Validation of the SCID-hu Thy/Liv mouse model with four classes of licensed antiretrovirals.

BackgroundThe SCID-hu Thy/Liv mouse model of HIV-1 infection is a useful platform for the preclinical evaluation of antiviral efficacy in vivo. We performed this study to validate the model with representatives of all four classes of licensed antiretrovirals.Methodology/principal findingsEndpoint analyses for quantification of Thy/Liv implant viral load included ELISA for cell-associated p24, branched DNA assay for HIV-1 RNA, and detection of infected thymocytes by intracellular staining for Gag-p24. Antiviral protection from HIV-1-mediated thymocyte depletion was assessed by multicolor flow cytometric analysis of thymocyte subpopulations based on surface expression of CD3, CD4, and CD8. These mice can be productively infected with molecular clones of HIV-1 (e.g., the X4 clone NL4-3) as well as with primary R5 and R5X4 isolates. To determine whether results in this model are concordant with those found in humans, we performed direct comparisons of two drugs in the same class, each of which has known potency and dosing levels in humans. Here we show that second-generation antiretrovirals were, as expected, more potent than their first-generation predecessors: emtricitabine was more potent than lamivudine, efavirenz was more potent than nevirapine, and atazanavir was more potent than indinavir. After interspecies pharmacodynamic scaling, the dose ranges found to inhibit viral replication in the SCID-hu Thy/Liv mouse were similar to those used in humans. Moreover, HIV-1 replication in these mice was genetically stable; treatment of the mice with lamivudine did not result in the M184V substitution in reverse transcriptase, and the multidrug-resistant NY index case HIV-1 retained its drug-resistance substitutions.ConclusionGiven the fidelity of such comparisons, we conclude that this highly reproducible mouse model is likely to predict clinical antiviral efficacy in humans

Incidence, risk factors and mortality of tuberculosis in Danish HIV patients 1995-2007

<p>Abstract</p> <p>Background</p> <p>Human Immunodeficiency Virus (HIV) infection predisposes to tuberculosis (TB). We described incidence, risk factors and prognosis of TB in HIV-1 infected patients during pre (1995-1996), early (1997-1999), and late Highly Active Antiretroviral Therapy (HAART) (2000-2007) periods.</p> <p>Methods</p> <p>We included patients from a population-based, multicenter, nationwide cohort. We calculated incidence rates (IRs) and mortality rates (MRs). Cox's regression analysis was used to estimate risk factors for TB infection with HAART initiation included as time updated variable. Kaplan-Meier was used to estimate mortality after TB.</p> <p>Results</p> <p>Among 2,668 patients identified, 120 patients developed TB during the follow-up period. The overall IR was 8.2 cases of TB/1,000 person-years of follow-up (PYR). IRs decreased during the pre-, early and late-HAART periods (37.1/1000 PYR, 12.9/1000 PYR and 6.5/1000 PYR respectively). African and Asian origin, low CD4 cell count and heterosexual and injection drug user route of HIV transmission were risk factors for TB and start of HAART reduced the risk substantially. The overall MR in TB patients was 34.4 deaths per 1,000 PYR (95% Confidence Interval: 22.0-54.0) and was highest in the first two years after the diagnosis of TB.</p> <p>Conclusions</p> <p>Incidence of TB still associated with conventional risk factors as country of birth, low CD4 count and route of HIV infection while HAART reduces the risk substantially. The mortality in this patient population is high in the first two years after TB diagnosis.</p

Expression of CIAPIN1 in human colorectal cancer and its correlation with prognosis

