This research was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute of Allergy and Infectious Diseases and, in part, by a National Institute of Allergy and Infectious Diseases contract to SoBran

This research was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute of Allergy and Infectious Diseases and, in part, by a National Institute of Allergy and Infectious Diseases contract to SoBran. Abbreviations Tregregulatory T cellTCRT cell receptorPEphycoerythrin. Footnotes The authors declare no conflict of interest. This article contains supporting information online at www.pnas.org/cgi/content/full/0610289104/DC1.. Th2 phenotype, and peripheral eosinophilia (4, 5). Examples of lymphopenia associated with a Th2 phenotype, hypereosinophilia, and/or elevated IgE have also been observed in mice. This phenotype is seen in mutants (6, 7). It has recently been reported that mice with limited numbers of CD4 T cells, such as MHC class II?/? mice Rabbit Polyclonal to TEP1 and mice, have elevated serum IgE (8). There are no mouse models, however, of lymphopenia in the context of normal thymic and peripheral development. Upon transfer into lymphopenic hosts, T cells undergo a process termed homeostatic or lymphopenia-induced proliferation. This proliferation is thought to be driven by cytokines as well as TCR engagement. It is unclear whether the peptides recognized by the proliferating T cells are derived from Lyn-IN-1 self-proteins, from gut flora, or from foreign antigens (9). We have reported that a reduced TCR repertoire with normal numbers of memory phenotype CD4 cells can be achieved by transferring small numbers of CD4+ T cells into lymphopenic recipients (10). The question arises as to whether this state of reduced repertoire could have deleterious effects for the recipient organism, much like the profound phenotype seen in the immunodeficient conditions mentioned above. Here we show that these mice develop a severe, multiorgan eosinophilic disease, strikingly elevated levels of serum IgE (when B cells are present), and a memory population of Th2-phenotype CD4 T cells. An important element in the development of this disease appears to be the limited repertoire of regulatory T cells (Tregs). Results and ?and and and and and ?and22peptide, did not induce disease when either 3 104 or 2 106 cells were transferred, although these AND cells underwent vigorous proliferation in the lymphopenic host. This finding indicates that not all proliferating T cells with limited receptor diversity (here, monoclonal) can induce disease (Table 1). Table 1. Summary of disease induced by transfer of CD4 or CD25? CD44lo CD4 T cells into stimulation than those that had received 2 106 cells. The rate of recurrence of IFN-producing cells was related in mice that experienced received small or large numbers of cells (Fig. 3and and or MHC class II?/? mice has recently been reported and has been attributed to IL-4 production from your few remaining CD4+ T cells in these immunodeficient mice (8). Furthermore, the simple intro of IL-13 or IL-4 into airways can induce airway hypersensitivity and mucus metaplasia (23), implying that local cytokine production in a sensitive environment in and of itself can induce immunopathology. While not mimicking every phenotype of disease associated with main human immune deficiencies associated with markedly reduced T cell repertoires, we have produced a model for lymphopenia and Th2 disease. This model may also be useful in studying other Th2-connected immunopathologic states such as allergy and extrinsic asthma. Antigen encounters during periods of limited TCR repertoire may predispose CD4 T cells toward Th2 differentiation, due to the lack of TCR specificity-matching between regulatory and effector T cells, an effector T cell intrinsic predisposition toward Th2 phenotype when TCR repertoires are reduced, or both. Long term study of such antigen-specific encounters in the context of lymphopenia are needed to elucidate the mechanism by which the Th2 phenotype emerges. Materials and Methods Mice. B10.A, Ly5.1 B10.A, C57BL/10, C57BL/10 AND TCR Tg, C57BL/10 em Rag2 /em ?/?, B10.A em Rag 2 /em ?/?, B10.A em CD3 /em ?/?, Ly5.1 C57BL/6, C57BL/6 em Rag2 /em ?/?, and C57BL/6 em IL-4 /em ?/? mice were from the National Institute of Allergy and Infectious Diseases contract facility at Taconic Farms (Germantown, NY). C57BL/6 mice were from The Jackson Laboratory (Pub Harbor, ME). Mice were managed under pathogen-free conditions in the National Institute of Allergy and Infectious Diseases animal facility. Adoptive Transfer. CD4, CD25+ CD4, CD25? CD4, or CD25?/CD44dull CD4 lymph node cells were obtained by sorting on a FACSVantage SE or FACSAria (Becton Dickinson, Franklin Lakes, NJ). Purity was 99%. In some cases, cells were labeled with CFSE (Molecular Probes, Carlsbad, CA) at a final concentration of 1 1.25 M. Cells suspended in PBS were transferred via tail vein injection into recipient mice. Circulation Cytometry. Lyn-IN-1 Anti-CD25-allophycocyanin (APC) (Personal computer61), CD4-FITC (3T4), CD44-phycoerythrin (PE), CD44 PE-cy5.5, CD45.1-PE, CD45.2-FITC, CD45.1 PE-cy5, IL-4-PE, IL-5-PE, and IFN-APC were purchased from BD Pharmingen (San Diego, CA). Lyn-IN-1 Anti-FoxP3 was purchased from eBiosciences (San Diego, CA). Anti-IL-13 (clone 38213) was purchased from R & D Systems (Minneapolis, MN) and conjugated to APC in the National Institute of Allergy and Infectious Diseases core custom antibody facility. All circulation cytometry was performed on a.