Staphylococcus aureus enterotoxins modulate IL-22-secreting cells in adults with atopic dermatitis
SCIENTIFIC REPORTS
Authors: Orfali, Raquel Leao; da Silva Oliveira, Luanda Mara; de Lima, Josenilson Feitosa; de Carvalho, Gabriel Costa; Leuzzi Ramos, Yasmim Alefe; Pereira, Natalli Zanete; Pereira, Naiura Vieira; Zaniboni, Mariana Colombini; Sotto, Mirian Nacagami; da Silva Duarte, Alberto Jose; Sato, Maria Notomi; Aoki, Valeria
Abstract
Atopic dermatitis (AD) is a chronic inflammatory immune-mediated skin disease characterized by skin colonization by Staphylococcus aureus. Interleukin (IL)-22, in cooperation with IL-17, triggers antimicrobial peptide elaboration and enhances certain immunological responses. In AD, IL-22 is related to epidermal hyperplasia, keratinocyte apoptosis, and inhibition of antimicrobial peptide (AMP) production. We aimed to evaluate the impact of staphylococcal enterotoxins on the Tc22/Th22 induction in the peripheral blood of AD patients and on CD4(+/)CD8(+)T cells expressing IL-22 in AD skin. Our study showed inhibition of the staphylococcal enterotoxins A and B (SEA and SEB) response by Th22 (CD4(+)IL22(+)IL-17A(-)IFN-gamma(-)) cells in AD patients. In contrast, Tc22 (CD8(+)IL-22(+)IL-17A(-)IFN-gamma(-)) cells were less susceptible to the inhibitory effects of staphylococcal enterotoxins and exhibited an enhanced response to the bacterial stimuli. In AD skin, we detected increased IL-22 transcript expression and T lymphocytes expressing IL-22. Together, our results provide two major findings in response to staphylococcal enterotoxins in adults with AD: dysfunctional CD4(+)IL-22 secreting T cells and increased Tc22 cells. Our hypothesis reinforces the relevance of CD8 T cells modulated by staphylococcal enterotoxins as a potential source of IL-22 in adults with AD, which is relevant for the maintenance of immunological imbalance.
Berberine attenuate staphylococcal enterotoxin B-mediated acute liver injury via regulating HDAC expression
AMB EXPRESS
Authors: Du, Jiying; Ding, Xiaohua; Zhang, Xiaoqin; Zhao, Xinyu; Shan, Huidong; Wang, Fanping
Abstract
Staphylococcal enterotoxin B (SEB) has been documented to be implicated in the pathogenesis of liver injury in the experimental models of hepatitis. However, the underlying mechanism of SEB-induced acute liver injury (ALI) remains to be further explored. In our study, we explored the therapeutic effectiveness of berberine (BBR), a natural isoquinoline alkaloid, in the SEB-induced ALI. In our study, we found that injection of SEB into D-galactosamine (D-gal)-sensitized mice induced ALI, as demonstrated by an increase of levels of alanine aminotransferase and aspartate aminotransferase, massive infiltration of immune cells into the liver, and pro-inflammatory cytokine release. However, intragastric administration of BBR attenuated SEB-induced ALI in mice. Meanwhile, we discovered that BBR treatment suppressed activation of splenocytes and pro-inflammatory cytokine release in SEB-stimulated splenocytes. Moreover, mechanistic analyses demonstrated that BBR was effective at inhibiting the expression of class I HDAC, but not class II, in SEB-stimulated splenocytes. Furthermore, trichostatin A, a standard HDAC inhibitor, alleviated activation of splenocytes and pro-inflammatory cytokine release in SEB-stimulated splenocytes. Taken together, we inferred from these results that BBR attenuated SEB-mediated ALI through repressing the class I HDAC enzyme, suggesting that BBR may constitute a novel therapeutic modality to prevent SEB-mediated inflammation and ALI.