小鼠PP、MLN和ILN中CD3~+、CD19~+细胞组成差异及四君子汤总多糖对其影响

对比研究口服四君子汤总多糖(SJTPS)对免疫抑制小鼠派氏集合淋巴结(PP)、肠系膜淋巴结(MLN)和腹股沟淋巴结(ILN)中淋巴细胞作用的差异。观察连续7 d口服1 g/kg.d SJTPS对100 mg/kg的环磷酰胺处理24 h后的小鼠PP、MLN、ILN中CD3+、CD19+细胞比例的变化。正常小鼠体内,PP中的CD19+淋巴细胞比例明显高于ILN和MLN中的CD19+淋巴细胞比例,而CD3+细胞的比例明显低于后两者,腹腔注射环磷酰胺后,小鼠PP、MLN、ILN中的CD3+细胞比例上升,CD19+细胞比例下降,口服SJTPS可以明显的对抗PP,MLN中的CD3+,CD19+细胞比例的变化,但对ILN中的CD3+、CD19+细胞比例变化的作用不显著。口服SJTPS对肠道黏膜免疫系统的作用强于对其他外周免疫系统的作用。     

四君子汤复方总多糖对小鼠肠道粘膜相关淋巴组织的影响

目的：通过环磷酰胺所致小鼠肠道粘膜相关淋巴组织损伤模型研究四君子汤复方总多糖对肠道粘膜免疫的影响。方法：观察口服1g/kg四君子汤复方总多糖对100mg/kg的环磷酰胺处理24h后小鼠Peyer‘s结的数目、Peyer‘s结内细胞总数、CD3^ 、IgA^ 细胞数量和细胞凋亡的情况。结果：四君子汤复方总多糖可对抗环磷酰胺诱导的小鼠肠道粘膜相关淋巴组织中Peyer‘s结数目、Peyer‘s结细胞总数、肠粘膜内CD3^ 、IgA^ 细胞量的减少。细胞凋亡程度也明显减轻。结论：四君子汤复方总多糖可对抗环磷酰胺诱导的小鼠肠粘膜相关淋巴组织损伤,提示多糖可能对肠道粘膜免疫具有改善作用。     

香菇多糖口服和注射给药对DTH小鼠耳后淋巴结和小肠派氏结中T淋巴细胞的影响

目的:通过比较口服和注射香菇多糖对DTH小鼠耳后淋巴结和小肠派氏结中T淋巴细胞的影响,探讨肠道粘膜免疫系统在口服药物发挥免疫调节作用中的重要性。方法:28只6～8周龄NIH小鼠随机分为对照组、环磷酰胺免疫抑制模型组、香菇多糖灌胃组、香菇多糖注射组,各组小鼠用2,4-二硝基氟苯背部致敏,4天后耳廓攻击。攻击30小时后,对比各组小鼠耳肿胀差异,并应用流式细胞术检测被攻击耳廓的耳后淋巴结和小肠派氏结中T淋巴细胞的比例变化和活化水平。结果:与环磷酰胺免疫抑制模型组比较,香菇多糖能有效增强小鼠DTH反应,降低耳后淋巴结和小肠派氏结的T细胞比例,提高T细胞活化水平,且口服组的作用明显优于注射组。结论:对比注射给药,口服香菇多糖可以更有效地调节肠道粘膜免疫系统和整体免疫系统功能,提示肠道粘膜免疫系统在口服药物发挥免疫调节作用中扮演着重要的角色。     

