Quantitative cytokine gene expression in human tonsils at excision and during histoculture assessed by standardized and calibrated real-time PCR and novel data processing

Is There a Difference between the Preoperative and Postoperative Serum Levels of Interleukin-6 and Tumor Necrosis Factor-α in Children Submitted to Adenotonsillectomy?

Introduction  Palatine and pharyngeal tonsils are the first line of defense against pathogens. Clinically, two alterations may require surgical removal of the tonsils: hypertrophy and recurrent tonsillitis. The two conditions probably result from a dysfunction of the immune system.

Objective  To evaluate possible differences in the plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in patients submitted to adenotonsillectomy.

Methods  Prospective, longitudinal study with 25 children undergoing adenotonsillectomy separated into 3 different groups: recurrent tonsillitis (RT), composed of 7 patients; recurrent hypertrophy tonsillitis (RTTH), with 8 patients; and the tonsillar hypertrophy (TH) group, with 10 patients. Ten healthy control children (SD) were also included in the study. Peripheral blood was collected, and plasma was separated to measure the levels of TNF-α, IL-6, and IL-10. The Mann-Whitney test was used for statistical analysis.

Results  The plasma level of IL-6 was higher in the RT ( p  = 0.0394) and TH ( p  = 0.0009) groups, compared with the control group. The TH group also had higher levels of IL-6 than the RT group ( p  = 0.039). The IL-6/IL-10 ratio was higher in the RT ( p  = 0.029) and TH ( p  = 0.0005) groups compared with the control group. Between the RT and RTTH groups, the IL-6/IL-10 ratio was higher in the RT group, with a statistically significant difference ( p  = 0.0091).

Conclusion  Patients with a history of chronic tonsillitis had higher levels of IL-6, compared with the control group.

Adhesion, proliferation and differentiation of human mesenchymal stem cell on chitosan/collagen composite scaffold

In vitro tissue engineering requires a progenitor cell source and a porous scaffold providing three dimensional (3D) supports for growth and differentiation to attain tissue architectures. This research focused on fabrication and characterization of 3D porous scaffolds using chitosan (CS), collagen (CG) and chitosan-collagen (CS-CG) composite to investigate their influence on human mesenchymal stem cell (hMSC) adhesion, proliferation and differentiation. Material dependent variations in porous morphology and mechanical behavior of the fabricated CS, CG and CS-CG scaffold showed significant impact on hMSC adhesion, proliferation and differentiation. The maximum hMSC adhesion and proliferation was reported on CS-CG scaffold among all fabricated scaffold groups. Interconnectivity of pores structure in CS-CG scaffold was considered as preferable attribute for such enhanced growth and distribution throughout the scaffold. Besides, CS scaffold with well interconnected pores showed poor adhesion and proliferation because of inadequate adhesion motifs. In case of CG scaffold, optimum growth and distribution of hMSC occurs only at the surface because of the absence of interconnectivity in their pore structures. Likewise, osteogenic differentiation of hMSC occurs most preferably in CS-CG composite scaffold among all scaffold groups. Such enhanced hMSC proliferation and differentiation in CS-CG scaffold significantly influenced on mechanical behavior of scaffold which is essential for in vivo application of a bone tissue implant. Thus CS-CG composite scaffold holds promise to be a suitable platform for in vitro engineering of bone tissue implant.

Effects of culture conditions on the mechanical and biological properties of engineered cartilage constructed with collagen hybrid scaffold and human mesenchymal stem cells

Mesenchymal stem cells (MSCs) has been used as one of the new cell sources in osteochondral tissue engineering. It has been well known that control of their differentiation into chondrocytes plays a key role in developing engineered cartilages. Therefore, this study aims to develop a fundamental protocol to control the differentiation and proliferation of MSCs to construct an engineered cartilage. We compared the effects of three different culture conditions on cell proliferation, extracellular matrix formation and the mechanical response of engineered cartilage constructed using a collagen-based hybrid scaffold and human MSCs. The experimental results clearly showed that the combined culture condition of the chondrogenic differentiation culture and the chondrocyte growth culture exhibited statistically significant cell proliferation, ECM formation and stiffness responses as compared to the other two combinations. It is thus concluded that the combination of the differentiation culture with the subsequent growth culture is recommended as the culture condition for chondrogenic tissue engineering using hMSCs.

Protein and mRNA expression of folic acid-associated enzymes as biomarkers for the cytotoxicity of the thymidylate synthase-targeted drugs, pemetrexed and S-1, in non-small cell lung cancer

