Generation of dendritic cells from human bone marrow mononuclear cells: advantages for clinical application in comparison to peripheral blood monocyte derived cells

GM-CSF Monocyte-Derived Cells and Langerhans Cells As Part of the Dendritic Cell Family

Dendritic cells (DCs) and macrophages (Mph) share many characteristics as components of the innate immune system. The criteria to classify the multitude of subsets within the mononuclear phagocyte system are currently phenotype, ontogeny, transcription patterns, epigenetic adaptations, and function. More recently, ontogenetic, transcriptional, and proteomic research approaches uncovered major developmental differences between Flt3L-dependent conventional DCs as compared with Mphs and monocyte-derived DCs (MoDCs), the latter mainly generated in vitro from murine bone marrow-derived DCs (BM-DCs) or human CD14⁺ peripheral blood monocytes. Conversely, in vitro GM-CSF-dependent monocyte-derived Mphs largely resemble MoDCs whereas tissue-resident Mphs show a common embryonic origin from yolk sac and fetal liver with Langerhans cells (LCs). The novel ontogenetic findings opened discussions on the terminology of DCs versus Mphs. Here, we bring forward arguments to facilitate definitions of BM-DCs, MoDCs, and LCs. We propose a group model of terminology for all DC subsets that attempts to encompass both ontogeny and function.

Clinical effects of autologous dendritic cells combined with anti-virus therapy on chronic hepatitis B virus infection

AIM: To evaluate the clinical effects of autologous HBsAg-loaded dendritic cells (DCs) combined with anti-viral treatment on patients with chronic hepatitis B virus (HBV) infection.

METHODS: A total of 41 chronic HBV infected subjects were treated with single interferon-α-2b for 6 mo before the trial, and the treatment was stopped for the irresponsive cases. Six months later, the irresponsive cases received the combined therapy of interferon-α-2b and autologous HBsAg-loaded DCs for another 6 mo (one course containing twice of re-transfusion). The changes of virology, serology and biochemistry indexes were observed one month after the end of treatment.

RESULTS: DCs were cultured in vitro. After proliferation for 6 d, DCs were incubated with HBsAg for 1 d to prepare the specific DCs vaccine. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significant decreased after the combined therapy as compared with those before (t = 2.976, P < 0.01; t = 2.049, P < 0.05). The response rate of HBV DNA was 53.7%, and the decrease of HBV DNA copies was greater than or equal to 2log10. Neither the injection times of DCs nor the HBV-carrying time had a correlation with the virological responses (r = 0.048, P > 0.05; r = 0.137, P > 0.05).

CONCLUSION: Combined treatment of autologous DCs vaccine and interferon-α-2b has a favorable effect on patients with chronic HBV infection.

Enrichment of functional CD8 memory T cells specific for MUC1 in bone marrow of patients with multiple myeloma

Multiple myeloma (MM) is one of the most common hematologic malignancies. Despite extensive therapeutical approaches, cures remain rare exceptions. An important issue for future immunologic treatments is the characterization of appropriate tumor-associated antigens. Recently, a highly glycosylated mucin MUC1 was detected on a majority of multiple myeloma cell lines. We analyzed bone marrow and peripheral blood of 68 patients with HLA-A2-positive myeloma for the presence and functional activity of CD8 T cells specific for the MUC1-derived peptide LLLLTVLTV. Forty-four percent of the patients with MM contained elevated frequencies of MUC1-specific CD8 T cells in freshly isolated samples from peripheral blood (PB) or bone marrow (BM) compared with corresponding samples from healthy donors. BM-residing T cells possessed a higher functional capacity upon specific reactivation than PB-derived T cells with regard to interferon gamma (IFN-gamma) secretion, perforin production, and cytotoxicity.

Functional comparison of DCs generated in vivo with Flt3 ligand or in vitro from blood monocytes: differential regulation of function by specific classes of physiologic stimuli

Dendritic cells (DCs) are a family of leukocytes that initiate T- and B-cell immunity against pathogens. Migration of antigen-loaded DCs from sites of infection into draining lymphoid tissues is fundamental to the priming of T-cell immune responses. In humans, the major peripheral blood DC (PBDC) types, CD1c+ DCs and interleukin 3 receptor-positive (IL-3R+) plasmacytoid DCs, are significantly expanded in vivo with the use of Flt3 ligand (FL). DC-like cells can also be generated from monocyte precursors (MoDCs). A detailed comparison of the functional potential of these types of DCs (in an autologous setting) has yet to be reported. Here, we compared the functional capacity of FL-expanded CD1c+ PBDCs with autologous MoDCs in response to 3 different classes of stimuli: (1) proinflammatory mediators, (2) soluble CD40 ligand trimer (CD40L), and (3) intact bacteria (Escherichia coli). Significant differences in functional capacities were found with respect to changes in phenotype, migratory capacity, cytokine secretion, and T-cell stimulation. MoDCs required specific stimuli for the expression of functions. They responded vigorously to CD40L or E coli, expressing cytokines known to regulate interferon-gamma (IFN-gamma) in T cells (IL-12p70, IL-18, and IL-23), but required prostaglandin E2 (PGE2) during stimulation to migrate to chemokines. In contrast, PBDCs matured in response to minimal stimulation, rapidly acquired migratory function in the absence of PGE2-containing stimuli, and were low cytokine producers. Interestingly, both types of DCs were equivalent with respect to stimulation of allogeneic T-cell proliferation and presentation of peptides to cytotoxic T lymphocyte (CTL) lines. These distinct differences are of particular importance when considering the choice of DC types for clinical applications.

Comparative research of dendritic cells cultured from mice bone marrow with different ways

AIM: To compare the biological characteristics of cultured mice bone marrow dendritic cell (BM-DC) in cultural media with peritoneum or with growth stimulating factor.

METHODS: DC progenitors of were isolated from bone marrow of Balb/C mice, and transformed into DC cell by culturing with secretary fluid of peritoneum, mGM-CSF, and mIL-4, respectively. The biological features and immunity of the DC cells were studied with mixed lymphocyte reaction, immunohistochemistry staining, light microscope and scanning electronic microscope.

RESULTS: After culturing for 6-8 days, the number of BM-DC (6x106) released from proliferating colony in media containing mGM-CSF and mIL-4 was higher than that in media containing peritoneum without significant difference. High level of expressed CD86 on BM-DC was demonstrated on day 7 in culture, MLR results indicated that the stimulating ability for proliferation of T cell was higher in media with mGM-CSF, mIL-4 than that with peritoneum, while the control media without stimulating factors showed no ability to stimulate the growth of T cells

CONCLUSION: These observations demonstrated that auto-peritoneum can substitute for cytokines in media and stimulate the growth of bone marrow-derived DCs, which possess the corresponding cellular biological features and cellular immunity.