Cell-mediated immunity to varicella-zoster virus

Area of Science:

• Immunology
• Virology
• Cellular Biology

Background:

• Varicella-zoster virus (VZV) infection and vaccination elicit T lymphocytes targeting viral glycoproteins (gpI-V) and immediate early/tegument protein (IE62).
• Understanding T cell recognition patterns is crucial for assessing vaccine efficacy and natural immunity.

Purpose of the Study:

• To investigate T cell recognition of VZV proteins after natural infection and vaccination.
• To compare T cell responses in naturally and vaccine-immune individuals.
• To evaluate the impact of exogenous VZV re-exposure on cellular immunity.

Main Methods:

• Limiting dilution assays to estimate responder cell frequencies.
• Proliferation and cytotoxicity assays to measure T cell responses.
• Analysis of CD4+ and CD8+ T cell-mediated cytotoxic T lymphocyte (CTL) recognition.

Main Results:

• Human T cells do not show preferential recognition of specific VZV proteins.
• Both gpI and IE62 are early targets of the CTL response post-vaccination.
• T cell proliferation and CTL function frequencies are comparable between natural and vaccine-induced immunity.
• Exogenous VZV re-exposure, including vaccination in immune individuals, significantly enhances T cell proliferation and circulating CTLs.

Conclusions:

• Both natural VZV infection and vaccination induce robust T cell immunity against viral proteins.
• Exogenous re-exposure to VZV is a key mechanism for maintaining long-term cellular immunity.
• Vaccination of previously immune individuals boosts VZV-specific T cell responses.