The thymidylate synthase (TS)-targeted drugs, pemetrexed and S-1, exert an important role in advanced non-small cell lung cancer (NSCLC) treatment; folic acid-associated enzymes are expected to behave as biomarkers, although their role has yet to be fully elucidated. In the present study, a single-institutional prospective analysis, in which the mRNA and protein expression levels of five folic acid-associated enzymes were evaluated with surgical specimens of NSCLC, was performed. Drug sensitivity was evaluated using a collagen gel droplet-embedded culture drug sensitivity test (CD-DST) in vitro. A total of 50 patients with NSCLC were enrolled, and the mRNA and protein expression levels of five enzymes were assessed in 47 and 46 patients, respectively. A significant association was identified between mRNA and protein expression in TS (r=0.6266), but the correlation between mRNA and protein expression levels for the other four enzymes was poor. TS mRNA expression was significantly higher in poorly differentiated tumors compared with moderately differentiated tumors (P=0.0399). TS protein expression was significantly higher in patients with pleural invasion or lymphatic invasion compared with those lacking them (P=0.027 and 0.030, respectively). CD-DST revealed that none of the tumors that were sensitive to pemetrexed, but not to S-1, were well differentiated, whereas none of the tumors that were sensitive to S-1, but not to pemetrexed, were poorly differentiated. More prominent vascular invasion was observed in the tumors that were sensitive to S-1. The only factors that exhibited the potential to discriminate the cytotoxicity of pemetrexed from S-1 were tumor differentiation grade and vascular invasion.

Impact of insulin-like growth factor-1 receptor and amphiregulin expression on survival in patients with stage II/III gastric cancer enrolled in the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer

BACKGROUND

Exploratory biomarker analysis was conducted to identify factors related to the outcomes of patients with stage II/III gastric cancer using data from the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer, which was a randomized controlled study comparing the administration of an orally active combination of tegafur, gimeracil, and oteracil with surgery alone.

METHODS

Formalin-fixed paraffin-embedded surgical specimens from 829 patients were retrospectively examined, and 63 genes were analyzed by quantitative real-time RT-PCR after TaqMan assay-based pre-amplification. Gene expression was normalized to the geometric mean of GAPDH, ACTB, and RPLP0 as reference genes, and categorized into low and high values based on the median. The impact of gene expression on survival was analyzed using 5-year survival data. The Benjamini and Hochberg procedure was used to control the false discovery rate.

RESULTS

IGF1R and AREG were most strongly correlated with overall survival, which was significantly worse in high IGF1R patients than low IGF1R patients, but better in high AREG patients than low AREG patients. The hazard ratio for death in the analysis of overall survival (S-1 vs. surgery alone) was reduced in the high IGF1R group compared with the low IGF1R group and in the low AREG group compared with the high AREG group. There were no significant interaction effects.

CONCLUSION

IGF1R gene expression was associated with poor outcomes after curative resection of stage II/III gastric cancer, whereas AREG gene expression was associated with good outcomes. No significant interaction effect on survival was evident between S-1 treatment and gene expression.

Variation of mechanical behavior of β-TCP/collagen two phase composite scaffold with mesenchymal stem cell in vitro

The primary aim of this study is to characterize the variational behavior of the compressive mechanical property of bioceramic-based scaffolds using stem cells during the cell culture period. β-Tricalcium phosphate (TCP)/collagen two phase composites and β-TCP scaffolds were fabricated using the polyurethane template technique and a subsequent freeze-drying method. Rat bone-marrow mesenchymal stem cells (rMSCs) were then cultured in these scaffolds for up to 28 days. Compression tests of the scaffolds with rMSCs were periodically conducted. Biological properties, such as the cell number, alkaline phosphatase (ALP) activity, and gene expressions of osteogenesis, were evaluated. The microstructural change due to cell growth and the formation of extracellular matrices was examined using a field-emission scanning electron microscope. The compressive property was then correlated with the biological properties and microstructures to understand the mechanism of the variational behavior of the macroscopic mechanical property. The porous collagen structure in the β-TCP scaffold effectively improved the structural stability of the composite scaffold, whereas the β-TCP scaffold exhibited structural instability with the collapse of the porous structure when immersed in a culture medium. The β-TCP/collagen composite scaffold exhibited higher ALP activity and more active generation of osteoblastic markers than the β-TCP scaffold.

Correlation between S-1 treatment outcome and expression of biomarkers for refractory thymic carcinoma

BACKGROUND

Thymic carcinoma is a rare cancer with minimal evidence of a survival benefit following chemotherapy. An oral fluoropyrimidine of S-1, however, is the recommended active cytotoxic chemotherapy agent for refractory thymic carcinoma based on a case series, whereas sunitinib or everolimus are recommended as molecular-targeted agents based on Phase II trials. We retrospectively investigated the efficacy of S-1 for refractory thymic carcinoma and performed a biomarker analysis.

METHODS

We assessed the clinicopathological variables of 14 consecutive patients who underwent S-1 for refractory thymic carcinoma and correlated the clinical outcomes with potential biomarkers using paraffin-embedded cancer tissues of eight patients in the cohort.

RESULTS

A total of 178 thymic malignancies were identified, of whom 14 patients included 12 cases of squamous cell carcinoma, one lymphoepithelioma-like carcinoma, and one undifferentiated carcinoma. Six patients exhibited a partial response (42.9 %: 95 % confidence interval [CI], 21.4-67.4) and the disease control rate was 85.7 % (60.0-96.0 %). After a median follow-up of 24.2 months, the median progression-free survival was 8.1 months (range, 2.6-12.2 months), and median overall survival was 30.0 months (range, 6.2-41.9 months). No significant correlation between biomarker expression and response was noted. However, thymidine synthase (TS)/dihydropyrimidine dehydrogenase and TS/orotate phosphoribosyltransferase were observed.

