特发性血小板减少性紫癜患者T细胞及B细胞亚群变化的研究

目的 探讨特发性血小板减少性紫癜(idiopathic thrombocytopenic purpura,ITP)患者T、B淋巴细胞亚群的变化.方法 从大理州人民医院收集ITP患者和健康者的外周血,用Sysmex血液分析仪及流式细胞术分析T细胞及B细胞亚群.结果 与健康人群比较,ITP患者CD3+T细胞百分率无明显变化,CD4+T细胞百分率降低(42.39％±12.12％,P＜0.05),CD8+T细胞百分率升高(46.93％±11.99％,P＜0.05);CD19+B细胞百分率升高(14.11％±10.28％,P＜0.05),T2B细胞百分率(34.51％±9,70％,P＜0.05)、成熟B细胞百分率(30.91％±7.12％,P＜0.05)及记忆性B细胞百分率(23.31％±8.23％,P＜0.05)增多,差异均有统计学意义.ITP患者T1 B细胞、Kappa+B细胞、Lambda+B细胞百分率与健康人差异无统计学意义.结论 ITP患者外周血T细胞亚群和B细胞亚群分布发生了变化,这种变化在ITP发病中的作用尚需进一步研究.     

28 色流式对中轴型脊柱关节炎患者外周血中T 细胞亚群差异的鉴定

目的:高通量(28色流式细胞术)分析中轴型脊柱关节炎(ax-SpA)患者与健康志愿者外周血中T细胞亚群差异。方法:利用流式细胞仪搭建并优化28通道针对T细胞的流式染色方案。收集ax-SpA患者和健康志愿者的外周血,用密度梯度离心法分离获得PBMC细胞。28色流式抗体共同染色,并上机检测。结合FlowJo和R语言对CD4~+ T细胞和CD8~+ T细胞进行大数据处理。结果:CD4~+ T细胞可以分为10个细胞亚群,但在ax-SpA患者和健康志愿者之间无明显差异;CD8~+ T细胞可以分为14个细胞亚群,其中亚群8在ax-SpA患者和健康志愿者之间存在显著差异,且表达CD103。结论:CD103~+CD8~+ T细胞在ax-SpA患者外周血中比例明显升高,可能在其发病过程中发挥重要作用。     

再生障碍性贫血患者外周血T细胞亚群和T细胞受体表达水平及其意义

采用流式细胞仪及间接免疫荧光法检测30例再生障碍性贫血患者外周血中T细胞亚群及T细胞表面受体表达水平,并与健康对照组相比,结果表明:70％再障患者存在CD4/CD8比例倒置及CD8~+％异常增高;50％再障患者外周血γδ-T细胞亚群及其在T淋巴细胞总体中所占比例均显著增高;而αβT细胞亚群及TirA~+细胞百分率与正常对照组相比无显著性差异。提示:半数以上再障患者外周血中存在异常增多的γδT细胞及Ts细胞亚群。并可通过其直接或间接作用抑制造血,从而导致再障的发生。     

人全血涂片中T淋巴细胞亚群的免疫细胞化学研究

用硷磷酶免疫细胞化学技术研究了在全血涂片中测定T淋巴细胞亚群的主要条件,比较了两种染色方法对两类制片中T淋巴细胞染色的影响,并对37名健康成人外周血T细胞亚群进行测定。结果表明:CD3,CD4和CD8在全血涂片和离心涂片中的阳性细胞比例分别为69.1±6.58％,47.0±4.85％,     

