[Dendritic cells: a new horizon in cell therapy for inflammatory bowel disease?]

The dynamic changes of CD3e-CD11c+ dendritic cells in spleens and bone marrow of mice infected with Schistosoma japonicum

Schistosoma japonicum as a pathogeny requires dendritic cells to activate immune response. So, the research is to study the dynamic changes of CD3e^-CD11c⁺ dendritic cells in mice infected with S. japonicum. Zero, 7, 28, 35, and 63 days were selected to study the variation of dendritic cells, and the proportions of CD3e^-CD11c⁺ dendritic cells and CD86⁺ mature dendritic cells in spleens and bone marrow were tested by flow cytometry. As a result, the variation trends of dendritic cells in spleen and bone marrow are similar as follows: the proportions of CD3e^-CD11c⁺ dendritic cells increased first and then decreased from day 35, but the percentages of CD86⁺ mature dendritic cells decreased from day 28 and increased in day 63. In vitro, cultured dendritic cells treated with SEA and SAWA were tested by flow cytometry, the variation trends of CD86 on dendritic cells are consistent with the results in days 28 and 63. Besides CD86, the expression of MHC-II also hints immune regulation. In conclusion, it is speculated that dendritic cells play a role of immune regulation through MHC-II and CD86 in S. japonicum infection. Immune regulation of dendritic cells is not only in favor of the survival of host and parasite but also can be used in the therapy for immune diseases.

Lost therapeutic potential of monocyte-derived dendritic cells through lost tissue homing: stable restoration of gut specificity with retinoic acid

Human monocyte-derived dendritic cells (DC) (MoDC) are utilized for immunotherapy. However, in-vitro immunological effects are often not mirrored in vivo. We studied the tissue-homing potential of MoDC. Circulating monocytes and DC expressed different tissue-homing markers and, during in-vitro development of MoDC, homing marker expression was lost resulting in a 'homeless' phenotype. Retinoic acid (RA) induced gut-homing markers (β7 and CCR9) and a regulatory phenotype and function [decreased human leucocyte antigen D-related (HLA-DR) and increased ILT3 and fluorescein isothiocyanate (FITC-dextran uptake) in MoDC]. RA-MoDC were less stimulatory and primed conditioned T cells with a gut-homing profile (β7(+)CLA(-)). Unlike the normal intestinal microenvironment, that from inflamed colon of ulcerative colitis (UC) patients did not induce regulatory properties in MoDC. However, RA-MoDC maintained their regulatory gut-specific properties even in the presence of UC microenvironment. Therefore, MoDC may be ineffectual for immunotherapy because they lack tissue-homing and tissue-imprinting specificity. However, MoDC rehabilitation with gut-homing potential by RA could be useful in promoting immunotherapy in pathologies such as UC.