<p>Abstract</p> <p>Background</p> <p>The cytokine-induced anti-apoptotic molecule (CIAPIN1) had been found to be a differentially-expressed gene involved in a variety of cancers, and it was also considered as a candidate tumour suppressor gene in gastric cancer, renal cancer and liver cancer. However, studies on the role of CIAPIN1 in colorectal cancer were still unavailable. The aim of this study was to determine the prognostic impact of CIAPIN1 in 273 colorectal cancer (CRC) samples and to investigate the CIAPIN1 expression in CRC cell lines after inducing differentiation.</p> <p>Methods</p> <p>Immunohistochemical analysis was performed to detect the expression of CIAPIN1 in CRC samples from 273 patients. The relationship between CIAPIN1 expression and patients' characteristics (gender, age, location of cancer, UICC stage, local recurrence and tumour grade factors) was evaluated. In addition, these patients were followed up for five consecutive years to investigate the relationship between CIAPIN1 expression and the prognosis of CRC. We induced the differentiation of the CRC cell lines HT29 and SW480, in order to detect the expression of CIAPIN1 in the process of CRC cells differentiation.</p> <p>Results</p> <p>Results indicated that CIAPIN1 was mainly expressed in the cytoplasm and nucleus, and that its expression level in cancer samples was significantly lower than in normal tissues. The Wilcoxon-Mann-Whitney test showed a significant difference in the differential expression of CIAPIN1 in patients with different T and UICC stages, and tumour grade (<it>P </it>= 0.0393, 0.0297 and 0.0397, respectively). The Kaplan-Meier survival analysis demonstrated that the survival time of CRC patients with high expression of CIAPIN1 was longer than those with low expression during the 5-year follow up period (<it>P </it>= 0.0002). COX regression analysis indicated that low expression of CIAPIN1, cancer stage of > pT1, distant organ metastasis (pM₁), regional lymph node metastasis (> pN₁) and local recurrence (yes) were independent, poor prognostic factors of CRC (<it>P </it>= 0.012, <it>P </it>= 0.032, <it>P <</it>0.001, <it>P <</it>0.001, <it>P <</it>0.001 respectively). Both Western blotting and RT-PCR showed that CIAPIN1 expression was increased with the degree of differentiation of HT29 and SW480 cells.</p> <p>Conclusions</p> <p>CIAPIN1 played an important role in the differentiation of CRC cells, and the differential expression of CIAPIN1 in CRC was closely related to prognosis.</p

A Randomized, Placebo Controlled, Double Masked Phase IB Study Evaluating the Safety and Antiviral Activity of Aprepitant, a Neurokinin-1 Receptor Antagonist in HIV-1 Infected Adults

Neurokinin-1 receptor (NK1R) antagonists have anti-HIV activity in monocyte-derived macrophages, decrease CCR5 expression and improve natural killer cell function ex vivo. Aprepitant is a NK1R antagonist approved by FDA as an antiemetic.We conducted a phase IB randomized, placebo controlled, double masked study to evaluate the safety, antiviral activity, pharmacokinetics and immune-modulatory effects of aprepitant in HIV-infected adults not receiving antiretroviral therapy, with CD4+ cell count ≥350 cells/mm(3) and plasma viral load ≥2,000 copies/ml. Subjects were stratified by viral load (< vs. ≥20,000 copies/ml) and randomized within each stratum to receive aprepitant at 125 mg QD(Low), or 250 mg QD(High), or placebo(PL) for 14 days, and followed for 42 days.Thirty subjects were randomized and 27 completed treatment (9, 8, 10 subjects in 125 (Low), 250 (High), and PL groups). 63% were male; 37% white; mean (SD) age 43 (9.3) years. Geometric mean baseline viral load (copies/ml) for Low, High, and PL was 15,709, 33,013, and 19,450, respectively. Mean (95%CI) change in log10 viral load at day 14 for Low, High, and PL was -0.02(-0.24,+0.20), -0.05(-0.21,+0.10), and +0.04(-0.08,+0.16), respectively. The number of subjects with AEs was 4(44.4%), 5(62.5%), and 1(10%) for Low, High, and PL. No Grade 4 AEs occurred.Adverse events of aprepitant were more common in the treated groups. At the dose used in this two-week phase IB study, aprepitant showed biological activity, but no significant antiviral activity.ClinicalTrials.gov NCT00428519

Rapid induction of p21WAF1 but delayed down-regulation of Cdc25A in the TGF-β-induced cell cycle arrest of gastric carcinoma cells

Transforming growth factor-beta (TGF-beta) is a multifunctional polypeptide that inhibits cellular proliferation in most epithelial cells. cdk4 and several cyclin-dependent kinase (cdk) inhibitors (p15(INK4B), p21(WAFI/Cip1) and p27(Kip1)) have been implicated in the TGF-beta-induced cell cycle arrest. More recently, down-regulation of Cdc25A, a cdk activator, was additionally suggested as a mechanism underlying growth inhibition by TGF-beta. The existence of diverse cellular mediators, of TGF-beta, however, raises the question of whether their involvement might occur in a redundant manner or coordinately in a certain cell type. Using two TGF-beta-sensitive gastric carcinoma cell lines (SNU-16 and -620), we addressed the contributory roles of several cdk inhibitors, and of cdk4 and Cdc25A, in TGF-beta-induced cell cycle arrest by comparing their temporal expression pattern in response to TGF-beta. Among the cdk inhibitors examined, p21 mRNA was most rapidly (in less than 1 h) and prominently induced by TGF-beta. In contrast, p15 mRNA was more slowly induced than p21 in SNU-620: cells, and not expressed in SNU-16 cells harbouring homozygous deletion of p15. Western blotting results confirmed the rapid increase of p21 while opposite patterns of p27 expression were observed in the two cell lines. The down-regulation of Cdc25A mRNA occurred, but was more delayed than that of p15 or p21. Until G1 arrest was established, changes in the protein levels of both Cdc25A and cdk4 were marginal. Co-immunoprecipitation with anti-cdk4 antibody showed that induced p21 associates with cdk4, and that its kinase activity is reduced by TGF-beta, which kinetically correlates closely with G1 arrest following TGF-beta treatment of both cell lines. These results suggest that in certain human epithelial cells, p21 may play an early role in TGF-beta-induced cell cycle arrest, and its cooperation with other cdk inhibitors is different depending on cell type. Delayed down-regulation of Cdc25A and cdk4 may contribute to cell adaptation to the quiescent state in the two gastric carcinoma cell lines studied