过敏性哮喘患儿外周血嗜酸性粒细胞及淋巴细胞CCR3的表达

目的 观察过敏性哮喘患儿外周血嗜酸性粒细胞及淋巴细胞表面趋化因子受体CCR3与CCR5表达的改变。方法 以16例急性发作及25例缓解期过敏性哮喘患儿和20例健康儿童为主要观察对象,用流式细胞术测定外周血粒细胞群及淋巴细胞群中CCR3与CCR5的表达。结果 过敏性哮喘患儿缓解组CCR3~+淋巴细胞亚群百分率[(4.2±1.9)％],尤其是CCR3~+嗜酸性粒细胞百分率[(3.5±1.6)％]较正常组[(3.0±1.3)％,(1.2±0.5)％]明显增高;急性发作组CCR3~+淋巴细胞亚群与嗜酸性粒细胞百分率[(3.5±1.5)％,(2.2±1.0)％]虽也高于正常组,但较缓解组则出现下降。发作组CCR5~+淋巴细胞亚群仅见增高趋势。结论 CCR3~+嗜酸性粒细胞与淋巴细胞亚群异常升高可能为过敏性哮喘患儿免疫系统异常的一个特征性表现;与缓解组比较,发作组CCR3~+嗜酸性粒细胞及淋巴细胞亚群反而降低,可能和该类细胞向炎症部位趋化并参与了过敏性免疫炎症反应有关。     

慢性肾炎患者外周血T细胞亚群和共刺激分子的表达及其意义

为研究慢性肾炎患者外周血T细胞亚群和共刺激分子的表达特点及其在慢性肾炎免疫病理机制中的作用 ,本文采用免疫荧光标记和流式细胞仪分析 ,对 35例慢性肾炎患者外周血T淋巴细胞亚群和共刺激分子CD2 8、 4 1BB等的表达进行研究。结果表明 :(1)慢性肾炎患者T细胞亚群明显失衡 ,表现为CD4减少 ,CD8增加 ,CD4/CD8比值显著降低 ;(2 )共刺激分子CD2 8表达显著低于正常对照组 (CD2 8表达百分率分别为 45 95± 5 6 7和 6 6 42± 4 5 8,P <0 0 0 1) ,且CD4+ CD2 8+ T细胞和CD8+ CD2 8+ T细胞均显著减少。治疗后缓解期患者T细胞亚群失衡明显纠正 ,CD2 8+ T细胞 ,尤其是CD4+ CD2 8+ T细胞显著增多 ,而且CD4+ CD2 8+ T细胞数与患者的 2 4h尿蛋白定量呈负相关 (r= 0 47,P <0 0 1) ;(3)慢性肾炎患者共刺激分子 4 1BB在T细胞中的表达显著高于正常对照组 (表达百分率分别为 30 5 7± 8 12和 0 74± 0 2 8,P <0 0 0 1) ,治疗后的 4 1BB表达水平显著降低 ,而且 4 1BB异常高表达与CD8+ T细胞数呈正相关 (r=0 6 3,P <0 0 5 )。从而表明慢性肾炎外周血T细胞亚群失衡和T细胞活化所必需的共刺激分子CD2 8、 4 1BB异常表达 ,可能在慢性肾炎发生和病变进展中起着重要作用。     

索拉非尼对大鼠佐剂性关节炎的抑制作用

目的探讨索拉非尼对大鼠佐剂性关节炎(AA)的抑制作用。方法 36只雄性SD大鼠均分为6组,除正常组外,其余各组大鼠均制备AA模型。足容积法检测AA大鼠继发侧足爪容积;流式细胞术检测外周血CD4~+及CD8~+T细胞亚群的变化;免疫组织化学链霉卵白素-过氧化物酶法(SP)检测滑膜组织微血管密度(MVD)的改变。结果与模型组相比,索拉非尼组大鼠足爪容积下降,滑膜组织MVD减小,其中索拉非尼(20、40mg/kg)组可使外周血CD4~+T细胞比例降低,CD8~+T细胞比例增加,差异均有统计学意义(P0.05)。结论索拉非尼具有抑制大鼠AA效应,该作用可能与索拉非尼引起AA大鼠外周血CD4~+,CD8~+T细胞亚群的偏移以及降低滑膜组织MVD有关。     