小鼠派氏集合淋巴结T细胞活化和调节性T细胞的分析

目的： 通过对小鼠派氏集合淋巴结（PPs）、肠系膜淋巴结（MLNs）和腹股沟淋巴结（ILNs）的比较性研究，以分析PPs T细胞活化和调节性T细胞的功能特点。 方法： 无菌分离小鼠PPs、MLNs和ILNs，分别制备单个淋巴细胞悬液，运用流式细胞术结合荧光抗体染色技术来检测CD3+T细胞、CD3+CD4+辅助性T细胞和CD4+CD25＋调节性T细胞的比例；用多克隆刺激剂刀豆蛋白A（Con A）、佛波醇酯（PDB）和离子霉素（Ion） 刺激活化淋巴细胞，随后运用流式细胞术结合双色荧光抗体染色技术来检测T细胞早期活化标志CD69的表达水平。 结果： PPs内CD3+T细胞所占比例明显低于MLNs和ILNs，然而CD4+CD25＋调节性T细胞的比例明显高于MLNs和ILNs；在没有加入刺激剂的培养条件下，PPs来源的T细胞CD69的表达水平明显高于MLNs和ILNs来源的T细胞，MLNs来源的T细胞CD69的表达水平明显高于ILNs来源的T细胞；而在加入Con A或者单纯PDB的培养条件下，PPs来源的T细胞却表现出低反应性；在加入PDB＋Ion的培养条件下，3者来源的T细胞CD69的表达水平没有明显差别。 结论： PPs内CD3+T细胞所占比例较低，CD4+CD25＋调节性T细胞的比例较高，这可能是PPs整体T细胞低反应性的原因之一；PPs来源T细胞的高基础活化率可能与其不断接触小肠来源的食物和共生菌抗原有关；PPs来源T细胞选择性地对某些刺激剂表现出低反应性，提示这群细胞处于某种程度的无能状态。上述特征的生物学意义在于避免因为不断接受小肠来源的食物和共生菌抗原的刺激而发生病理性炎症的同时还保留对病原微生物抗原的应答。     

环磷酰胺对小鼠Peyer‘s结和肠道粘膜相关淋巴细胞的影响

目的：研究环磷酰胺对Peyer‘s结和肠道粘膜相关淋巴细胞的影响。建立肠道粘膜免疫障碍模型。方法：剂量为100mg/kg的环磷酰胺,观察不同时间处理后小鼠Peyer‘s结数目在24h时降低最明显,结内细胞数量和CD3^ 、IgA^ 细胞也明显减少,而细胞凋亡明显增加。结论：环磷酰胺可诱导肠粘膜免疫障碍,这可能是其引起淋巴细胞的细胞凋亡而产生的。     

环磷酰胺和地塞米松对小鼠肠道黏膜免疫抑制的比较

目的:观察环磷酰胺和地塞米松对小鼠肠道黏膜免疫的抑制作用.方法:筛选地塞米松和环磷酰胺的给药天数和剂量;CCK-8检测肠系膜淋巴结(Mesenteric lymph nodes,MLN)细胞转化增殖;流式细胞术检测MLN及派氏结(Peyer's Patch,PPs)中T、B淋巴细胞的数量及活化比例;ELISA试剂盒检测肠道sIgA的分泌.结果:地塞米松40 mg/kg和环磷酰胺100 mg/kg腹腔注射给药一次,有效降低小鼠胸腺、脾脏脏器指数和减少派氏结个数,抑制MLN细胞增殖;与正常组相比,地塞米松降低MLN和PPs中T细胞比例,抑制T、B细胞的活化;而环磷酰胺降低MLN和PPs中B细胞的比例,对MLN中B细胞活化有明显的抑制作用;地塞米松和环磷酰胺均降低肠道sIgA的分泌.结论:地塞米松和环磷酰胺皆能对肠道黏膜免疫产生抑制作用,但地塞米松对MLN和PPs中T细胞抑制作用较强,而环磷酰胺对B细胞的抑制作用较强.     

环孢霉素A对小鼠自然流产模型外周CD4~+CD25~+T细胞及妊娠结局的影响

为探讨着床期应用环孢霉素A(CsA)对小鼠自然流产模型外周CD4+CD25+T细胞及其妊娠结局的影响,以CBA/J♀×DBA/2♂为自然流产模型,在孕第4天给孕鼠单次口服不同剂量的CsA。孕第14天计数胚胎吸收率;并采用流式细胞术分析孕鼠脾脏CD4+CD25+T细胞比例。结果表明:与自然流产模型孕鼠比较,于着床期给予0.1 mg/kg、1 mg/kg、10mg/kg CSA,可显著降低自然流产模型胚胎吸收率(P<0.05)。在应用CsA后,自然流产模型孕鼠脾脏CD4+CD25+细胞占CD4+T细胞的比例显著增加(P<0.05)。表明CsA可通过上调外周CD4+CD25+T细胞,从而诱导母胎免疫耐受,改善妊娠预后。     

