Analysis of phenotypic and functional profile of Natural Killer cells and CD8 + T lymphocytes in Lichen planus

Author(s)

Gabriel Costa de Carvalho

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2016-05-24

Examining board members

Maria Notomi Sato; Niels Olsen Saraiva Câmara; Ricardo Romiti; Jose Antonio Sanches Junior; Jane Tomimori

• Advisor: Maria Notomi Sato

Abstract

BACKGROUND: Lichen planus (LP) is a mucocutaneous inflammatory chronic disease of unknown etiology. Alterations in the innate immune response such as the pathogen-associated molecular pattern (PAMPs) and damage-associated molecular pattern (DAMPs) can lead to chronic inflammation and contribute to the pathogenesis of LP. OBJECTIVE: Evaluate the effect of the activation trough the DAMP S100A8 and the Toll-like receptor 4 (TLR-4) on the Natural killer cells (NK) and cytotoxic TCD8 cells and their memory / effector subsets in LP disease. METHODS: We selected 25 patients with LP (22 women, 3 men) with a mean age of 43.46 years ± 8.46 and a control group of 25 subjects (22 women, 3 men) with a mean age of 42 ± 5, 5. The transcriptional determination and protein expression by immunohistochemistry of DAMPs, S100A8 and HMGB-1 as well as TLR-4 and RAGE was performed on biopsies of skin lesions from patients with LP, and serum levels of S100A8, HMGB-1, MICA and MICB were determined by ELISA. Peripheral blood mononuclear cells (PBMCs) were assessed by flow cytometry to evaluate the frequency of TNF, IL-1beta and the degranulation marker CD107a in CD8+ T cells and CD56 + NK cells and their subsets. The evaluation of the TLR signaling pathway in purified CD8 + T cells activated with S100A8 were analyzed by PCR array and the determination of mRNA expression of inflammasome components on CD8 + T cells activated by S100A8 was measured by real time PCR. RESULTS: It was shown in the LP individuals an increased expression of the S100A8 protein in the cutaneous lesions and HMGB-1, TLR-4 and RAGE in the dermis, in parallel to increased level of mRNAs for S100A8 and S100A9 and decreased expression of RAGE. Moerover, increased serum levels of the dimer S100A8 / A9 was detected in patients compared to controls, in contrast to DAMP HMGB1 that revealed similar levels in both groups. The influence of S100A8 in CD8 + T cells and NK cells, was analyzed in PBMC activating with lipopolysaccharide and recombinant protein S100A8, both ligands of TLR-4. It was detected in LP individuals, an increased cytotoxic response of CD8+ T lymphocytes and CD56bright NK cells trough CD107a degranulation marker expression. The S100A8 protein was able to induce the pro-inflammatory genes expressions such as IL-1beta, TNF and IL-6 in CD8 + T cells of LP patients in contrast to healthy subjects who promoted IL-10 expression and type I IFN. CD8 + T cells of LP individuals activated or not with S100A8 are able to express NLRP1, NLRP3 and AIM-2 and IL-1beta production at similar levels to healthy controls. Moreover, CD8 + T cells activated with S100A8 showed increased expression of TLR3, TLR5, TLR7 and TLR8 in LP compared to biopsies from healthy controls. The increased CD8 + T cells cytotoxic response was mediated by the subtype of effector memory (TEM CD45RA- CCR7). The increased baseline expression of activating receptor NKG2D and the inhibitory NKG2A in the NK CD56dim cells in LP individulas, and the similar level of MICB soluble in both groups. CONCLUSION: These results shows that innate immunity components, such as S100A8 protein may contribute to the maintenance of LP inflammatory profile (AU)

• FAPESP's process: 11/21267-0 - Analysis of phenotypic and functional profile of Natural Killer and CD8 + T cells in Lichen Planus
• Grantee: Gabriel Costa de Carvalho
• Support Opportunities: Scholarships in Brazil - Doctorate