Gene expression based evidence of innate immune response activation in the epithelium with oral lichen planus

Immunotherapy for keratinocyte cancers. Part I: Immune-related epidemiology, risk factors, pathogenesis, and immunotherapy management of keratinocyte cancers

The important role of the immune system in the surveillance and control of keratinocyte cancers (KCs), namely squamous and basal cell carcinomas, is increasingly appreciated, as new immunotherapies have recently become available. As the field of immunotherapy is rapidly evolving, this review synthesizes key concepts and highlights important cellular components within the immune system responsible for attacking KCs. We review the most current data on the epidemiology, risk factors, and immunotherapy management for KCs. Patients will seek advice from dermatologists to help explain why immunotherapies work for KCs and whether they might be appropriate for different clinical scenarios. Collaboration with medical colleagues across different disciplines to evaluate KCs for response to immunotherapy and early recognition of immune-related adverse events will help to optimize patient outcomes.

The Tipped Balance of ILC1/ILC2 in Peripheral Blood of Oral Lichen Planus Is Related to Inflammatory Cytokines

Oral lichen planus (OLP) is an immune-inflammatory disease mediated by T cells. Innate lymphoid cells (ILCs) constitute a novel family of immune cells that initially originate from common innate lymphoid progenitors. Termed “T cells counterparts,” ILCs play a prominent role in inflammatory-immune diseases. However, the characterization of ILCs and their related induced factors were unclear in OLP. In the present study, the phenotypic characteristics of ILCs and their correlation with inflammatory cytokines were explored in the peripheral blood of OLP patients and healthy controls. We found that the proportion of total ILCs was expanded in OLP and was positively correlated with disease severity. The highly skewed distribution of ILC subpopulations was notable in OLP. Specifically, the frequency of ILC1s was significantly increased, while that of ILC2s was significantly reduced in total ILCs of OLP, resulting in the markedly elevated ILC1/ILC2 ratio in OLP. Correspondingly, ILCs in OLP displayed high expression of T-bet but low expression of GATA3. In addition, the IFN-γ expression level was elevated in ILC1s, whereas the IL-4 expression level was decreased in ILC2s. Moreover, ILC-associated activators IL-12, IL-18, and IL-1β were upregulated in OLP plasma, with IL-12 and IL-1β both positively correlated with the ILC1/ILC2 ratio. Further in vitro stimulation tests indicated that OLP plasma remarkedly increased the ILC1/ILC2 ratio, especially that IL-12 and IL-1β tipped the balance between ILC1s and ILC2s toward ILC1s in total ILCs. Overall, elevated levels of IL-12 and IL-1β might act as environmental cues in tipping the balance of ILC1/ILC2 in the peripheral blood of OLP, contributing to the immune dysregulation in OLP.

Lichen Planus

Lichen planus (LP) is a T cell-mediated disease affecting the stratified squamous epithelia of the skin and/or mucus membrane. Histologically, the disease is characterized by a lichenoid inflammatory infiltrate and vacuolar degeneration of the basal layer of the epidermis. LP has three major subtypes: Cutaneous, mucosal and appendageal LP. Rarely, it may affect the nails in the absence of skin and/or mucosal changes. LP may also be induced by several drugs, typically anti-hypertensive medication or be associated with infections, particularly viral hepatitis. The diagnosis is based on the clinical presentation and characteristic histological findings. Although the disease is often self-limiting, the intractable pruritus and painful mucosal erosions result in significant morbidity. The current first-line treatment are topical and/or systemic corticosteroids. In addition, immunosuppressants may be used as corticosteroid-sparing agents. These, however are often not sufficient to control disease. Janus kinase inhibitors and biologics (anti-IL-12/23, anti-IL17) have emerged as novel future treatment options. Thus, one may expect a dramatic change of the treatment landscape of LP in the near future.

Effects of cold physical plasma on oral lichen planus: An in vitro study (Effects of CAP on OLP)

OBJECTIVES

In the search for more effective and safe treatment avenues, we investigated cold physical plasma as a new treatment modality for therapy of oral lichen planus (OLP).

MATERIAL AND METHODS

Healthy and diseased human mucosal tissue samples with a size of 3 mm in diameter obtained from OLP patients were subjected to plasma treatment ex vivo or were left untreated. Tissue sections were quantified for immune-infiltration of CD4+ , CD8+ , CD45RA+ , and CD45R0+ T cells. Moreover, the tissues' inflammatory profile was assessed by analyzing 12 different cytokines in the surrounding media.

RESULTS

A significantly increased infiltrate of CD8+ and CD45-R0+ T cells was detected in OLP tissue samples when compared to healthy tissue. A higher concentration of interleukin (IL) 1β, IL6, IL8, and granulocyte macrophage-colony stimulating factor (GM-CMF) was detected in OLP samples compared to healthy mucosal tissue. For all cytokines and chemokines investigated, 23 out of 24 comparisons showed a decrease in tendency (significant for IL1β, IL2, IL10, and GM-CSF) in response to plasma treatment. In ex vivo-treated tissue, a decrease of T-cell infiltrate in OLP lesions compared with healthy tissue was observed.

