A herpes simplex virus-derived replicative vector expressing LIF limits experimental demyelinating disease and...

Area of Science:

• Neurovirology
• Gene Therapy
• Immunology

Background:

• Herpes simplex virus type 1 (HSV-1) possesses neurotropic properties beneficial for gene delivery to the nervous system.
• Experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis, is characterized by CNS inflammation and demyelination.
• Leukemia inhibitory factor (LIF) is a cytokine with potential to mitigate demyelination and oligodendrocyte loss in CNS autoimmune conditions.

Purpose of the Study:

• To construct and evaluate a novel HSV-1-based gene therapy vector expressing LIF for treating EAE.
• To investigate the efficacy of the HSV-LIF vector in ameliorating EAE symptoms and immune responses in the CNS.

Main Methods:

• A replicative HSV-1 vector, deleted of the neurovirulence gene γ134.5 and engineered to express LIF using a bacterial artificial chromosome (BAC), was constructed.
• SJL/J mice with induced EAE were treated intracranially with the HSV-LIF vector.
• Disease parameters, immune responses, vector presence, and oligodendrocyte survival in the CNS were assessed.

Main Results:

• The HSV-LIF vector replicated within the CNS, spread to the spinal cord, and demonstrated non-virulence.
• Significant amelioration of EAE symptoms was observed in HSV-LIF treated mice compared to controls.
• Treated mice exhibited a higher number of oligodendrocytes in the brain and favorable immunomodulatory changes in the CNS.

Conclusions:

• BAC-derived HSV vectors are suitable for gene therapy targeting CNS diseases.
• HSV-LIF therapy effectively ameliorated EAE and holds therapeutic potential for CNS autoimmune disorders.
• This approach can be utilized to test immunomodulatory factors for EAE and potentially multiple sclerosis treatment.