Kinetics of primary and memory cytotoxic T lymphocyte responses to herpes simplex virus 1 infection: granzyme B mediated CTL activity.

Background: Herpes simplex virus type 1 is one of the most common viruses among human population. Studies demonstrate the essential role of cell mediated immunity, especially CD8+ T cells, in prevention and clearance of HSV1.

Objective: It is of great importance to improve our knowledge about the kinetics of CTL responses to primary and secondary HSV-1 infection.

Methods: Using a sensitive technique for detection and analysis of CD8+ T cells, granzyme B ELISA, the CTL activity in the spleens of Balb/c mice at various time points after intraperitoneal administration of HSV1 (strain KOS) in primary and secondary infections were determined.

Results: During acute HSV-1 infection, virus specific cytotoxic T cells were detected at day 5 post virus inoculation and peaked at day 7. Six hours after secondary infection the activity of memory CD8+ T cells was detected and peaked at 12 hours post infection.

Conclusion: The peak of CTL activity was found to be day 7 post infection in primary HSV-1 infections which decreased with time. In secondary infections, the activity of CTLs reached the highest level at 12 hours post infection.