Serum level of interleukin-22 in patients with cutaneous warts: A case-control study

Interleukins in the Pathogenesis of Warts: Insight from the Last Decade-A Narrative Review

Human papillomavirus (HPV) is the etiological agent of a wide spectrum of diseases, from benign lesions to neoplasms. In most cases, in the first few years after infection, viral clearance occurs; however, in some cases, the infection remains persistent, allowing the progression of the lesions. The host immune response plays a key role in the resolution of the infection. The immune response to HPV is regulated by the dynamic interaction between numerous interleukins that exert pro- or anti-inflammatory effects. The role of interleukins in malignant lesions caused by HPV has been intensively studied, but in the case of benign lesions including warts, data are limited. This review compiles data from the last 10 years on the involvement of interleukins in the pathogenesis of warts, with the aim of providing new perspectives on this topic. Elucidating the role of interleukins will not only increase our knowledge of the pathogenesis of HPV infection but will also provide the foundation for the development of new therapies.

JAK Signaling Is Critically Important in Cytokine-Induced Viral Susceptibility of Keratinocytes

Little is known about whether type 1 (IFNγ), 2 (IL-4/IL-13), or 3 (IL-17A/IL-22) cytokines affect the susceptibility of keratinocytes (KC) to viruses. These immune pathways predominate in various skin diseases: lupus, atopic dermatitis (AD), and psoriasis, respectively. Janus kinase inhibitors (JAKi) are approved to treat both AD and psoriasis, and are in clinical development for lupus. We evaluated whether these cytokines alter viral susceptibility of KC and determined if this effect is modulated by treatment with JAKi. Viral susceptibility to vaccinia virus (VV) or herpes simplex virus-1 (HSV-1) ± JAKi was assessed in immortalized and primary human KC pretreated with cytokines. Exposure to type 2 (IL-4 + IL-13) or the type 3 (IL-22) cytokines significantly increased KC viral susceptibility. Specifically, there was a peak increase of 12.2 ± 3.1-fold (IL-4 + IL-13) or 7.7 ± 2.8-fold (IL-22) in VV infection as measured by plaque number. Conversely, IFNγ significantly reduced susceptibility to VV (63.1 ± 64.4-fold). The IL-4 + IL-13-induced viral susceptibility was reduced (44 ± 16%) by JAK1 inhibition, while the IL-22-enhanced viral susceptibility was diminished (76 ± 19%) by TYK2 inhibition. IFNγ-mediated resistance to viral infection was reversed by JAK2 inhibition (366 ± 294% increase in infection). Cytokines expressed in AD skin (IL-4, IL-13, IL-22) increase KC viral susceptibility while IFNγ is protective. JAKi that target JAK1 or TYK2 reversed cytokine-enhanced viral susceptibility, while JAK2 inhibition reduced the protective effects of IFNγ.

Current Knowledge of Th22 Cell and IL-22 Functions in Infectious Diseases

T helper 22 (Th22) cells, a newly defined CD4+ T-cell lineage, are characterized by their distinct cytokine profile, which primarily consists of IL-13, IL-22 and TNF-α. Th22 cells express a wide spectrum of chemokine receptors, such as CCR4, CCR6 and CCR10. The main effector molecule secreted by Th22 cells is IL-22, a member of the IL-10 family, which acts by binding to IL-22R and triggering a complex downstream signaling system. Th22 cells and IL-22 have been found to play variable roles in human immunity. In preventing the progression of infections such as HIV and influenza, Th22/IL-22 exhibited protective anti-inflammatory characteristics, and their deleterious proinflammatory activities have been demonstrated to exacerbate other illnesses, including hepatitis B and Helicobacter pylori infection. Herein, we review the current understanding of Th22 cells, including their definition, differentiation and mechanisms, and the effect of Th22/IL-22 on human infectious diseases. According to studies on Th22 cells, Th22/IL-22 may be a promising therapeutic target and an effective treatment strategy for various infections.