CONCLUSIONS

S-1 for refractory thymic carcinoma offered clinical activity and achieved an 85 % disease control rate. Although the biomarkers did not correlate with clinical outcome, the study results showed efficacy of S-1 as a cytotoxic chemotherapy for refractory thymic carcinoma, which warrants future investigation.

In vitro bone formation by mesenchymal stem cells with 3D collagen/β-TCP composite scaffold

Recent years, various kinds of natural polymers and bioceramics has been used to develop porous scaffolds for bone tissue engineering. Among of them, collagen guarantees good biological conditions, and β-tricalcium phosphate (β-TCP) possesses good oseteoconductivity, cellular adhesion, accelerated differentiation and mechanical property. In this study, rat bone marrow mesenchymal stem cells (rMSC) were cultured in β-TCP/collagen composite scaffolds up to 28 days in order to assess the time-dependent behavior of the extracellular matrix formation and the mechanical performance of the scaffold-cell system. The cell number and ALP activity were evaluated using a spectrophotometric plate reader. Gene expression of osteogenesis was analyzed using the real-time PCR reactions. Compression tests were also conducted periodically by using a conventional testing machine to evaluate the elastic modulus. The increasing behaviors of cell number and ALP activity in the composite scaffold were much better than in the collagen scaffold. The gene expression of osteocalcin and collagen type-I in collagen/β-TCP scaffold was higher than that of the collagen scaffold. The compressive modulus also increased up to 28 days. These results clearly showed that the distribution of micro β-TCP particles is very effective to increase the elastic modulus and promote cell growth.

Immunoregulatory cytokines and chronic tonsillitis

The purposes of the present study were to determine the distribution of cells producing cytokines: tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) in different morphological sections of tonsils in patients with tonsillar hypertrophy (TH) and recurrent tonsillitis (RT), to analyze the level of production of these cytokines in TH and RT and evaluate the potential of peripheral blood lymphocytes for production of interferon-γ (IFN-γ) and interleukin 4 (IL-4). Analyzed materials consisted of the tonsils after tonsillectomy and blood taken from patients right before tonsillectomy (study group) and blood taken from healthy donors (control group).We used histological and immunohistochemical method, morphometric methods for the quantification of TNF-α and IL- 6 producing cells and immunological methods for determining the concentration of IFN-γ and IL-4. Most of TNF-α producing cells are settled in the subepithelial region (55%). Numerical density of TNF-α producing cells in the crypt epithelium, subepithelial and interfollicular region was significantly higher in RT compared with TH. The concentration of IFN-γ is three times higher in RT then in TH. After the stimulation of peripheral blood lymphocytes in culture there was no significant increase in concentrations of IL- 4. The index of stimulation of IFN-γ was the highest in the RT, and of IL- 4 in TH. The production of Th1-type cytokines (TNF-α and IFN-γ) is higher in RT compared with TH. In both forms of tonsillitis, production of Th1-type cytokines is higher in relation to the production of Th2-type cytokines (IL-6 and IL-4).

Effects of proliferation and differentiation of mesenchymal stem cells on compressive mechanical behavior of collagen/β-TCP composite scaffold

The primary aim of this study is to characterize the effects of cell culture on the compressive mechanical behavior of the collagen/β-tricalcium phosphate (TCP) composite scaffold. The composite and pure collagen scaffolds were fabricated by the solid-liquid phase separation technique and the subsequent freeze-drying method. Rat bone marrow mesenchymal stem cells (rMSCs) were then cultured in these scaffolds up to 28 days. Compression test of the scaffolds with rMSCs were conducted periodically. Biological properties such as cell number, alkaline phosphatase (ALP) activity, and gene expressions of osteogenetic bone markers were evaluated during cell culture. The microstructural changes in the scaffolds during cell culture were also examined using a scanning electron microscope. The compressive elastic modulus was then correlated with those of the biological properties and microstructures to understand the mechanism of variational behavior of the macroscopic elastic property. The composite scaffold exhibited higher ALP activity and more active generation of osteoblastic markers than the collagen scaffold, indicating that β-TCP can activate the differentiation of rMSCs into osteoblasts and extracellular matrix (ECM) formation such as type I collagen and the following mineralization. The variational behavior of the compressive modulus of the composite scaffold was affected by both the material degradation and the proliferation of cells and the ECM formation. In the first stage, the modulus of the composite scaffold tended to increase due to cell proliferation and the following formation of network structure. In the second stage, the modulus tended to decrease because the material degradation such as ductile deformation of collagen and decomposition of β-TCP were more effective on the property than the ECM formation. In the third stage, active calcification by formation and growth of mineralized nodules resulted in the recovery of modulus. It is concluded that the introduction of β-TCP powder into the porous collagen matrix is very effective to improve the mechanical and biological properties of collagen scaffold prepared for bone tissue engineering. Furthermore, the compressive modulus of the composite scaffold is strongly affected by the material degradation and the ECM formation by stem cells under in vitro culture condition.

