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Antigen presentation to naive CD4 T cells in the lymph node

Abstract

Although the presentation of peptide–major histocompatibility complex class II (pMHC class II) complexes to CD4 T cells has been studied extensively in vitro, knowledge of this process in vivo is limited. Unlike the in vitro situation, antigen presentation in vivo takes place within a complex microenvironment in which the movements of antigens, antigen-presenting cells (APCs) and T cells are governed by anatomic constraints. Here we review developments in the areas of lymph node architecture, APC subsets and T cell activation that have shed light on how antigen presentation occurs in the lymph nodes.

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Figure 1: Location of DC subsets in the lymph node.
Figure 2: Localization of lymph node DCs, injected soluble antigen and collagen network in situ.

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References

  1. Banchereau, J. & Steinman, R.M. Dendritic cells and the control of immunity. Nature 392, 245–252 (1998).

    Article  CAS  PubMed  Google Scholar 

  2. Hawiger, D. et al. Dendritic cells induce peripheral T cell unresponsiveness under steady state conditions in vivo. J. Exp. Med. 194, 769–780 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Bonifaz, L. et al. Efficient targeting of protein antigen to the dendritic cell receptor DEC-205 in the steady state leads to antigen presentation on major histocompatibility complex class I products and peripheral CD8+ T cell tolerance. J. Exp. Med. 196, 1627–1638 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Askew, D., Gatewood, J., Olivas, E., Havenith, K. & Walker, W.S. A subset of splenic macrophages process and present native antigen to naive antigen-specific CD4+ T-cells from mice transgenic for an αβ T-cell receptor. Cell. Immunol. 166, 62–70 (1995).

    Article  CAS  PubMed  Google Scholar 

  5. Cassell, D.J. & Schwartz, R.H. A quantitative analysis of antigen-presenting cell function: activated B cells stimulate naive CD4 T cells but are inferior to dendritic cells in providing costimulation. J. Exp. Med. 180, 1829–1840 (1994).

    Article  CAS  PubMed  Google Scholar 

  6. Jenkins, M.K. et al. In vivo activation of antigen-specific CD4 T cells. Annu. Rev. Immunol. 19, 23–45 (2001).

    Article  CAS  PubMed  Google Scholar 

  7. von Andrian, U.H. & Mackay, C.R. T-cell function and migration. N. Engl. J. Med. 343, 1020–1034 (2000).

    Article  CAS  PubMed  Google Scholar 

  8. Reinhardt, R.L., Khoruts, A., Merica, R., Zell, T. & Jenkins, M.K. Visualizing the generation of memory CD4 T cells in the whole body. Nature 410, 101–105 (2001).

    Article  CAS  PubMed  Google Scholar 

  9. Witmer, M.D. & Steinman, R.M. The anatomy of peripheral lymphoid organs with emphasis on accessory cells: light-microscopic immunocytochemical studies of mouse spleen, lymph node, and Peyer's patch. Am. J. Anat. 170, 465–481 (1984).

    Article  CAS  PubMed  Google Scholar 

  10. Witmer-Pack, M.D. et al. Identification of macrophages and dendritic cells in the osteopetrotic (op/op) mouse. J. Cell Sci. 104, 1021–1029 (1993).

    PubMed  Google Scholar 

  11. Chang, M.D., Stanley, E.R., Khalili, H., Chisholm, O. & Pollard, J.W. Osteopetrotic (op/op) mice deficient in macrophages have the ability to mount a normal T-cell-dependent immune response. Cell. Immunol. 162, 146–152 (1995).

    Article  CAS  PubMed  Google Scholar 

  12. Zhong, G., Sousa, C.R. & Germain, R.N. Antigen-unspecific B cells and lymphoid dendritic cells both show extensive surface expression of processed antigen-major histocompatibility complex class II complexes after soluble protein exposure in vivo or in vitro. J. Exp. Med. 186, 673–682 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Lanzavecchia, A. Antigen-specific interaction between T and B cells. Nature 314, 537–539 (1985).

    Article  CAS  PubMed  Google Scholar 

  14. Itano, A.A. et al. Distinct dendritic cell populations sequentially present a subcutaneous antigen to CD4 T cells and stimulate different aspects of cell-mediated immunity. Immunity 19, 47–57 (2003).

    Article  CAS  PubMed  Google Scholar 

  15. Epstein, M.M., Rosa, F.D., Jankovic, D., Sher, A. & Matzinger, P. Successful T cell priming in B cell-deficient mice. J. Exp. Med. 182, 915–922 (1995).