CD34~+CD38~+造血干细胞移植MISTRG小鼠的人源化免疫特征研究

目的研究人脐带血CD34~+CD38~+造血干细胞移植入MISTRG免疫缺陷小鼠体内的人源化免疫特征。方法利用Ficoll密度梯度离心法从新生儿脐带血中分离单个核细胞,并结合免疫磁珠法分选hCD34~+造血干细胞,然后经体外扩增培养后利用流式细胞技术检测CD34~+CD38~+细胞的比例。取2×105细胞数注射至辐照后的新生MISTRG小鼠肝脏内,分别于第3、6、9、12周采血检测人源免疫细胞的分化与表达情况。结果免疫磁珠法分选人的CD34~+CD38~+造血干细胞纯度高达92.0%。移植小鼠外周血中的hCD45~+细胞初始浓度水平大于10.0%,淋巴细胞群包含人源T(hCD3~+CD45~+)、B(hCD3-CD19~+)和NK(hCD3-CD56~+)淋巴细胞,其中B(hCD3-CD19~+)淋巴细胞所占比值最大(初始水平为49.0%±7.4%),髓系细胞群则主要由巨噬细胞组成(初始水平为82.3%±4.5%)。小鼠外周血中hCD45~+细胞比值和T细胞占免疫细胞的比值随着时间的推移逐渐下降,B淋巴细胞和巨噬细胞所占的比例逐渐升高,而NK细胞基本完全消失。结论人源CD34~+CD38~+造血干细胞在新生MISTRG小鼠中可有效分化为人源淋系和髓系免疫细胞。在移植后的12周内hCD45~+细胞的比例逐渐下降,MISTRG免疫缺陷小鼠最佳的人源化免疫系统维持时间为第3～6周。     

内毒素耐受状态下胸腺CD4~+ SP细胞比例变化及意义

初步探讨内毒素耐受状态下胸腺CD4~+ SP细胞的比例变化及意义。以5mg/kg LPS腹腔注射C57BL/6小鼠,建立内毒素耐受模型。注射72h、8d后检测胸腺大小、重量及细胞总数;HE染色检测胸腺组织结构病理变化;FACS检测胸腺CD4~+单阳性(single positive,SP)细胞比例并计算总数变化,同时检测CD4~+SP细胞功能相关分子CD62L表达变化;PI染色法检测CD4~+SP细胞的凋亡情况。结果显示,与对照组相比,LPS注射72h后胸腺大小、重量及细胞总数均明显降低(P0.05),且发生病理形态学异常;胸腺中CD4~+SP细胞比例显著增加,但数量减少(P0.05);此外,CD4~+SP细胞的CD62L表达水平及凋亡比例明显增加(P0.05)。LPS注射8d后胸腺大小、重量及细胞总数均与对照组相比差异不明显(P0.05),且胸腺组织结构未见明显改变;然而,胸腺中CD4~+SP细胞比例及数量仍减少(P0.05);且CD4~+SP细胞中CD62L表达水平降低。结果表明,在内毒素耐受状态下,胸腺CD4~+SP细胞比例发生显著改变,可能与细胞活化和凋亡变化有关。     

