CDw108 expression during T-cell development

We recently reported a gene encoding the human CDw108, a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein that is preferentially expressed on activated T lymphocytes and erythrocytes. The present study investigated the expression of CDw108 on various tissues and cells, particularly on T cells during development. The murine CDw108 cDNA was cloned initially, and it was highly homologous to the human CDw108 (88.0% or 89.3% similarity at the nucleotide or amino acid level, respectively) or identical to the murine semaphorin K1/Sema7A. The CDw108 mRNA was demonstrated in a few tissues including thymus and brain with the highest expression coming on day 7 in whole embryo followed by relatively consistent expression during development. Cell-surface expression of the CDw108 during T-cell development was further examined by flow cytometry in the human umbilical cord blood and thymus. It was preferentially expressed on a CD34+ stem cell population of umbilical cord blood, and CD3dull CD34+/- CD117 (c-kit)+ CD4bright CDbright cells in the thymus that are involved in the stage of positive selection. These results suggest the contribution of CDw108 in T-cell development, especially in the stage of positive selection in the thymus.     

Convergence of skin reflex and corticospinal effects in segmental and propriospinal pathways to forelimb motoneurones in the cat

The organization of facilitatory convergence from cutaneous afferents (Skin) and the corticospinal tract (pyramidal tract, Pyr) in pathways to forelimb motoneurones of mainly distal muscles was studied in anaesthetized cats by analysing postsynaptic potentials (PSPs), which were spatially facilitated by combinations of stimuli to the two sources at different time intervals. Conditioning Pyr volleys facilitated Skin-evoked PSPs of fixed (1.2–3.6 ms) central latencies (Skin PSPs), suggesting that disynaptic and polysynaptic skin reflex pathways are facilitated from the pyramidal tract. The shortest latencies (1.2–1.7 ms) of pyramidal facilitation suggested direct connection of pyramidal fibres with last order neurones of skin reflex pathways. Conditioning Skin volleys facilitated Pyr-evoked PSPs of fixed, mostly disynaptic latencies (1.0–2.5 ms; Pyr PSPs), suggesting that pyramido-motoneuronal pathways are facilitated from Skin at a premotoneuronal level. The shortest pathway from skin afferents to the premotor neurones appeared to be monosynaptic. Although Pyr and Skin volleys were mutually facilitating, the facilitation curve of Pyr PSPs and that of Skin PSPs were discontinuous to each other, with the peak facilitation at different Skin-Pyr volley intervals. Transection of the dorsal column (DC) at the C5/C6 border had little effect on the latencies or amplitudes evoked by maximal stimulation and the pyramidal facilitation of Skin PSPs. In contrast, the facilitation of Pyr PSPs by Skin stimulation was greatly decreased after the DC transection, and the facilitation curve of Pyr PSPs was continuous to that of Skin PSPs, with no separate peak. Latencies of Pyr PSPs ranged similarly to those in DC intact preparations. More rostral DC transection (C4/C5 border) reduced Skin-facilitated Pyr excitatory PSPs (EPSPs) less than C5/C6 lesions, suggesting that the C5 segment also contains neurones mediating Skin-facilitated Pyr EPSPs. The results show that convergence from skin afferents and the corticospinal tract occurs at premotor pathways of different cervical segments. We suggest that corticospinal facilitation of skin reflex occurs mostly in the brachial segments and Skin facilitation of cortico-motoneuronal effects takes place largely in the rostral cervical segments and partly in the brachial segments.     