    Article  CAS  PubMed  Google Scholar 

  16. Topham, D.J., Tripp, R.A., Hamilton-Easton, A.M., Sarawar, S.R. & Doherty, P.C. Quantitative analysis of the influenza virus-specific CD4+ T cell memory in the absence of B cells and Ig. J. Immunol. 157, 2947–2952 (1996).

    CAS  PubMed  Google Scholar 

  17. Townsend, S.E. & Goodnow, C.C. Abortive proliferation of rare T cells induced by direct or indirect antigen presentation by rare B cells in vivo. J. Exp. Med. 187, 1611–1621 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Valdez, Y. et al. Major histocompatibility complex class II presentation of cell-associated antigen is mediated by CD8α+ dendritic cells in vivo. J. Exp. Med. 195, 683–694 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Garside, P. et al. Visualization of specific B and T lymphocyte interactions in the lymph node. Science 281, 96–99 (1998).

    Article  CAS  PubMed  Google Scholar 

  20. Fulcher, D.A. et al. The fate of self-reactive B cells depends primarily on the degree of antigen receptor engagement and availability of T cell help. J. Exp. Med. 183, 2313–2328 (1996).

    Article  CAS  PubMed  Google Scholar 

  21. Steinman, R.M., Pack, M. & Inaba, K. Dendritic cells in the T-cell areas of lymphoid organs. Immunol. Rev. 156, 25–37 (1997).

    Article  CAS  PubMed  Google Scholar 

  22. MacPherson, G., Kushnir, N. & Wykes, M. Dendritic cells, B cells and the regulation of antibody synthesis. Immunol. Rev. 172, 325–334 (1999).

    Article  CAS  PubMed  Google Scholar 

  23. Gerosa, F. et al. Reciprocal activating interaction between natural killer cells and dendritic cells. J. Exp. Med. 195, 327–333 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Ingulli, E., Mondino, A., Khoruts, A. & Jenkins, M.K. In vivo detection of dendritic cell antigen presentation to CD4+ T cells. J. Exp. Med. 185, 2133–2141 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Byersdorfer, C.A. & Chaplin, D.D. Visualization of early APC/T cell interactions in the mouse lung following intranasal challenge. J. Immunol. 167, 6756–6764 (2001).

    Article  CAS  PubMed  Google Scholar 

  26. Miller, M.J., Wei, S.H., Parker, I. & Cahalan, M.D. Two-photon imaging of lymphocyte motility and antigen response in intact lymph node. Science 296, 1869–1873 (2002).

    Article  CAS  PubMed  Google Scholar 

  27. Hommel, M. & Kyewski, B. Dynamic changes during the immune response in T cell-antigen-presenting cell clusters isolated from lymph nodes. J. Exp. Med. 197, 269–280 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Huleatt, J.W. & Lefrancois, L. Antigen-driven induction of CD11c on intestinal intraepithelial lymphocytes and CD8+ T cells in vivo. J. Immunol. 154, 5684–5693 (1995).

    CAS  PubMed  Google Scholar 

  29. del Hoyo, G.M. et al. Characterization of a common precursor population for dendritic cells. Nature 415, 1043–1047 (2002).

    Article  PubMed  Google Scholar 

  30. Ruedl, C., Koebel, P., Bachmann, M., Hess, M. & Karjalainen, K. Anatomical origin of dendritic cells determines their life span in peripheral lymph nodes. J. Immunol. 165, 4910–4916 (2000).

    Article  CAS  PubMed  Google Scholar 

  31. Anjuere, F. et al. Definition of dendritic cell subpopulations present in the spleen, Peyer's patches, lymph nodes, and skin of the mouse. Blood 93, 590–598 (1999).

    CAS  PubMed  Google Scholar 

  32. Shortman, K. & Liu, Y.J. Mouse and human dendritic cell subtypes. Nat. Rev. Immunol. 2, 151–161 (2002).

    Article  CAS  PubMed  Google Scholar 

  33. Vremec, D. & Shortman, K. Dendritic cell subtypes in mouse lymphoid organs: cross-correlation of surface markers, changes with incubation, and differences among thymus, spleen, and lymph nodes. J. Immunol. 159, 565–573 (1997).

    CAS  PubMed  Google Scholar 

  34. Traver, D. et al. Development of CD8α-positive dendritic cells from a common myeloid progenitor. Science 290, 2152–2154 (2000).

    Article  CAS  PubMed  Google Scholar 

  35. del Hoyo, G.M., Martin, P., Arias, C.F., Marin, A.R. & Ardavin, C. CD8α+ dendritic cells originate from the CD8α dendritic cell subset by a maturation process involving CD8α, DEC-205, and CD24 up-regulation. Blood 99, 999–1004 (2002).