CONCLUSION

Our findings suggest cold physical plasma can be a promising therapeutic option for OLP that requires further validation in vivo.

Oral lichen planus: a microbiologist point of view

Oral lichen planus (OLP) is a chronic disease of uncertain etiology, although it is generally considered as an immune-mediated disease that affects the mucous membranes and even the skin and nails. Over the years, this disease was attributed to a variety of causes, including different types of microorganisms. This review analyzes the present state of the art of the disease, from a microbiological point of view, while considering whether or not the possibility of a microbial origin for the disease can be supported. From the evidence presented here, OLP should be considered an immunological disease, as it was initially proposed, as opposed to an illness of microbiological origin. The different microorganisms so far described as putative disease-causing agents do not fulfill Koch’s postulates; they are, actually, not the cause, but a result of the disease that provides the right circumstances for microbial colonization. This means that, at this stage, and unless new data becomes available, no microorganism can be envisaged as the causative agent of lichen planus.

The immunopathogenesis of oral lichen planus-Is there a role for mucosal associated invariant T cells?

Oral lichen planus (OLP) is a chronic, T-cell-mediated, immune condition of unknown cause. OLP may present with painful symptoms requiring treatment, as well as lesions outside the oral cavity. It is likely that what initiates the OLP disease process is a complex interaction of host susceptibility and environmental triggers. While it is possible that OLP represents a true autoimmune condition against an epithelial autoantigen, the mechanisms that lead to this immune dysregulation are still poorly understood. In this review article, we discuss current concepts relating to the immunopathogenesis of OLP, as well as the potential contributory roles the oral microbiota and mucosal-associated invariant T (MAIT) cells.

Microarray analysis of human keratinocytes from different anatomic sites reveals site-specific immune signaling and responses to human papillomavirus type 16 transfection

BACKGROUND

Stratified human keratinocytes (SHKs) are an essential part of mucosal innate immune response that modulates adaptive immunity to microbes encountered in the environment. The importance of these SHKs in mucosal integrity and development has been well characterized, however their regulatory immunologic role at different mucosal sites, has not. In this study we compared the immune gene expression of SHKs from five different anatomical sites before and after HPV16 transfection using microarray analyses.

METHODS

Individual pools of human keratinocytes from foreskin, cervix, vagina, gingiva, and tonsils (HFKs, HCKs, HVKs, HGKs and HTLKs) were prepared. Organotypic (raft) cultures were established for both normal and HPV16 immortalized HFKs, HCKs, HVKs, HGKs and HTLKs lines which stably maintained episomal HPV16 DNA. Microarray analysis was carried out using the HumanHT-12 V4 gene chip (Illumina). Immune gene expression profiles were obtained by global gene chip (GeneSifter) and Ingenuity pathway analysis (IPA) for each individual site, with or without HPV16 transfection.

RESULTS

We examined site specific innate immune response gene expression in SHKs from all five different anatomical sites before and after HPV16 transfection. We observed marked differences in SHK immune gene repertoires within and between mucosal tracts before HPV 16 infection. In addition, we observed additional changes in SHKs immune gene repertoire patterns when these SHKs were productively transfected with HPV16. Some immune response genes were similarly expressed by SHKs from different sites. However, there was also variable expression of non-immune response genes, such as keratin genes, by the different SHKs.

CONCLUSIONS

Our results suggest that keratinocytes from different anatomical sites are likely hard wired in their innate immune responses, and that these immune responses are unique depending on the anatomical site from which the SHKs were derived. These observations may help explain why select HPV types predominate at different mucosal sites, cause persistent infection at these sites, and on occasion, lead to HPV induced malignant and benign tumor development.

TLR1-10, NF-κB and p53 expression is increased in oral lichenoid disease

Toll-like receptors (TLRs) and nuclear factor-κB (NF-κB) in keratinocytes play an important role in dermatological autoimmune diseases. Tumour suppressor protein p53 regulates TLR expression. The aim of this study was to compare the expression of TLR1-TLR10, p53 and NF-κB in patients with oral lichenoid disease (OLD) with healthy mucosa. Oral mucosal biopsies from 24 patients with OLD and 26 healthy controls (HC) were analysed for the expression of TLR1-TLR10, NF-κB and p53 by immunohistochemistry. The expression of all TLRs was increased in OLD epithelia compared to HC samples and the difference was significant in TLR1, TLR3, TLR4, TLR5, TLR6 and TLR7. In the basement membrane zone, the immunoreactivity of TLR5 was significantly more intense in OLD compared to HC. In the intermediate layer, the immunoreactivity of NF-κB was significantly stronger in OLD, whereas the staining for p53 was more intense in all layers of OLD compared to HC samples. In OLD, a positive correlation between TLR2 and NF-κB in the basal layer and between TLR5, p53 and NF-κB in the intermediate layers was discovered. The expression of TLRs, p53 and NF-κB is increased in OLD, which may play a role in the pathogenesis of this chronic immune-mediated mucosal disease.