A new reporter vector system based on flow-cytometry to detect promoter activity

In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity.

Natural killer T cells promote collagen-induced arthritis in DBA/1 mice

The role of NKT cells in the pathogenesis of collagen-induced arthritis (CIA) remains unclear since most studies have used C57BL/6 (B6) mice, which are less susceptible to CIA than mice with a DBA/1 background. To clarify the immunological functions of NKT cells in CIA, it is necessary to analyze in detail the effects of NKT cell deficiency on CIA development in DBA/1 mice. The incidence and severity of CIA were significantly exacerbated in DBA/1CD1d(+/-) mice as compared to DBA/1CD1d(-/-) mice. In DBA/1CD1d(+/-) mice, antigen-specific responses of B and T cells against CII were remarkably increased and inflammatory cytokine levels were also increased in vivo and in vitro. The number of IL-17-producing NKT cells significantly increased in DBA/1CD1d(+/-) mice as the disease progressed. Our results clearly show that NKT cells are involved not only in accelerating the severity and incidence of CIA but also in perpetuating the disease progression.

Exercise in, and adaptations to a cold environment have no effect on SIgA

AIM

The authors hypothesized that inconsistent SIgA response to exercise is caused by the different adaptative status of subjects to a cold environment. The purposes of the study were to examine whether moderate-intense exercise in a cold environment decreases SIgA and whether adaptation to a cold environment has any effect on SIgA.

METHODS

Young male skaters, short track (N=9) and inline (N=10), participated in this study. All subjects cycled for 60 min at 65% VO(2max) in cold (ambient temperature: 5 +or - 1 degrees Celsius, relative humidity 41 + or - 9%) and thermoneutral (ambient temperature: 21 + or - 1 degrees Celsius, relative humidity 35 + or - 5%) conditions. Saliva samples were collected as follows: before and after 1hour of environmental exposure; immediately, 30-min, 60-min and 120-min after the exercise.

RESULTS AND CONCLUSIONS

Salivary SIgA and saliva flow rate decreased after the exercise in both groups only in thermoneutral conditions. The SIgA secretion rate did not decrease after moderate-high intensity exercise in a cold environment, and the SIgA response to exercise was not affected by the different adaptative status of subjects to the cold environment.

Phase I/II study of docetaxel and 153Sm for castrate metastatic prostate cancer (CMPC): Summary of dose-escalation cohorts and first report on the expansion cohort

5057

Background: We previously reported (ASCO 2008) that full doses of docetaxel (Tax) and Sm can be repetitively delivered safely using a schedule of q 3 week (wk) Tax and q 6–9 wk Sm. Here we summarize the dose-escalation cohorts and safety/efficacy data from the expansion cohort of 24 pts. Methods: Cohorts of 3–6 pts with CPMC were defined by: 65, 70, 75, 75, 75 mg/m2 of Tax and Sam 0.5, 0.5, 0.5, 0.75, 1 mCi/kg. Each cycle was 6 wks. The expansion cohort used 75 mg/m2 Tax (q 3 wk) and 1 mCi/kg Sm (q 9 wk). Pts with an ANC of grade 0–1 and platelet count of > 100,000/mm3 at the end of cycle 1 received additional cycles until progression or toxicity. Results: 52 pts have been treated. 28 pts were taxane naïve, 11 received previous taxanes but were not refractory, and 13 were taxane refractory. As anticipated, side effects were primarily hematologic. However, the leading cause for treatment termination was disease progression, involving 16/52 (31%) pts, rather than toxicity. 12/52 (23%) pts came off for thrombocytopenia, and 2/52 (4%) pts experienced neutropenic fever. Cohort 3 tolerated the highest cumulative dose and total number of doses of docetaxel (mean of 8 doses, range 4–12; mean total dose 600 mg/m2, range 300–900 mg/m2). Cohort 5 tolerated the highest exposure to Sm (mean of 3 doses, range 1–5). 50 pts are evaluable for response; 22 (44%) achieved a ≥ 50% decline in PSA. 50% of the taxane naïve patients achieved a significant PSA decline, as did 55% of the taxane exposed, and 23% of the taxane refractory pts. Mean time to progression in the taxane naïve, treated, and refractory groups were: 7.5 (range 1.4–22.6), 5.8 (range 0.7–13.7), and 4.3 (range 0.7–11.2) months. Conclusions: This regimen is safe and appears to be active both in taxane naïve and taxane refractory patients, as reflected by favorable toxicity profiles, and rates of significant PSA declines and times to progression. The optimal phase II dose may differ by the population treated. For studies involving taxane naïve patients, the regimen of cohort 3 maximizes docetaxel exposure; for studies of taxane refractory patients, cohort 5 maximizes Sm exposure. Support: EUSA, NIH CA102544.