    Article  Google Scholar 

  36. Naik, S., Vremec, D., Wu, L., O'Keeffe, M. & Shortman, K. CD8α+ mouse spleen dendritic cells do not originate from the CD8 dendritic cell subset. Blood 102, 601–604 (2003).

    Article  CAS  PubMed  Google Scholar 

  37. Nakano, H., Yanagita, M. & Gunn, M.D. CD11c+B220+GR-1+ cells in mouse lymph nodes and spleen display characteristics of plasmacytoid dendritic cells. J. Exp. Med. 194, 1171–1178 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Ingulli, E., Ulman, D.R., Lucido, M.M. & Jenkins, M.K. In situ analysis reveals physical interactions between CD11b+ dendritic cells and antigen-specific CD4 T cells after subcutaneous injection of antigen. J. Immunol. 169, 2247–2252 (2002).

    Article  CAS  PubMed  Google Scholar 

  39. Julia, V. et al. A restricted subset of dendritic cells captures airborne antigens and remains able to activate specific T cells long after antigen exposure. Immunity 16, 271–283 (2002).

    Article  CAS  PubMed  Google Scholar 

  40. Yrlid, U. & Wick, M.J. Antigen presentation capacity and cytokine production by murine splenic dendritic cell subsets upon Salmonella encounter. J. Immunol. 169, 108–116 (2002).

    Article  CAS  PubMed  Google Scholar 

  41. Pooley, J.L., Heath, W.R. & Shortman, K. Intravenous soluble antigen is presented to CD4 T cells by CD8 dendritic cells, but cross-presented to CD8 T cells by CD8+ dendritic cells. J. Immunol. 166, 5327–5330 (2001).

    Article  CAS  PubMed  Google Scholar 

  42. Iyoda, T. et al. The CD8+ dendritic cell subset selectively endocytoses dying cells in culture and in vivo. J. Exp. Med. 195, 1289–1302 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Manickasingham, S. & Reis e Sousa, C. Microbial and T cell-derived stimuli regulate antigen presentation by dendritic cells in vivo. J. Immunol. 165, 5027–5034 (2000).

    Article  CAS  PubMed  Google Scholar 

  44. Henri, S. et al. The dendritic cell populations of mouse lymph nodes. J. Immunol. 167, 741–748 (2001).

    Article  CAS  PubMed  Google Scholar 

  45. Asselin-Paturel, C. et al. Mouse type I IFN-producing cells are immature APCs with plasmacytoid morphology. Nat. Immunol. 2, 1144–1150 (2001).

    Article  CAS  PubMed  Google Scholar 

  46. Fonteneau, J.F. et al. Activation of influenza virus-specific CD4+ and CD8+ T cells: a new role for plasmacytoid dendritic cells in adaptive immunity. Blood 101, 3520–3526 (2003).

    Article  CAS  PubMed  Google Scholar 

  47. Dalod, M. et al. Dendritic cell responses to early murine cytomegalovirus infection: subset functional specialization and differential regulation by interferon α/β. J. Exp. Med. 197, 885–898 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Krug, A. et al. Interferon-producing cells fail to induce proliferation of naive T cells but can promote expansion and T helper 1 differentiation of antigen-experienced unpolarized T cells. J. Exp. Med. 197, 899–906 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Salomon, B., Cohen, J.L., Masurier, C. & Klatzmann, D. Three populations of mouse lymph node dendritic cells with different origins and dynamics. J. Immunol. 160, 708–717 (1998).

    CAS  PubMed  Google Scholar 

  50. Kamath, A.T., Henri, S., Battye, F., Tough, D.F. & Shortman, K. Developmental kinetics and lifespan of dendritic cells in mouse lymphoid organs. Blood 100, 1734–1741 (2002).

    CAS  PubMed  Google Scholar 

  51. Geissmann, F. et al. Accumulation of immature Langerhans cells in human lymph nodes draining chronically inflamed skin. J. Exp. Med. 196, 417–430 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Randolph, G.J., Inaba, K., Robbiani, D.F., Steinman, R.M. & Muller, W.A. Differentiation of phagocytic monocytes into lymph node dendritic cells in vivo. Immunity 11, 753–761 (1999).

    Article  CAS  PubMed  Google Scholar 

  53. Lappin, M.B., Kimber, I. & Norval, M. The role of dendritic cells in cutaneous immunity. Arch. Dermatol. Res. 288, 109–121 (1996).

    Article  CAS  PubMed  Google Scholar 

  54. Macatonia, S.E., Knight, S.C., Edwards, A.J., Griffiths, S. & Fryer, P. Localization of antigen on lymph node dendritic cells after exposure to the contact sensitizer fluorescein isothiocyanate. J. Exp. Med. 166, 1654–1667 (1987).