Placental expression of VEGF is increased in pregnancies with hydatidiform mole: possible association with developing very early onset preeclampsia

BACKGROUND

Hydatidiform mole is an abnormal pregnancy with over-proliferation of the placenta, which causes the dysfunction of placenta. Although more than 80% of hydatidiform moles are benign with good outcome, hydatidiform moles are associated with developing very early onset preeclampsia. However the association between hydatidiform mole and very early onset preeclampsia is unclear. Preeclampsia is associated with altered levels of angiogenic factors, like vascular endothelial growth factor (VEGF) and soluble endoglin.

AIM

The aim of this study is to investigate the levels of VEGF and endoglin in hydatidiform molar placenta.

STUDY DESIGN

21 placentas from complete hydatidiform mole, 9 placentas from partial hydatidiform mole and 18 placentas from gestation matched placenta were collected in this study.

SUBJECTS

The subjects of this study are human placentas.

OUTCOME MEASURES

The protein levels and mRNA levels of VEGF and endoglin were measured using immunohistochemistry, western blotting and real time PCR.

RESULTS

The protein levels of VEGF measured by immunohistochemistry and western blotting were significant increased, as well as mRNA levels of VEGF quantified by real time PCR in hydatidiform molar placenta in comparison to normal controls. There was no difference in the protein levels of VEGF between complete and partial hydatidiform moles. In contrast, the levels of protein and mRNA in endoglin were no difference between hydatidiform molar placenta and normal controls.

CONCLUSION

In this study our data show that hydatidiform moles produce more VEGF than normal early pregnant placenta. The increased levels of angiogenic factors VEGF in hydatidiform moles may link to the mechanism of developing very early onset preeclampsia.

Increased expression of Rab25 in breast cancer correlates with lymphatic metastasis

Breast cancer is the most common cancer in women worldwide. Studies have suggested that Ras-related protein 25 (Rab25), a member of Rab small GTPase family, is involved in the pathogenesis of breast cancer. In this study, we investigated whether the expression of Rab25 correlated with lymphatic metastasis in breast cancer and whether the expression of Rab25 was positively correlated with oestrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer. Breast cancer tissues from 42 invasive ductal breast cancer patients with or without lymphatic metastasis were collected and the levels of Rab25 mRNA and protein measured by quantitative real-time PCR and immunohistochemistry, respectively. The mRNA level of Rab25 was significantly increased in invasive ductal breast cancer with lymphatic metastasis compared to that in invasive ductal breast cancer without lymphatic metastasis. Immunohistochemical analysis demonstrated that Rab25 and vascular endothelial growth factor (VEGF) were highly expressed in invasive ductal breast cancer with lymphatic metastasis regardless of whether the cancer is ER and PR positive or negative. Higher expression of Rab25 positively correlated with VEGF expression. However, the expressions of Rab25 in ER and PR-positive cancers were much higher than ER and PR-negative cancers regardless of whether lymphatic metastasis occurred. These data suggest that higher level of Rab25 was associated with lymphatic metastasis, specifically in ER and PR-positive breast cancer. The better understanding of the mechanism of Rab25 may provide a basis for the development of a novel therapeutic target in breast cancer.

Predicting ulcerative colitis-associated colorectal cancer using reverse-transcription polymerase chain reaction analysis

BACKGROUND

Widespread genetic alterations are present not only in ulcerative colitis (UC)-associated neoplastic lesions but also in the adjacent normal colonic mucosa. This suggests that genetic changes in nonneoplastic mucosa might be effective markers for predicting the development of UC-associated cancer (UC-Ca). This study aimed to build a predictive model for the development of UC-Ca based on gene expression levels measured by reverse-transcription polymerase chain reaction (RT-PCR) analysis in nonneoplastic rectal mucosa.

PATIENTS AND METHODS

Fifty-three UC patients were examined, of which 10 had UC-Ca and 43 did not (UC-NonCa). In addition to the 40 genes and transcripts previously shown to be predictive for developing UC-Ca in our microarray studies, 149 new genes, reported to be important in carcinogenesis, were selected for low density array (LDA) analysis. The expression of a total of 189 genes was examined by RT-PCR in nonneoplastic rectal mucosa.

RESULTS

We identified 20 genes showing differential expression in UC-Ca and UC-NonCa patients, including cancer-related genes such as CYP27B1, RUNX3, SAMSN1, EDIL3, NOL3, CXCL9, ITGB2, and LYN. Using these 20 genes, we were able to build a predictive model that distinguished patients with and without UC-Ca with a high accuracy rate of 83% and a negative predictive value of 100%.

CONCLUSION

This predictive model suggests that it is possible to identify UC patients at a high risk of developing cancer. These results have important implications for improving the efficacy of surveillance by colonoscopy and suggest directions for future research into the molecular mechanisms of UC-associated cancer.

A TaqMan low-density array to predict outcome in advanced Hodgkin's lymphoma using paraffin-embedded samples

PURPOSE

Despite major advances in the treatment of classic Hodgkin's lymphoma (cHL), approximately 30% of patients in advanced stages may eventually die as result of the disease, and current methods to predict prognosis are rather unreliable. Thus, the application of robust techniques for the identification of biomarkers associated with treatment response is essential if new predictive tools are to be developed.

