scholarly journals The antigen-presenting activities of Ia+ dendritic cells shift dynamically from lung to lymph node after an airway challenge with soluble antigen.

1995 ◽  
Vol 181 (4) ◽  
pp. 1275-1283 ◽  
Author(s):  
W Xia ◽  
C E Pinto ◽  
R L Kradin

Dendritic cells (DC) are widely distributed in the lung where they are distinguished by their morphology and class II major histocompatibility complex (Ia) antigen expression. Although a role for DC as pulmonary antigen-presenting cell (APC) has been suggested, little is currently known concerning how these cells respond to inhaled antigens in vivo. Hen-egg lysozyme (HEL) was injected intratracheally into Lewis rats; DC were subsequently purified from the lung and regional lymph nodes (LN) at intervals of up to 14 d and examined for their ability to stimulate the proliferation of HEL-immune T cells in vitro in the absence of added HEL. Pulmonary DC displayed APC activities at 3 h and for up to 7 d after the injection of antigen. Dendritic cells in the draining hilar LN showed APC activities that appeared at 24 h, peaked at day 3, and then diminished progressively. After the primary sensitization, HEL-immune T cells were detected in hilar LN but not in the lung. A second airway challenge with HEL at day 14 yielded an antigen-specific pulmonary immune response, characterized histologically by the accumulation of mononuclear cells around lung venules. We conclude that APC activities shift from lung to lymph node during the response to inhaled antigen.

1992 ◽  
Vol 175 (1) ◽  
pp. 267-273 ◽  
Author(s):  
N Bhardwaj ◽  
S M Friedman ◽  
B C Cole ◽  
A J Nisanian

Dendritic cells are a small subset of human blood mononuclear cells that are potent stimulators of several T cell functions. Here we show they are 10-50-fold more potent than monocytes or B cells in inducing T cell responses to a panel of superantigens. Furthermore, dendritic cells can present femtomolar concentrations of superantigen to T cells even at numbers where other antigen-presenting cells (APCs) are inactive. Although dendritic cells express very high levels of the major histocompatibility complex products that are required to present superantigens, it is only necessary to pulse these APCs for 1 hour with picomolar levels of one superantigen, staphylococcal enterotoxin B, to maximally activate T cells. Our results suggest that very small amounts of superantigen will be immunogenic in vivo if presented on dendritic cells.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3808-3808
Author(s):  
Zhen Cai ◽  
Wenye Huang ◽  
Wenji Sun

Abstract Mycophenolate mofetil (MMF) is a newly developed immunosuppressor, currently widely used in allogeneic bone marrow transplantation. Its active metabolite, mycophenolic acid (MPA) is a noncompetitive, reversible inhibitor of the enzyme inosine 59-monophosphate dehydrogenase, which plays a major role in the de novo synthesis of guanosine nucleotides. Unlike other cells that also use the salvage pathway for purine biosynthesis, proliferating B and T cells are dependent on the de novo pathway generate guanosine. Thus, MMF exerts its immunosuppressive effects of lymphocyte proliferation. Recently, some studies found that MPA could inhibit the immun immune function of antigen presenting cells. Dendritic cells (DCs), the most potent antigen presenting cells with the unique ability to prime naive T cells, play a central role in antigen processing and presentation to induce T cell response in vitro and in vivo. This study is to evaluate the effects of MPA, the in vivo active metabolite of MMF, on the maturation and immune function of murine bone marrow-derived dendritic cells, and to explore the underlying mechanisms of MMF in graft versus host disease. Bone marrow-derived dendritic cells (DC) were cultured with GM-CSF and IL-4 in the presence of MPA at doses of 0.01 and 0.1μmol/L. The ability of the allostimulatory activities of the DCs on allogeneic T cells was assessed by MLR. IL-12 production in culture supernatant and the Th1/Th2 cytokines such as IL-2, IFN-g, IL-4 and IL-10 levels in mixed lymphocyte reaction (MLR) supernatant were examined by ELISA assays. The activity of NF-κB in DCs was measured with Western blot assays. Our results showed that DCs cultured in the presence of MPA expressed lower levels of CD40, CD80 and CD86, exhibited weaker activity of stimulating the allogeneic T cell proliferation and weaker in antigen presenting function with a concurrent reduction of IL-12 production. MPA-treated DCs stimulated allogeneic T cells to secrete higher levels of Th2 cytokines IL-4 and IL-10 but lower levels of Th1 cytokines IL-2 and IFN-g than did DCs not treated with MPA. The activity of NF-κB was decreased in DCs treated with MPA in a dose-dependent manner. We conclude that MPA, and hence MMF, exerts a negative effect on the maturation and immune function of in vitro cultured DCs, and drives a shift of Th1 cytokines to Th2 cytokines in MLR. This negative effect is associated with a decrease in NF-κB activity. Say something about the significance of this finding regarding GVHD.


