痢疾杆菌免疫小鼠的GALT中T淋巴细胞亚群的应答状态

以鼠伤寒杆菌Ｇ３０株为对照，应用间接免疫荧光法检测了痢疾杆菌福氏２ａ经口服及腹腔免疫后，小鼠派伊尔氏（ＰＰ）节结、肠系膜淋巴结（ＭＬＮ）及脾脏（ＳＰｔ）中Ｌ３Ｔ４～＋、Ｌｙｔ２～＋Ｔ细胞亚群的变化；并以ＭＴＴ比色法测定了ＣｏｎＡ诱导的淋巴细胞增殖反应。实验发现：无论是口服还是腹腔途径，这两种细菌都诱导出基本相似的Ｔ淋巴细胞反应，即Ｌ３Ｔ４亚群在ＰＰ及ＭＬＮ中均有显著升高，而Ｌｙｔ２亚群均无明显变化；口服途径仅ＰＰ淋巴细胞的增殖反应有明显升高，腹腔途径主要为ＭＬＮ出现淋巴细胞显著的增殖反应。提示：在痢疾菌感染免疫中以Ｌ３Ｔ４亚群起主要作用；ＰＰ作为粘膜免疫的诱导部位；经口途径主要诱导肠道局部淋巴细胞的免疫应答，经腹腔途径虽能诱导多部位免疫应答但有否抗粘膜感染保护作用尚待研究。     

Predominant and stable T cell responses to regions of myelin basic protein can be detected in individual patients with multiple sclerosis

T lymphocytes from patients with multiple sclerosis (MS) recognize multiple myelin basic protein (MBP) epitopes. This situation complicates the design of specific immunotherapies. We investigated to which extent the T cell response to MBP is heterogeneous in single subjects in terms of preferentially recognized regions of the molecule, major histocompatibility complex (MHC) restriction, and stability over time. From each of nine patients with MS, a minimum of six MBP-specific T lymphocyte lines (TLL) were assayed for the proliferative response to a panel of overlapping peptides, encompassing the whole MBP. Predominant Tcell recognitions of distinct MBP regions were present in three patients, all HLA-DR2⁺, independently of the clinical features of their disease. Tcell reactivity was preferentially directed to residues 16-38 in one patient. In this case the response was also stable over time, during different phases of the disease. Predominant reactivity to residues 86-99 was detected in the two other DR2⁺ patients. In each of the patients with other HLA-DR haplotypes (DR2^?), as well as in three DR2⁺ non-MS donors, the Tcell response to MBP appeared to be considerably more heterogeneous. The HLA restriction element varied among TLL recognizing the same MBP region, even when raised from the same individual. The genomic HLA typing, performed on the DRB1 and DRB5 genes in the DR2⁺ subjects, showed no obvious correspondence between preferential responses to regions of MBP and HLA-DR2 subtypes. In this context, a simple, new method for the genomic typing of the HLA-DRB1 gene in individuals with the HLA-DR2 serological specificity is also described. We conclude that predominant and stable T cell responses to a single MBP region can be detected in some patients with MS. In these individuals, the MHC restriction of the T cell recognition of predominant regions appears to be variable. Polymorphisms of the HLA-DR2 gene products alone do not account for the selection of the dominant MBP Tcell epitope.     

The Regulation of FasL Expression—A Distinguishing Feature Between Monocytes and T Lymphocytes/NK Cells with Possible Implications for SLE

Monocytes and lymphocytes from patients with systemic lupus erythematosus (SLE) had a higher cell surface expression of FasL than the corresponding cells from healthy individuals. Inhibitors of metalloproteases upregulated the surface expression of FasL in peripheral blood lymphocytes (PBL), indicating that a metalloprotease is responsible for the cleavage of FasL. The level of sFasL in serum was slightly increased in the patient group compared to the controls. Therefore, the possible contribution of various mononuclear cell types to the release of FasL was analyzed. Isolated NK cells and T lymphocytes released FasL into the medium and the release was prevented by inhibitors of metalloproteases. In contrast, isolated monocytes did not release FasL. FasR expression was elevated in patients with inverted CD4/CD8 ratio, while FasL expression showed no relationship to CD4/CD8 ratio. The absence of FasL release by isolated cells and a high level of surface expression of FasL distinguish monocytes and T lymphocytes/NK cells.     