Primary non-Hodgkin's lymphoma of the intestine: a morphological, immunohistochemical and clinical study of 31 Chinese cases

Thirty-one cases of primary non-Hodgkin's lymphoma of the intestine were investigated. Twenty-one were of B-cell and 10 of T-cell origin. The B-cell lymphomas comprised two cases of low-grade B-cell lymphoma of mucosaassociated lymphoid tissue (MALT), one of centroblastic/centrocytic type, three of high-grade B-cell lymphoma coexisting with a low-grade B-cell lymphoma of MALT, nine of centroblastic, three of immunoblastic and three of Burkitt type. Of the T-cell lymphomas, eight were of pleomorphic medium-to large-sized cell type and two of large cell anaplastic type. All the B-cell lymphomas expressed CD20 (L26) and/or Ki-B5; in six there was monotypic immunoglobulin light chain restriction. Membrane positivity for CD45RO (UCHL1) was observed in the 10 cases of T-cell lymphoma, but the tumour cells did not express monocyte-macrophage markers. Clinically, the patients with T-cell lymphomas were usually young males with constitutional symptoms and their prognosis was significantly worse than those of patients with intestinal B-cell lymphoma.     

Regulation of Abortion by γλ T Cells

PROBLEM: T cells are present at the feto-maternal interface, but their function during pregnancy has not been fully elucidated. T cells bearing γλ T-cell receptor (TCR) may be particularly important, as some subsets can react to trophoblast cells by producing cytokines, such as interleukin-2 (IL-2). METHOD: We depleted T cells bearing the γλ receptor by injecting monoclonal antibodies (mAB) into females of the abortion-prone animal model CBA x DBA/2. We investigated the percentage and number of γλ T-cell receptor positive (TCR)⁺ cells in decidua and spleen during pregnancy in control and γλ-depleted female mice. Pregnant females were also exposed to ultrasonic sound stress to boost the abortion rate. RESULTS: Stress failed to increase the abortion rate in the γλ TCR-depleted mice. FACScan analysis show that the ratio of cells bearing the γλ TCR dramatically decreased after injection of mAB to the γλ TCR in spleen and decidua, these cells recovered six days after depletion, showing a change in cytokine pattern. Levels of TNF-α in decidual γλ T cells decreased; similar effects of decreasing Th₁ cytokines could be observed in splenic γλ T cells. We further identified increased levels of intracellular TNF-α in the Vλ4 subset in the decidua, compared to spleen. CONCLUSIONS: Trophoblast recognition by the Vλ4 T-cell subset in the decidua may cause the release of abortogenic cytokines such as TNF-α. Depletion of such γλ TCR T cells during early pregnancy may promote successful pregnancy outcome in normal pregnancy and prevent stress-induced abortions.     

The pattern and frequency of t(14;18) translocation and immunophenotype in Asian follicular lymphoma

AIMS: Follicular lymphoma is frequently associated with t(14;18)(q32;q21) translocation. This study was undertaken to determine the pattern of Bcl-2, CD10 and Bcl-6 expression in relation to t(14;18) translocation in follicular lymphoma from a cohort of a multi-ethnic Asian population. METHODS AND RESULTS: Sixty-two cases of follicular lymphoma were retrieved for immunohistochemistry, and t(14;18) translocation analysis by polymerase chain reaction and fluorescent in-situ hybridization techniques. Bcl-2 expression was present in 74% of the cases. CD10 expression was also relatively low (61%), with decreasing frequency of expression in high-grade tumours. Bcl-6 protein was expressed in most of the tumours (88%) regardless of the tumour grade. The t(14;18) translocation was detected in 46 cases (74%) with an extremely high rate of t(14;18) translocation in ethnic Indian cases (100%). CONCLUSION: The frequency of t(14;18) translocation in this series of follicular lymphomas was higher when compared with previous Asian reports, but in accordance with European and North American findings. CD10 expression is strongly associated with a t(14;18) translocation event, but the overall CD10 expression was relatively low, possibly due to the high proportion of high-grade tumours in the series. t(14;18) translocation was not associated with Bcl-2 or Bcl-6 expression.     

