Dendritic cell line AP284 supports Th17 amplification.

Dendritic cells (DC) have the unique ability to capture microorganisms and activate naive T lymphocytes. Obtaining DC derived from progenitors demands high cost and prolonged cultivation. Different immortalized DC has been isolated but most of them have immature phenotype and depending on growing factors or other stimuli to be used. In this study we characterized the cell line AP284 as a DC. AP284 cells express high levels of CD11b, MHC class II, 33D1 and CD209b. They also express high amounts of CD80 costimulatory molecule and different toll like receptors (TLR). After stimuli with TLR agonist they produce surprising amount of IL-12p40 related to IL-23 formation but not IL-12p70. They are also able to produce IL-6 and favor amplification of a Th17 but not Th1 profile. This DC line may be useful for a better understanding of factors and cellular interactions responsible for the induction of IL-12p40, IL-23 and Th17 generation.

Upregulation of Cardiac IL-10 and Downregulation of IFN-γ in Balb/c IL-4-/- in Acute Chagasic Myocarditis due to Colombian Strain of Trypanosoma cruzi.

Inflammatory response in Chagas disease is related to parasite and host factors. However, immune system regulation has not been fully elucidated. Thus, this study is aimed at evaluating IL-4 influence on acute phase of Trypanosoma cruzi experimental infection through dosage of cytokine levels in cardiac homogenate of infected Balb/c WT and Balb/c IL-4-/- as well as its histopathological repercussions. For such purpose, mice were divided into two groups: an infected group with 100 forms of the Colombian strain and an uninfected group. After 21 days of infection, animals were euthanized and the blood, spleen, and heart were collected. The spleen was used to culture splenic cells in 48 h. Subsequently, cytokines TNF-α, IL-12p70, IL-10, IFN-γ, and IL-17 were measured in the blood, culture supernatant, and heart apex by ELISA. The base of the heart was used for histopathological analysis. From these analysis, infected Balb/c IL-4-/- mice showed milder inflammatory infiltrate compared to Balb/c WT, but without changes in nest density and collagen deposition. IL-4 absence culminated in lower cardiac tissue IFN-γ production, although it did not affect TNF-α expression in situ. It also decreased TNF-α systemic production and increased IL-10, both systemically and in situ. In addition, IL-4 absence did not influence IL-17 expression. Splenocytes of IL-4-deficient mice produced higher amounts of IFN-γ, TNF-α, and IL-17 and lower amounts of IL-10. Thus, IL-4 absence in acute phase of experimental infection with T. cruzi Colombian strain reduces myocarditis due to lower IFN-γ production and greater IL-10 production in situ and this pattern is not influenced by splenocyte general repertoire.