Serum immunomodulatory factors in gastrointestinal diseases. A 30-50-kD serum fraction in Crohn''s disease capable of modulating lymphocyte activation.

We tested the hypothesis that serum factors present in Crohn's disease interfere with the process of lymphocyte activation. The mitogen-induced proliferation and the expression of early activation antigens by normal lymphocytes cultured in the presence of either Crohn's disease sera or sera from different controls were evaluated. The mitogen-induced proliferation was significantly impaired in the presence of Crohn's disease sera. These sera markedly inhibited the mitogen-induced interleukin-2 receptor (IL-2R) expression (48% inhibition), while the effect of sera on the expression of the transferrin receptor and the 4F2 antigen was much less pronounced. Diafiltration experiments showed that the inhibitory effect was confined to a 30-50-kD serum fraction. Such a serum property was not related to the patients' disease activity and disappeared after surgical removal of the affected bowel. The capability of inhibiting the mitogen-induced IL-2R expression was not restricted to Crohn's disease and was observed with sera from other inflammatory and neoplastic gastrointestinal disorders. This study indicates that a marked inhibition of the IL-2R is a mechanism underlying the immunosuppressive property of the serum in Crohn's disease and in other gastrointestinal conditions.     

Cord blood contains cells secreting antibodies to nervous system components.

Umbilical cord blood of newborns and peripheral blood of healthy adults were investigated by an immunospot assay for cells secreting IgG, IgA and IgM antibodies against myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG) and myelin oligodendrocyte glycoprotein (MOG) which represent putative antigens for an autoimmune attack in multiple sclerosis (MS) and against acetylcholine receptor (AChR) which is considered an important autoantigen in myasthenia gravis. Cells secreting antibodies against one or more of these autoantigens were detected in 18 out of 24 newborns, and in eight out of 20 adults. Eight of the cord blood samples contained cells secreting antibodies of IgG, IgA and/or IgM isotypes to one antigen, five to two antigens, two to three antigens, two to four antigens, and one to five antigens. Most prominent were anti-MBP IgG antibody secreting cells which were detected in 13 newborns at a mean number of 1/20,000 cord blood cells, and in six adults at a mean number of 1/10(5) peripheral blood cells. Anti-AChR IgG antibody secreting cells were detected in four out of 12 newborns versus four out of 14 peripheral blood specimens, at mean values of 1/10(5) cells in both instances. Cells secreting autoantibodies of IgA and IgM isotypes were less frequent both in cord blood and peripheral blood. The occurrence of nervous tissue autoantibody secreting cells in newborns must be related to a possible primary role of such autoantibodies in MS and myasthenia gravis.     

Interaction between mitogenic lectins and plasma membranes of lymphocytes

Mitogenic signals from concanavalin A and phytohemagglutinin were shown to undergo summation in time under conditions when each mitogen separately, if the duration of contact with lymphocytes during the experiment was the same (14 or 20 h), did not induce mitogenesis. The results are discussed from the standpoint of cell-cell interaction between lymphocytes. It is suggested that the ability of these signals to undergo time summation lies at the basis of the nonspecific mechanism of protection against tolerance.Laboratory of Physical Chemistry of Biological Membranes, Biological Faculty, M. V. Lomonosov Moscow University. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 89–91, July, 1979.     

Changes in lymphocyte chromatin in Down's syndrome revealed by the thermal denaturation method

A luminescence-microscopic study using acridine orange with a short-term culture of human cells showed that DNA melting profiles of the chromatin of intact lymphocytes of healthy donors are curves with maxima (F 530) in the temperature regions of 45, 65, 78, 85, 88, and 92°C (P<0.01). The melting profiles of lymphocytes of patients with Down's syndrome are curves with maxima in the temperature regions of 65, 85, 88, and 92°C (P<0.01). The absence of a decrease in the intensity of fluorescence between 78 and 85°C is evidently due to the greater degree of condensation of certain regions of the chromatin complex of the trisomic cells. The possible mechanisms of the structural changes in the interphase chromatin, of human lymphocytes under the influence of temperature are discussed.Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 6, pp. 672–674, June, 1976.     