Immunohistochemical analysis of cleaved caspase-3 detects high level of apoptosis frequently in diffuse large B-cell lymphomas of the central nervous system

The purpose of the present paper was to examine the level of apoptosis and the relationships among apoptosis, apoptosis-associated proteins, and proliferating potential in lymphoma tissues to clarify the characteristics of apoptosis in diffuse large B-cell lymphomas (DLBCL) of the central nervous system (CNS). The formalin-fixed, paraffin-embedded tissues of CNS and non-CNS DLBCL (20 cases each) were studied by terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) and immunohistochemistry, using antibodies against single-stranded DNA (ssDNA), cleaved caspase-3, bcl-2, bax, p53, Fas and Ki-67. The cleaved caspase-3 immunohistochemistry detected apoptosis of the lymphoma cells most sensitively compared to TUNEL and ssDNA immunohistochemistry. High expression (grade + + or + + +) of cleaved caspase-3 was found more frequently in CNS DLBCL (11 cases, 55%) than non-CNS DLBCL (three cases, 15%; P = 0.009). Bax-positivity of lymphoma cells was increased in six cases of CNS DLBCL, which also showed high positivity of cleaved caspase-3. There was no significant correlation between the cleaved caspase-3-positivity and the Ki-67 positivity. The present study indicates that the number of apoptotic cells and expression level of cleaved caspase-3 were significantly higher in CNS DLBCL than non-CNS DLBCL, and that the correlation of bax and cleaved caspase-3 expression was often present in CNS DLBCL.     

Follicular dendritic cells in extranodal non-Hodgkin lymphomas of MALT and non-MALT type

Extranodal lymphomas of the thyroid (n=19), kidney (n=15) and testis (n=30) were investigated histologically and immunohistochemically for follicular dendritic cell pattern using the monoclonal antibody Ki-FDC1P. This recognizes follicular dendritic cells in paraffin sections. Follicular dendritic cells were most predominant in lymphomas of the thyroid. These thyroid lymphomas showed the morphological features of mucosa-associated lymphoid tissue (MALT) type lymphomas in 18 of 19 cases and were classified as high-grade malignant lymphoma of MALT type with evidence of a low-grade malignant component (n=18). Ten of these cases contained destroyed reactive follicles of follicular dendritic cells. In 6 of these 10 cases follicular dendritic cells occurred in a pattern of tumour-associated abortive follicle type. The remaining lymphoma of the thyroid was an immunoblastic lymphoma of B-cell type showing no detectable follicular dendritic cells. In extranodal lymphomas of non-MALT type follicular dendritic cells occurred in only two cases where immunocytoma involved the kidney. Malignant lymphomas of the kidney (chronic lymphocytic leukaemia,n=2; immunocytoma,n=4; centroblastic lymphoma,n=9) and of the testis (immunocytoma,n=2; centroblastic lymphoma,n=27; immunoblastic lymphoma of B-cell type,n=1) revealed no characteristics of MALT type lymphoma, cytologically or with respect to follicular dendritic cells. Classical lymphoepithelial lesions formed by centrocyte-like cells, a hallmark of MALT, occurred exclusively in thyroid lymphomas of MALT type. Although occurrence of classical lymphoepithelial lesions formed by centrocyte-like cells was limited to thyroid lymphomas of MALT type, a growth pattern of lymphoid blasts, with formation of lesions mimicking lymphoepithelial lesions superficially, was found in 6 of 27 testicular centroblastic lymphomas. Follicular dendritic cells in non-Hodgkin's lymphomas of MALT type show distinct follicular patterns not found in other extranodal lymphomas such as those found in the kidney and testis.     

凋亡肿瘤细胞负载的树突状细胞对抗原特异性CTL的激活

为探讨凋亡Daudi细胞负载的树突状细胞 (DC )激发诱导肿瘤抗原特异性CTL及其生物学特性 ,采用常规方法从人外周血单个核细胞 (PBMC )诱导DC ,激发型CD40mAb联合 50Gyγ射线辐照诱导Daudi凋亡后负载DC ,然后与自体T细胞共育 ,并联合IL 2激发诱导肿瘤特异性CTL ;采用免疫荧光标记和流式细胞仪测定分析膜分子的表达 ;ELISA检测细胞因子的产生 ;Dextran FITC内吞实验分析DC的抗原摄取能力 ;3H掺入试验和51 Cr释放试验分别测定CTL的增殖和细胞毒效应。结果 :(1 )细胞因子序贯体外诱导 7d的DC ,对Dextran吞噬能力最强 ;(2 )CD40mAb诱导联合γ射线辐照 ,能有效介导Daudi细胞的凋亡 ;(3 )抗原负载联合CD40mAb激发可使DC上调表达CD1a、CD80、CD86和HLA DR ,并能促进IL 1 2的分泌 ;(4)凋亡Daudi负载后的DC在激发型CD40mAb作用下 ,能激发和扩增对Daudi细胞具有高效和特异杀伤作用的细胞毒性T细胞。因而认为凋亡肿瘤细胞负载联合CD40mAb刺激的DC可有效激活和扩增肿瘤特异性CTL。     