丙种球蛋白输注对川崎病患儿外周血CD4~+CD25~+调节T细胞与淋巴细胞亚群分布的影响

目的探讨丙种球蛋白输注对川崎病患儿外周血CD4~+CD25~+调节T细胞(Treg)与淋巴细胞亚群分布的影响及临床意义。方法流式细胞术检测40例川崎病患儿和30例体检健康儿童外周血中CD4~+CD25~+Treg细胞的表达水平以及108例川崎病患儿和41例体检健康儿童外周血中淋巴细胞亚群分布。ELISA法检测川崎病患儿血浆中TGF-β1浓度。108例川崎病患儿中有30例收集到对应的丙种球蛋白(IVIG)治疗后全血,流式细胞术检测CD4~+CD25~+Treg、TGF-β1及淋巴细胞亚群在川崎病患儿丙种球蛋白(IVIG)治疗前后表达水平的差异。结果与健康体检组相比,川崎病患儿CD4~+CD25~+Treg细胞及血浆TGF-β1的表达水平明显降低,外周血CD3+、CD8~+T细胞及NK细胞的表达水平明显降低,CD4~+T细胞、B细胞及CD4~+/CD8~+水平明显增高,差异均有统计学意义(均P0.01)。与IVIG治疗前相比,川崎病患儿IVIG治疗后外周血CD4~+CD25~+Treg细胞及血浆TGF-β1的表达水平明显增高(均P0.05),外周血CD3+、CD8~+T细胞及NK细胞的表达水平明显增高(均P0.05),CD4~+T细胞、B细胞及CD4~+/CD8~+水平明显降低(均P0.05)。治疗后患儿外周血CD4~+CD25~+Treg水平、血浆TGF-β1浓度及淋巴细胞亚群表达水平与健康对照相比无差异(P0.05)。结论 Treg细胞与淋巴细胞比例失常是导致儿童川崎病免疫紊乱的重要原因。检测CD4~+CD25~+调节T细胞及淋巴细胞亚群分布对评估川崎病患儿的细胞免疫状况,辅助诊断和指导治疗具有重要的临床价值。     

全血淋巴细胞流式细胞术精细免疫分型方法的建立

目的建立双平台法(流式细胞仪和血细胞计数仪)检测人外周血淋巴细胞亚类绝对数及相对数的流式方法 ,分析更精细的淋巴细胞亚群数量,全面评估被测者免疫功能。方法取人EDTA抗凝外周血500μl,200μl用于血细胞计数仪测得淋巴细胞绝对数;300μl用于流式细胞分析,测得所需淋巴细胞亚群相对数。各淋巴细胞亚群相对数(百分率)×淋巴细胞绝对数,即得到各淋巴细胞亚群绝对数。此方法用同一标本的全血和PBMC进行分析,评价用微量全血进行精细免疫分型的可行性。结果利用双平台法,采用微量全血标本分析了辅助T细胞、细胞毒性T细胞和B细胞的14个细胞亚群,得到其绝对数和相对数。用本方法对同一标本的全血和PBMC进行检测,结果无统计学差异。结论成功建立使用微量全血检测精细淋巴细胞亚群的多色流式分析方法,较全面地评估被测者免疫功能,为免疫相关疾病早期诊断提供线索和依据,对临床治疗具有重要指导作用。     

CD4+CD25+FoxP3+调节T细胞抑制肺结核患者特异细胞免疫

  目的 了解结核患者外周血中CD4+CD25+FoxP3+调节T细胞在抑制结核患者结核特异细胞免疫反应中的作用。 方法 使用细胞分离、流式细胞分析、细胞增殖和细胞因子测定等方法,比较结核患者及健康正常人群外周血中CD4+CD25+FoxP3+调节T细胞的量及功能特征的差异。 结果 结核患者外周血中CD4+CD25+FoxP3+调节T细胞数占CD4+细胞总数的比例显著高于健康正常人群;在BCG及ESAT-6的刺激下,结核患者外周血单个核细胞增殖能力和产生γ-干扰素的能力比健康正常人群明显增强。在BCG刺激下,结核患者外周血CD4-细胞产生γ-干扰素(1289.62±519.01)及白介素-10(1045.40±534.12)的能力比结核患者外周血BPMCs细胞产生γ-干扰素(624.50±261.13)及白介素-10(377.00±249.56)的能力显著增强(均p<0.05);在BCG及ESAT-6的刺激下,结核患者外周血CD4+CD25+调节T细胞显著抑制结核患者外周血CD4+CD25-细胞产生γ-干扰素及白介素-10。 结论 结核患者CD4+CD25+FoxP3+调节T细胞数量增多,抑制结核患者结核特异细胞免疫反应功能增强,可能与结核的发生、发展及转归有密切关系。     

