Citations

ABSTRACT The Ref1 and Lv1 postentry restrictions in human and monkey cells have been analyzed for lentiviruses in the primate and ungulate groups, but no data exist for the third (feline) group. We compared feline immunodeficiency virus (FIV) to other restricted (human immunodeficiency virus type 1 [HIV-1], equine infectious anemia virus [EIAV]) and unrestricted (NB-tropic murine leukemia virus [NB-MLV]) retroviruses across wide ranges of viral inputs in cells from multiple primate and nonprimate species. We also characterized restrictions conferred to permissive feline and canine cells engineered to express rhesus and human TRIM5α proteins and performed RNA interference (RNAi) against endogenous TRIM5α. We find that expression of rhesus or human TRIM5α proteins in feline cells restricts FIV, impairing pseudotyped vector transduction and viral replication, but rhesus TRIM5α is more restricting than human TRIM5α. Notably, however, canine cells did not support restriction by human TRIM5α and supported minimal restriction by rhesus TRIM5α, suggesting that these proteins may not function autonomously or that a canine factor interferes. Stable RNAi knockdown of endogenous rhesus TRIM5α resulted in marked increases in FIV and HIV-1 infectivities while having no effect on NB-MLV. A panel of nonprimate cell lines varied widely in susceptibility to lentiviral vector transduction, but normalized FIV and HIV-1 vectors varied concordantly. In contrast, in human and monkey cells, relative restriction of FIV compared to HIV-1 varied from none to substantial, with the greatest relative infectivity deficit for FIV vectors observed in human T-cell lines. Endogenous and introduced TRIM5α restrictions of FIV could be titrated by coinfections with FIV, HIV-1, or EIAV virus-like particles. Arsenic trioxide had complex and TRIM5α-independent enhancing effects on lentiviral but not NB-MLV infection. Implications for human gene therapy are discussed.

ABSTRACTThe attenuation of eosinophilia by the administration of monoclonal antibodies to CCR3 consistently correlates with impairment in worm elimination following primary intraperitonealBrugia pahangiinfections in mice. Host protection was unimpaired in mice deficient in eosinophil peroxidase (EPO) or major basic protein 1 (MBP-1), suggesting that eosinophils are essential in host protection but that neither EPO nor MBP-1 alone is.

Objective— We hypothesized that apolipoprotein E (apoE) −/− /low-density lipoprotein (LDL) −/− double knockout mice might develop vasa vasorum (VV) in association with advanced lesion formation. Methods and Results— Aortas from apoE −/− /LDL −/− mice aged 16, 18, 20, or 80 weeks were infused in situ with Microfil, harvested, and scanned with micro-computed tomography (CT). We characterized plaque volume and CT “density” as well as VV luminal volume along the aorta using Analyze 6.0 software. Results were complemented by a detailed histological plaque classification according to American Heart Association guidelines. From 16 to 80 weeks, plaque volume and VV opacified lumen volume increased with age ( P <0.001). The 3-dimensional micro-CT images of arterial and venous VV trees allowed perfusion territories to be delineated. The spatial location and magnitude of VV density and adventitial inflammation were strongly correlated in advanced atherosclerotic lesions ( r =0.91) and identified as an independent correlate to advanced lesions. At age 80 weeks, VV luminal volume was increased 20-fold compared with animals at age 16 weeks ( P <0.001). Micro-CT showed that adventitial VV communicate with intraplaque microvessels. Conclusion— Our results show that apoE −/− /LDL −/− double knockout mice develop VV and advanced atheromas along the aorta. Lesion volume was closely associated with amount of neovascularization in advanced atheromas.

A number of recently developed and promising approaches to antitumoral immunotherapy are being investigated as potential treatments for advanced prostate cancer. These approaches largely revolve around strategies to increase antigen-specific T-cell activation against prostate tumors as well as precise manipulations of critical co-regulatory receptors that help to maintain and prolong the activity of antigen-presenting cells and T cells that are capable of mediating tumor regression. Herein, we describe the experience with the most recent and promising approaches pertaining to prostate cancer immunotherapy. Additionally, we discuss the mechanistic basis for these approaches as well as current limitations that must still be addressed in order to propel immunotherapy into the forefront of prostate cancer treatment.

