Indirect involvement of allergen-captured mast cells in antigen presentation.
It is generally thought that mast cells influence T-cell activation nonspecifically through the release of inflammatory mediators. In this report, we provide evidence that mast cells may also affect antigen-specific T-cell responses by internalizing immunoglobulin E-bound antigens for presentation to antigen-specific T cells. Surprisingly, T-cell activation did not require that mast cells express major histocompatibility complex class II, indicating that mast cells were not involved in the direct presentation of the internalized antigens. Rather, the antigen captured by mast cells is presented by other major histocompatibility complex class II(+) antigen-presenting cells. To explore how this may occur, we investigated the fate of mast cells stimulated by antigen and found that FcepsilonRI crosslinking enhances mast cell apoptosis. Cell death by antigen-captured mast cells was required for efficient presentation because protection of mast cell death significantly decreased T-cell activation. These results suggest that mast cells may be involved in antigen presentation by acting as an antigen reservoir after antigen capture through specific immunoglobulin E molecules bound to their FcepsilonRI. This mechanism may contribute to how mast cells impact the development of T-cell responses.
Kambayashi
Taku
T
Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160, USA.
Baranski
Jan D
JD
Baker
Rebecca G
RG
Zou
Tao
T
Allenspach
Eric J
EJ
Shoag
Jonathan E
JE
Jones
Peter L
PL
Koretzky
Gary A
GA
D000485:Allergens / Q000276:immunology*; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000941:Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D016923:Cell Death / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology; D008407:Mast Cells / Q000166:cytology / Q000276:immunology*; D051379:Mice; D017455:Receptors, IgE / Q000276:immunology
D000485:Allergens; D000941:Antigens; D000949:Histocompatibility Antigens Class II; D017455:Receptors, IgE; D007073:Immunoglobulin E