Petar J. Popovic

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The ability of cancer cells to evade apoptosis may permit survival of a recombinant vaccinia lacking antiapoptotic genes in cancer cells compared with normal cells. We have explored the deletion of two vaccinia virus host range/antiapoptosis genes, SPI-1 and SPI-2, for their effects on the viral replication and their ability to induce cell death in infected(More)
For many years, dietary arginine supplementation, often combined with other substances, has been used as a mechanism to boost the immune system. Considerable controversy, however, exists as to the benefits and indications of dietary arginine due in part to a poor understanding of the role played by this amino acid in maintaining immune function. Emerging(More)
Plasmacytoid dendritic cells (PDC) are innate immune effector cells that are recruited to sites of chronic inflammation, where they modify the quality and nature of the adaptive immune response. PDCs modulate adaptive immunity in response to signals delivered within the local inflammatory milieu by pathogen- or damage-associated molecular pattern,(More)
We have recently demonstrated that cytolysis of human melanoma cells by immune effectors (both NK and T cells) is associated with release of the nuclear chromatin protein, high mobility group box I (HMGB1). Extracellular HMGB1 mediates a number of important functions including endothelial cell activation, stromagenesis, recruitment and activation of innate(More)
BACKGROUND Nitric oxide (NO) is a highly reactive free radical essential for antimicrobial and tumor immunity as well as endothelial function. Arginine is a limiting factor in NO synthesis. Citrulline can be converted to arginine and might restore NO production when arginine availability is limited, while glutamine may competitively inhibit citrulline(More)
OBJECTIVE To delineate the role of T-helper 2 (Th2) cytokines in the induction of trauma induced myeloid suppressor cells (TIMSC) and the regulation of nitric oxide production. BACKGROUND Trauma induces myeloid cells that express CD11b+/Gr1+ and arginase 1 and exhibit an immune suppressing activity. This article explores the mechanisms that induce TIMSC(More)
We have explored a unique combination therapy for metastatic colorectal cancer. This strategy combines a potent and new oncolytic poxvirus expressing a membrane-bound tumor necrosis factor-related apoptosis-inducing ligand (TRAIL or TNFSF10) and oxaliplatin (Ox) chemotherapy. We hypothesized that TRAIL expression would increase the efficacy of the oncolytic(More)
BACKGROUND Myeloid cells that express arginase 1 are upregulated by different stimuli, including trauma, and are capable of depleting arginine from the surrounding environment. Through arginine depletion, myeloid cells are capable of regulating T-cell function. We have previously reported increased arginase 1 expression in the peripheral blood mononuclear(More)
Dendritic cells (DC) and natural killer (NK) cells are essential components of the innate immune system, which rapidly sense and eliminate invading pathogens and transformed cells, mediate inflammation, and initiate adaptive immune responses. During the early immune events, DC and NK cells interact and regulate each other. The cellular "cross talk" and its(More)
The modern word immunity is derived from the Latin word immunis, which referred to exemption from military services, tax payments, or other public services. Throughout the medical history literature, the term immunity referred to those who were disease free or protected from getting disease. Immunity as a medical term defines a state of having sufficient(More)