Over the past decade, there has been increasing attention on the interaction between microbiota and bile acid metabolism. Bile acids are not only involved in the metabolism of nutrients, but are also important in signal transduction for the regulation of host physiological activities. Microbial-regulated bile acid metabolism has been proven to affect many diseases, but there have not been many studies of disease regulation by microbial receptor signaling pathways. This review considers findings of recent research on the core roles of farnesoid X receptor (FXR), G protein-coupled bile acid receptor (TGR5), and vitamin D receptor (VDR) signaling pathways in microbial–host interactions in health and disease. Studying the relationship between these pathways can help us understand the pathogenesis of human diseases, and lead to new solutions for their treatments.

This study was aimed to investigate the quantity and subtypes of dendritic cells (DC) in patients with immune related pancytopenia (IRP) and to explore the role of DC in pathogenesis of IRP. The quantity of plasmacytoid dendritic cells (pDC, Lin(-)HLA-DR(+) CD123(+) cells) and myeloid dendritic cells (mDC, Lin(-)HLA-DR(+) CD11c(+)cells) in peripheral blood of 65 patients with IRP (37 new diagnosed and 28 remitted) and 17 healthy controls were analyzed by flow cytometry. The results indicated that the ratio of pDC in peripheral blood mononuclear cells (PBMNC) was (0.91 ± 064)% in new diagnosed group, which was significantly higher than that in remission group (0.39 ± 0.11)% and control group (0.29 ± 0.13)% (P < 0.01), while this ratio of pDC in remission group was higher than that in control group (P < 0.05). The ratio of mDC in PBMNC was (0.21 ± 0.20)% in new diagnosed group and (0.34 ± 0.21)% in remission group respectively, there was no statistical difference as compared with control group (0.29 ± 0.09)% (P > 0.05). The ratio of pDC to mDC in new diagnosed group was 6.75 ± 7.11, which was significantly higher than that in remission group (1.55 ± 0.93) and control group (1.07 ± 0.43, P < 0.01), there was no statistical difference between the ratio of remission group and control group (P > 0.05). The ratio of pDC in PBMNC of IRP group negatively correlated to ratio of Th1/Th2 (r = -0.347, P < 0.05), and positively correlated to the ratio of auto-antibody on membrane of BMMNC (r = 0.606, P < 0.05) and to the quantity of CD5(+)B cells (r = 0.709, P < 0.05), while it negatively correlated to the levels of hemoglobin (r = -0.381, P < 0.01) and platelets (r = -0.343, P < 0.01). The ratio of mDC in PBMNC positively correlated to the ratio of Th1/Th2 (r = 0.595, P < 0.05) and the level of hemoglobin (r = 0.292, P < 0.05). The ratio of pDC/mDC negatively correlated to ratio of Th1/Th2 (r = -0.395, P < 0.05), it positively correlated to the level of antibody on membrane of BMMNC (r = 0.421, P < 0.05) and the quantity of CD5(+)B cells (r = 0.423, P < 0.05), while it negatively correlated to the levels of hemoglobin (r = -0.304, P < 0.05) and platelets (r = -0.287, P < 0.05). It is concluded that the quantity of pDC in peripheral blood of IRP patients increases, which may be related to the immunopathogenesis of IRP.
Adolescent ; Adult ; Blood Cell Count ; Case-Control Studies ; Child ; Child, Preschool ; Dendritic Cells ; cytology ; immunology ; Female ; Flow Cytometry ; Humans ; Male ; Middle Aged ; Pancytopenia ; blood ; immunology ; Young Adult

OBJECTIVETo investigate the function of dendritic cells (DC) of patients with immune related pancytopenia (IRP) and explore the role of DC in IRP.

METHODSThe expression of CD80 and CD86 on myeloid DC (mDC, Lin-HLA-DR(+) CD11c(+) cells) and plasmacytoid DC (pDC, Lin-HLA-DR(+) CD123(+) cells) of 65 IRP (37 untreated and 28 remitted) patients and 17 healthy controls were analyzed by flow cytometry.

RESULTSThe expression of CD86 on pDC was (82.47 ± 13.17)% in untreated group and (60.08 ± 14.29)% in remission group, which were significantly higher than that of controls (47.95 ± 18.59)% (P < 0.05), while the expression in untreated group was higher than that of remission group (P < 0.05). The expression of CD80 on pDC was (6.31 ± 4.49)% in untreated group, which was significantly higher than that of remitted patients (3.09 ± 2.93)% and controls (2.33 ± 2.25)% (P < 0.05). The expression of CD86 on mDC was (97.06 ± 4.82)% in untreated group and (91.35 ± 12.20)% in control group, while the expression in untreated group was higher than that of control group (P < 0.05). The expression of CD80 on mDC was (6.20 ± 5.44)% in untreated group and (3.97 ± 3.24)% in remission group, which were significantly higher than that of controls (1.86 ± 1.73)% (P < 0.05). The expression of CD86 on pDC was negatively correlated to Th1/Th2 (r = -0.733, P < 0.05), it was positively correlated to the antibody on membrane of BMMNC (r = 0.283, P < 0.05) and the quantity of CD5(+)B cells (r = 0.436, P < 0.05), while it was negatively correlated to the level of hemoglobin, platelets and white blood cells (r = -0.539, P < 0.05; r = -0.519, P < 0.05; r = -0.567, P < 0.05, respectively). The expression of CD80 on pDC was negatively correlated to the level of hemoglobin and platelets (r = -0.431, P < 0.05; r = -0.464, P < 0.05).

CONCLUSIONThe function of pDC in PB of IRP were strengthened, which was relevant to the immunopathogenesis of IRP.

Adolescent ; Adult ; Autoimmune Diseases ; complications ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; Case-Control Studies ; Child ; Child, Preschool ; Dendritic Cells ; metabolism ; Female ; Flow Cytometry ; Humans ; Male ; Middle Aged ; Pancytopenia ; blood ; etiology ; pathology ; Young Adult

Over the past decade, there has been increasing attention on the interaction between microbiota and bile acid metabolism. Bile acids are not only involved in the metabolism of nutrients, but are also important in signal transduction for the regulation of host physiological activities. Microbial-regulated bile acid metabolism has been proven to affect many diseases, but there have not been many studies of disease regulation by microbial receptor signaling pathways. This review considers findings of recent research on the core roles of farnesoid X receptor (FXR), G protein-coupled bile acid receptor (TGR5), and vitamin D receptor (VDR) signaling pathways in microbial-host interactions in health and disease. Studying the relationship between these pathways can help us understand the pathogenesis of human diseases, and lead to new solutions for their treatments.
Bile Acids and Salts/metabolism* ; Gastrointestinal Microbiome ; Humans ; Inflammation/metabolism* ; Metabolic Syndrome/metabolism* ; Receptors, Calcitriol/physiology* ; Receptors, Cytoplasmic and Nuclear/physiology* ; Receptors, G-Protein-Coupled/physiology* ; Signal Transduction/physiology*