microRNA-7基因敲减对小鼠CD4~+SP细胞胸腺发育的影响

目的:研究microRNA-7(miRNA-7,miR-7)基因敲减对小鼠CD4+SP细胞胸腺发育的影响。方法:检测miR-7基因敲减(miR-7 knock down,miR-7KD)和野生型(Wild-type,WT)小鼠胸腺重量及细胞总数变化;HE染色观察miR-7KD小鼠胸腺的形态学结构改变;FACS检测胸腺CD4+单阳性(Single positive,SP)细胞的比例并计算细胞总数,同时检测CD4+SP细胞CD44及CD62L表达变化;核抗原Ki-67染色法检测CD4+SP细胞的增殖情况;FACS检测CD4+SP细胞的凋亡变化;Western blot技术检测胸腺中总ERK1/2和磷酸化ERK1/2表达水平变化。结果:与WT小鼠相比,miR-7KD小鼠胸腺体积、重量以及细胞总数均显著减少,且形态学结构发生改变(P0.05);FACS结果显示,miR-7KD小鼠胸腺CD4+SP细胞比例明显降低,且细胞总数减少(P0.05)。此外,CD4+SP细胞的CD44表达水平显著增加,而CD62L表达水平明显减少(P0.05);同时,CD4+SP细胞增殖及凋亡比例均显著增加(P0.01);最后,miR-7KD小鼠胸腺中ERK1/2以及磷酸化ERK1/2的表达均明显下调(P0.05)。结论:miR-7基因敲减后可显著影响CD4+SP细胞的胸腺发育,这可能与细胞活化水平及ERK1/2信号通路改变有关。     

Deficiency of the expression of CD45RA isoform of CD45 common leukocyte antigen in CD4+ T lymphocytes in children with infantile cholestasis

The immunological background of the pathological changes that appear in infantile cholestasis (infections, inflammatory process in the liver) is largely unknown. With the use of double color flow cytometry, we assessed the distribution of functionally different lymphocyte subpopulations in the peripheral blood of 29 infants with extra and intra-hepatic cholestasis (12 and 17 patients, respectively), aged from 1 to 8.6 months. Control group consisted of 15 age-matched, healthy infants. We examined: (1) the expression of CD3, CD4, CD8, CD19 lymphocyte surface receptors; and (2) the distribution of lymphocyte subsets with distinctive surface Ag characteristics of 'naive' (CD45RA+) and 'memory' (CD45RO+) cells in both CD4+ and CD8+ cell populations. The surface markers expression was evaluated in terms of percentage of positive cells and receptor density. The following changes in the expression of lymphocyte surface markers are described: (1) a decrease in the percentage of total CD3+, CD4+ cells but normal percentage of CD8+ cells and elevated proportion of CD19+ B cells; (2) a reduction of the proportion of 'naive' CD4+ lymphocytes but normal percentage of 'naive' CD8+ as well as 'memory' CD4+ and CD8+ cell subsets; (3) a decrease in density of CD3, CD4+, CD8 receptors, and D45RA isoform in a subset of 'naive' CD4+ cells. We conclude that deficiency of 'naive' CD4+ T cell subset which possess important effector and immunoregulatory functions, and low expression of certain lymphocyte receptors known to be engaged in T cell activation, possibly reflect a defect of cell mediated immunity that may account for viral and bacterial infections, often observed in infants with cholestasis.     

T-cell lung granulomas induced by sepharose-coupled Mycobacterium tuberculosis protein antigens: immunosuppressive phenomena reversed with cyclophosphamide and indomethacin.

We induced lung granulomas in BALB/c mice by intratracheal instillation of Sepharose beads coated with a Mycobacterium tuberculosis protein extract. Granulomas composed of macrophages and lymphocytes were induced. The granulomatous reaction reached its peak 3-7 days after challenge and lasted for approximately 1 month. Immunolabelling of tissue sections and bronchial washings revealed that granulomas were predominantly composed of T lymphocytes with the cytotoxic-suppressor phenotype (CD8+). Granulomas were associated with a significant decrease in anti-mycobacterial immunity manifested by a drop in delayed-type hypersensitivity reactions and antibody titres. The immunosuppressive phenomena were abolished with cyclophosphamide or indomethacin. Control granulomas induced with methylated bovine serum albumin (BSA) were smaller and composed by similar numbers of CD4+ and CD8+ cells. BSA granulomas did not alter antibody titres but they decreased delayed-type hypersensitivity to BSA which was restored to normal with indomethacin but not with cyclophosphamide. Our findings show that mycobacterial proteins anchored to Sepharose beads are granulomatogenic and that they preferentially recruit CD8+ cells which, together with locally produced prostaglandins, down-modulate cell-mediated and humoral immunity to mycobacterial antigens.     