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Regulation of secondary antigen-specific CD8(+) T-cell responses by natural killer T cells

The physiologic function of natural killer T (NKT) cells in adaptive immunity remains largely unknown because most studies have used NKT cell agonists. In the present study, the role of NKT cells during the secondary effector phase was investigated separately from the primary immunization phase via adoptive transfer of differentiated effector T cells into naive recipients. We found that secondary antitumor CD8(+) T-cell responses were optimal when NKT cells were present. Tumor-specific CD8(+) effector T cells responded less strongly to tumor cell challenge in NKT cell-deficient recipients than in recipients with intact NKT cells. NKT cell-mediated enhancement of the secondary antitumor CD8(+) T-cell response was concurrent with increased number and activity of tumor-specific CD8(+) T cells. These findings provide the first demonstration of a direct role for NKT cells in the regulation of antigen-specific secondary T-cell responses without the use of exogenous NKT cell agonists such as alpha-galactosylceramide (alpha-GalCer). Furthermore, forced activation of NKT cells with alpha-GalCer during the secondary immune response in suboptimally immunized animals enhanced otherwise poor tumor rejection responses. Taken together, our findings strongly emphasize the importance of NKT cells in secondary CD8(+) T-cell immune responses.

Anti-tumor immunostimulatory effect of heat-killed tumor cells

As a part of our ongoing search for a safe and efficient anti-tumor vaccine, we attempted to determine whether the molecular nature of certain tumor antigens would influence immune responses against tumor cells. As compared with freeze-thawed or formaldehyde-fixed tumor antigens, heat-denatured tumor antigens elicited profound anti-tumor immune responses and greatly inhibited the growth of live tumor cells. The heat-denatured tumor antigens induced a substantial increase in the anti-tumor CTL response in the absence of any adjuvant material. This response appears to be initiated by strong activation of the antigen-presenting cells, which may recognize heat-denatured protein antigens. Upon recognition of the heat-denatured tumor antigens, macrophages and dendritic cells were found to acutely upregulate the expression of co-stimulatory molecules such as B7.2, as well as the secretion of inflammatory cytokines such as IL-12 and TNF-alpha. The results of this study indicate that heat-denatured tumor extracts might elicit protective anti-tumor adaptive immune responses and also raise the possibility that a safe and efficient adjuvant-free tumor vaccine might be developed in conjunction with a dendritic cell-based tumor vaccine.

Identification of human metapneumovirus-induced gene networks in airway epithelial cells by microarray analysis

Human metapneumovirus (hMPV) is a major cause of lower respiratory tract infections in infants, elderly and immunocompromised patients. Little is known about the response to hMPV infection of airway epithelial cells, which play a pivotal role in initiating and shaping innate and adaptive immune responses. In this study, we analyzed the transcriptional profiles of airway epithelial cells infected with hMPV using high-density oligonucleotide microarrays. Of the 47,400 transcripts and variants represented on the Affimetrix GeneChip Human Genome HG-U133 plus 2 array, 1601 genes were significantly altered following hMPV infection. Altered genes were then assigned to functional categories and mapped to signaling pathways. Many up-regulated genes are involved in the initiation of pro-inflammatory and antiviral immune responses, including chemokines, cytokines, type I interferon and interferon-inducible proteins. Other important functional classes up-regulated by hMPV infection include cellular signaling, gene transcription and apoptosis. Notably, genes associated with antioxidant and membrane transport activity, several metabolic pathways and cell proliferation were down-regulated in response to hMPV infection. Real-time PCR and Western blot assays were used to confirm the expression of genes related to several of these functional groups. The overall result of this study provides novel information on host gene expression upon infection with hMPV and also serves as a foundation for future investigations of genes and pathways involved in the pathogenesis of this important viral infection. Furthermore, it can facilitate a comparative analysis of other paramyxoviral infections to determine the transcriptional changes that are conserved versus the one that are specific to individual pathogens.