    Article  CAS  PubMed  Google Scholar 

  55. Romani, N. et al. Migration of dendritic cells into lymphatics-the Langerhans cell example: routes, regulation, and relevance. Int. Rev. Cytol. 207, 237–270 (2001).

    Article  CAS  PubMed  Google Scholar 

  56. Nalefski, E.A. & Rao, A. Nature of the ligand recognized by a hapten- and carrier-specific, MHC-restricted T cell receptor. J. Immunol. 150, 3806–3816 (1993).

    CAS  PubMed  Google Scholar 

  57. Wang, B., Amerio, P. & Sauder, D.N. Role of cytokines in epidermal Langerhans cell migration. J. Leukoc. Biol. 66, 33–39 (1999).

    Article  CAS  PubMed  Google Scholar 

  58. Cumberbatch, M. & Kimber, I. Dermal tumour necrosis factor-alpha induces dendritic cell migration to draining lymph nodes, and possibly provides one stimulus for Langerhans' cell migration. Immunology 75, 257–263 (1992).

    CAS  PubMed  PubMed Central  Google Scholar 

  59. Stoitzner, P. et al. Visualization and characterization of migratory Langerhans cells in murine skin and lymph nodes by antibodies against Langerin/CD207. J. Invest. Dermatol. 120, 266–274 (2003).

    Article  CAS  PubMed  Google Scholar 

  60. Peeler, J.S. & Niederkorn, J.Y. Antigen presentation by Langerhans cells in vivo: donor-derived Ia+ Langerhans cells are required for induction of delayed-type hypersensitivity but not for cytotoxic T lymphocyte responses to alloantigens. J. Immunol. 136, 4362–4371 (1986).

    CAS  PubMed  Google Scholar 

  61. Kumamoto, T. et al. Induction of tumor-specific protective immunity by in situ Langerhans cell vaccine. Nat. Biotechnol. 20, 64–69 (2002).

    Article  CAS  PubMed  Google Scholar 

  62. Rudensky, A., Rath, S., Preston-Hurlburt, P., Murphy, D.B. & Janeway, C.A., Jr. On the complexity of self. Nature 353, 660–662 (1991).

    Article  CAS  PubMed  Google Scholar 

  63. Murphy, D.B. et al. Monoclonal antibody detection of a major self peptide. MHC class II complex. J. Immunol. 148, 3483–3491 (1992).

    CAS  PubMed  Google Scholar 

  64. Inaba, K. et al. Efficient presentation of phagocytosed cellular fragments on the major histocompatibility complex class II products of dendritic cells. J. Exp. Med. 188, 2163–2173 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Valladeau, J. et al. Langerin, a novel C-type lectin specific to Langerhans cells, is an endocytic receptor that induces the formation of Birbeck granules. Immunity 12, 71–81 (2000).

    Article  CAS  PubMed  Google Scholar 

  66. Vermaelen, K.Y., Carro-Muino, I., Lambrecht, B.N. & Pauwels, R.A. Specific migratory dendritic cells rapidly transport antigen from the airways to the thoracic lymph nodes. J. Exp. Med. 193, 51–60 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  67. Constant, S.L. et al. Resident lung antigen-presenting cells have the capacity to promote Th2 T cell differentiation in situ. J. Clin. Invest. 110, 1441–1448 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  68. Zhao, X. et al. Vaginal submucosal dendritic cells, but not Langerhans cells, induce protective Th1 responses to herpes simplex virus-2. J. Exp. Med. 197, 153–162 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  69. Randolph, G.J., Beaulieu, S., Lebecque, S., Steinman, R.M. & Muller, W.A. Differentiation of monocytes into dendritic cells in a model of transendothelial trafficking. Science 282, 480–483 (1998).

    Article  CAS  PubMed  Google Scholar 

  70. Qu, C., Moran, T.M. & Randolph, G.J. Autocrine type I IFN and contact with endothelium promote the presentation of influenza A virus by monocyte-derived APC. J. Immunol. 170, 1010–1018 (2003).

    Article  CAS  PubMed  Google Scholar 

  71. Ebnet, K., Kaldjian, E.P., Anderson, A.O. & Shaw, S. Orchestrated information transfer underlying leukocyte endothelial interactions. Annu. Rev. Immunol. 14, 155–177 (1996).

