Infection of C57BL/6 mice with mouse hepatitis virus (MHV) results in a demyelinating encephalomyelitis characterized by mononuclear cell infiltration and white matter destruction similar to the pathology of the human demyelinating disease multiple sclerosis. The contributions of CD4 ؉ and CD8 ؉ T cells in the pathogenesis of the disease were investigated. Significantly less severe inflammation and demyelination were observed in CD4؊/؊ mice than in CD8 ؊/؊ and C57BL/6 mice (P < 0.002 and P < 0.001, respectively). Immunophenotyping of central nervous system (CNS) infiltrates revealed that CD4؊/؊ mice had a significant reduction in numbers of activated macrophages/microglial cells in the brain compared to the numbers in CD8 ؊/؊ and C57BL/6 mice, indicating a role for these cells in myelin destruction. Furthermore, CD4 ؊/؊ mice displayed lower levels of RANTES (a C-C chemokine) mRNA transcripts and protein, suggesting a role for this molecule in the pathogenesis of MHV-induced neurologic disease. Administration of RANTES antisera to MHV-infected C57BL/6 mice resulted in a significant reduction in macrophage infiltration and demyelination (P < 0.001) compared to those in control mice. These data indicate that CD4 ؉ T cells have a pivotal role in accelerating CNS inflammation and demyelination within infected mice, possibly by regulating RANTES expression, which in turn coordinates the trafficking of macrophages into the CNS, leading to myelin destruction.Demyelination is a complex neuropathological process in which the myelin sheath that insulates and protects axons is damaged or destroyed. Several animal models of demyelination have been developed that have provided valuable contributions to the understanding of the immunopathological events that may drive human demyelinating diseases such as multiple sclerosis (MS) (22,31). Among these is the neurotropic mouse hepatitis virus (MHV) model of virus-induced demyelination (12,18). MHV is a positive-strand RNA virus that causes a variety of clinical diseases in susceptible strains of mice (23). Neurovirulent strains of MHV cause an acute encephalomyelitis that may ultimately progress to demyelinating disease characterized clinically by abnormal gait and hind-limb paralysis. Histologically, affected animals exhibit mononuclear cell infiltration and myelin destruction. Early studies suggested that the demyelination observed in MHV-infected mice was the result of virus-induced damage or destruction of oligodendrocytes (9, 36). However, more recent reports have indicated that MHV-induced demyelination is more complex and may also involve immunopathologic responses against viral antigens expressed in infected tissues (5, 35).As T cells are considered central to the development of demyelinating lesions in animal models of demyelination as well as MS, it is imperative to better understand the mechanisms by which these cells exert their pathological effect (24, 25). We sought to evaluate the contributions of CD4 ϩ and CD8 ϩ T cells in MHV-induced central nervous system (CNS) d...

The contribution of the T cell chemoattractant chemokine IFN-inducible protein 10 (IP-10) in host defense following viral infection of the CNS was examined. IP-10 is expressed by astrocytes during acute encephalomyelitis in mouse hepatitis virus-infected mice, and the majority of T lymphocytes infiltrating into the CNS expressed the IP-10 receptor CXCR3. Treatment of mice with anti-IP-10 antisera led to increased mortality and delayed viral clearance from the CNS as compared with control mice. Further, administration of anti-IP-10 led to a &gt;70% reduction (p ≤ 0.001) in CD4+ and CD8+ T lymphocyte infiltration into the CNS, which correlated with decreased (p ≤ 0.01) levels of IFN-γ. These data indicate that IP-10 functions as a sentinel molecule in host defense and is essential in the development of a protective Th1 response against viral infection of the CNS.

Infection of the central nervous system (CNS) of susceptible mice with mouse hepatitis virus (MHV), a positive-strand RNA virus that is a member of the Coronaviridae family, reproducibly results in an acute encephalomyelitis followed by a demyelinating disease similar to the human demyelinating disease multiple sclerosis (MS). MHV infection triggers a robust cell-mediated response in which both CD4+ and CD8+ T cells are essential in controlling viral replication and spread. However, viral clearance is incomplete and viral RNA and protein can persist within white matter tracts, areas of viral persistence are often associated with demyelinating lesions, and recent studies have indicated an important role for both T cells and macrophages in contributing to myelin destruction. The molecular mechanisms governing leukocyte trafficking and accumulation within the CNS of MHV-infected mice are just now being understood and recent studies indicate that chemokines and chemokine receptors have an important role in this process. This article will provide an overview on how these molecules regulate T cell and macrophage trafficking into the CNS of MHV-infected mice and illustrate the delicate balance that exists with regards to expression of chemokines and their receptors as it relates to both host defense and disease development.

The role of nitric oxide synthase type-2 (NOS2)-derived nitric oxide (NO) in the pathogenesis of mouse hepatitis virus (MHV)-induced central nervous system disease was examined. Infection of NOS2 knockout ((-/-)) and NOS2(+/+) mice with MHV resulted in similar kinetics of viral clearance from the brain and comparable levels of demyelination. MHV-infected NOS2(-/-) mice displayed a marked decrease in mortality as compared to infected NOS2(+/+) mice that correlated with a significant decrease (P < or = 0.001) in the number of apoptotic cells (determined by TUNEL staining) present in the brain. Confocal microscopy revealed that the majority of cells (>70%) undergoing apoptosis were neurons. These studies indicate that NOS2-generated NO contributes to apoptosis of neurons but not demyelination following MHV infection.

Non-dilutive funding and equity capital are two key reasons why life sciences companies pursue strategic partnerships. In fact alliances are also strong contributors to successful “exits”, whether Mergers and Acquisitions (M&A) (~ 40% of partnerships ultimately resulted in acquisition by the partner) or stand-alone market entry (80% of approved biopharmaceutical products from 2000-2010 had a commercial partner on board)1. In the current environment, strategic alliances and funding can come from many sources, including the traditional “large pharma” universe – but the question remains: How best for a small management team to gain access to and maximize success with these sources? The focus of this article is to describe how entrepreneurs can leverage external expertise, intermediaries to achieve their near term and longer-term objectives.