Citation Details

Journal Article

Androgens; Animals; Bioware; Cell Transformation, Neoplastic; Disease Models, Animal; Genes, Reporter; Humans; Image Processing, Computer-Assisted; In Situ Hybridization; Luciferases, Firefly; Luminescent Measurements; Male; Mice; Mice, Transgenic; PC-3M-luc; Promoter Regions, Genetic; Prostate; Prostate-Specific Antigen; Prostatic Neoplasms

Several transgenic mouse models of prostate cancer have been developed recently that are able to recapitulate many key biological features of the human condition. It would, therefore, be desirable to employ these models to test the efficacy of new therapeutics before clinical trial; however, the variable onset and non-visible nature of prostate tumor development limit their use for such applications. We now report the generation of a transgenic reporter mouse that should obviate these limitations by enabling noninvasive in vivo bioluminescence imaging of normal and spontaneously transformed prostate tissue in the mouse. We used an 11-kb fragment of the human prostate-specific antigen (PSA) promoter to achieve specific and robust expression of firefly luciferase in the prostate glands of transgenic mice. Ex vivo bioluminescence imaging and in situ hybridization analysis confirmed that luciferase expression was restricted to the epithelium in all four lobes of the prostate. We also show that PSA-Luc mice exhibit decreased but readily detectable levels of in vivo bioluminescence over extended time periods following androgen ablation. These results suggest that this reporter should enable in vivo imaging of both androgen-dependent and androgen-independent prostate tumor models. As proof-of-principle, we show that we could noninvasively image SV40 T antigen-induced prostate tumorigenesis in mice with PSA-Luc. Furthermore, we show that our noninvasive imaging strategy can be successfully used to image tumor response to androgen ablation in transgenic mice and, as a result, that we can rapidly identify individual animals capable of sustaining tumor growth in the absence of androgen.

Journal Article

Animals; Bioware; Disease Models, Animal; Female; Lung; Mice; Mice, Inbred BALB C; Pneumococcal Infections; pXen-5; Serotyping; Streptococcus pneumoniae, Xen10, Xen7, Xen35

The variability of the course of infection by Streptococcus pneumoniae is well known but poorly understood. Most animal models of pneumonia, sepsis or meningitis have been forced to use site-specific bacterial inoculation to mimic localized human infection. This study examined the differences in the progression of disease-causing strains D39 (serotype 2), A66.1 (serotype 3) and TIGR4 (serotype 4) using isolates transformed with the Gram-positive lux transposon cassette, Tn4001 luxABCDE Km(r). Expression of the lux operon results in bioluminescence, permitting the detection of the bacteria within a living animal while using a CCD camera. Mice infected intranasally with A66.1 developed only pneumonia, those challenged with D39 experienced high-grade sepsis, while TIGR4 infection resulted in low-grade pneumonia and bacteremia ultimately progressing to meningitis. Quantitative analysis of bacterial titers confirmed these patterns, which were consistent across different lineages of mice. Mice anesthetized with ketamine and xylazine developed more severe forms of the disease compared with isoflurane. These studies unambiguously characterize 3 distinct models of the natural course of pneumococcal infection. Mapping these models provides a framework for detailed molecular modeling of pneumococcal virulence determinants at specific stages of disease.

Journal Article

Amine Oxidase (Copper-Containing); Animals; Bacterial Adhesion; Bioware; Cell Adhesion Molecules; Coxsackievirus Infections; Immunity, Mucosal; Immunoglobulin A; Lymphocyte Count; Lymphocytes; Lymphoid Tissue; Mice; Mice, Inbred C57BL; Mice, Knockout; Peyer's Patches; Receptors, Lymphocyte Homing; Staphylococcal Vaccines; Staphylococcus aureus; Xen36

VAP-1, an ecto-enzyme expressed on the surface of endothelial cells, is involved in leukocyte trafficking between the blood and tissues under physiological and pathological conditions. In this study, we used VAP-1-deficient mice to elucidate whether absence of VAP-1 alters the immune system under normal conditions and upon immunization and microbial challenge. We found that VAP-1-deficient mice display age-dependent paucity of lymphocytes, in the Peyer's patches of the gut. IgA concentration in serum was also found to be lower in VAP-1(-/-) animals than in wild-type mice. Although there were slightly less CD11a on B and T cells isolated from VAP-1-deficient mice than on those from wild-type mice, there were no differences in the expression of gut-homing-associated adhesion molecules or chemokine receptors. Because anti-VAP-1 therapies are being developed for clinical use to treat inflammation, we determined the effect of VAP-1 deletion on useful immune responses. Oral immunization with OVA showed defective T and B cell responses in VAP-1-deficient mice. Antimicrobial immune responses against Staphylococcus aureus and coxsackie B4 virus were also affected by the absence of VAP-1. Importantly, when the function of VAP-1 was acutely neutralized using small molecule enzyme inhibitors and anti-VAP-1 Abs rather than by gene deletion, no significant impairment in antimicrobial control was detected. In conclusion, VAP-1-deficient mice have mild deviations in the mucosal immune system and therapeutic targeting of VAP-1 does not appear to cause a generalized increase in the risk of infection.

Journal Article

Animals; Bacteremia; Bacterial Proteins; Cerebrospinal Fluid; Disease Models, Animal; Female; Lung; Meningitis, Pneumococcal; Mice; Mice, Inbred BALB C; Mutation; N-Acetylmuramoyl-L-alanine Amidase; Nasopharynx; Neuraminidase; Pneumococcal Infections; Pneumonia, Pneumococcal; Pyruvate Oxidase; Streptococcus pneumoniae; Streptolysins; Virulence Factors; Xen7

We assessed the ability of Streptococcus pneumoniae mutants deficient in either choline binding protein A (CbpA), pneumolysin (Pln), pyruvate oxidase (SpxB), autolysin (LytA), pneumococcal surface protein A, or neuraminidase A (NanA) to replicate in distinct anatomical sites and translocate from one site to the next. Intranasal, intratracheal, and intravenous models of disease were assessed in 4-week-old BALB/cJ mice by quantitation of bacterial titers in the relevant organs. Mice were also observed by use of real-time bioluminescent imaging (BLI). BLI allowed visualization of the bacteria in sites not tested by sampling. All mutants were created in D39 Xen7, a fully virulent derivative of capsular type 2 strain D39 that contains an optimized luxABCDE cassette. NanA, SpxB, and, to a lesser extent, CbpA contributed to prolonged nasopharyngeal colonization, whereas CbpA and NanA contributed to the transition to the lower respiratory tract. Once lung infection was established, Pln, SpxB, and LytA contributed to bacterial replication in the lungs and translocation to the bloodstream. In the bloodstream, only Pln and LytA were required for high-titer replication, whereas CbpA was required for invasion of the cerebrospinal fluid. We conclude that transitions between body sites require virulence determinants distinct from those involved in organ-specific replication.

Journal Article

Xen41, Xen39

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