    Article  CAS  PubMed  Google Scholar 

  72. Picker, L.J. & Siegelman, M.H. in Fundamental Immunology (ed. Paul, W.E.) 145–197 (Raven, New York, 1993).

    Google Scholar 

  73. Kaldjian, E.P., Gretz, J.E., Anderson, A.O., Shi, Y. & Shaw, S. Spatial and molecular organization of lymph node T cell cortex: a labyrinthine cavity bounded by an epithelium-like monolayer of fibroblastic reticular cells anchored to basement membrane-like extracellular matrix. Int. Immunol. 13, 1243–1253 (2001).

    Article  CAS  PubMed  Google Scholar 

  74. Gretz, J.E., Norbury, C.C., Anderson, A.O., Proudfoot, A.E. & Shaw, S. Lymph-borne chemokines and other low molecular weight molecules reach high endothelial venules via specialized conduits while a functional barrier limits access to the lymphocyte microenvironments in lymph node cortex. J. Exp. Med. 192, 1425–1440 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  75. Okada, S., Albrecht, R.M., Aharinejad, S. & Schraufnagel, D.E. Structural aspects of the lymphocyte traffic in rat submandibular lymph node. Microsc. Microanal. 8, 116–133 (2002).

    Article  CAS  PubMed  Google Scholar 

  76. Ruedl, C., Koebel, P. & Karjalainen, K. In vivo-matured Langerhans cells continue to take up and process native proteins unlike in vitro-matured counterparts. J. Immunol. 166, 7178–1782 (2001).

    Article  CAS  PubMed  Google Scholar 

  77. Turley, S.J. et al. Transport of peptide-MHC class II complexes in developing dendritic cells. Science 288, 522–527 (2000).

    Article  CAS  PubMed  Google Scholar 

  78. Finkelman, F.D., Lees, A., Birnbaum, R., Gause, W.C. & Morris, S.C. Dendritic cells can present antigen in vivo in a tolerogenic or immunogenic fashion. J. Immunol. 157, 1406–1414 (1996).

    CAS  PubMed  Google Scholar 

  79. Lu, Q. & Lemke, G. Homeostatic regulation of the immune system by receptor tyrosine kinases of the Tyro 3 family. Science 293, 306–311 (2001).

    Article  CAS  PubMed  Google Scholar 

  80. Scott, R.S. et al. Phagocytosis and clearance of apoptotic cells is mediated by MER. Nature 411, 207–211 (2001).

    Article  CAS  PubMed  Google Scholar 

  81. Savill, J. & Fadok, V. Corpse clearance defines the meaning of cell death. Nature 407, 784–788 (2000).

    Article  CAS  PubMed  Google Scholar 

  82. Fadok, V.A. et al. A receptor for phosphatidylserine-specific clearance of apoptotic cells. Nature 405, 85–90 (2000).

    Article  CAS  PubMed  Google Scholar 

  83. Fadok, V.A. et al. Macrophages that have ingested apoptotic cells in vitro inhibit proinflammatory cytokine production through autocrine/paracrine mechanisms involving TGF-β, PGE2, and PAF. J. Clin. Invest. 101, 890–898 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  84. Ding, L., Linsley, P.S., Huang, L.Y., Germain, R.N. & Shevach, E.M. IL-10 inhibits macrophage costimulatory activity by selectively inhibiting the up-regulation of B7 expression. J. Immunol. 151, 1224–1234 (1993).

    CAS  PubMed  Google Scholar 

  85. Inaba, K. et al. High levels of a major histocompatibility complex II-self peptide complex on dendritic cells from the T cell areas of lymph nodes. J. Exp. Med. 186, 665–672 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  86. Zhong, G., Reis e Sousa, C. & Germain, R.N. Production, specificity, and functionality of monoclonal antibodies to specific peptide-major histocompatibility complex class II complexes formed by processing of exogenous protein. Proc. Natl. Acad. Sci. USA 94, 13856–13861 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  87. Dadaglio, G., Nelson, C.A., Deck, M.B., Petzold, S.J. & Unanue, E.R. Characterization and quantitation of peptide-MHC complexes produced from hen egg lysozyme using a monoclonal antibody. Immunity 6, 727–738 (1997).

    Article  CAS  PubMed  Google Scholar 

  88. Porgador, A., Yewdell, J.W., Deng, Y., Bennink, J.R. & Germain, R.N. Localization, quantitation, and in situ detection of specific peptide- MHC class I complexes using a monoclonal antibody. Immunity 6, 715–726 (1997).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

We thank T. Leonard for help with the animation. Supported by grants from the National Institutes of Health and the Irvington Institute of Immunological Research.

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Itano, A., Jenkins, M. Antigen presentation to naive CD4 T cells in the lymph node. Nat Immunol 4, 733–739 (2003). https://doi.org/10.1038/ni957

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