Interleukin-18 serum level before and after intralesional immunotherapy with tuberculin purified protein derivative in patients with cutaneous and genital warts

BACKGROUND

Several studies demonstrated the efficacy of intralesional purified protein derivative (PPD) immunotherapy in warts eradication. Nevertheless, the precise induced immune mechanisms are undetermined. Injected PPD is hypothesized to induce a delayed hypersensitivity reaction associated with cytokines release. Interleukin (IL)-18 has a major role in defense against viral infection via inducing interferon-γ release from T-helper 1 and natural killer (NK) cells. Moreover, IL-18 triggers Fas ligand expression on cytotoxic T cells and NK cells enhancing their cytotoxicity against virally infected cells.

AIM

The aim of this study was to assess the role of IL-18 in the response to intralesional PPD injection in patients with warts.

METHODS

The study included 25 patients with warts and 25 HCs. Patients underwent PPD skin test, and only patients with positive tests were included and received intralesional PPD injections starting 72 h after the test then every 2 weeks until wart clearance or a maximum of 3 sessions. Serum IL-18 level was measured via enzyme-linked immune-sorbent assay in patients (pre-treatment and 2 weeks after the last injection) and HCs.

RESULTS

After 3 sessions of injection, six (24%) patients were designated responders, nine (36%) patients showed partial response, and 10 (40%) patients were designated non-responders. Serum IL-18 level, post-treatment, was significantly higher than pre-treatment level (p = 0.025) and level in HCs (p = 0.036). Furthermore, the post-treatment level was significantly higher in responders than non-responders (p = 0.025).

CONCLUSION

IL-18 is probably implicated in the immune mechanisms induced by PPD injection that cause eradication of warts.

Altered Vaginal Microbiota Composition Correlates With Human Papillomavirus and Mucosal Immune Responses in Women With Symptomatic Cervical Ectopy

Cervical ectopy is a benign condition of the lower genital tract that is frequently detected in women of reproductive age. Although cervical ectopy is regarded as a physiological condition, some women experience symptoms such as leucorrhoea, persistent bleeding and recurrent vaginal infections that require medical intervention. Cervical ectopy has not been linked to cervical cancer, but it is thought to facilitate the acquisition of sexually transmitted diseases (STDs), like Human Papillomavirus (HPV) infection, as it provides a favorable microenvironment for virus infection and dissemination. We and others have described the presence of oncogenic HPV types in women with symptomatic cervical ectopy. The relevance of this finding and the impact of symptomatic cervical ectopy on the cervicovaginal microenvironment (vaginal microbiota, immune and inflammatory responses) are currently unknown. To shed some light into the interplay between HPV, the vaginal microbiota and mucosal immune and inflammatory responses in the context of this condition, we enrolled 156 women with symptomatic cervical ectopy and determined the presence of HPV using a type-specific multiplex genotyping assay. Overall, HPV was detected in 54.48% women, oncogenic HPV types were found in more than 90% of HPV-positive cases. The most prevalent HPV types were HPV16 (29.4%), HPV31 (21.17%) and HPV18 (15.29%). Next, we evaluated the vaginal microbial composition and diversity by 16S rDNA sequencing, and quantified levels of cytokines and chemokines by flow cytometry using bead-based multiplex assays in a sub-cohort of 63 women. IL-21 and CXCL9 were significantly upregulated in HPV-positive women (p=0.0002 and p=0.013, respectively). Women with symptomatic cervical ectopy and HPV infection had increased diversity (p<0.001), and their vaginal microbiota was enriched in bacterial vaginosis-associated anaerobes (Sneathia, Shuttleworthia, Prevotella, and Atopobium) and depleted in Lactobacillus spp. Furthermore, the vaginal microbiota of women with symptomatic cervical ectopy and HPV infection correlated with vaginal inflammation (IL-1β, rho=0.56, p=0.0004) and increased mucosal homeostatic response (IL-22, rho=0.60, p=0.0001). Taken together, our results suggest that HPV infection and dysbiotic vaginal communities could favor a vaginal microenvironment that might delay the recovery of the cervical epithelium in women with symptomatic cervical ectopy and favor STDs acquisition.