不同年龄和部位女性皮肤微循环变化

目的观察不同部位皮肤血管结构和形态差异,研究年龄对真皮微循环功能的影响.方法采用活体电视毛细血管镜(Intravital Video-capillaroscopy)和激光多谱勒血流仪(laser Doppler flowrnetry)对50名年龄在20～74岁,光皮肤类型为Ⅱ～Ⅲ型白人女性志愿者的前额、眼角、前臂内侧和手背血管作初步观察.并用计算机图象处理技术,对前臂和手背活体真皮血管密度作定量分析.结果真皮乳头毛细血管襻在活体电视毛细血管镜下为点状或逗点状;乳头下的血管丛表现为线条状或网状;年轻人皮肤血管排列整齐,年龄较大者血管扩张增粗、扭曲,排列不规则.年龄与襻状血管数、襻状血管面积显著负相关;与襻状血管间距、平行血管总长正相关;真皮血流量面部高于肢端;随年龄的增加真皮血流有逐渐增加趋势.结论年龄影响真皮微循环的形态和功能.两种无创性检测技术联合应用能动态研究活体真皮血管的形态和结构,在皮肤血管性疾病的诊断和治疗方面有较高的应用前景.     

Dendritic reticulum cell-related immunostaining for laminin in follicular and diffuse B-cell lymphomas

Summary We performed a comparative immunohisto-cytochemical study of the distribution patterns of laminin and follicular dendritic reticulum cells (DRCs) within their follicular microenvironment in both nodular or diffuse B-cell non Hodgkin's lymphomas (NHLs). Twenty nine cases of immunophenotypically diagnosed B-cell NHLs (19 of follicular center cell origin-FCCL- and 10 of the diffuse well differentiated lymphocytic type-WDLL-) and five reactive lymph nodes with follicular hyperplasia were analyzed by immunoperoxidase and immunofluorescence techniques. Serial frozen sections and cytospin preparations were tested either with single antibodies anti laminin and DRC-1, or paired reagents in double labeling immunofluorescence. Our results indicated consistently that within both the reactive germinal centers and the neoplastic nodules of FCCL laminin immunostaining visualized a punctate-granular pattern apart from the linear vascular basement membrane positivity. Double immunofluorescence assay demonstrated that there was a close parallelism between this laminin staining pattern and DRC-1 distribution showing a well developed DRCs meshwork; in the diffuse tumour areas of both FCCL and WDLL, laminin immunoreactivity was found only in those cases in which nests of DRCs were observed. Double immunofluorescence studies performed on cytospin preparations demonstrated that the groups of cells containing DRC-1 positive cells, contained a positivity for laminin, although within the cell the staining for DRC-1 was intense and diffuse, while that for laminin was granular and more sparse. Our results suggested that these laminin and DRC-1 positive reactive sites may be present on the same cells. Since the reduction in number or loss of both DRCs and their related immunostaining for laminin within the microenvironment was consistently associated with a loss of nodularity by lymphoma cells, whereas nodularity in reactive and neoplastic conditions was associated with a rich DRCs meshwork and the related laminin immunostaining, a trapping function of DRCs exercised in the presence of laminin should be considered.This work was supported in part by a Grant N 87.02799.44 from the Consiglio Nazionale delle Ricerche, Progetto Finalizzato Oncologia, Rome, and by the Associazione Italiana per la Ricerca sul Cancro, Milan, Italy