Background and Purpose— Mitral annular calcification (MAC) and aortic valve (AV) sclerosis have each been linked to cardiovascular disease. Whether MAC and AV sclerosis are risk factors for stroke independent of other echocardiographic or laboratory predictors has not been established. We evaluated the relationship between MAC, AV sclerosis, and first stroke events in a population-based cohort. Methods— Our study cohort consisted of 2723 American Indians participating in the Strong Heart Study who were free of prevalent cardiovascular disease. Participants underwent standardized clinical, echocardiographic, and laboratory evaluation, and incident stroke was ascertained using validated methods. Results— During a median follow-up of 7 years, 86 strokes occurred. Age- and sex-adjusted incidence rates of stroke were significantly increased for MAC (rate ratio [RR], 3.12; 95% CI, 1.77 to 5.25) but not for AV sclerosis (RR, 1.15; 95% CI, 0.45 to 2.49). MAC was also associated with a reduced time to first stroke events after adjustment for clinical variables and the inflammatory markers C-reactive protein and fibrinogen (hazard ratio [HR], 2.42; 95% CI, 1.39 to 4.21) or the echocardiographic covariates left ventricular hypertrophy and left atrial enlargement (HR, 1.89; 95% CI, 1.04 to 3.41). Individuals with and without AV sclerosis showed no significant difference in stroke-free survival in unadjusted analyses ( P =0.698). Crossing of the survival curves precluded multivariable analysis using Cox models. Conclusions— In this cohort of American Indians without clinical cardiovascular disease, the presence of MAC, but not AV sclerosis, proved to be a strong risk factor for incident stroke after extensive adjustment for other predictors. Individuals exhibiting MAC may benefit from aggressive risk factor modification, but this will require further investigation.

ABSTRACT HlyD, a member of the membrane fusion protein family, is essential for the secretion of the RTX hemolytic toxin HlyA from Escherichia coli . Random point mutations affecting HlyA secretion were obtained, distributed in most periplasmic regions of the HlyD molecule. Analysis of the secretion phenotypes of different mutants allowed the identification of regions in HlyD involved in different steps of HlyA translocation. Four mutants, V349-I, T85-I, V334-I and L165-Q, were conditionally defective, a phenotype shown to be linked to the presence of inhibitory concentrations of Ca 2+ in extracellular medium. Hly mutant T85-I was defective at an early stage in secretion, while mutants V334-I and L165-Q appeared to accumulate HlyA in the cell envelope, indicating a block at an intermediate step. Mutants V349-I, V334-I, and L165-Q were only partially defective in secretion, allowing significant levels of HlyA to be transported, but in the case of V349-I and L165-Q the HlyA molecules secreted showed greatly reduced hemolytic activity. Hemolysin molecules secreted from V349-I and V334-I are defective in normal folding and can be reactivated in vitro to the same levels as HlyA secreted from the wild-type translocator. Both V349-I and V334-I mutations mapped to the C-terminal lipoyl repeat motif, involved in the switching from the helical hairpin to the extended form of HlyD during assembly of the functional transport channel. These results suggest that HlyD is an integral component of the transport pathway, whose integrity is essential for the final folding of secreted HlyA into its active form.

Purpose Surgical resection of liver-only metastases from colorectal cancer has undergone extensive evaluation and review. The use of neoadjuvant chemotherapy to improve the likelihood of resection in disease that is not optimally resectable has not been as well studied. Patients and Methods Patients with liver-only metastases from colorectal cancer deemed not optimally resectable by a surgeon with expertise in liver surgery received fluorouracil, leucovorin, and oxaliplatin (FOLFOX4). Patients were periodically reassessed for resectability. Surgical response was classified as completely resectable (S-CR), partially resectable (S-PR), or unresectable (S-UR). Study design specified the accrual of 39 patients, with two or more S-CRs considered evidence of promising activity with respect to increasing the S-CR rate. Results Forty-two of 44 patients were assessable for this analysis. Twenty-five patients (60%) had tumor reduction by serial imaging. Seventeen patients (40%) underwent surgery (S-CR, n = 14; S-PR, n = 1; and S-UR, n = 2) after a median of 6 months of chemotherapy. With a median postsurgical follow-up of 22 months (range, 13 to 32 months), 11 recurrences have occurred in the 15 S-CR and S-PR patients. Median survival time was 26 months. Conclusion Our data suggest that FOLFOX4 has a high response rate (complete response, partial response, or reduction) in patients with liver-only metastases from colorectal cancer, allowing for successful resection of disease in a portion of patients initially not judged to be optimally resectable. However, a high recurrence rate after surgery was observed, which, in 73% of patients, involved the liver. Further trials are indicated based on the promising results observed in this trial.