Exhaustion of CD8 T cell immune functions in spleen of mice with different doses of Echinococcus multilocularis infections / 中国血吸虫病防治杂志

ObjectiveTo examine the changes in the immune functions of CD8+ T cells in the spleen of mice following Echinococcus multilocularis infections at various doses and at different time points. MethodsThe E. multilocularis protoscoleces were collected, and E. multilocularis infection was modeled in mice via the hepatic portal vein at doses of 50 (low-dose), 500 (medium-dose) and 2 000 protoscoleces (high-dose), while physiological saline served as controls. Mouse spleen was isolated 2 (earlystage), 12 (middle-stage) and 24 weeks post-infection (late-stage), and spleen lymphocytes were harvested. The phenotype of memory CD8+ T cells and 2B4 expression were quantified in the mouse spleen, and the secretion of interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-17A and IL-10 was measured. Results A central-memory phenotype was predominant in the CD8+ T cells in the spleen of mice at the early stage of high-dose protoscolece infections, and the proportion of central-memory CD8+ T cells was significantly greater in the high-dose group than in the control group (35.50% ± 2.00% vs. 25.90% ± 2.46%, P < 0.01), while a effector- memory phenotype was predominant in the CD8+ T cells in the spleen of mice at the late stage of medium- and high-dose protoscolece infections, and the proportions of effector-memory CD8+ T cells were significantly greater in the medium- (25.70% ± 4.12%) and high-dose group (28.40% ± 4.12%) than in the control group (10.50% ± 6.45%) (P < 0.05). The proportions of the central-memory CD8+ T cells were significantly higher in the high-dose group than at middle and late stages than at the early stage (P < 0.01), and the proportion of effector-memory CD8+ T cells was significantly greater in the high-dose group at the late stage than at early and middle stages (P < 0.05). The secretion of IFN-γ and IL-17A by spleen CD8+ T cells was elevated in the low- and medium-dose groups at the early stage of infection, and high-dose protoscolece infection promoted the secretion of IFN-γ and TNF-α by spleen CD8+ T cells; however, the levels of IFN-γ and TNF-α were significantly lower at the late stage than at the early and middle stages (P < 0.05). In addition, high 2B4 expression was detected in spleen CD8+ T cells in the middle- and high-dose groups at the late stage of infection, and the 2B4 expression was significantly higher in the medium(4.73% ± 1.56%) and high-dose groups (4.94% ± 1.90%) than in the low-dose group (2.49% ± 0.58%) and the control group (2.92% ± 0.60%) (P < 0.05). Conclusions E. multilocularis may be killed and eliminated through the host immune responses at the middle and late stages of low- and medium-dose protoscolece infections, while high-dose protoscolece infections may trigger the upregulation of 2B4 expression in mouse spleen CD8+ T cells at the late stage, which leads to immune exhaustion and the resultant chronic infections.

