Increased expression of TCR vbeta5.1 and 8 in mucosal T-cell lines cultured from patients with Crohn disease.
BACKGROUND
Characterization of the T-cell receptor variable beta chain (Vbeta) repertoire in inflamed mucosa has been used to identify disease-relevant T-cell populations and antigens in Crohn disease (CD). In vitro expansion of mucosal T cells may reveal changes in Vbeta repertoire not apparent in fresh isolates and we aimed to identify Vbeta subpopulations implicated in Crohn disease.


METHODS
In vivo activated mucosal T cells were cultivated using IL-2 and IL-4 from biopsies of whole colonic mucosa without use of Vbeta-modifying exogenous antigen or feeder cells. The Vbeta gene expression in mucosal T-cell cultures was determined in 30 patients with CD and 12 healthy controls using reverse transcriptase polymerase reaction (RT-PCR) covering all 23 functional Vbeta families and the Vbeta receptor prevalence was evaluated by flow cytometry in selected cultures.


RESULTS
Early T-cell cultures from both CD patients and healthy controls showed a polyclonal Vbeta gene expression that narrowed during culture, which in CD cultures led to a significant over-expression of the Vbeta5.1 (P = 0.04) and Vbeta8 gene segments (P = 0.03). Together with Vbeta6 and Vbeta18, these Vbeta chains form a pattern of staphylococcal enterotoxin type E (SEE) responsive Vbeta chains, also over-expressed in CD cultures (P = 0.02). Further in vitro stimulation of CD cultures with SEE caused expansion of Vbeta8 receptor positive cells together with a proinflammatory cytokine response.


CONCLUSIONS
CD may be associated with (super)antigen-specific Vbeta subpopulations selected during long-term cultivation of mucosal biopsies from inflamed colon.
Kelsen
J
J
Dept of Medicine V, Aarhus University Hospital, Denmark. jekel@akh.aaa.dk
Agnholt
J
J
Hoffmann
H J
HJ
Kaltoft
K
K
Dahlerup
J F
JF
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D018929:Cell Culture Techniques; D003106:Colon / Q000473:pathology; D003424:Crohn Disease / Q000235:genetics* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D019674:Genes, T-Cell Receptor beta; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000502:physiology*
D016693:Receptors, Antigen, T-Cell, alpha-beta; C075784:T cell receptor Vbeta8