BIO-PROTOCOL ◽  
2017 ◽  
Vol 7 (17) ◽  
Author(s):  
Songjie Cai ◽  
Masayuki Fujino ◽  
Lina Lu ◽  
Xiao-Kang Li

2019 ◽  
Vol 17 (1) ◽  
pp. 142-150
Author(s):  
Ying Liu ◽  
Qian Wu ◽  
Peng Li ◽  
Weijie Liu ◽  
Yongri Jin ◽  
...  

AbstractGinsenoside Rh2 is one of the rare ginsenosides extracted from Panax ginseng C. A. Mey. The anti-allergic activity of ginsenoside Rh2 has been documented in some literature. In this work, an anti-allergic mechanism of ginsenoside Rh2 was investigated by focusing on the differentiation of T cells through Langerhans cells (LCs). Langerhans cell-like dendritic cells (LDCs) were generated in vitro and were used as substitute for LCs.In vivo the mRNA expression for IFN-γ and CXCR3 of T cells was increased after being injected with ginsenoside Rh2-treated LDCs thereby increasing the concentration of IFN-γ in the culture supernatants of CD3+/CD28+ T lymphocytes. However,in vitro, the expression of mRNA for CD40 and CD80 on ginsenoside Rh2-treated LDCs was up-regulated significantly and the endocytic activity of LDCs was down-regulated slightly. These findings indicate that T cells differentiation could be regulated by ginsenoside Rh2 through LDCs in vivo by altering the antigen presenting capacity, maturation and phagocytosis of LDCs.


1999 ◽  
Vol 189 (3) ◽  
pp. 593-598 ◽  
Author(s):  
Adrian L. Smith ◽  
Barbara Fazekas de St. Groth

Two subsets of murine splenic dendritic cells, derived from distinct precursors, can be distinguished by surface expression of CD8α homodimers. The functions of the two subsets remain controversial, although it has been suggested that the lymphoid-derived (CD8α+) subset induces tolerance, whereas the myeloid-derived (CD8α−) subset has been shown to prime naive T cells and to generate memory responses. To study their capacity to prime or tolerize naive CD4+ T cells in vivo, purified CD8α+ or CD8α− dendritic cells were injected subcutaneously into normal mice. In contrast to CD8α− dendritic cells, the CD8α+ fraction failed to traffic to the draining lymph node and did not generate responses to intravenous peptide. However, after in vitro pulsing with peptide, strong in vivo T cell responses to purified CD8α+ dendritic cells could be detected. Such responses may have been initiated via transfer of peptide–major histocompatibility complex complexes to migratory host CD8α− dendritic cells after injection. These data suggest that correlation of T helper cell type 1 (Th1) and Th2 priming with injection of CD8α+ and CD8α− dendritic cells, respectively, may not result from direct T cell activation by lymphoid versus myeloid dendritic cells, but rather from indirect modification of the response to immunogenic CD8α− dendritic cells by CD8α+ dendritic cells.


Blood ◽  
2007 ◽  
Vol 110 (13) ◽  
pp. 4293-4302 ◽  
Author(s):  
Sayuri Yamazaki ◽  
Anthony J. Bonito ◽  
Radek Spisek ◽  
Madhav Dhodapkar ◽  
Kayo Inaba ◽  
...  

