Dendritic cell-based vaccines in treating recurrent herpes labialis: Results of pilot clinical study

Recurrent herpes simplex labialis caused predominantly with herpes simplexvirus 1(HSV-1) is a major problem, for which various treatments have minimal impact. Given the important role of the immune system in controlling virus infection, an activation of virus-specific immune responses, in particular,using dendritic cell (DCs) vaccines, seems to be a promising approach for the treatment of patients with frequent recurrences of herpes labialis. The current paper presents the results of a pilot study of the safety and efficacy of DC vaccines in 14 patients with recurrent HSV-1 infections. DCs were generated in presence of GM-CSF and IFN-alpha and were loaded with HSV-1 recombinant viral glycoprotein D (HSV1gD). DCs cells were injected subcutaneously as 2 courses of vaccination during 9 months. Immunotherapy with DCs did not induce any serious side effects and resulted in more than 2-fold reduction in the recurrence rate and significant enhancement of the inter-recurrent time during the 9 months of treatment and subsequent 6-month follow-up period. An obvious clinical improvement was accompanied with an induction of an antigen-specific response to HCV1gD and a normalization of reduced mitogenic responsiveness of mono-nuclear cells. According to long-term survey data (on average 48 months after the beginning of therapy), 87% of respondents reported the decreased incidence of recurrent infection. At this time, most patients (85.7%) responded to HCV1gD stimulation. The data obtained suggests that dendritic cell vaccines may be a promising new approach for the treatment of recurrent labial herpes.