Echinococcus multilocularis infection leads to increased expression of proliferation and anti-apoptosis factors in liver cells in BALB/c mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of Echinococcus multilocularis on host liver cell proliferation in vivo using a BALB/c mouse alveolar hydatid infection model.</p><p><b>METHODS</b>Sixty-five 8-10-week-old female BALB/c mice were randomly divided into an experimental group (n = 40) and a control group (n = 25) and administered an abdominal injection into the left liver lobe of E. multilocularis protoscolices in saline solution or saline solution alone, respectively. At post-injection day 2, 8, 30, 60, and 90, liver samples were collected for analysis of lesions and lesion-adjacent tissue by hematoxylin-eosin staining and differential expression of proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin A, and cyclin B1 by immunohistochemical staining. The significance of intergroup differences was assessed by Student's t-test.</p><p><b>RESULTS</b>The control group showed normal liver histology at all time points. The experimental group developed E. multilocularis lesions that showed increased severity of pathological features, such as inflammatory cell invasion, steatosis and fibrous connective tissue hyperplasia, over time. At post-injection days 2 and 8, enlarged, binuclear and apocyte hepatocytes were observed close to the lesions. At post-injection days 30, 60, and 90, the number of hepatocytes expressing PCNA progressively increased in the experimental group, and the numbers were significantly higher than in the control group (7.01 +/- 1.89 vs. 1.03 +/- 0.52, 8.41 +/- 2.80 vs. 0.93 +/- 0.31, and 13.4 +/- 4.43 vs. 1.07 +/- 0.94; all P < 0.05). The same progressively increasing trend was seen in the number of hepatocytes expressing CyclinD1, but was only significantly different from controls at post-injection days 30 and 60 (6.73 +/- 2.52 vs. 0.48 +/- 0.43 and 8.22 +/- 3.09 vs. 0.55 +/- 0.34; both P < 0.05). In contrast, the number of hepatocytes expressing cyclin A was significantly increased at post-injection day 30 and then showed a decreasing trend at days 60 and 90, although the numbers of expressing cells remained significantly higher than control levels at all time points (7.75 +/- 3.05 vs. 0.69 +/- 0.36, 3.42 +/- 1.80 vs. 1.14 +/- 0.42, and 3.03 +/- 1.50 vs. 0.69 +/- 0.31; all P < 0.05). The number of hepatocytes expressing CyclinB1 in the experimental group was less robust than the other cyclins (with a general temporal trend of increase followed by decrease), but the differential expression was not significantly different from the control levels at any time point.</p><p><b>CONCLUSION</b>E. multilocularis infection may promote the expression of host factors related to proliferation and anti-apoptosis in liver. This pathogen-mediated modulation of host cell-survival mechanisms may provide a rationale explanation for the clinical observations of hepatomegaly and the unexpected survival of alveolar echinococcosis patients following major hepatic resection.</p>

Diagnostic value of absent ductular reaction at hepatocellular-stromal boundaries in early stage hepatocellular carcinoma / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the role of absent ductular reaction (DR) at hepatocellular-stromal boundaries in early stage hepatocellular carcinoma (HCC) with cirrhosis in patients with chronic hepatitis B.</p><p><b>METHODS</b>Cytokeratin (CK)7 and CK19 expression was detected by the SP immunohistochemistry method in 112 hepatic nodules taken from 20 cases of early HCC, 26 cases of HCC with nodules more than 3 cm, 20 cases of high-grade dysplastic nodule (HGDN), 26 cases of low-grade dysplastic nodule (LGDN), and 20 cases of cirrhosis (CIR). DR/CK7 and DR/CK19 were assessed separately on a semi-quantitative scale and statistically analyzed.</p><p><b>RESULTS</b>The mean age of the patients in the study was 53.71 years-old, and the study population consisted of 73 males and 39 females. The follow-up time ranged from 3 to 90 months. Positive CK7 and CK19 staining was detected in the cytoplasm of DR-positive hepatobiliary cells, interlobular bile duct, and a portion of hepatic cells. All of the DR/CK7- and DR/CK19-positive cells were localized around the non-invasive nodules. Specimens with focal or diffuse DR/CK7- and DR/CK19-loss had more robust stromal invasion. Specimens from early HCC cases showed greater DR/CK19 loss than specimens from HGDN cases, LGDN cases and CIR cases (all P less than 0.01). DR/CK7 loss of early HCC was less than HCC with nodules more than 3 cm (P less than 0.05), and more than LGDN cases and CIR cases (both P less than 0.01).The area under the receiver operating characteristic curve of DR/CK7 was very similar to that of DR/CK19 (P more than 0.05). Pearson's correlation analysis indicated that DR/CK7 and DR/CK19 were positively correlated with tumor-free time (P less than 0.01) and negatively correlated with early recurrence time as well as death rate (both P less than 0.01). Furthermore, cases showing DR/CK7 or DR/CK19 loss had lower overall survival rate and tumor-free survival rate (P less than 0.01) and higher early recurrence rate (P less than 0.01).</p><p><b>CONCLUSION</b>DR/CK7 and DR/CK19 immunostaining may help to distinguish non-invasive HGDNs from both minimally-invasive and overtly-invasive HCCs by identifying small foci of invasion and predicting increased risk of invasiveness.</p>