Foxp3+CD25+CD4+ regulatory T cells are produced in the thymus (natural T regs) but can also differentiate from peripheral Foxp3−CD4+ precursors (induced or adaptive T regs). We assessed antigen presenting cell (APC) requirements for the latter differentiation. With added transforming growth factor (TGF)-β, both immature and mature populations of dendritic cells (DCs) induced antigen-specific Foxp3+ T regs from Foxp3− precursors. Using endogenous TGF-β, DCs from gut-associated mesenteric lymph nodes were capable of differentiating Foxp3+T regs. Spleen DCs were 100-fold more potent than DC-depleted APCs for the induction of T regs and required 10-fold lower doses of peptide antigen. Interleukin-2 (IL-2) was essential, but could be provided endogenously by T cells stimulated by DCs, but not other APCs. The required IL-2 was induced by DCs that expressed CD80/CD86 costimulatory molecules. The DC-induced Foxp3+T regs divided up to 6 times in 6 days and were comprised of CD62L and CD103 positive and negative forms. The induced Foxp3+T regs exerted suppression in vitro and blocked tumor immunity in vivo. These results indicate that DCs are specialized to differentiate functional peripheral Foxp3+T regs and help set the stage to use DCs to actively suppress the immune response in an antigen-specific manner.


2008 ◽  
Vol 205 (13) ◽  
pp. 2965-2973 ◽  
Author(s):  
Susan Gilfillan ◽  
Christopher J. Chan ◽  
Marina Cella ◽  
Nicole M. Haynes ◽  
Aaron S. Rapaport ◽  
...  

Natural killer (NK) cells and CD8 T cells require adhesion molecules for migration, activation, expansion, differentiation, and effector functions. DNAX accessory molecule 1 (DNAM-1), an adhesion molecule belonging to the immunoglobulin superfamily, promotes many of these functions in vitro. However, because NK cells and CD8 T cells express multiple adhesion molecules, it is unclear whether DNAM-1 has a unique function or is effectively redundant in vivo. To address this question, we generated mice lacking DNAM-1 and evaluated DNAM-1–deficient CD8 T cell and NK cell function in vitro and in vivo. Our results demonstrate that CD8 T cells require DNAM-1 for co-stimulation when recognizing antigen presented by nonprofessional antigen-presenting cells; in contrast, DNAM-1 is dispensable when dendritic cells present the antigen. Similarly, NK cells require DNAM-1 for the elimination of tumor cells that are comparatively resistant to NK cell–mediated cytotoxicity caused by the paucity of other NK cell–activating ligands. We conclude that DNAM-1 serves to extend the range of target cells that can activate CD8 T cell and NK cells and, hence, may be essential for immunosurveillance against tumors and/or viruses that evade recognition by other activating or accessory molecules.


1992 ◽  
Vol 176 (5) ◽  
pp. 1431-1437 ◽  
Author(s):  
M Croft ◽  
D D Duncan ◽  
S L Swain

Because of the low frequency of T cells for any particular soluble protein antigen in unprimed animals, the requirements for naive T cell responses in specific antigens have not been clearly delineated and they have been difficult to study in vitro. We have taken advantage of mice transgenic for the V beta 3/V alpha 11 T cell receptor (TCR), which can recognize a peptide of cytochrome c presented by IEk. 85-90% of CD4+ T cells in these mice express the transgenic TCR, and we show that almost all such V beta 3/V alpha 11 receptor-positive cells have a phenotype characteristic of naive T cells, including expression of high levels of CD45RB, high levels of L-selectin (Mel-14), low levels of CD44 (Pgp-1), and secretion of interleukin 2 (IL-2) as the major cytokine. Naive T cells, separated on the basis of CD45RB high expression, gave vigorous responses (proliferation and IL-2 secretion) to peptide antigen presented in vitro by a mixed antigen-presenting cell population. At least 50% of the T cell population appeared to respond, as assessed by blast transformation, entry into G1, and expression of increased levels of CD44 by 24 h. Significant contributions to the response by contaminating memory CD4+ cells were ruled out by demonstrating that the majority of the CD45RB low, L-selectin low, CD44 high cells did not express the V beta 3/V alpha 11 TCR and responded poorly to antigen. We find that proliferation and IL-2 secretion of the naive CD4 cells is minimal when resting B cells present peptide antigen, and that both splenic and bone marrow-derived macrophages are weak stimulators. Naive T cells did respond well to high numbers of activated B cells. However, dendritic cells were the most potent stimulators of proliferation and IL-2 secretion at low cell numbers, and were far superior inducers of IL-2 at higher numbers. These studies establish that naive CD4 T cells can respond vigorously to soluble antigen and indicate that maximal stimulation can be achieved by presentation of antigen on dendritic cells. This model should prove very useful in further investigations of activation requirements and functional characteristics of naive helper T cells.


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