Ability of yeast Ty-VLPs (virus-like particles) containing varicella-zoster virus (VZV)gE and assembly protein fragments to induce in vitro proliferation of human lymphocytes from VZV immune patients

Yeast Ty virus-like particles (VLPs) containing viral protein inserts have previously been shown to be potent immunogens, inducing both humoral and ce ll mediated immunity (CMI). The antigenicity of hybrid VLPs containing frag ments of the varicella-zoster virus (VZV) gE protein or the assembly protei n (AP) was assessed by lymphocyte proliferation. Peripheral blood mononucle ar cells (PBMCs) from patients with a recent natural VZV infection were sti mulated in vitro with VZV-VLPs together with control antigens. PBMC samples from both varicella (85%) and tester (75%) patients proliferated in respon ses to at least one of the gE VZV-VLPs. As reported for the first time, VZV specific lymphocyte responses were also identified towards the VZV AP in t wo varicella and two tester patient samples. The results demonstrate specif ic CMI recognition of the VZV gE fragments tested and the VZV AP delivered in the form of recombinant Ty-VLPs, and highlights their potential use as a recombinant antigen delivery system for vaccination. (C) 1999 Wiley-Liss, Inc.