小鼠NIH3T3细胞上的表达及其补体溶破保护功能的研究

目的 :在小鼠NIH3T3细胞转染表达人天然GPI锚固型CD5 5和重组跨膜型CD5 5 TM分子 ,观察比较它们对人补体溶破异源细胞的抑制功能。方法 :将带有CD5 5cDNA、CD5 5 TMcDNA的重组逆病毒表达质粒CD5 5 pLXSN、CD5 5TM pLXSN经脂质体法转染PA317细胞 ,用病毒上清感染小鼠成纤维母细胞NIH3T3。经G418加压筛选 ,利用FACS检测获得表达CD5 5和CD5 5 TM分子的阳性细胞克隆 ,通过MTT比色法比较两种分子对人血清补体溶破细胞的抑制功能有无差别。结果 :细胞转染筛选获得多个表达跨膜型人CD5 5分子的NIH3T3细胞克隆 ,补体杀伤试验证实其具有抑制人补体溶破的功能 ,且两种分子的补体抑制功能无明显差异。结论 :成功地建立了稳定表达天然CD5 5、跨膜型CD5 5分子的小鼠NIH3T3细胞 ,证实其表达的GPI型CD5 5分子和CD5 5TM分子均具有抑制人补体溶破细胞的功能 ,为进一步探讨应用跨膜型的CD5 5分子对PNH进行基因治疗奠定了基础。     

Effect of “Re Du Qing” on the activation,proliferation and membrane fluidity of lymphocytes

Summary Effects of Chinese Medicinal Preparation “Re Du Qing” (RDQ) on the activation, proliferation and membrane fluidity of T lymphocytes from human peripheral blood Were studied by means of³H-TdR incorporation and DPH fluorescence polarization. The results showed that “RDQ” can:1) significantly inhibit the activation of T lymphocytes; 2) restrain the proliferation of activated T lymphoblasts in the presence of exogenous interleukin-2 (IL-2); and 3) increase the membrane fluidity of T lymphocytes and antagonize the decreased fluidity of lymphocyte membrane mediated by Con A or PHA. The functional abnormalities of T lymphocytes in some autoimmune diseases such as arthritis and the usefulness of RDQ in the treatment of these diseases were also discussed.     

T Cell Receptor Vβ Repertoires of Angioimmunoblastic Lymphadenopathy-like T Cell Lymphoma

To elucidate the pathogenesis of angioimmunoblastic lymphadenopathy-like T cell lymphoma (AILD-T) we investigated the T cell receptor Vβ gene repertoires of four AILD-Ts and compared them with those of other histological types of lymphomas and three cases with reactive disorders. All lymphoma patients had rearrangement bands detected by Southern blot analysis. Only 1 of the 4 cases of AILD-T showed a single predominant usage of Vβ 20 gene by PCR with 20 different Vβ specific primers and the others had repertoires somewhat restricted but similar to reactive lesions. Subsequent sequencing of this PCR product revealed that only 2 of 7 clones were identical. These results suggest the monoclonal malignant cells in AILD-T are scant and that the infiltrating T cells show a reactive pattern. In the only AILD-T case with a single dominant Vβ usage, the relationships of this repertoire and lymphoma cells seems to be of some consequence.     

Modulation of human T cell functions by surface sulphydryl groups: differential effects on IL-2 production and responsiveness.

An impermeable thiol blocker has been used to investigate the role of sulphydryl (SH) groups in the production of and responsiveness to IL-2 by normal human T lymphocytes. Surface SH blockade of mononuclear cells prior to incubation with mitogen (phytohaemagglutinin, concanavalin A, CD3 MoAb) had no effect on production of IL-2 but markedly impaired cellular responsiveness to exogenous IL-2. Studies using MoAbs indicated that this effect was accompanied by decreased expression of both the CD25 and p75 subunits of the IL-2 receptor. Blocking surface SH groups did not affect binding of IL-2 to p75 on unstimulated mononuclear cells, but inhibited binding to high-affinity receptors on a T lymphoma cell line. The data are consistent with the hypothesis that sulphydryl groups on the IL-2 receptor are required for its function and may be involved in the interaction of the CD25 and p75 subunits leading to generation of the high-affinity binding site. The surface thiol identified on the IL-2 receptor may be a candidate for oxidation on cells from patients with chronic inflammatory diseases such as rheumatoid arthritis and thus contribute to the aberrant function of T cells in these patients.     

Potential value of localized skin reactions (chancres) induced by Trypanosoma congolense transmitted by Glossina morsitans centralis for the analysis of metacyclic trypanosome populations

Goats infected with Trypanosoma congolense transmitted by Glossina morsitans centralis and then treated with the trypanocidal drug diminazene aceturate are immune to tsetse-transmitted infection with a homologous, but not heterologous trypanosome clone. Immune animals fail to develop localized skin reactions (chancres) and do not become infected, whereas on heterologous challenge chancres appear followed by parasitaemia. In this study, the feasibility of using chancre reactions to characterize several different metacyclic populations of T. congolense was evaluated. Provided goats were immunized, it was found that the chancre reaction could be used to distinguish different populations of T. congolense. However, problems were encountered when attempts were made to induce immunity against more than one trypanosome population. When goats were infected by tsetse flies with four antigenically unrelated metacyclic populations of T. congolense, either simultaneously or at 4 day intervals, adequate immunological priming was not always achieved. In fact, goats exposed to superinfection 8 to 12 days after a primary infection did not develop chancres or an immune response to the second infection (although they were immune to the organism used for primary infection). Following trypanocidal treatment these animals were subsequently completely susceptible to homologous infection with the metacyclic population used for superinfection, indicating that some form of interference phenomenon effective at the level of the skin appears to prevent or delay the development of the second trypanosome population following superinfection of infected animals.     

