The tragic fate of group 3 innate lymphoid cells during HIV-1 infection

Type 3 Innate Lymphoid Cells as Regulators of the Host-Pathogen Interaction

Type 3 Innate lymphoid cells (ILC3s) have been described as tissue-resident cells and characterized throughout the body, especially in mucosal sites and classical first barrier organs such as skin, gut and lungs, among others. A significant part of the research has focused on their role in combating pathogens, mainly extracellular pathogens, with the gut as the principal organ. However, some recent discoveries in the field have unveiled their activity in other organs, combating intracellular pathogens and as part of the response to viruses. In this review we have compiled the latest studies on the role of ILC3s and the molecular mechanisms involved in defending against different microbes at the mucosal surface, most of these studies have made use of conditional transgenic mice. The present review therefore attempts to provide an overview of the function of ILC3s in infections throughout the body, focusing on their specific activity in different organs.

The Role of Plasmacytoid Dendritic Cells in Gut Health

Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.

Intestinal bacterium-derived cyp27a1 prevents colon cancer cell apoptosis

The pathogenesis of metastasis of colon cancer (Cca) is to be further investigated. The dysfunction of apoptotic mechanism plays a role in the cancer cell over growth. This study tests a hypothesis by which intestinal bacterium-derived cyp27a1 prevents apoptosis in colon cancer cells. In this study, the levels of cyp27a1 in human stool samples were assessed by enzyme-linked immunosorbent assay. The apoptosis of Cca cells was observed by flow cytometry. The expression of cyp27a1 was assessed by real time RT-PCR and Western blotting. We observed higher levels of cyp27a1 in the stool samples of Cca patients than that from healthy subjects. Cca colon epithelial biopsy contained high levels of cyp27a1 protein, but not the cyp27a1 mRNA. Cyp27a1 prevented Cca cell apoptosis induced by vitamin D3. In conclusion, intestinal bacterium-derived cyp27a1 facilitates Cca survival by inhibiting Cca cell apoptosis.