EXPERIMENTAL DESIGN

We used gene expression data from advanced cHL patients to identify transcriptional patterns from the tumoral cells and their nonneoplastic microenvironment, associated with lack of maintained treatment response. Gene-Set Enrichment Analysis was used to identify functional pathways associated with unfavorable outcome that were significantly enriched in either the Hodgkin's and Reed-Sternberg cells (regulation of the G2-M checkpoint, chaperones, histone modification, and signaling pathways) or the reactive cell microenvironment (mainly represented by specific T-cell populations and macrophage activation markers).

RESULTS

To explore the pathways identified previously, we used a series of 52 formalin-fixed paraffin-embedded advanced cHL samples and designed a real-time PCR-based low-density array that included the most relevant genes. A large majority of the samples (82.7%) and all selected genes were analyzed successfully with this approach.

CONCLUSIONS

The results of this assay can be combined in a single risk score integrating these biological pathways associated with treatment response and eventually used in a larger series to develop a new molecular outcome predictor for advanced cHL.

Quantification of mRNA encoding cytokines and chemokines and assessment of ciliary function in canine tracheal epithelium during infection with canine respiratory coronavirus (CRCoV)

One of the first lines of defence against viral infection is the innate immune response and the induction of antiviral type I interferons (IFNs). However some viruses, including the group 2 coronaviruses, have evolved mechanisms to overcome or circumvent the host antiviral response. Canine respiratory coronavirus (CRCoV) has previously been shown to have a widespread international presence and has been implicated in outbreaks of canine infectious respiratory disease (CIRD). This study aimed to quantify pro-inflammatory cytokine mRNAs following infection of canine air-interface tracheal cultures with CRCoV. Within this system, immunohistochemistry identified ciliated epithelial and goblet cells as positive for CRCoV, identical to naturally infected cases, thus the data obtained would be fully transferable to the situation in vivo. An assay of ciliary function was used to assess potential effects of CRCoV on the mucociliary system. CRCoV was shown to reduce the mRNA levels of the pro-inflammatory cytokines TNF-α and IL-6 and the chemokine IL-8 during the 72 h post-inoculation. The mechanism for this is unknown, however the suppression of a key antiviral strategy during a period of physiologic and immunological stress, such as on entry to a kennel, could potentially predispose a dog to further pathogenic challenge and the development of respiratory disease.

Novel human CD4+ T lymphocyte subpopulations defined by CD300a/c molecule expression

The CD300c (CMRF-35A) and CD300a (CMRF-35H) molecules are leukocyte surface proteins that are part of a larger family of immunoregulatory molecules encoded by a gene complex on human chromosome 17. The CMRF-35 monoclonal antibody binds to an epitope common to both molecules, expressed on most human leukocyte populations, apart from B lymphocytes and a subpopulation of CD4(+) and CD8(+) T lymphocytes. We describe the CMRF-35(pos) and CMRF-35(-) fractions of CD4(+) T lymphocytes. The CMRF-35(pos) fraction can further be divided into CMRF-35(++) and CMRF-35(+)CD4(+) T lymphocyte subpopulations. Resting peripheral CD4(+) T lymphocytes express CD300a mRNA and very low amounts of CD300c. Activation results in an initial decrease in CD300a gene expression before an increase in both CD300a and CD300c gene expression. The up-regulated expression of these genes was associated with increased CMRF-35 binding to activated T lymphocytes. The CMRF-35(-) fraction of CD4(+) T lymphocytes proliferated to a greater extent than the CMRF-35(pos) fraction, in response to mitogens or allogeneic antigen. The poor proliferation of the CMRF-35(pos) CD4(+) in response to mitogens was explained by increased apoptosis within this subpopulation. The recall antigen, tetanus toxoid, stimulated the CMRF-35(++)CD4(+)CD45RO(+) but not the CMRF-35(-)CD4(+)CD45RO(+) subpopulation. Resting CMRF-35(++) CD4(+) lymphocytes express low levels of IFN-gamma mRNA. Within 18 h following in vitro activation, CMRF-35(++) CD4(+) lymphocytes express more IFN-gamma mRNA and protein compared with the CMRF-35(-)CD4(+) lymphocytes, however, after 24 h, both the CMRF-35(+) and CMRF-35(-)CD4(+) T lymphocytes were able to produce IFN-gamma. The CMRF-35(++)CD4(+) T lymphocyte population contains the Th(1) memory effector cells.

Immune activation suppresses initiation of lytic Epstein-Barr virus infection

Primary infection with Epstein-Barr virus (EBV) is asymptomatic in children with immature immune systems but may manifest as infectious mononucleosis, a vigorous immune activation, in adolescents or adults with mature immune systems. Infectious mononucleosis and chronic immune activation are linked to increased risk for EBV-associated lymphoma. Here we show that EBV initiates progressive lytic infection by expression of BZLF-1 and the late lytic genes gp85 and gp350/220 in cord blood mononuclear cells (CBMC) but not in peripheral blood mononuclear cells (PBMC) from EBV-naive adults after EBV infection ex vivo. Lower levels of proinflammatory cytokines in CBMC, used to model a state of minimal immune activation and immature immunity, than in PBMC were associated with lytic EBV infection. Triggering the innate immunity specifically via Toll-like receptor-9 of B cells substantially suppressed BZLF-1 mRNA expression in acute EBV infection ex vivo and in anti-IgG-stimulated chronically latently EBV-infected Akata Burkitt lymphoma cells. This was mediated in part by IL-12 and IFN-gamma. These results identify immune activation as critical factor for the suppression of initiation of lytic EBV infection. We hypothesize that immune activation contributes to EBV-associated lymphomagenesis by suppressing lytic EBV and in turn promotes latent EBV with transformation potential.