香菇茯苓银耳复合多糖对小鼠巨噬细胞功能的作用研究

目的：研究香菇茯苓银耳复合多糖对不同状态下巨噬细胞功能的调节作用。方法：将巨噬细胞株RAW264.7细胞分别与复合多糖（CP）、复合多糖联合LPS（CP+LPS）、复合多糖预孵育后联合LPS（Pre-CP+LPS）共孵育,采用荧光显微镜和流式细胞仪检测RAW264.7细胞吞噬荧光微球情况;采用Griess试剂检测RAW264.7细胞分泌NO水平;采用流式细胞术检测巨噬细胞表面活化标志物CD40、CD80和CD86的表达水平。结果：RAW264.7细胞与复合多糖共孵育条件下,复合多糖可以增强RAW264.7细胞对荧光微球的吞噬作用,且随着时间的延长愈加明显;复合多糖低浓度对RAW264.7细胞分泌NO无影响,当浓度达1 000 μg/ml时才能促进其显著分泌NO;复合多糖可以提高RAW264.7细胞CD40、CD80和CD86分子表达水平。在LPS刺激条件下,复合多糖联合LPS与复合多糖预孵育后联合LPS两种处理都可以减轻LPS导致的CD40、CD80和CD86活化标志过表达现象。结论：复合多糖对不同状态下巨噬细胞功能具有调节作用,即可以促进静息状态下巨噬细胞活化和吞噬作用,而对活化状态的巨噬细胞功能具有抑制作用。     

T-cell subsets in healthy teenagers: transition to the adult phenotype

Little is known about the normal range and variability of T-cell subsets in older children. We analyzed peripheral blood mononuclear cell subsets in 112 healthy children, ages 12-19 years (mean +/- SD: 15.4 +/- 1.9 years), using monoclonal antibodies and flow cytometry. The study population included 28 blacks and 84 whites, with 59 boys and 53 girls. The mean +/- SD cell subset values were: CD3+ T cells, 74.0 +/- 7.8%; CD4+ helper-inducer T cells, 46.8 +/- 6.9%; CD8+ suppressor-cytotoxic T cells, 27.3 +/- 5.7%; CD4:CD8 helper:suppressor ratio, 1.81 +/- 0.57; CD16+ natural killer cells, 4.4 +/- 3.1%; CD19+ B cells, 10.0 +/- 5.3%; CD14+ monocytes, 20.0 +/- 6.5%; and HLA-DR cells, 15.4 +/- 4.8%. Overall, boys had a higher proportion of HLA-DR+ cells than girls, attributable to an increase in CD19+ B cells. Blacks tended to have a higher proportion of HLA-DR+ cells than whites, apparently due to an increase in activated T cells. Detailed analysis by age group revealed a striking transition in the pattern of CD4+ and CD8+ cell populations. The CD4:CD8 ratio, higher in boys than girls for ages 12-16, was reversed to the "adult" pattern in 17-19 year olds, with a higher CD4:CD8 ratio in girls. These data provide important baseline values for healthy children and stress the importance of establishing normative ranges for pediatric subjects separately from adults.     

Correlation between profile of circulating mononuclear cells and clinical manifestations in patients with pemphigus vulgaris

