Bacterial ghosts (BGs)—Advanced antigen and drug delivery system

Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2–3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy.     

多发性骨髓瘤患者血浆尿激酶型纤溶酶原激活物及其可溶性受体的检测与临床意义

目的 :研究多发性骨髓瘤 ( MM)患者血浆尿激酶型纤溶酶原激活物 ( u- PA )及其可溶性受体 ( su PAR )的水平变化 ,并探讨其临床意义。方法 :用 ELISA法检测 34例 MM患者血浆 u- PA及 su PA R的浓度 ,同时观察其中6例 MM患者化疗前后血浆 u- PA及 su PAR的浓度变化。结果 :MM患者血浆 u- PA及 su PA R水平均明显高于正常对照组 ,其中进展期 MM患者血浆 u- PA及 su PAR水平明显高于正常对照组和稳定期 MM患者 ( P <0 .0 1) ,而稳定期 MM患者血浆 u- PA及 su PA R水平与正常对照组无显著性差异 ( P>0 .0 5)。 6例 MM患者化疗后血浆 u- PA及 su PA R水平 ,明显低于化疗前血浆 u- PA及 su PAR水平 ( P<0 .0 5)。骨髓涂片瘤细胞比例 >2 0 %的 MM患者血浆 u- PA及 su PA R水平 ,明显高于瘤细胞比例≤ 2 0 % M M患者 ( P<0 .0 5;P<0 .0 1)。M M患者血浆 u- PA及su PA R水平均与骨髓瘤细胞百分比及血清球蛋白呈正相关 ,而与血清白蛋白呈负相关。结论 :血浆 u- PA及 su PA R水平升高可能与多发性骨髓瘤的发生、发展有密切关系 ;其水平可作为临床分期、判断疗效、了解疾病进展情况及预后的一个重要指标。     

瘦素受体在条件性厌味大鼠脑的表达

目的 :观察瘦素受体 (LR)在条件性厌味 (CTA)大鼠脑的表达 .方法 :采用高度特异的抗瘦素受体血清 ,用免疫组化ABC法观察LR在CTA和对照大鼠脑的分布与表达 .结果 :与对照组大鼠相比 ,CTA大鼠皮层Ⅲ层、视交叉上核、弓状核、杏仁基底外侧核、海马CA3、下丘脑外侧区等核团瘦素受体表达增加 (14 6vs 12 0 ,138vs 92 ,118vs 78,10 7vs70 ,85vs 38cells·mm-2 ,P <0 .0 5 ) ,而下丘脑前区、脑桥臂旁核、杏仁中央核瘦素受体表达减弱 (13vs2 6 ,70vs5 5 ,12 2vs 16 2cells·mm-2 ,P <0 .0 5 ) ,孤束核瘦素受体的表达与对照大鼠无显著性差异 (5 0vs 5 7cells·mm-2 ,P >0 .0 5 ) .结论 :瘦素可能通过杏仁核、臂旁核、海马、皮层的瘦素受体参与CTA的形成与维持     

性别差异对脓毒症大鼠肝脏Toll样受体4和髓样分化蛋白-2基因表达的影响

目的探讨性别差异对脓毒症大鼠肝脏组织Toll样受体4(TLR4)和髓样分化蛋白- 2(MD-2)基因表达的影响。方法以脂多糖(LPS)按5 mg/kg体重由大鼠腹腔注射制作脓毒症动物模型,注射后2 h留取肝脏组织检测TLR4、MD-2和肿瘤坏死因子-α(TNF-α)基因表达,同时测定各组大鼠血浆中丙氨酸氨基转移酶(ALT)及雌二醇含量。结果正常雌雄性大鼠肝脏组织均可表达少量TLR4、MD-2、TNF-α基因,其中雌性组分别为0．175±0．034、0．211±0．044、0．201±0．068; 雄性组分别为0．205±0．061、0．243±0．049、0．243±0．063,两组数据差异无统计学意义(P> 0．05),但LPS刺激后雌性大鼠肝脏组织上述指标分别为0．615±0．089、0．708±0．181、0．730± 0．118,血浆中ALT含量为(81．07±10．72)U／L;雄性组分别为0．723±0．091、1．123±0．272、 0．881±0．156,ALT含量为(106．39±14．21)U／L,雌性组各项指标均明显低于雄性大鼠(P< 0．05)。相关分析表明雌性及雄性脓毒症大鼠肝脏组织TLR4及TNF-α基因表达与相应性别大鼠血浆中雌二醇含量呈显著负相关(P<0．05)。结论 LPS刺激后大鼠肝脏组织TLR4、MD-2及 TNF-α基因表达存在性别差异,内源性雌激素的作用可能导致雌性脓毒症大鼠肝脏组织损伤较雄性轻。     