Zebularine reactivates silenced E-cadherin but unlike 5-Azacytidine does not induce switching from latent to lytic Epstein-Barr virus infection in Burkitt's lymphoma Akata cells

Epigenetic silencing of regulatory genes by aberrant methylation contributes to tumorigenesis. DNA methyltransferase inhibitors (DNMTI) represent promising new drugs for anti-cancer therapies. The DNMTI 5-Azacytidine is effective against myelodysplastic syndrome, but induces switching of latent to lytic Epstein-Barr virus (EBV) in vitro and results in EBV DNA demethylation with the potential of induction of lytic EBV in vivo. This is of considerable concern given that recurrent lytic EBV has been linked with an increased incidence of EBV-associated lymphomas. Based on the distinct properties of action we hypothesized that the newer DNMTI Zebularine might differ from 5-Azacytidine in its potential to induce switching from latent to lytic EBV. Here we show that both 5-Azacytidine and Zebularine are able to induce expression of E-cadherin, a cellular gene frequently silenced by hypermethylation in cancers, and thus demonstrate that both DNMTI are active in our experimental setting consisting of EBV-harboring Burkitt's lymphoma Akata cells. Quantification of mRNA expression of EBV genes revealed that 5-Azacytidine induces switching from latent to lytic EBV and, in addition, that the immediate-early lytic infection progresses to early and late lytic infection. Furthermore, 5-Azacytidine induced upregulation of the latent EBV genes LMP2A, LMP2B, and EBNA2 in a similar fashion as observed following switching of latent to lytic EBV upon cross-linking of the B-cell receptor. In striking contrast, Zebularine did not exhibit any effect neither on lytic nor on latent EBV gene expression. Thus, Zebularine might be safer than 5-Azacytidine for the treatment of cancers in EBV carriers and could also be applied against EBV-harboring tumors, since it does not induce switching from latent to lytic EBV which may result in secondary EBV-associated malignancies.

Overexpression of a member of the pentraxin family (PTX3) in human soft tissue liposarcoma

A unique feature of human soft tissue liposarcoma is a stable (12;16)(q13;p11) translocation observed mainly in myxoid and roundcell liposarcomas. This translocation results in FUS/CHOP fusion transcripts with a corresponding oncogenic protein. We hypothesised that genes downstream of FUS/CHOP might serve as attractive candidates for novel tumour associated antigens. Among a panel of analysed genes, only pentraxin related gene (PTX3) demonstrated high expression in liposarcomas as compared to normal tissues. The analysis of RNA and protein expression demonstrated concordant results. However, the level of RNA and protein overexpression did not correlate in all cases. Finally, PTX3 expression was not related to presence of a FUS/CHOP fusion transcript within the liposarcoma tissues. PTX3 has been associated with adipocyte differentiation and now, additionally, is characterised by a markedly increased expression in human soft tissue liposarcoma. This finding mandates further research efforts to clarify the exact role of PTX3 in liposarcoma oncogenesis.

Human tonsillar tissue block cultures differ from autologous tonsillar cell suspension cultures in lymphocyte subset activation and cytokine gene expression

Lymphoid tissues cultured either as tissue blocks or as cell suspensions are used to study the behaviour of immune cells within their habitat. The preservation of tissue structures in tissue blocks, which is considered to be a major advantage, has been poorly defined. We characterised the morphological evolution of tissue cultures from human palatine tonsils and compared their lymphocyte subsets and the constitutive cytokine gene expression to those in autologous tonsillar single-cell suspension cultures over time, and after adding cyclosporin A (CsA) to mimic the situation in individuals treated with immunosuppressive drugs. Density and morphology of follicles were conserved up to 4 days, during which tissue cultures exhibited similar cell viability as suspension cultures, but a significantly less frequent increase of CD95 expression in T cells, smaller variation of the proportion of CD4(+) cells and better CD21(+)/CD23(-) B-cell survival. Treatment with cyclosporin A at higher concentrations resulted in superior histologic preservation of lymphoid tissue structures and seemed to further prevent the expression of CD95 by CD3(+) cells and the activation in tissue culture of CD21(+) cells. Constitutive gene expression levels of the stromal cytokines interleukin (IL)-1beta and interleukin-6 in tissue culture were significantly higher than those in suspension cultures. These results suggest that tonsillar tissue cultures preserve their structure only for a limited time, during which they more closely reflect processes in vivo, including a state of iatrogenic immunosuppression, than do their cell suspension counterparts.

Quantitative profiling of housekeeping and Epstein-Barr virus gene transcription in Burkitt lymphoma cell lines using an oligonucleotide microarray

Background

The Epstein-Barr virus (EBV) is associated with lymphoid malignancies, including Burkitt's lymphoma (BL), and can transform human B cells in vitro. EBV-harboring cell lines are widely used to investigate lymphocyte transformation and oncogenesis. Qualitative EBV gene expression has been extensively described, but knowledge of quantitative transcription is lacking. We hypothesized that transcription levels of EBNA1, the gene essential for EBV persistence within an infected cell, are similar in BL cell lines.

