Nevertheless, cellular immunity plays a key role in the defence against all HPV-induced infections or lesions by destroying HPV-infected or -transformed keratinocytes. Indeed, the incidence of HPV infections and diseases increases significantly with CD4+ T cell impairment in immunosuppressed individuals, such as transplanted or human immunodeficiency virus (HIV)-infected patients [7–10]. In asymptomatic HPV-16 infections, most women resolve their infection spontaneously without clinical Ixazomib molecular weight disease [11] concomitantly with blood anti-HPV-16

T helper type 1 (Th1) CD4+ T cell responses [12,13]. Similarly, regression of condyloma is associated with a dense epithelial cellular infiltrate made up of both CD4+ and CD8+ T lymphocytes [14], with a Th1 cytokine profile as measured by cytokine mRNAs in interferon (IFN)-treated condylomas [15,16]. Proliferative CD4+ T cell responses are

also associated with spontaneously regressive CIN3 [17]. The evolution of CIN3 towards invasive cancers is featured by a decrease of CD4+ cellular infiltrate, an increase of CD8+ T lymphocytes [18–20], the appearance of suppressive T lymphocytes [21] and a loss of blood anti-HPV-16 CD4+ activity [22,23]. In high-grade CIN, positive intradermal reaction after intradermal injection of five HPV-16 Obeticholic Acid in vitro E7 large peptides correlated with the spontaneous clearance of the lesions, which further indicates the presence and the very important role of HPV-specific CD4+ T lymphocytes [24]. Sixteen consecutive classic VIN patients aged 24–67 years (mean 41 ± 9·6 years) (Table 1) entered the study.

Classic VIN first symptoms had appeared from 6 to 168 months (mean 37 months ± 52 months) prior to inclusion (Table 1). Diagnosis was confirmed by standard pathological analysis. HPV-16 was isolated from the lesions of all patients. All except Lepirudin one were HIV-negative. Human leucocyte antigen (HLA) class I and class II antigens were determined in every case. At the time of study, 11 patients (nos 2, 3, 4, 5, 6, 8, 10, 11, 13, 14, 16) had suffered from recurrent lesions for more than 6 months and experienced numerous relapses despite multiple destructive treatments (cryotherapy, electrocoagulation or laser surgery), local topical therapy (5-fluorouracil, imiquimod) or systemic immunotherapy using IFN-α. The five remaining patients (nos 1, 7, 9, 12, 15) were previously untreated.