Cure of chronic viral infection by neutralizing antibody treatment

Persistent infections can pose severe health risks. In many cases individuals fail to clear the virus and consequently chronic infection, often associated with severe immunopathology, occurs. For some chronic infections it is known that systemic IL-10 production can be increased. However, it is unclear, whether IL-10 affects the outcome of infection, amount of immunopathology and could be the actual cause for persistence. Conventional interferons (IFN) or anti-viral immunotherapies attempting to augment anti-viral immunity directly in persistent infected individuals have failed to affect the outcome so far, but lowering the viral antigenic load has clear beneficial effects. Therefore, approaching the problem from a different angle is important. The use of neutralizing antibodies is one of the most successful methods to interfere with receptor-ligand interactions in vivo. Optimal designs of therapeutic antibody treatment regimen are important in order to achieve maximal effects with minimal duration of immunosuppression or hyperactivation. In this review we reflect on the effects of a short time administration of a neutralizing cytokine receptor antibody treatment of a chronic infection resulting in the establishment of anti-viral immune responses and viral clearance and speculate on the potential mechanisms involved in this successful therapeutic treatment. (C) 2006 Elsevier B.V. All rights reserved.