Effect of Prolonged Monoclonal Antibody Administration on Cardiac Allograft Survival in the Rat

After heterotopic cardiac transplantation in the rat, monoclonal antibodies (MoAb) specific for rat T-cell subsets were administered until rejection. Across combined major histocompatibility complex (MHC) and non-MHC differences (WF to Lew) and isolated non-MHC differences (WF to Lew.1W) cardiac allografts were rapidly rejected in unmodified hosts (7.7 +/- 1.0 days and 12.2 +/- 0.8 days respectively). Across combined MHC and non-MHC differences, administration of MoAb OX-19 (pan T-cell) on days -1, 0, and 1 (where day 0 was the day of transplantation) and alternate days thereafter until rejection significantly prolonged allograft survival (28.5 +/- 10.2 days, P less than 0.01). Administration of MoAb W3/25 (helper T cell) and MoAb OX-39 (interleukin 2 (IL-2) receptor) prolonged allograft survival (11.3 +/- 2.6 days, P less than 0.05 and 13.3 +/- 2.0 days, P less than 0.01 respectively), whereas MoAb OX-8 (cytotoxic/suppressor T cell) administration had no effect on allograft survival. In contrast, across non-MHC differences (WF to Lew.1W) administration of MoAb OX-8 markedly prolonged allograft survival (85, greater than 100 x 3 days) whereas MoAb W3/25 administration had no effect. The effect of MoAb administration on lymphocyte subsets at rejection was assessed by flow cytometry. The relationship between depletion of targeted T-cell subsets and graft survival was variable. Across both combined MHC and non-MHC and isolated non-MHC differences MoAb OX-8 administration resulted in a marked reduction of OX-8+ cells at rejection with no prolongation of graft survival in the former and indefinite graft survival in the latter. In contrast, OX-19 administration resulted in prolonged graft survival but at rejection there were significant numbers of OX-19+ cells present. Administration of MoAb W3/25 failed to affect a significant reduction in W3/25+ cells, but allograft survival was nonetheless prolonged.     

Immunosuppressive activity of FK-506 in rats: flow cytometric analysis of lymphocyte populations in blood, spleen and thymus during treatment and following drug withdrawal.

Rats were immunized systemically with sheep red blood cells (SRBC) and given either FK-506 (1 mg/kg) or drug vehicle by i.m. injection for 7 days. In animals receiving FK-506, there was suppression (87%) of the splenic plaque-forming cell response on day 4 and marked reductions in the serum antibody titre throughout the 3-week period following immunization. Sequential flow cytometric analyses of blood lymphocytes revealed statistically significant attenuation, by FK-506, of the increase in relative numbers of OX-12+ (B) cells between days 4 and 7. Following drug withdrawal, OX-12 values remained elevated, whereas in control animals a decline was observed. These changes were reflected in concomitant increases in the relative numbers of OX-19+ (CD3+), W3/25+ (CD4+) and OX-8+ (CD8+) T cells; however, due to an overall reduction in lymphocytes by day 7, absolute values were not significantly affected compared with controls. The pattern of changes in OX-6+ (MHC class II+) cells in blood was similar to that observed for B cells. FK-506 also suppressed increases in the small proportion of blood-borne OX-40+ (activated CD4+) cells and OX-39+ (interleukin-2 receptor+) cells in the 7 day period following immunization; thereafter values for activation marker expression between treatment and control groups were similar. In the spleen, there were fewer significant differences between FK-506 and control groups in the incidences of cells expressing the above markers. OX-8+ cells, however, were significantly higher in drug-treated animals on day 7, and there were also reductions in the small proportions of OX-39+ and OX-40+ cells when compared with controls. In the thymus, reversible medullary atrophy induced by FK-506 was accompanied on day 7 by increases in the incidence of CD4+ and CD8+ cells and by a concomitant reduction in OX-44+ mature, medullary thymocytes. Two weeks after drug withdrawal, the phenotypic marker expression profile had been restored to normal in blood, spleen and thymus. These data provide new information on the apparent capacity of FK-506 to interfere with T cell maturation and its influence on lymphocyte activation in vivo.     