Association between cord blood IgE and genetic polymorphisms of interleukin-4, the β-subunit of the high-affinity receptor for IgE, lymphotoxin-α, and tumor Necrosis factor-α

High cord blood immunoglobulin E (cbIgE) is known to be associated with increased risks of atopic diseases in childhood. The relationship between genetic polymorphisms and high cbIgE has not been well documented. A cross-sectional study was conducted to assess the association between cbIgE and genetic polymorphisms of interleukin (IL)-4 -590C/T, the beta-subunit of the high-affinity receptor for IgE (FcepsilonRI-beta) E237G, lymphotoxin (LT)-alphaNcoI alleles, and tumor necrosis factor (TNF)-alpha -308G/A. A total of 320 mother-neonate pairs were recruited from four maternity hospitals from different locations of Taiwan. Cord blood was obtained and assayed for cbIgE. Polymerase chain reaction followed by restriction fragment length polymorphism was used to assess the genotypes. Three hundred pairs of mothers and neonates were included in the final analysis. Infants with IL-4 -590 C allele were found to have higher risk of elevated cbIgE (> or =0.35 IU/ml, 24.3%) (p = 0.004). After adjusting for gender, birth order, maternal age, and history of allergic disease in maternal and paternal families, odds ratios for CC and CT genotypes were 4.41 and 3.16 (95% confidence interval 0.78-22.67, and 1.66-6.13), respectively, using TT genotype as reference. The genotypes of FcepsilonRI-beta, LT-alpha, and TNF-alpha were not associated with cbIgE before or after the adjustment. Our finding suggested a significant association of cbIgE with genetic polymorphism of IL-4 -590C/T, but not with the genotypes of FcepsilonRI-beta, LT-alpha, and TNF-alpha.     

Expression profile of chemokines and chemokine receptors in epithelial cell layers of oral lichen planus

BACKGROUND: To understand the immunopathological features of oral lichen planus (OLP), we analyzed the expression of chemokines in the epithelial cell layers. Methods: Epithelia from OLP or healthy gingiva were collected by laser microdissection. The chemokine and chemokine receptor expressions in the epithelia were analyzed by DNA microarray. RESULTS: High levels of MIP-3alpha/LARC/CCL20 and its receptor CCR6 were expressed in the lesional epithelia. Furthermore, DC-CK1/CCL18, ELC/CCL19, SDF-1/CXCL12 and CXCR4 expressions were also increased. Immunohistologial analysis showed that high numbers of Langerhans cells (LCs) were present in the epithelia of OLP. Lesional epithelia also expressed high levels of the ligands specific for CXCR3 (e.g. MIG/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11) and CCR5 (e.g. RANTES/CCL5). CONCLUSIONS: Infiltration of LCs is orchestrated by CCR6. Further, LCs residing in the lesional epithelia may be a mature phenotype. Moreover, infiltration of T cells in OLP could be mediated by signaling pathways through CXCR3 and CCR5.     