Phenotypes of 38 samples of mononuclear (PBMC) cells from 11 different patients with pemphigus vulgaris (PV) at different stages of the disease were explored looking for a possible relationship between cell immunity, mucocutaneous or mucosal lesion intensity and capacity of serum autoantibodies to elicit the disease in mice. PBMC from 5 patients with mucocutaneous lesions and sera with IgG capable of inducing the disease in neonatal mice had a high proportion of mature monocytes with CD14low DRhigh, and co-expressing CD16 and CD11b. In addition, a high proportion of CD19+CD5+ activated B cells and a very low proportion of naive CD4+CD45RA+ and CD8+CD11b+ T lymphocytes was observed. Monocytes from these patients expressed inducible nitric oxide synthase (iNOS). In contrast, PBMC from 6 patients, with lesions restricted to mucosal membranes and IgG lacking the capacity to induce the disease in mice, contained a high proportion of CD14high DRlow co-expressing CD16 circulating macrophages, CD8+CD11b+ T cells, and a low proportion of activated B lymphocytes. The results suggest a possible association between proportion of different antigen presenting cells (monocytes with high HLA-DR and low CD14 expression and activated B lymphocytes, or differentiated monocytes/macrophages), type of PV and capacity of serum autoantibodies to elicit the disease in mice.     

Poor immune reconstitution after four or five major HLA antigens mismatched T cell-depleted allogeneic and autologous stem cell transplantation

Two adults with primary liver cancer underwent liver transplantation from 5/6 and 4/6 major HLA-antigen mismatched unrelated donors. They were then conditioned with 4 x 2 Gy of total lymphoid irradiation, 120 mg/kg cyclophosphamide, 7.5 Gy total body irradiation and anti-T cell antibodies. Thereafter, the patients received T cell-depleted autologous: unrelated mismatched bone marrow in a proportion of 0.5:3.0 and 0.35:1.1 x 10(6) CD34+ cells/kg, respectively. After allogeneic stem cell transplantation (ASCT), both became mixed chimeras, as determined with polymerase chain reaction amplification of variable number tandem repeats from DNA obtained from CD3+, CD19+ and CD45+ magnetic bead-separated cells. Due to a reduction in donor T cells, the first patient was given 10(5) donor T cells/kg and became a complete donor chimera within 3 months. The second patient rejected all donor cells within 1 month after ASCT. Leucocytes normalized in both patients within 1 month. CD8+ cells normalized after 4 and 2 months in the two patients, respectively. However, CD4+, CD56+ and CD19+ cells remained low, except for a transient increase in patient 2. Lymphocyte responses to mitogens were negative in patient 1 from 1 to 5 months after ASCT. This patient also showed an oligoclonal pattern of the B cell repertoire, performed by CDR3 spectratyping. Epstein-Barr virus DNA in lymphocytes increased by 4-5 log in both patients. Prior to ASCT, recipients and donors were mutually reactive in mixed lymphocyte cultures (MLC). In the first patient, who became a complete donor chimera, the chimera cells showed no response to recipient or donor, but a positive response to third party. In the other patient, recipient cells reacted vigorously against donor lymphocytes at the time of rejection. Both patients suffered from overwhelming bacterial, fungal and viral infections, and died of pneumonia 5 and 3 months after ASCT, respectively. To conclude, with a major HLA-mismatch barrier, stable mixed chimerism seems difficult to achieve. The first patient became a full donor chimera and the second one rejected the graft. Both suffered from immune incompetence.     

儿童系统性红斑狼疮患者外周血淋巴细胞表面CD95的表达及临床意义

目的:探讨儿童系统性红斑狼疮(systemic lupus erythematosus,SLE)外周血淋巴细胞表达CD95的特征及与疾病活动性和其他免疫学指标间的关系.方法:使用流式细胞术检测60例SLE患儿和20例对照外周血T淋巴细胞亚群和B淋巴细胞表面CD95的表达,并分析其与SLE疾病活动性以及实验室检查之间的关系.结果:初发SLE患儿外周血中CD4+T细胞表面CD95的表达显著高于对照组,差异有统计学意义(P<0.05);初发SLE患儿外周血中CD19+B细胞表面CD95的表达显著高于健康儿童(P<0.05);CD19+CD95+B细胞的比例和SLE疾病活动性呈正相关(r=0.4,P<0.05);CD4+CD95+T细胞的比例和SLE疾病活动性呈正相关(r=0.3,P<0.05),CD4+CD95+T细胞的比例和外周血抗双链DNA抗体(anti-dsDNA Abs)的水平呈正相关(r=0.2,P<0.05);治疗后SLE患儿外周血中CD19+CD95+B细胞和CD4+CD95+T细胞的比例均有显著下降,差异有统计学意义(P<0.05).结论:儿童SLE患者外周血中淋巴细胞表达CD95的水平显著升高,且与SLE的疾病活动性及血清中抗双链DNA抗体相关,可以作为SLE的评价指标.     