Distribution of Ia antigens and T lymphocyte subpopulations in rat lungs.

In order to examine the mechanism of specific immunity in the lung, the distribution of Ia antigens and T lymphocyte populations was determined using immunoperoxidase-staining of cryostat sections of lungs from specific pathogen-free rats. BALT was found to be divided into three regions of lymphoid tissue. The central region was primarily composed of B cells, and was surrounded by a peripheral region of T cells (MRC OX-19+) which included both T helper (W3/25+) and T suppressor/cytotoxic (MRC OX-8+) cells. The subepithelial region contained a dense network of W3/25+, non-T cells. A majority of BALT cells, including the lymphoepithelial cells, were Ia+. The alveolar walls were found to contain numerous Ia+ dendritic-shaped cells. Alveolar macrophages found in sections, as well as those collected using bronchoalveolar lavage, were Ia- and W3/25-. Mechanisms for the induction of immunity within both BALT and the alveolar region are proposed.     

Influence of FK506 and cyclosporin A on alloantibody production and lymphocyte activation following blood transfusion.

The effect of administration of cyclosporin A (CyA) or the novel macrolide FK506 was investigated in AO rats given DA blood transfusions. CyA (10 mg/kg, orally) or FK506 (1 mg/kg, intramuscularly) administered for 14 days from the time of transfusion effectively inhibited primary anti-MHC class I alloantibody production. This profound inhibitory effect persisted throughout the 2-month investigation period, with little increase in 'secondary' alloantibody production following a challenge injection 28 days after drug withdrawal. Flow cytometric analysis revealed no significant differences in the absolute numbers of W3/25+ (CD4+), OX-8+ (CD8+) or OX-12+ (B lymphocytes), in either the spleen or peripheral blood of transfused compared with normal, untreated animals. However, a small but significant increase in the numbers of splenocytes expressing the activation marker OX-40 (activated CD4+ cells) was observed in transfused animals. Either CyA or FK506 significantly reduced the number of cells expressing OX-39 (interleukin-2 receptors) and OX-40. Treatment of transfused animals with CyA, but not FK506 for 14 days resulted in minor, transient reduction in peripheral blood OX-19+ and W3/25+ cells, while 'sparing' the OX-8+ cells; these changes were not observed in spleens. In contrast, the absolute spleen cell numbers of OX-19+, W3/25+ and OX-8+ cells were significantly reduced in transfused animals given 14 days of FK506 treatment, while the corresponding blood cells were unaffected. Induction of splenic lymphoproliferative responses by the T cell mitogen concanavalin A remained normal in animals receiving transfusion alone or with CyA. In contrast, profound inhibition of mitogenic responses was observed in FK506-treated animals and this inhibitory effect declined gradually following drug withdrawal. No non-specific suppressor cell activity was detected in the spleens of rats given transfusion alone or in CyA or FK506-treated transfused animals.     

