The dynamics of dendritic cell: mediated innate immune regulation

Impact of surface chemistry and topography on the function of antigen presenting cells

The impact of biomaterial surface topography and chemistry on antigen presenting cells’ phenotype and function.

Difference in immune effect of dendritic cells activated by HBsAg between patients with chronic HBV infection and healthy people

AIM: To compare the difference in immune effect of dendritic cells activated by HBsAg in patients with chronic HBV and healthy people.

METHODS: Dendritic cells (DCs) and cytokine-induced killer (CIK) cells were cultured and amplified from the peripheral blood of patients with chronic HBV infection and healthy people. DCs were stimulated with pure HBsAg in cell culture medium prior to maturation. DC and CIK phenotypes were detected by flow cytometry. ELISA was used to detect the level of IL-12 in the supernatants of co-cultured DCs and CIK cells. The cell-killing activity of DC-induced CIK cells against HepG2.2.15 cells was measured using CCK-8 colorimetric assay.

RESULTS: Except HLA-DR, the positive rates of DC surface markers Cdla, CD80, and CD83 in DCs from healthy people were higher than those in DCs from patients with chronic HBV infection (all P < 0.05), but the positive rates of all four surface markers in healthy people DCs activated by HBsAg were significantly higher than in DCs from patients with chronic HBV infection (P < 0.01). There was no significant difference in the positive rates of DC surface markers between HBsAg-pulsed and non-pulsed DCs from patients with chronic HBV infection. The percentage of CD3⁺/CD8⁺ or CD3⁺/CD56⁺ CIK cells in HBsAg-pulsed healthy people was significantly higher than those in patients with chronic HBV infection and non-pulsed healthy people (P < 0.01, P < 0.05), but there was no significant difference between HBsAg-pulsed and non-pulsed patients with chronic HBV infection (P > 0.05). The cell-killing activity of HBsAg-pulsed DC-induced CIK cells against HepG2.2.15 cells was significantly higher in healthy people than in patients with chronic HBV infection (P < 0.01). The level of IL-12 in supernatants of co-cultured HBsAg-pulsed DC-CIK cells from healthy people was much higher than that from patients with chronic HBV infection (P < 0.001), but there was no significant difference between HBsAg-pulsed and non-pulsed DCs from patients with chronic HBV infection (P > 0.05).

CONCLUSION: The immune effect of HBsAg-pulsed DCs for HepG2.2.15 cells was significantly stronger in healthy people than in patients with chronic HBV infection.

Analysis of CD83 antigen expression in human breast fibroadenoma and adjacent tissue

CONTEXT AND OBJECTIVE

Dendritic cell maturation is considered essential for starting an immune response. The CD83 antigen is an important marker of dendritic cell maturation. The objectives here were to analyze CD83 antigen expression in human breast fibroadenoma and breast tissue adjacent to the lesion and to identify clinical factors that might influence this expression.

DESIGN AND SETTING

This was a retrospective study at a public university hospital, in which 29 histopathological samples of breast fibroadenoma and adjacent breast tissue, from 28 women of reproductive age, were analyzed.

METHODS

The immunohistochemistry method was used to analyze the cell expression of the antigen. The antigen expression in the cells was evaluated by means of random manual counting using an optical microscope.

RESULTS

Positive expression of the CD83 antigen in the epithelial cells of the fibroadenoma (365.52; standard deviation ± 133.13) in relation to the adjacent breast tissue cells (189.59; standard deviation ± 140.75) was statistically larger (P < 0.001). Several clinical features were analyzed, but only parity was shown to influence CD83 antigen expression in the adjacent breast tissue, such that positive expression was more evident in nulliparous women (P = 0.042).

CONCLUSIONS

The expression of the CD83 antigen in the fibroadenoma was positive and greater than in the adjacent breast tissue. Positive expression of the antigen in the adjacent breast tissue was influenced by parity, and was significantly more evident in nulliparous women.

Surfactant protein-A and toll-like receptor-4 modulate immune functions of preterm baboon lung dendritic cell precursor cells

Lung infections are important risk factors for an increased morbidity and mortality in prematurely-delivered babies. Immaturity of the innate immune components makes them extremely susceptible to infection. Recently, we isolated lung dendritic cell (DC)-precursor cells from preterm fetal baboons. The isolated cells were found to be defective in phagocytosing Escherichia coli under basal conditions. In this study, we investigated the effects of exogenously-added purified native lung surfactant protein (SP)-A and recombinant toll-like receptor (TLR)-4-MD2 proteins on phagocytic uptake and cytokine secreting ability of fetal baboon lung DC-precursor cells. The cells were pulsed with SP-A and/or TLR4-MD2 proteins and the phagocytic function was investigated by incubating the cells with fluorescent-labeled E. coli bioparticles and analyzed by spectrofluorometry. The amounts of TNF-α secreted in cell-free supernatants were measured by ELISA. Our results demonstrate that SP-A and TLR4-MD2 proteins, whether added alone or together, induce phagocytosis of E. coli (p<0.05). The SP-A does not affect TNF-α secretion, while the TLR4-MD2 protein induces TNF-α. However, simultaneous addition of SP-A with TLR4-MD2 protein reduces the TLR4-MD2-protein induced TNF-α to basal level. In conclusion, our results indicate that an exogenous administration of SP-A can potentially induce phagocytic activity and anti-inflammatory effect in preterm babies, and help control infection and inflammation.

Ontogeny and phagocytic function of baboon lung dendritic cells

Dendritic cells (DCs) are the most potent antigen-presenting cells, but the ontogeny and functions of lung DCs are not known during prenatal period. Here, we isolated lung DC population from fetal (125 −175dGA) and adult baboons. The cells were stained with fluorochrome-conjugated-HLA-DP, DQ, DR, CD1a, CD11c, CD14, CD40, CD80, CD86, CD209, CMKLR1, ILT7-specific antibodies, and staining was analyzed by Flow-cytometry. The phagocytic function was investigated by incubating the cells with fluorescent-labeled Escherichia coli bioparticles and analyzed by Flow-cytometry and fluorescence microscopy. The fetal baboon lung DCs expressed low levels of HLA-DP, DQ, DR, CD11c and CD86 as compared to adult baboon lung DCs and showed distinct DC morphology. The fetal lung DCs were also less capable of phagocytosing E. coli as compared to the adult lung DCs (p<0.05). In conclusion, the fetal lung DCs are not only phenotypically immature, but also less efficient in phagocytosing E. coli.