Expressão imunoistoquímica dos receptores Toll-like 5 e 9 e do fator de transcrição Foxp3 em lesões orais de líquen plano e lúpus eritematoso

Abstract

The present study aimed at analyzing the expression of toll-like receptors (TLR) 5 and 9 and forkhead box p3 regulatory T cells transcription factor (Foxp3) in oral lesions of lichen planus and lupus erythematosus. Twenty-one biopsy specimens of lichen planus, 21 of lupus erythematosus and 21 of inflammatory fibrous hyperplasia (control group) were subjected to immunohistochemical staining with anti-TLR5, anti-TLR-9 and anti-Foxp3, whose expressions were quantified using Image Pro Plus 4.5.1 software (Media Cybernetics). Immunostaining for Foxp3 differed significantly between the three groups, where the highest levels were shown by lichen planus and the lowest ones by controls. TLR5 expression did not differ significantly between lupus erythematosus and control group, but it was significantly greater in these two groups than in lichen planus. When we considered the two types of lupus separately, there was no significant difference of TLR5 between lichen planus and systemic lupus erythematosus, but discoid lupus erythematosus as well as the control group showed significantly greater values than lichen planus. TLR9 immunostaining did not differ significantly between the groups analyzed. A weak negative correlation was observed between Foxp3 and TLR5 (r= -0.279), while there was no other correlation. When this analysis was performed within each group, no correlation was observed between the variables. In conclusion, Foxp3 expression is increased in oral lesions of lichen planus and lupus erythematosus, whereas TLR5 and TLR9 do not show increased expression in these lesions. Foxp3 and TLR5 are inversely correlated. Further investigations analyzing Treg cells and proinflammatory cytokines in these diseases are warranted.