Phenytoin desensitization monitored by antigen specific T cell response using carboxyfluorescein succinimidyl ester dilution assay

We evaluated drug-specific T cell responses in a patient with refractory partial seizures and paroxysmal kinesigenic choreoathetosis successfully treated with clinical desensitization to phenytoin. Drug-induced lymphocyte transformation test before desensitization was negative with a stimulation index of 130%. The frequencies and cytokine-producing phenotypes of phenytoin-specific T cells were examined simultaneously by using a carboxyfluorescein succinimidyl ester (CFSE) dilution assay. Before desensitization, the proportion of CFSElow CD4+ cells in whole CD4+ was 3.09%; 13.6% of CFSElow CD4+ cells were stained with anti-interferon gamma antibody. After desensitization, phenytoin-specific CFSElow CD4+ cells decreased to background level. These results indicate that CFSE dilution assay will be useful for the diagnosis and monitoring of drug hypersensitivity.     

Suppressor-cell dysfunction in children with histiocytosis-X

Suppressor-cell activity of peripheral blood mononuclear cells were examined and lymphocyte subsets analyzed in children with histocytosis-X and in healthy, age-matched subjects. Suppressor-cell function was assessed by two methods, the indomethacin stimulation of mitogen-activated cultures and the concanavalin A-inducible suppressor-cell assay. The results of these two assays indicate that children with active disease have significantly decreased suppressor-cell activity. Additionally, the percentage and absolute number of OKT8⁺ lymphocytes were decreased in children with active disease. Suppressor-cell activity and lymphocyte subsets returned to normal, baseline levels with disease remission. This study documents for the first time suppressor-cell dysfunction and supports previous investigations in which suppressor T lymphocytes are deficient in children with active disease. These findings may explain certain clinical manifestations seen in children with histiocytosis-X.     

IgE and atopy in perinatally HIV-infected children

Elevated serum immunoglobulin E (IgE) and increased prevalence of atopy is reported in patients infected with human immunodeficiency virus (HIV). The elevated serum IgE may be attributed to polyclonal stimulation of B cells or IgE production against allergens, viruses, fungi and bacteria. This study investigates the prevalence of atopy in perinatally HIV-infected children, and the relationships between serum IgE (and other serum immunoglobulins) with atopy, CD4+ cell count and HIV-disease stage. Serum immunoglobulin levels, epicutaneous skin test for common aeroallergens, clinical Centers for Disease Control and Prevention (CDC) classification, CD4+ cell counts and allergy history were extracted from the charts of perinatally HIV-infected children on highly active antiretroviral therapy. The prevalence of atopy (52%) and the pattern of aeroallergen sensitivity were comparable with the US pediatric population. Serum IgE levels did not correlate with clinical disease stage. However, in non-atopic patients, serum IgE levels increased with disease progression (p = 0.02). There was an inverse relationship between the prevalence of elevated serum IgE levels and atopy with progression of disease (p = 0.019). Serum IgE did not correlate with atopy, CD4+ cell count, or duration of HIV infection or levels of serum immunoglobulins. This is the first study to show no increased prevalence of atopy in perinatally HIV-infected children compared with the general population. In advanced stages of HIV, elevated serum IgE may be specific for antigens other than those known as allergens.     

Enhancing and suppressive effects of tumour necrosis factor/cachectin on growth of Trypanosoma musculi

The effect of human recombinant TNF on the growth of T. musculi has been investigated. When added to parasites cultured in vitro, TNF inhibited their growth. In the presence of thioglycollate-elicited peritoneal exudate cells, the opposite effect was seen and TNF enhanced the growth of trypanosomes in vitro. Similarly, administration of TNF in vivo during the course of infection led to a net increase in the parasite population. It is suggested that TNF exerts a direct antitrypanosomal effect while simultaneously promoting the growth of the parasite through an indirect effect mediated via the host's cells, possibly the macrophages.     

内皮素与P-选择素在冠心病中的意义

目的：研究内皮素（ET－1）、P－选择素、肌钙蛋白I（CTn1)在急性心肌梗死（AMI）和不稳定性心绞痛（UA）中的意义，方法：用放射免疫法测ET－1，流式细胞术测定P－选择素，Access化学发光测CTn1，共检测23例AMI患、21例UA患及28例健康对照。结果：AMI组的ET－1、P－选择素、CTn1值均显高于对照组（P＜0．05－0．005）；UA组的ET－1、P－选择素显高于对照组（P＜0．05）；UA组的CTn1与对照组差异无显性（P＞0．05）；UA组的P－选择素、CTn1显低于AMI组（P＜0．05）。多元回归分析发现P－选择与CTn1相关，相关系数r=0.404，P＜0．01。结论：ET－1、P－选择素是检测血栓前状态的敏感指标。