Effect of Echinococcus granulosus cyst fluid on the proliferation of HepG2 cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate whether Echinococcus granulosus cyst fluid-infected host liver cells had differential expression of mitogen-activated protein kinases (MAPKs) or differential cell cycle activity.</p><p><b>METHODS</b>Human liver cells cultured with different concentrations of hydatid cyst fluid (HCF) were tested by the MTT method to determine effects on proliferation. The cell cycle was assessed by flow cytometry. Western blotting was used to detect changes in protein expressions of p-ERK, PCNA, cyclin-A, cyclin-B1, cyclin-D1, and cyclin-E.</p><p><b>RESULTS</b>Forty-eight, 72 and 96 h of HCF at 15%, 30% and 60% concentrations in the cell media significantly promoted cell proliferation (F=67.845, P less than 0.01) and compared to controls (P less than 0.05). Cells exposed to 15% HCF for 48 h showed significantly induced expression of p-ERK (F=1.916, P less than 0.01), higher than controls (P less than 0.01). Cells exposed to 15% HCF for 24 h showed significantly induced expression of cyclin-Dl (F=3.901, P less than 0.01), higher than controls (P less than 0.01). Cells exposed to 15% HCF for 48 h or 30% HCF for 72 h showed significantly induced expression of PCNA (F=91.140, P less than 0.01), higher than controls (P less than 0.01). Cells exposed to 15% HCF for 48 h or 30% HCF for 72 h shed significantly induced expression of cyclin-A (F=18.587, P=0.002), higher than controls (P less than 0.01). Cells exposed to 15% HCF for either 48 h or 72 h showed significantly induced expression of cyclin-B1 (F=2.064, P less than 0.01), higher than controls (P less than 0.01). Cells exposed to 30% HCF for 96 h showed significantly induced expression of cyclin-E (F=1.068, P less than 0.01), higher than controls (P less than 0.01).</p><p><b>CONCLUSION</b>Hydatid cyst fluid exerts no inhibitory effect on primary cultured host liver cells, but may promote cellular proliferation.</p>

Molecular characterization of a signal-regulated kinase homolog from Echinococcus granulosus / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cystic echinococcosis due to Echinococcus granulosus (E. granulosus) is one of the most important chronic helminthic diseases, especially in sheep/cattle-raising regions. The larval stage of the parasite forms a cyst that grows in the liver, lung, or other organs of the host. To ensure a long life in the host tissues, the parasite establishes complex inter-cellular communication systems between its host to allow its differentiation toward each larval stage. Recent studies have reported that this communication is associated with the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase cascade in helminth parasites, and in particular that these protein kinases might serve as effective targets for a novel chemotherapy for cystic echinococcosis. The aim of the present study investigated the biological function of a novel ERK ortholog from E. granulosus, EgERK.</p><p><b>METHODS</b>DNA encoding EgERK was isolated from protoscolices of E. granulosus and analyzed using the LA Taq polymerase chain reaction (PCR) approach and bioinformatics. Reverse transcription PCR (RT-PCR) was used to determine the transcription level of the gene at two different larval tissues. Western blotting was used to detect levels of EgERK protein. The expression profile of EgERK in protoscolices was examined by immunofluorescence.</p><p><b>RESULTS</b>We cloned the entire Egerk genomic locus from E. granulosus. In addition, two alternatively spliced transcripts of Egerk, Egerk-A, and Egerk-B were identified. Egerk-A was found to constitutively expressed at the transcriptional and protein levels in two different larval tissues (cyst membranes and protoscolices). Egerk-A was expressed in the tegumental structures, hooklets, and suckers and in the tissue surrounding the rostellum of E. granulosus protoscolices.</p><p><b>CONCLUSIONS</b>We have cloned the genomic DNA of a novel ERK ortholog from E. granulosus, EgERK (GenBank ID HQ585923), and found that it is constitutively expressed in cyst membrane and protoscolex. These findings will be useful in further study of the biological functions of the gene in the growth and development of Echinococcus and will contribute to research on novel anti-echinococcosis drug targets.</p>