Editorial [Hot topic: Microbiota, Innate Immune and Anti-Inflammation (Guest Editor: Jun Sun)]

Welcome to the 2009 Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry (HOT TOPIC) Vol. 8, No. 3. The theme we have chosen for this volume is Microbiota, innate immune, and anti-inflammation. We attempt to highlight the current state-of-the-art relevant to innate immunity regulation and inflammation, functions of the anti-inflammatory bacterial proteins, application of the probiotics in digestive diseases, and evolution of the non-steroidal anti-inflamamtory drugs (NSAIDs). In particular, Sahni features the current understanding of pathogenic rickettsiae infection, host response, and apoptotic death mechanisms. This review summarizes critical roles for infection-induced oxidative stress, nuclear factor-kappa B, and p38 MAP kinase pathways in the regulation of innate immune responses and in preventing apoptosis during infection. Sun discusses the mechanisms of the bacterial proteins in inhibiting inflammation in the host cells. The anti-inflammatory roles of the bacterial proteins and the research progress on the bacterial protein structures are highlighted. Insights in the antiinflammatory mechanisms of the bacterial proteins will provide promising opportunities for therapeutical intervention. It is clear that bacteria in the colon, and perhaps in the small intestine, are significant players in the development of GI diseases, such as inflammatory bowel diseases (IBD) and necrotizing enterocolitis (NEC). Bacterial activation of the innate immune system can have both inflammatory as well as protective healing roles in the intestine. Gibson et al. review on the current state of knowledge underlying the bacteria's role for innate immunity in the gastrointestinal tract, and discuss the strengths and weaknesses of the chemical and infectious models used in these studies. In addition, they discuss preliminary evidence that exaggerated microbial activation of the innate immune system may cause the fibrotic responses that develop in some patients with IBD. Claud focuses on bacterial colonization patterns, intestinal barrier function, and inflammatory responses of immature enterocytes leading to a unique vulnerability of the preterm gut in NEC. In addition the possible therapeutic potential of factors in human milk and probiotic bacteria is discussed.