Quantitative imaging and dynamics of tumor therapy with viruses.

Cancer therapy remains challenging due to the myriad presentations of the disease and the vast genetic diversity of tumors that continuously evolve and often become resistant to therapy. Viruses can be engineered to specifically infect, replicate, and kill tumor cells (tumor virotherapy). Moreover, the viruses can be "armed" with therapeutic genes to enhance their oncolytic effect.

Preclinical development of CD126 CAR-T cells with broad antitumor activity.

Chimeric antigen receptor T (CAR-T) cell therapy is a transformative approach to cancer eradication. CAR-T is expensive partly due to the restricted use of each CAR construct for specific tumors. Thus, a CAR construct with broad antitumor activity can be advantageous.

In vitro and in silico multidimensional modeling of oncolytic tumor virotherapy dynamics.

Tumor therapy with replication competent viruses is an exciting approach to cancer eradication where viruses are engineered to specifically infect, replicate, spread and kill tumor cells. The outcome of tumor virotherapy is complex due to the variable interactions between the cancer cell and virus populations as well as the immune response. Oncolytic viruses are highly efficient in killing tumor cells in vitro, especially in a 2D monolayer of tumor cells, their efficiency is significantly lower in a 3D environment, both in vitro and in vivo.

Imaging of Oncolytic Measles Virus Propagation with Single-Cell Resolution.

Recombinant measles viruses (MVs) have oncolytic activity against a variety of human cancers. However, their kinetics of spread within tumors has been unexplored. We established an intravital imaging system using the dorsal skin fold chamber, which allows for serial, non-invasive imaging of tumor cells and replication of a fusogenic and a hypofusogenic MV.

Estimation of Oncolytic Virus Populations within Tumors.

The use of replication-competent viruses as oncolytic agents is rapidly expanding, with several oncolytic viruses approved for cancer therapy. As responses to therapy are highly variable, understanding the dynamics of therapy is critical for optimal application of virotherapy in practice. Although mathematical models have been developed to understand the dynamics of tumor virotherapy, a scarcity of data has made difficult parametrization of these models.

Human CRM1 augments production of infectious human and feline immunodeficiency viruses from murine cells.

Productive replication of human immunodeficiency virus type 1 (HIV-1) occurs efficiently only in humans. The posttranscriptional stages of the HIV-1 life cycle proceed poorly in mouse cells, with a resulting defect in viral assembly and release. Previous work has shown that the presence of human chromosome 2 increases HIV-1 production in mouse cells.

Feline immunodeficiency virus Gag is a nuclear shuttling protein.

Lentiviral genomic RNAs are encapsidated by the viral Gag protein during virion assembly. The intracellular location of the initial Gag-RNA interaction is unknown. We previously observed feline immunodeficiency virus (FIV) Gag accumulating at the nuclear envelope during live-cell imaging, which suggested that trafficking of human immunodeficiency virus type 1 (HIV-1) and FIV Gag may differ.

Live-cell coimaging of the genomic RNAs and Gag proteins of two lentiviruses.

Human immunodeficiency virus type 1 (HIV-1) Gag and genomic RNA determinants required for encapsidation are well established, but where and when encapsidation occurs in the cell is unknown. We constructed MS2 phage coat protein labeling systems to track spatial dynamics of primate and nonprimate lentiviral genomic RNAs (HIV-1 and feline immunodeficiency virus [FIV]) vis-à-vis their Gag proteins in live cells. Genomic RNAs of both lentiviral genera were observed to traffic into the cytoplasm, and this was Rev dependent.

The critical role of proximal gag sequences in feline immunodeficiency virus genome encapsidation.

Retroviral RNA encapsidation is mediated by specific interactions between viral Gag proteins and cis-acting packaging sequences in genomic RNA. Feline immunodeficiency virus (FIV) RNA encapsidation determinants have been shown to be discrete and noncontinuous, comprising one region at the 5' end of the genomic mRNA (R-U5) and another region that mapped within the proximal 311 nt of gag. To aid comparative understanding of lentiviral encapsidation and refinement of FIV vector systems, we used RNase protection assays (RPAs) of cellular and virion RNAs to investigate in detail the gag element.

Mapping the encapsidation determinants of feline immunodeficiency virus.

Encapsidation of retroviral RNA involves specific interactions between viral proteins and cis-acting genomic RNA sequences. Human immunodeficiency virus type 1 (HIV-1) RNA encapsidation determinants appear to be more complex and dispersed than those of murine retroviruses. Feline lentiviral (feline immunodeficiency virus [FIV]) encapsidation has not been studied.