Application of natural killer T cells in antitumor immunotherapy

NKT cells are a unique subset of T cells that recognize glycolipid antigens presented by CD1d molecules. NKT cells have the potential to produce key cytokines of both Th1 and Th2 T cells and are involved in the control of several types of immune response. Furthermore, NKT cells perform spontaneous tumor immunosurveillance. Upon specific activation with alpha-GalCer, NKT cells show strong antitumor immune responses through direct cytotoxicity and indirect activation of a cascade of antitumor effector cells such as natural killer (NK) cells and CD8+ cytotoxic T cells. In addition to alpha-GalCer, many other CD1d ligands, including self and bacterial glycolipids and modified synthetic glycolipid antigens, have also been discovered. Structurally different glycolipid antigens have the distinct ability to activate NKT cells. Thus, it seems that we are now close to a position in which we can control the activation status of NKT cells; this makes NKT cells an ideal target of anticancer immunotherapies. Clinical trials with soluble alpha-GalCer or alpha-GalCer-pulsed dendritic cells aimed at in vivo reconstitution and activation of human NKT cells have provided both promising and challenging results. In this review, we discuss NKT-cell-mediated antitumor immune responses, as well as the early outcomes and implications of recent clinical studies.

Negative selection of Th1-skewed NKT cells by the thymic epithelial CD1d (82.8)

NKT cells are a specialized subset of T cells mainly utilizing invariant Vα14-Jα18 chain for their T cell receptor. Unlike conventional T cells which are dependent on MHC class I or II, NKT cells are dependent on a MHC class I-like molecule, CD1d, for their development. Unlike MHC class I and II molecules, which support both of the positive and negative selection of conventional T cells, it was not clear whether CD1d also participate in negative selection of NKT cells. By comparing the NKT cell population and their characteristics in CD1d-deficient Vα14 transgenic mouse and CD1d-deficient Vα14/Eα-CD1d double transgenic mouse, we found that a subset of NKT cells with the phenotype of NK1.1+, CD44high, CD69high and showing Th1-skewed cytokine production was subjected to the negative selection by the CD1d expressed in thymic epithelial tissue. These results suggest that CD1d is critical not only for the positive selection of NKT cells, but also for the negative selection of NKT cells which have potentially harmful excessive self reactivity.

CD4+T Cells in the Absence of the CD8+Cytotoxic T Cells Are Critical and Sufficient for NKT Cell-Dependent Tumor Rejection

NKT cells perform crucial roles in tumor surveillance, functioning as regulators of early host response. In this study, we have assessed the effects of NKT activation at the time of tumor Ag immunization, and have evaluated the contributions of CD4+ and CD8+ T cells in tumor rejection during adaptive immune response against live tumor cells. Our data indicate that CD4+ T cells play critical roles, not only in assisting CTL, but also in the orchestration of host response against the tumor. The CD4+ T cells were found to reject the transplanted tumor cells very efficiently under conditions in which the CTLs were removed either genetically, or via the action of anti-CD8 Ab in mice that had been immunized with tumor extracts and alpha-galactosylceramide. Immunization resulted in an NKT cell-dependent antitumor adaptive immune response, which was associated with both CD4+ T cells and cytokine IFN-gamma.

Asthma is induced by intranasal coadministration of allergen and natural killer T-cell ligand in a mouse model

BACKGROUND

Allergic asthma is an inflammatory lung disease caused by a T(H)2-driven immune response. However, intranasal exposures to soluble antigen lead to mucosal tolerance, and the mechanism involved in generation of T(H)2 responses to inert inhaled allergens is unknown.

OBJECTIVE

The aim of this study was to investigate whether CD1d-restricted natural killer T (NKT) cells can contribute to the induction of T(H)2-dependent allergic asthma in a mouse model.