Early Mortality and AIDS Progression Despite High Initial Antiretroviral Therapy Adherence and Virologic Suppression in Botswana

Background Adverse outcomes occurring early after antiretroviral therapy (ART) initiation are common in sub-Saharan Africa, despite reports of high levels of ART adherence in this setting. We sought to determine the relationship between very early ART adherence and early adverse outcomes in HIV-infected adults in Botswana. Methods This prospective cohort study of 402 ART-naïve, HIV-infected adults initiating ART at a public HIV clinic in Gaborone, Botswana evaluated the relationship between suboptimal early ART adherence and HIV treatment outcomes in the initial months after ART initiation. Early adherence during the interval between initial ART dispensation and first ART refill was calculated using pill counts. In the primary analysis patients not returning to refill and those with adherence \u3c0.95 were considered to have suboptimal early adherence. The primary outcome was death or loss to follow-up during the first 6 months of ART; a secondary composite outcome included the primary outcome plus incident opportunistic illness (OIs) and virologic failure. We also calculated the percent of early adverse outcomes theoretically attributable to suboptimal early adherence using the population attributable risk percent (PAR%). Results Suboptimal early adherence was independently associated with loss to follow-up and death (adjusted OR 2.3, 95% CI 1.1–4.8) and with the secondary composite outcome including incident OIs and virologic failure (adjusted OR 2.6, 95% CI 1.4–4.7). However, of those with early adverse outcomes, less than one-third had suboptimal adherence and approximately two-thirds achieved virologic suppression. The PAR% relating suboptimal early adherence and primary and secondary outcomes were 14.7% and 17.7%, respectively. Conclusions Suboptimal early adherence was associated with poor outcomes, but most early adverse outcomes occurred in patients with optimal early adherence. Clinical care and research efforts should focus on understanding early adverse outcomes that occur despite optimal adherence

Identification of a Novel TGFβ/PKA Signaling Transduceome in Mediating Control of Cell Survival and Metastasis in Colon Cancer

Understanding drivers for metastasis in human cancer is important for potential development of therapies to treat metastases. The role of loss of TGFβ tumor suppressor activities in the metastatic process is essentially unknown.Utilizing in vitro and in vivo techniques, we have shown that loss of TGFβ tumor suppressor signaling is necessary to allow the last step of the metastatic process - colonization of the metastatic site. This work demonstrates for the first time that TGFβ receptor reconstitution leads to decreased metastatic colonization. Moreover, we have identified a novel TGFβ/PKA tumor suppressor pathway that acts directly on a known cell survival mechanism that responds to stress with the survivin/XIAP dependent inhibition of caspases that effect apoptosis. The linkage between the TGFβ/PKA transduceome signaling and control of metastasis through induction of cell death was shown by TGFβ receptor restoration with reactivation of the TGFβ/PKA pathway in receptor deficient metastatic colon cancer cells leading to control of aberrant cell survival.This work impacts our understanding of the possible mechanisms that are critical to the growth and maintenance of metastases as well as understanding of a novel TGFβ function as a metastatic suppressor. These results raise the possibility that regeneration of attenuated TGFβ signaling would be an effective target in the treatment of metastasis. Our work indicates the clinical potential for developing anti-metastasis therapy based on inhibition of this very important aberrant cell survival mechanism by the multifaceted TGFβ/PKA transduceome induced pathway. Development of effective treatments for metastatic disease is a pressing need since metastases are the major cause of death in solid tumors

Lymphocyte proliferation to mycobacterial antigens is detectable across a spectrum of HIV-associated tuberculosis