Results

To compare quantitative gene transcription in the BL cell lines Namalwa, Raji, Akata, Jijoye, and P3HR1, we developed an oligonucleotide microarray chip, including 17 housekeeping genes, six latent EBV genes (EBNA1, EBNA2, EBNA3A, EBNA3C, LMP1, LMP2), and four lytic EBV genes (BZLF1, BXLF2, BKRF2, BZLF2), and used the cell line B95.8 as a reference for EBV gene transcription. Quantitative polymerase chain reaction assays were used to validate microarray results. We found that transcription levels of housekeeping genes differed considerably among BL cell lines. Using a selection of housekeeping genes with similar quantitative transcription in the tested cell lines to normalize EBV gene transcription data, we showed that transcription levels of EBNA1 were quite similar in very different BL cell lines, in contrast to transcription levels of other EBV genes. As demonstrated with Akata cells, the chip allowed us to accurately measure EBV gene transcription changes triggered by treatment interventions.

Conclusion

Our results suggest uniform EBNA1 transcription levels in BL and that microarray profiling can reveal novel insights on quantitative EBV gene transcription and its impact on lymphocyte biology.

Clusterin decreases oxidative stress in lung fibroblasts exposed to cigarette smoke

RATIONALE

Cigarette smoke causes injury to lung fibroblasts, partly by means of oxidative stress, and oxidative stress can lead to various lung diseases, such as chronic obstructive pulmonary disease. Clusterin is a widely distributed protein with many functions, including cellular protection in response to oxidative stress.

OBJECTIVES

To determine whether clusterin is involved in the defense of the lung against cigarette smoke, we investigated the effects of cigarette smoke extract on clusterin expression and its protective effect, if any, against oxidative stress.

METHODS

Fibroblasts were coincubated with conditioned medium and cigarette smoke extract, and bronchial biopsy specimens obtained from nonsmokers, smokers, and ex-smokers were analyzed by immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

At concentrations of 2.5 and 5.0%, cigarette smoke extract induced oxidative stress. It also markedly increased the expression of two clusterin isoforms (60 and 76-80 kD) and the 76-80-kD isoform was secreted in the incubation medium. Coincubation of fibroblasts with conditioned medium significantly decreased the cellular oxidation caused by the cigarette smoke extract. Immunohistochemical analysis of clusterin on bronchial biopsy specimens obtained from smokers and ex-smokers showed localization of clusterin mainly in the submucosa.

CONCLUSIONS

We conclude that clusterin may have a protective effect against cigarette smoke-induced oxidative stress in lung fibroblasts.

Expression of HIV receptors, alternate receptors and co-receptors on tonsillar epithelium: implications for HIV binding and primary oral infection

Background

Primary HIV infection can develop from exposure to HIV in the oral cavity. In previous studies, we have documented rapid and extensive binding of HIV virions in seminal plasma to intact mucosal surfaces of the palatine tonsil and also found that virions readily penetrated beneath the tissue surfaces. As one approach to understand the molecular interactions that support HIV virion binding to human mucosal surfaces, we have examined the distribution of the primary HIV receptor CD4, the alternate HIV receptors heparan sulfate proteoglycan (HS) and galactosyl ceramide (GalCer) and the co-receptors CXCR4 and CCR5 in palatine tonsil.

Results

Only HS was widely expressed on the surface of stratified squamous epithelium. In contrast, HS, GalCer, CXCR4 and CCR5 were all expressed on the reticulated epithelium lining the tonsillar crypts. We have observed extensive variability, both across tissue sections from any tonsil and between tonsils, in the distribution of epithelial cells expressing either CXCR4 or CCR5 in the basal and suprabasal layers of stratified epithelium. The general expression patterns of CXCR4, CCR5 and HS were similar in palatine tonsil from children and adults (age range 3–20). We have also noted the presence of small clusters of lymphocytes, including CD4⁺ T cells within stratified epithelium and located precisely at the mucosal surfaces. CD4⁺ T cells in these locations would be immediately accessible to HIV virions.

Conclusion

In total, the likelihood of oral HIV transmission will be determined by macro and micro tissue architecture, cell surface expression patterns of key molecules that may bind HIV and the specific properties of the infectious inoculum.

qPCR-DAMS: a database tool to analyze, manage, and store both relative and absolute quantitative real-time PCR data

Quantitative real-time PCR is an important high-throughput method in the biomedical sciences. However, existing software has limitations in handling both relative and absolute quantification. We designed quantitative PCR data analysis and management system (qPCR-DAMS), a database tool based on Access 2003, to deal with such shortcomings by the addition of integrated mathematical procedures. qPCR-DAMS allows a user to choose among four methods for data processing within a single software package: 1) ratio relative quantification, 2) absolute level, 3) normalized absolute expression, and 4) ratio absolute quantification. qPCR-DAMS also provides a tool for multiple reference gene normalization. qPCR-DAMS has three quality control steps and a data display system to monitor data variation. In summary, qPCR-DAMS is a handy tool for real-time PCR users.