The participation of adenosine receptors in the adenosine 5''-triphosphate-induced relaxation in the isolated rabbit corpus cavernosum penis

AIM: To investigate the participation of adenosine receptors in the adenosine 5'-triphosphate (ATP)-induced relaxation in the corpus cavernosum penis (CCP) of rabbits. METHODS: The ATP-induced relaxation was assessed on the noradrenaline precontracted CCP of rabbits in the presence and absence of 8-(3-chlorostyryl)caffeine (CSC); an adenosine A(2A) receptor antagonist; alloxazine and MRS1754; adenosine A(2B) receptor antagonists; and ARL67156, an inhibitor of ecto-nucleoside triphosphate diphosphohydrolases. RESULTS: Adenosine and ATP relaxed the noradrenaline precontracted CCP of rabbits in a concentration-dependent manner. The adenosine- and ATP-induced relaxations were suppressed by alloxazine and MRS1754, but not by 8-(3-chlorostyryl)caffeine. ARL67156 potentiated the ATP-induced relaxation but not the adenosine-induced one. MRS1754 suppressed the ATP-induced relaxation potentiated by ARL67156. CONCLUSIONS: The above results suggest that, in the CCP of rabbits, the adenosine receptor mediating adenosine-induced relaxation is of the A(2B) receptor and the ATP directly causes relaxation through the A(2B) receptor on the CCP.     

Correlation between 5-HT7 receptor affinity and protection against sound-induced seizures in DBA/2J mice

Audiogenic seizures can be induced in DBA/2J mice following intense auditory stimulation. A number of neurotransmitters, including 5-hydroxytryptamine (5-HT), are believed to be involved in mediating this effect since it has been shown previously that depletion of 5-HT or blockade of 5-HT receptors protects DBA/2J mice from these audiogenic seizures. The present study was undertaken to determine whether antagonism of the newly identified 5-HT₇ receptor may protect DBA/2J mice from audiogenic seizures by attempting to correlate in vivo potency of compounds with their affinity at the 5-HT₇ receptor. All compounds used in the correlation were shown to be antagonists at the 5-HT₇ receptor and a statistically significant correlation was observed between 5-HT₇ affinity and doses for half-maximal response (ED₅₀) for protection of DBA/2J mice from sound-induced seizures (r = 0.80; P < 0.05). No significant correlation was observed between in vivo activity and affinity at either 5-HT_1A, 5-HT_2A or 5-HT_2C receptors. It is also unlikely that interactions between the 5-ht₅ receptor will protect DBA/2J mice from audiogenic seizures since metergoline and mesulergine which are both active in this in vivo model have no affinity for the 5-ht₅ receptor. There are similarities between the pharmacology of the 5-HT₇ receptor and that of the 5-HT_1A receptor, however the correlation between the in vivo potency in DBA/2J mice and 5-HT_1A affinity was not significant. Furthermore, the 5-HT_1A receptor antagonist WAY 100135 did not protect DBA/2J mice from audiogenic seizures at doses that antagonise 5-HT_1A receptor-mediated effects in mice. These data suggest that antagonism of 5-HT₇ receptors may protect against audiogenic seizures in DBA/2J mice although a definitive conclusion must await studies with selective 5-HT₇ antagonists. Received: 20 March 1997 / Accepted: 10 August 1997     

Nonspecific immunity in pregnancy: monocyte surface Fcγ receptor expression and function

The state of pregnancy is an immunological enigma during which the body must prevent rejection of the antigenically foreign fetus while at the same time maintain sufficient maternal host defense mechanisms to combat infection. Although most studies on the immunology of pregnancy focus on immune suppression, several studies have shown an increase in nonspecific host defense, which is postulated to be a compensatory mechanism for decreased specific immunity during pregnancy. Studies in this laboratory have shown that monocyte surface FcγRI (CD64) and FcγRII (CD32) expression progressively increase throughout pregnancy, while surface MHC class II expression remains unchanged. Functional studies revealed that the number of phagocytic monocytes which could be isolated from pregnant women was increased. These cells exhibited an increased capacity to ingest IgG-opsonized human erythrocytes. This study shows for the first time that monocyte surface FcγR expression and FcγR-mediated functions are increased during pregnancy. These results support the hypothesis that nonspecific immunity as represented by FcγR expression and function is increased during pregnancy.