Viral escape from the neutralizing antibody response: the lymphocytic choriomeningitis virus model

In addition to CD8(+) cytotoxic T lymphocyte (CTL) responses, neutralizing antibodies contribute substantially to the long-term immune control of nonc ytopathic viruses, as demonstrated during infection with the lymphocytic ch oriomeningitis virus (LCMV). The high virus load during the initial phase o f an infection and the ability of this RNA virus to spontaneously acquire m utations are important prerequisites for escaping an ongoing immune respons e. In this con text, LCMV escape from the humoral response by single point mutations in neutralizing envelope protein determinants may occur, particul arly during conditions of CTL deficiency, leading to virus persistence.