METHODS

To investigate the effect of NKT cells on the development of asthma, NKT cell ligand, alpha-galactosylceramide (alphaGC), was used with antigens. We intranasally sensitized Balb/c mice with various combinations of antigen and alphaGC for 3 consecutive days and challenged them 2 weeks later with an aerosol of ovalbumin. NKT cell-deficient or T(H) cell-deficient mice were immunized by administering ovalbumin and alphaGC together, and ovalbumin inhalation.

RESULTS

Only when immunized with ovalbumin plus alphaGC, airway hyperreactivity, airway eosinophils, elevated IgE level, and T(H)2-cytokine production were observed in Balb/c mice. Ovalbumin alone, alphaGC alone, or BSA plus alphaGC-immunized mice did not induce asthma. Studies in NKT cell-deficient, or CD4(+) T-cell-deficient mice intranasally exposed to ovalbumin plus alphaGC did not show the development of asthma. An increase of NKT cells in bronchoalveolar lavage was observed in the pathologic states.

CONCLUSION

These data demonstrate that NKT cells can play crucial roles in allergen sensitization and pathologic states in asthma. Furthermore, our new asthma model using alphaGC will be very useful to induce asthma and to dissect the role of NKT cells and other cells in asthma.

Current status of coronary multislice CT angiography

Multislice computed tomography (MSCT) is an emerging technique which has an enormous potential to improve the current practice of coronary artery imaging. This article reviews the current status of coronary MSCT angiography (MSCTA) with emphasis on the imaging techniques and clinical utilities of 16-slice CTA. Results and experiences gained from coronary MSCTA in the past few years have taught us that accurate diagnosis of coronary artery disease relies on good technical studies and can be achieved by optimizing image parameters including image timing and image reconstruction ECG-trigger delay. Current clinical applications of coronary MSCTA include: quantitative assessment of coronary artery stenosis, characterization of coronary atherosclerotic plaques, and follow-up of coronary artery stent and bypass graft. Furthermore, MSCT has brought an increasing awareness to the amount of radiation used in CT. This has prompted CT researchers and manufacturers to improve various techniques and develop new strategies to reduce radiation dose. It is anticipated that MSCT will become a sensitive and accurate tool for detecting coronary artery disease and monitoring outcomes after treatment for coronary artery disease.

Immune function, telomerase, and angiogenesis in patients with primary, operable nonsmall cell lung carcinoma: tumor size and lymph node status remain the most important prognostic features

BACKGROUND

Lung carcinoma usually is advanced at the time of presentation and frequently shows metastatic spread. In recent times, prognostic factors such as c-erbB-2 in patients with breast carcinoma have provided useful information and beneficial therapeutic targets. The objective of this study was to evaluate angiogenesis, immune function, and telomerase expression in patients with nonsmall cell lung carcinoma (NSCLC) to determine their prognostic significance.

METHODS

Immunohistochemistry was used to evaluate the expression of human telomerase reverse transcriptase (hTERT; n = 115 patients), interleukin-2r (IL-2r; n = 40 patients), microvessel density (MVD; n = 81 patients), and vascular endothelial growth factor (VEGF; n = 61 patients). Three-year survival follow-up information was available for most patients, and a comprehensive review of clinicopathologic features was carried out.

RESULTS

Fifty percent of tumors showed nuclear staining for hTERT, 55% of tumors showed some degree of lymphocyte IL-2r expression, 33% of tumors were recorded with an MVD that was higher than average, and VEGF staining was detected in 85% of tumors. None of the parameters measured had an impact on survival. hTERT expression was correlated with lymph node status. Lymph node status and tumor size were identified as independent prognostic factors.

CONCLUSIONS

This study failed to identify a marker of prognosis for patients with NSCLC other than tumor size and lymph node status in this population. Telomerase expression was associated with metastases, raising the possibility that this enzyme is involved in the metastatic process. Tumor cell VEGF expression was identified frequently: This growth factor may have potential as a target for antiangiogenic therapy. Lung carcinoma typically is the result of large numbers of mutations. Further understanding of the biologic implications of these mutations will lead to the development of effective prognostic markers and treatments for patients with NSCLC.