Cyclophosphamide augments inflammation by reducing immunosuppression in a mouse model of allergic airway disease

BACKGROUND: Allergic asthma is a TH2 cell-driven immunological disease, characterized by eosinophilic inflammation. The cytotoxic agent cyclophosphamide paradoxically augments several immune responses. OBJECTIVE: We studied the proposal that cyclophosphamide may aggravate airway inflammation in allergic mice, and these features might result from the loss of regulatory T cells. METHODS: BALB/c mice were immunized with ovalbumin on days 0 and 14 and challenged with aerosolized ovalbumin from days 21 to 27. Some mice also received cyclophosphamide on days -2 and 12. RESULTS: In the lungs of cyclophosphamide-treated animals, pronounced worsening of inflammatory features was noted, including increased eosinophil infiltration, epithelial thickness, mucus occlusion, and eosinophil numbers in bronchoalveolar lavage fluid. There was also increased total and ovalbumin-specific serum IgE, increased IL-4 and IL-5 secretion by peritracheal lymph node cells, and reduced lung mRNA expression of IL-10 and TGF-beta in animals treated with cyclophosphamide. The expression of FoxP3, a marker of regulatory T cells, was significantly reduced in lymphoid organs after the second injection of cyclophosphamide, and in the lung tissue after allergen challenge in cyclophosphamide-treated mice. Lung IL-10+CD4+ T cells and cytotoxic T lymphocyte-associated antigen 4+CD4+ T cells were reduced after allergen challenge in cyclophosphamide-treated mice. CONCLUSION: Cyclophosphamide worsened features of allergic pulmonary inflammation in this model, in association with increased production of IgE and TH2 cytokines. The reduced expression of FoxP3 and immunosuppressive cytokines by cyclophosphamide is consistent with the possibility that toxicity to regulatory T cells may contribute to the increased inflammation.     

Aflatoxin B1 albumin adduct levels and cellular immune status in Ghanaians

Although aflatoxins (AFs) have been shown to be immune-suppressive agents in animals, the potential role of AFs in modifying the distribution and function of leukocyte subsets in humans has never been assessed. We examined the cellular immune status of 64 Ghanaians in relation to levels of aflatoxin B1 (AFB1)-albumin adducts in plasma. The percentages of leukocyte immunophenotypes in peripheral blood, CD4+ T cell proliferative response, CD4+ T(h) and CD8+ T cell cytokine profiles and monocyte phagocytic activity were measured using flow cytometry. NK cell cytotoxic function was determined by perforin and tumor necrosis factor-alpha expression in CD3-CD56+ NK cells. AFB1-albumin adducts levels ranged from 0.3325 to 2.2703 (mean = 0.9972 +/- 0.40, median = 0.9068) pmol mg(-1) albumin. Study participants with high AFB1 levels had significantly lower percentages of CD3+ and CD19+ cells that showed the CD69+ activation marker (CD3+CD69+ and CD19+CD69+) than participants with low AFB1 levels (P = 0.002 for both). Also, the percentages of CD8+ T cells that contained perforin or both perforin and granzyme A were significantly lower in participants with high AFB1 levels compared with those with low AFB1 (P = 0.012 for both). Low levels of CD3+CD69+ (r = -0.32, P = 0.016) and CD19+CD69+ (r = -0.334, P = 0.010) cells were significantly associated with high AFB1 levels using correlation analysis. By multivariate analysis, there were strong negative correlations between the percentages of these cells (CD3+CD69+: b = -0.574, P = 0.001, and CD19+CD69+: b = -0.330, P = 0.032) and AFB1 levels. These alterations in immunological parameters in participants with high AFB1 levels could result in impairments in cellular immunity that could decrease host resistance to infections.