Limited CD4 T-cell diversity associated with colitis in T-cell receptor alpha mutant mice requires a T helper 2 environment.
OBJECTIVE
T-cell receptor alpha mutant (TCRalpha(-/-)) mice spontaneously develop chronic colitis mediated by CD4(+) TCRalpha(-)beta(+) T cells. The aim of this study was to analyze the mechanisms of expansion of these cells by characterization of the TCRbeta repertoire.


METHODS
TCRbeta repertoire was analyzed by reverse-transcription polymerase chain reaction/Southern blot and DNA sequencing. Clonality of T cells was examined in the lymphoid tissues and colons of TCRalpha(-/-) mice and interleukin 4-deficient TCRalpha(-/-) mice. In addition, an in vitro culture system using syngeneic colonic epithelial cells as antigens was used.


RESULTS
The clonal expansion of a restricted subset of Vbeta8.2(+) T cells was characterized by conservation of a single negatively charged amino acid residue in the second position of the complementarity-determining region 3 (CDR3). These T cells were observed in the diseased colon and appendix (cecal patch) of TCRalpha(-/-) mice, but not germfree TCRalpha(-/-) mice. Culture of polyclonal T cells from young TCRalpha(-/-) mice with colonic epithelial cells under T helper 2 conditions resulted in the survival of Vbeta8.2(+) T cells characterized by the same CDR3 pattern. In addition, the transfer of the cultivated T cells induced mild colitis in recombination-activating gene 1 mutant mice.


CONCLUSIONS
In the TCRalpha(-/-) mice, the development of colitis is associated with the presence of a restricted diversity of Vbeta8. 2(+) T-cell subsets characterized by a specific TCR motif. The limited diversity of lamina propria T cells that are derived from naive T cells expanded by reacting with luminal bacterial antigens is likely caused by the survival of these T cells after stimulation with self-antigens in the presence of a T helper 2 environment.
Mizoguchi
A
A
Department of Pathology, Massachusetts General Hospital, Boston 02114, USA.
Mizoguchi
E
E
Saubermann
L J
LJ
Higaki
K
K
Blumberg
R S
RS
Bhan
A K
AK
D000595:Amino Acid Sequence; D000818:Animals; D000916:Antibody Diversity; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003092:Colitis / Q000235:genetics* / Q000276:immunology*; D003106:Colon / Q000276:immunology; D019673:Genes, T-Cell Receptor alpha; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology; D015847:Interleukin-4 / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000172:deficiency / Q000235:genetics / Q000276:immunology*
D018398:Homeodomain Proteins; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; C064658:RAG-1 protein; D015847:Interleukin-4