Identification and characterization of intestinal peyer's patch interferon-α producing (plasmacytoid) dendritic cells
Introduction
Most antigens (Ag) gain entry to the body via mucosal surfaces. They are taken up and processed by professional Ag-presenting cells (APC), in particular dendritic cells (DC) that transport the Ag via lymphatics to T-cell areas of regional lymphoid organs. Cells within gut-associated lymphoid tissue (GALT) are able to discriminate effectively between innocuous and harmful Ags, and either immunologic unresponsiveness (oral tolerance) or local and systemic immune reactivity is induced 1, 2, 3. Peyer's patches (PP) are organized lymphoid aggregates within the wall of the small intestine. They are considered the main sites of the GALT where microbial and food Ags are presented to immune effector cells. DC are uniquely well-equipped professional APCs that are believed to play key roles both in the initiation and modulation of mucosal immune responses 2, 4, 5.
In the murine PP, three distinct subsets of DC have been identified based on their differential expression of specific cell surface markers and their characteristic localization 6, 7, 8. All subsets express CD11c and major histocompatibility complex (MHC) class II Ags, but differ in their expression of CD8α and CD11b. CD11c+CD8α+ “lymphoid-related” DC are localized in the interfollicular regions of PP. Myeloid DC (CD11c+CD11b+) are found under the follicle-associated epithelium in the subepithelial dome of PP, where they are ideally situated for the uptake of luminal Ags transported by M cells [9]. A third population of “double-negative” (CD8α−CD11b−) PPDC has also been described, in both sites [7]. Recent data support the view that lymphoid-related or double-negative PPDC induce T helper 1 (Th1) cell differentiation, whereas myeloid PPDCs are better able to skew T-cell responses to Th2 differentiation [7].
Recently, a novel subset of murine CD11c+ cells that expresses high levels of surface B220 has been identified in spleen, lymph nodes, and bone marrow 10, 11. Unlike other DC, these CD11c+B220+ cells exhibit a plasmacytoid morphology and, when challenged with virus, produce type-1 interferon-α (IFN-α). Based on these morphologic and functional features, this DC subset has been proposed as the murine equivalent of human plasmacytoid DC (pDC) [12]. This DC population is able to induce a non-anergic state of T-cell unresponsiveness that involves the differentiation of T-regulatory (T reg) cells with ability to inhibit Ag-specific T-cell proliferation. pDC may represent a subset of potentially tolerogenic DC 13, 14. In this study, we describe a novel CD11c+B220+ DC subset within the PP of mice treated with fms-like tyrosine-3 kinase ligand (Flt3L), a potent endogenous hematopoietic growth factor that expands DC in vivo without modifying their activation status 8, 15. These cells appear as immature plasmacytoid cells when freshly isolated, but develop a distinct dendritic morphology when incubated overnight with IL-3 and anti-CD40 monoclonal antibody (mAb). They also exhibit very low T-cell stimulatory activity when freshly isolated and produce IFN-α when infected with herpes simplex virus (HSV) [16]. These characteristics of CD11c+B220+ PPDC are similar to those reported for human pDC. PPpDC may play an important role in the regulation of mucosal immune reactivity, including antiviral and alloimmune responses.
Section snippets
Experimental animals
Ten- to 12- week-old C57BL/10 (B10; H2Kb, IAb, IE−) and C3H/HeJ (C3H; H2Kk, IAk, IEk) mice were purchased from The Jackson Laboratory (Bar Harbor, ME, USA) and maintained in the specific pathogen-free Central Animal Facility of the University of Pittsburgh Medical Center. They received Purina rodent chow (Ralstan Purina, St. Louis, MO, USA) and tap water ad libitum. Experiments were conducted in accordance with the National Institutes of Health Guide for use and care of laboratory animals and
Flt3L administration expands PP CD11c+ DC without modifying DC subset localization
Treatment of mice with the endogenous hematopoietic growth factor Flt3L expands DC in lymphoid and nonlymphoid tissues, without modifying their functional state and overcomes the problem of their scarcity in normal tissues [8]. We first examined the influence of Flt3L on numbers of CD11c+ in PP using immunofluorescence microscopy and flow cytometric analysis. Sections were stained for the DC marker CD11c, using anti-CD11c mAb (red) alone or in combination with mAbs against CD11b, CD8α, or B220
Discussion
In this study we have used immunophenotypic, morphologic, and functional analyses to identify and characterise CD11c+B220+ DC isolated from C57BL/10 mouse PP. The hematopoietic growth factor Flt3L that binds to the Flk2/Flt3 receptor (CD135) is a valuable tool for the study of DC in situ. It does not induce their activation 8, 15, and was used in this investigation to expand DC in vivo. This growth factor has already been reported by others to regulate pDC generation in vivo because
Acknowledgements
We thank the Immunex Corporation (now Amgen) for providing Flt3L; Dr. P. Toby Coates, Mr. J. William Shufesky, Mr. F Jason Duncan, and Ms. Audrey Lau for helpful discussion and suggestions; Ms. Alison Logar for assistance with flow sorting and analysis; Dr. Antonio Francavilla (University of Bari, Italy) for support and encouragement; and Ms. Miriam Meade for skillful manuscript preparation. The study was supported by National Institutes of Health grants R01 DK49745, R01 AI41011, U01 AI51698
References (34)
- et al.
Mucosal antigen presentation and the control of tolerance and immunity
Trends Immunol
(2001) Isolation and characterization of plasmacytoid dendritic cells from Flt3 ligand and granulocyte-macrophage colony-stimulating factor-treated mice
Blood
(2001)- et al.
Characterization of a new subpopulation of mouse CD8alpha+ B220+ dendritic cells endowed with type 1 interferon production capacity and tolerogenic potential
Blood
(2002) - et al.
Human and mouse plasmacytoid dendritic cells
Hum Immunol
(2002) - et al.
Activation of influenza virus-specific CD4+ and CD8+ T cells: a new role for plasmacytoid dendritic cells in adaptive immunity
Blood
(2003) - et al.
Depletion of circulating natural type 1 interferon-producing cells in HIV-infected AIDS patients
Blood
(2001) - et al.
Granulocyte-colony stimulating factor mobilizes T helper 2-inducing dendritic cells
Blood
(2000) - et al.
The anatomical basis of intestinal immunity
Immunol Rev
(1997) The mucosal milieu creates tolerogenic dendritic cells and T(R)1 and T(H)3 regulatory cells
Nat Immunol
(2001)- et al.
Modulating dendritic cells to optimize mucosal immunization protocols
J Immunol
(1999)
Murine Peyer's patches favor development of an IL-10-secreting, regulatory T cell population
J Immunol
Freshly isolated Peyer's patch, but not spleen, dendritic cells produce interleukin 10 and induce the differentiation of T helper type 2 cells
J Exp Med
Unique functions of CD11b+, CD8 alpha+, and double-negative Peyer's patch dendritic cells
J Immunol
Expanding dendritic cells in vivo enhances the induction of oral tolerance
J Immunol
The role of dendritic cells, B cells, and M cells in gut-oriented immune responses
J Immunol
CD11c(+)B220(+)Gr-1(+) cells in mouse lymph nodes and spleen display characteristics of plasmacytoid dendritic cells
J Exp Med
The enigmatic plasmacytoid T cells develop into dendritic cells with interleukin (IL)-3 and CD40-ligand
J Exp Med
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