Showing papers by "Suresh Mahalingam published in 2009"

Amelioration of alphavirus-induced arthritis and myositis in a mouse model by treatment with bindarit, an inhibitor of monocyte chemotactic proteins.

Abstract: Objective Alphaviruses such as chikungunya virus, Sindbis virus, o'nyong-nyong virus, Mayaro virus, and Ross River virus (RRV), are commonly associated with arthralgias and overt arthritides worldwide. Understanding the processes by which arthritogenic viruses cause disease is a prerequisite in the quest for better treatments. In this regard, we have recently established that monocyte/macrophages are mediators of alphavirus-induced arthritis in mice. We hypothesized that chemokines associated with monocyte/macrophage recruitment may play an important role in disease. The aim of the present investigations was to determine whether bindarit, an inhibitor of monocyte chemotactic protein (MCP) synthesis, could ameliorate alphavirus-induced rheumatic disease in mice. Methods Using our recently developed mouse model of RRV-induced arthritis, which has many characteristics of RRV disease (RRVD) in humans, the effects of bindarit treatment on RRVD in mice were determined via histologic analyses, immunohistochemistry, flow cytometry, real-time polymerase chain reaction analysis, enzyme-linked immunosorbent assay, and electrophoretic mobility shift assay. Results Bindarit-treated RRV-infected mice developed mild disease and had substantially reduced tissue destruction and inflammatory cell recruitment as compared with untreated RRV-infected mice. The virus load in the tissues was not affected by bindarit treatment. Bindarit exhibited its activity by down-regulating MCPs, which in turn led to inhibition of cell infiltration and lower production of NF-κB and tumor necrosis factor α, which are involved in mediating tissue damage. Conclusion Our data support the use of inhibitors of MCP production in the treatment of arthritogenic alphavirus syndromes and suggest that bindarit may be useful in treating RRVD and other alphavirus-induced arthritides in humans.

Human Metapneumovirus Establishes Persistent Infection in the Lungs of Mice and Is Reactivated by Glucocorticoid Treatment

Abstract: Human metapneumovirus (HMPV) has been identified as a worldwide agent of serious upper and lower respiratory tract infections in infants and young children. HMPV is second only to respiratory syncytial virus (RSV) as a leading cause of bronchiolitis, and, like RSV, consists of two major genotypes that cocirculate and vary among communities year to year. Children who have experienced acute HMPV infection may develop sequelae of wheezing and asthma; however, the features contributing to this pathology remain unknown. A possible mechanism for postbronchiolitis disease is that HMPV might persist in the lung providing a stimulus that could contribute to wheezing and asthma. Using immunohistochemistry to identify HMPV-infected cells in the lungs of mice, we show that HMPV mediates biphasic replication in respiratory epithelial cells then infection migrates to neuronal processes that innervate the lungs where the virus persists with no detectable infection in epithelial cells. After glucocorticoid treatment, the virus is reactivated from neural fibers and reinfects epithelial cells. The findings show that HMPV persists in neural fibers and suggest a mechanism for disease chronicity that has important implications for HMPV disease intervention strategies.