Generation of Large Granular Lymphocytes and Lymphocyte Subset Changes Linked with Cyclophosphamide-Induced Eosinophilia in Rats—and the Effects of Ciclosporin

Administration of cyclophosphamide (Cy: 150 mg/kg i.p.) to rats 48 h before immunization with a T-dependent antigen (ovalbumin) resulted in a striking absolute eosinophilia in blood, bone marrow, and secondary lymphoid organs after 10 to 14 days. This eosinophilia was preceded by a significant increase in the W3/25+/OX-8+ (T helper/inducer to T cytotoxic/suppressor) ratio in lymph nodes and spleen and accompanied by a pronounced rise in splenic OX-12+ (B cell) numbers. There was also a concomitant increase in cells with the morphology and immunophenotype (OX-8+, OX-19-) of large granular lymphocytes (LGL). It is suggested that the eosinophilia linked with the B lymphocytosis may be due to cell-derived soluble factors, including a possible equivalent of eosinophil differentiation factor (EDF = interleukin 5), which also has B-cell growth factor activity (BCGF II) in mice. Ciclosporin (CsA; 25 mg/kg/day per os) from the time of immunization, did not affect the incidence of W3/25+ cells in spleen or lymph nodes, but abrogated Cy-induced eosinophilia and reduced the extent of B-cell proliferation. In addition, CsA caused a further, marked increase in the incidence of OX-8+, OX-19-LGL within the spleen. The functional role(s) of these latter cells remains to be defined.     

慢性疲劳综合征患者外周血淋巴细胞亚群及CD25^＋调节性T细胞表达的研究

研究慢性疲劳综合征（CFS）患者外周血淋巴细胞亚群及CD25＋调节性T细胞的表达情况。使用流式细胞仪检测84例CFS患者（CFS组）、50例健康体检者（健康对照组）外周血淋巴细胞亚群（T细胞、CD4＋T细胞、CD8＋T细胞、B细胞、NK细胞）及CD25＋调节性T细胞的表达情况。结果显示,CFS组与健康对照组的T细胞、CD8＋T细胞百分率以及CD4＋/CD8＋比值无显著差别（P〉0.05）;而CFS组NK细胞、CD4＋T细胞及CD25＋调节性T细胞百分率显著增高,B细胞百分率显著降低（P〈0.05）。结论：慢性疲劳综合征患者外周血淋巴细胞各亚群比例异常,提示其免疫功能失衡,而CD25＋T调节性细胞可能在该病进程中有重要意义。     

流式细胞术检测调节性T细胞方法的建立

目的建立流式细胞术（FCM）检测外周血CD4＋CD25＋调节性T细胞（Tregs）的方法，并观察紫杉醇联合卡铂治疗对晚期肺癌和乳腺癌患者外周血CD4＋CD25＋Tregs数量的影响。 方法19例晚期肺癌和10例乳腺癌患者均给予紫杉醇联合卡铂方案化疗，于化疗前1d和化疗后第7天采集患者外周血，分别加入鼠抗人CD4-FITC（异硫氰酸荧光素）/CD8-PE（藻红蛋白）/CD3-PerCP（多甲藻叶绿素蛋白）、CD25-FITC/CD127-PE/CD4-PerCP、CD3-FITC/CD（16＋56）-PE/CD45-PerCP单抗，并以分别加入同型鼠抗人IgG1-FITC、IgG1-PE、IgG1-PerCP抗体作为阴性对照。采用流式细胞术（FCM）检测化疗前后外周血CD3＋、CD4＋、CD8＋T细胞和CD4＋CD25＋Tregs、NK细胞所占比例并进行数据分析。实验重复3次。 结果与化疗前比较，晚期肺癌和乳腺癌患者化疗后外周血CD4＋CD25＋Tregs的比例均明显降低（6.82%±3.11%vs.5.48%±2.13%，P=0.045；6.38%±1.84%vs.3.88%±1.69%，P=0.007）；晚期肺癌患者化疗后外周血CD4＋T细胞的比例升高（48.84%±16.44%vs.56.35%±14.50%，P=0.006），CD8＋T细胞的比例降低（51.18%±16.44%vs.43.65%±14.50%，P=0.006），CD4＋/CD8＋T细胞比值升高（1.12±0.60vs.1.57±0.88，P=0.008），而CD3＋T细胞和NK细胞的比例均无明显变化；乳腺癌患者化疗后外周血CD3＋、CD4＋、CD8＋T细胞、NK细胞的比例和CD4＋/CD8＋T细胞比值均无明显变化。 结论成功建立了FCM检测CD4＋CD25＋Tregs的方法，联合应用CD4、CD25、CD127检测CD4＋CD25＋Tregs简便可行、重复性好，检测结果可靠、准确，比较适用于临床检验。紫杉醇联合卡铂能够降低晚期肺癌和乳腺癌患者外周血CD4＋CD25＋Tregs的数量。     