TLR7/8 Triggering Exerts Opposing Effects in Acute versus Latent HIV Infection

TLRs trigger innate immunity by recognizing conserved motifs of microorganisms. Recently, ssRNAs from HIV and influenza virus were shown to trigger TLR7 and 8. Thus, we hypothesized that HIV ssRNA, by triggering TLR7/8, affects HIV pathogenesis. Indeed, HIV ssRNA rendered human lymphoid tissue of tonsillar origin or PBMC barely permissive to HIV replication. The synthetic compound R-848, which also triggers TLR7/8, showed similar anti-HIV activity. Loss of R-848's activity in lymphoid tissue depleted of B cells suggested a role for B cells in innate immunity. TLR7/8 triggering appears to exert antiviral effects through soluble factors: conditioned medium reduced HIV replication in indicator cells. Although a number of cytokines and chemokines were increased upon adding R-848 to lymphoid tissue, blocking those cytokines/chemokines (i.e., IFN-alpha receptor, IFN-gamma, MIP-1alpha, -1beta, RANTES, and stromal cell-derived factor-1) did not result in the reversal of R-848's anti-HIV activity. Thus, the nature of this soluble factor(s) remains unknown. Unlike lymphoid tissue acutely infected with HIV, triggering latently infected promonocytic cells induced the release of HIV virions. The anti-HIV effects of triggering TLR7/8 may inhibit rapid killing, while pro-HIV effects may guarantee a certain replication level. Compounds triggering TLR7/8 may be attractive drug candidates to purge latent HIV while preventing new infections.

CpG oligodeoxynucleotides block human immunodeficiency virus type 1 replication in human lymphoid tissue infected ex vivo

Oligodeoxynucleotides (ODNs) with immunomodulatory motifs control a number of microbial infections in animal models, presumably by acting through toll-like receptor 9 (TLR9) to induce a number of cytokines (e.g., alpha interferon and tumor necrosis factor alpha). The immunomodulatory motif consists of unmethylated sequences of cytosine and guanosine (CpG motif). ODNs without CpG motifs do not trigger TLR9. We hypothesized that triggering of TLR9 generates a cellular environment unfavorable for human immunodeficiency virus (HIV) replication. We tested this hypothesis in human lymphocyte cultures and found that phosphorothioate-modified ODN CpG2006 (type B ODNs) inhibited HIV replication nearly completely and prevented the loss of CD4(+) T cells. ODNs CpG2216 and CpG10 (type A ODNs) were less effective. CpG2006 blocked HIV replication in purified CD4(+) T cells and T-cell lines; CpG10 was ineffective in this setting, indicating that type A ODNs may inhibit HIV replication in CD4(+) T-cell lines indirectly through a separate cell subset. However, control ODNs without CpG motifs also showed anti-HIV effects, indicating that these effects are nonspecific and not due to TLR9 triggering. The mechanism of action is not clear. CpG2006 and its control ODN blocked syncytium formation in a cell fusion-based assay, but CpG10, CpG2216, and their control ODNs did not. The latter types interfered with the HIV replication cycle during disassembly or reverse transcription. In contrast, CpG2006 and CpG2216 specifically induced cytokines critical to initiation of the innate immune response. In summary, the nonspecific anti-HIV activity of CpG ODNs, their ability to stimulate HIV replication in latently infected cells, potentially resulting in their elimination, and their documented ability to link the innate and adaptive immune responses make them attractive candidates for further study as anti-HIV drugs.

HIV-1 does not provoke alteration of cytokine gene expression in lymphoid tissue after acute infection ex vivo

The cytokine response to invading microorganisms is critical for priming the adaptive immune response. During acute HIV infection, the response is disrupted, but the mechanism is poorly understood. We examined the cytokine response in human lymphoid tissue, acutely infected ex vivo with HIV. Lymphoid tissue was cultured either as blocks or as human lymphocyte aggregate cultures (HLAC) of tonsils and lymph nodes. This approach allowed us to examine the effects of HIV on cytokines using distinct culture techniques. In contrast to HLAC, mock-infected tissue blocks displayed a 50- to 100-fold up-regulation of mRNAs for IL-1beta, -6, and -8 in the first 6 days of culture. Parallel increases were also noted at the protein level in the supernatants. Although IL-1beta, -6, and -8 are known to synergistically enhance HIV replication, peak HIV replication (measured as p24 Ag) was similar in tissue blocks and HLAC. Surprisingly, vigorous HIV replication of CXCR4- and CCR5-tropic HIV strains did not result in characteristic mRNA profiles for IL-1beta, -2, -4, -6, -8, -10, -12, -15, IFN-gamma, TNF-alpha, TGF-beta, and beta-chemokines in tissue blocks or HLAC. The increased expression of IL-1beta, -6, and -8 in tissue blocks may approximate clinical situations with heightened immune activation; neutralization of these cytokines resulted in inhibition of HIV replication, suggesting that these cytokines may contribute to HIV replication in certain clinical settings. These results also indicate that different molecular mechanisms govern HIV replication in tissue blocks and HLAC. Prevention of effective cytokine responses may be an important mechanism that HIV uses during acute infection.