Bcl-3 Acts as an Innate Immune Modulator by Controlling Antimicrobial Responses in Keratinocytes

Innate immune responses involve the production of antimicrobial peptides (AMPs), chemokines, and cytokines. We report here the identification of B-cell leukemia (Bcl)-3 as a modulator of innate immune signaling in keratinocytes. In this study, it is shown that Bcl-3 is inducible by the Th2 cytokines IL-4 and IL-13 and is overexpressed in lesional skin of atopic dermatitis (AD) patients. Bcl-3 was shown to be important to cutaneous innate immune responses as silencing of Bcl-3 by small-interfering RNA (siRNA) reversed the downregulatory effect of IL-4 on the HBD3 expression. Bcl-3 silencing enhanced vitamin D3 (1,25D3)-induced gene expression of cathelicidin AMP in keratinocytes, suggesting a negative regulatory function on cathelicidin transcription. Furthermore, 1,25D3 suppressed Bcl-3 expression in vitro and in vivo. This study identified Bcl-3 as an important modulator of cutaneous innate immune responses and its possible therapeutic role in AD

Macrophage/cancer cell interactions mediate hormone resistance by a nuclear receptor derepression pathway. Cell 124: 615–629

Defining the precise molecular strategies that coordinate patterns of transcriptional responses to specific signals is central for understanding normal development and homeostasis as well as the pathogenesis of hormone-dependent cancers. Here we report specific prostate cancer cell/macrophage interactions that mediate a switch in function of selective androgen receptor antagonists/modulators (SARMs) from repression to activation in vivo. This is based on an evolutionarily conserved receptor N-terminal L/HX 7LL motif, selectively present in sex steroid receptors, that causes recruitment of TAB2 as a component of an N-Co

Antimicrobials from human skin commensal bacteria protect against Staphylococcus aureus and are deficient in atopic dermatitis

The microbiome can promote or disrupt human health by influencing both adaptive and innate immune functions. We tested whether bacteria that normally reside on human skin participate in host defense by killing Staphylococcus aureus, a pathogen commonly found in patients with atopic dermatitis (AD) and an important factor that exacerbates this disease. High-throughput screening for antimicrobial activity against S. aureus was performed on isolates of coagulase-negative Staphylococcus (CoNS) collected from the skin of healthy and AD subjects. CoNS strains with antimicrobial activity were common on the normal population but rare on AD subjects. A low frequency of strains with antimicrobial activity correlated with colonization by S. aureus The antimicrobial activity was identified as previously unknown antimicrobial peptides (AMPs) produced by CoNS species including Staphylococcus epidermidis and Staphylococcus hominis These AMPs were strain-specific, highly potent, selectively killed S. aureus, and synergized with the human AMP LL-37. Application of these CoNS strains to mice confirmed their defense function in vivo relative to application of nonactive strains. Strikingly, reintroduction of antimicrobial CoNS strains to human subjects with AD decreased colonization by S. aureus These findings show how commensal skin bacteria protect against pathogens and demonstrate how dysbiosis of the skin microbiome can lead to disease