B and T lymphocyte subsets enter peripheral lymph nodes and Peyer's patches without preference in vivo: no correlation occurs between their localization in different types of high endothelial venules and the expression of CD44, VLA-4, LFA-1, ICAM-1, CD2 or L-selectin

Many lymphocytes enter tissues such as peripheral lymph nodes and Peyer's patches through high endothelial venules (HEV). It is known that HEV differ in the expression of adhesion molecules as lymphocyte subsets do. Through the interaction of these molecules B and T lymphocyte subsets are thought to be preferentially directed into lymphoid organs. However, it is unclear which role these mechanisms play in vivo, since there are no studies demonstrating that blood lymphocyte subsets preferentially interact with different types of HEV in vivo. Therefore, in the present study the frequency of B, T, CD4⁺ and CD8⁺ lymphocytes in the wall of the HEV of rat peripheral lymph nodes and Peyer's patches was analyzed by immunohistology. In addition, the expression of CD44, VLA-4, LFA-1, ICAM-1, CD2 and L-selectin on B and T lymphocyte subsets of the blood was determined by flow cytometry. Although B and T lymphocytes showed significantly different levels of expression for each adhesion molecule investigated, the relation of B and T lymphocytes within the HEV of peripheral lymph nodes and Peyer's patches was strikingly comparable (38.0 ± 5.2% vs. 40.6 ± 5.7% and 62.0 ± 5.2% vs. 59.4 ± 5.7%, respectively). The same was true for CD4⁺ and CD8⁺ cells. Thus, although HEV and the blood lymphocyte subsets differ markedly in their expression pattern of adhesion molecules, the existing levels are sufficient to mediate comparable entrance of B and T lymphocyte subsets into both types of HEV.     

T Lymphocytes Subsets in Experimental Iron Overload

Several abnormalities of the immune system have been reported in association with clinical and experimental iron overload. To dissect further such abnormalities, changes in lymphocyte subsets were evaluated in iron-loaded male Sprague-Dawley rats. The iron-loading protocol consisted of a total dose of iron-dextran (1.5 mg/Kg body weight) divided in daily intramuscular injections over twenty consecutive days. At days 0, 20, and 50 after initiation of iron injections lymphocyte subsets in blood, spleen and mesenteric lymph nodes were estimated by indirect immunofluorescence using monoclonal antibodies recognizing T cells (W3.13), the subset of helper T cells in (W3.25), and the subset of cytotoxic T cells (OX.8). By day 20, there was no change in the number of W3.25+ T cells in the blood of iron-loaded animals as compared to the controls, but the OX.8 + T cells were significantly elevated. At this time, the ratio W3.25 ⁺/OX.8⁺ cells was significantly decreased (0.5 in experimental rats vs 2.0 in controls). Similar results were obtained at day 50. In the spleen, there was a decrease in the proportion of W3.25 ⁺T cells and an increase in OX.8⁺ T cells at day 20. However, these values returned to normal by day 50. A negative correlation between W3.25 ⁺/OX.8⁺ ratio and serum ferritin was observed in blood and spleen during iron administration. These changes were associated with abnormalities in lymphocyte proliferative response. No changes in W3.25 ⁺/OX.8⁺ ratio were observed in mesenteric lymph nodes. These results demonstrate that iron overload alters the distribution of T lymphocytes in various compartments of the immune system.