Gamma/delta T cells and the diagnosis of coeliac disease.

Gamma/delta T cells are increased in the gut epithelium of patients with coeliac disease compared with normal controls. The aim of this study was to determine whether the increase in gamma delta intraepithelial lymphocytes (IEL) is specific for coeliac disease, in which case it could be of diagnostic importance. Biopsies were obtained from children with no intestinal disease, coeliac disease, cow-milk-sensitive enteropathy/post-enteritis syndrome (CMSE PES) and miscellaneous other enteropathies (n = 67). Intraepithelial CD3+ and gamma delta T cells were identified in frozen sections using peroxidase immunohistochemistry. In normal biopsies there were 0-7 gamma delta IEL/100 cells in the epithelium. In untreated coeliac patients this increased to 9-22 gamma delta IEL/100 cells in the epithelium (P = 0.000004). Of 27 patients with morphologic intestinal damage which was not due to coeliac disease, four with CMSE/PES had gamma delta IEL/100 cells in the epithelium in the same range as the patients with coeliac disease. Of these, two had high densities of CD3+ IEL in the epithelium and were indistinguishable from patients with untreated coeliac disease. The other two could be excluded as possible coeliacs because their CD3+ IEL/100 epithelial cells were in the normal range. Thus an increase in gamma delta IEL is not specific for coeliac disease. However, enumeration of both of gamma delta IEL and CD3+ IEL densities will be useful in the exclusion of coeliac disease as a diagnosis in some children.     

Occurrence of lymphocytotoxins in multi-case rheumatoid arthritis families: relation to HLA.

The presence of lymphocytotoxic antibodies (LCA) and their association with HLA haplotypes has been studied in 27 multi-case rheumatoid arthritis (RA) families (13 multiplex and 14 simplex) in Northern India. Of the total 59 RA patients, 69.4% had cytotoxins in their sera as compared with 2.5% of healthy controls. No differences were observed in the frequency of LCA in relation to sex and rheumatoid factor. LCA against B cells were significantly more predominant than those against T cells. Twenty families studied for correlation of HLA with LCA showed greater intensity of reaction with DR4+ haplotypes, particularly in simplex families. Similarly, the frequency of LCA among patients and unaffected parents was greater in simplex compared with multiplex families. Haplotype sharing with the patient was increased in the relatives positive for cytotoxins in these families. An immunogenetic contribution made by the affected parent and a common environmental stimulus may be responsible for the increased production of LCA in multi-case families with RA.     

人sCD40L-Ig重组腺病毒载体的构建、表达及功能检测

目的:构建含有分泌型人胞外区CD40L融合蛋白(sCD40L-Ig)基因的重组腺病毒载体,确定其表达和功能学意义。方法:通过PCR获得人源IgGFc和sCD40L基因并予以连接,将其插入到腺病毒穿梭质粒pAdTrack-CMV中,构建重组质粒pAdTrack-sCD40L-Ig。将其与pAdEasy-1-BJ5183菌行同源重组后,用293细胞包装,通过观察绿色荧光蛋白(GFP)和Western blot分析等方法鉴定重组腺病毒,并进行双向混合淋巴细胞反应(MLR)以确定其功能。结果:所构建的sCD40L-Ig基因的重组腺病毒,经酶切和PCR鉴定正确。原代腺病毒的滴度达到2.69×1011pfu/L,并有相对分子质量(Mr)为61×103的目的蛋白表达。MLR显示,重组腺病毒对淋巴细胞的增殖有抑制作用。结论:成功地构建了含有sCD40L-Ig基因的重组腺病毒,并对MLR有抑制作用。