<p>Abstract</p> <p>Background</p> <p>Identifying novel TB diagnostics is a major public health priority. We explored the diagnostic characteristics of antimycobacterial lymphocyte proliferation assays (LPA) in HIV-infected subjects with latent or active TB.</p> <p>Methods</p> <p>HIV-infected subjects with bacille Calmette Guérin (BCG) scars and CD4 counts ≥ 200 cells/mm³entering a TB booster vaccine trial in Tanzania had baseline in vivo and in vitro immune tests performed: tuberculin skin tests (TST), LPA and five day assays of interferon gamma (IFN-γ) release. Assay antigens were early secreted antigenic target 6 (ESAT-6), antigen 85 (Ag85), and <it>Mycobacterium tuberculosis </it>whole cell lysate (WCL). Subjects were screened for active TB at enrollment by history, exam, sputum smear and culture. We compared antimycobacterial immune responses between subjects with and without latent or active TB at enrollment.</p> <p>Results</p> <p>Among 1885 subjects screened, 635 had latent TB and 13 had active TB. Subjects with latent TB were more likely than subjects without TB to have LPA responses to ESAT-6 (13.2% vs. 5.5%, P < 0.0001), Ag85 (18.7% vs. 3.1%, P < 0.0001), and WCL (45.7% vs. 17.1%, P < 0.0001). Subjects with active TB also were more likely than those without active TB to have detectable LPA responses to ESAT-6 (38.5% vs. 8.1%, P = 0.0001), Ag85 (46.2% vs. 8.5%, P < 0.0001), and WCL (61.5% vs. 27.0%, P = 0.0053). In subjects with a positive TST, LPA responses to ESAT-6, Ag85 and WCL were more common during active TB (p < 0.0001 for all tests). In diagnosing active TB, in vivo and in vitro tests of mycobacterial immune responses had sensitivity and specificity as follows: TST 84.6% and 65.5%, ESAT-6 LPA 38.5% and 92.0%, Ag85 LPA 46.2% and 91.5%, and WCL LPA 61.5% and 73.0%. Detectable LPA responses were more common in patients with higher CD4 counts, and higher HIV viral loads.</p> <p>Conclusion</p> <p>Lymphoproliferative responses to mycobacteria are detectable during HIV-associated active TB, and are less sensitive but more specific than TST.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier NCT00052195.</p

Investigation of three new mouse mammary tumor cell lines as models for transforming growth factor (TGF)-β and Neu pathway signaling studies: identification of a novel model for TGF-β-induced epithelial-to-mesenchymal transition

INTRODUCTION: This report describes the isolation and characterization of three new murine mammary epithelial cell lines derived from mammary tumors from MMTV (mouse mammary tumor virus)/activated Neu + TβRII-AS (transforming growth factor [TGF]-β type II receptor antisense RNA) bigenic mice (BRI-JM01 and BRI-JM05 cell lines) and MMTV/activated Neu transgenic mice (BRI-JM04 cell line). METHODS: The BRI-JM01, BRI-JM04, and BRI-JM05 cell lines were analyzed for transgene expression, their general growth characteristics, and their sensitivities to several growth factors from the epidermal growth factor (EGF) and TGF-β families (recombinant human EGF, heregulin-β(1 )and TGF-β(1)). The BRI-JM01 cells were observed to undergo a striking morphologic change in response to TGF-β(1), and they were therefore further investigated for their ability to undergo a TGF-β-induced epithelial-to-mesenchymal transition (EMT) using motility assays and immunofluorescence microscopy. RESULTS: We found that two of the three cell lines (BRI-JM04 and BRI-JM05) express the Neu transgene, whereas, unexpectedly, both of the cell lines that were established from MMTV/activated Neu + TβRII-AS bigenic tumors (BRI-JM01 and BRI-JM05) do not express the TβRII-AS transgene. The cuboidal BRI-JM01 cells exhibit a short doubling time and are able to form confluent monolayers. The BRI-JM04 and BRI-JM05 cell lines are morphologically much less uniform, grow at a much slower rate, and do not form confluent monolayers. Only the BRI-JM05 cells can form colonies in soft agar. In contrast, all three cell lines form colonies in Matrigel, although the BRI-JM04 and BRI-JM05 cell lines do so more efficiently than the BRI-JM01 cell line. All three cell lines express the cell surface marker E-cadherin, confirming their epithelial character. Proliferation assays showed that the three cell lines respond differently to recombinant human EGF and heregulin-β(1), and that all are growth inhibited by TGF-β(1), but that only the BRI-JM01 cell line undergoes an EMT and exhibits increased motility upon TGF-β(1 )treatment. CONCLUSION: We suggest that the BRI-JM04 and BRI-JM05 cell lines can be used to investigate Neu oncogene driven mammary tumorigenesis, whereas the BRI-JM01 cell line will be useful for studying TGF-β(1)-induced EMT