T cells play a pivotal role in initiating and orchestrating allergic responses in @entity565 . The goal of this work was to learn whether ragweed challenge in the lungs alters the T-cell repertoire expressed in the blood and lungs of @entity1097 . Analyses of cell numbers, differentials, and T-cell subsets in bronchoalveolar lavage (BAL) fluids showed that ragweed challenge was associated with preferential recruitment of @entity404 + T cells into the lungs. A reverse transcriptase-polymerase chain reaction (RT-PCR) was used to amplify T-cell receptor (TCR) gene transcripts from unfractionated, @entity404 +, and @entity405 + T cells in blood and BAL fluids. As judged by RT-PCR, the usage of TCR Valpha and Vbeta gene families in BAL fluids was similar to that in blood. Ragweed challenge did not change the levels of expression of these V gene families. The clonality of T cells was estimated by analyzing the diversity of TCR V-(D)-J junctional region @entity377 lengths associated with each Valpha and Vbeta gene family, using sequencing gel electrophoresis. Most V gene families in blood and BAL fluids were associated with multiple junctional region lengths before and after ragweed challenge, indicating polyclonal expression. Some V gene families were expressed in an oligoclonal manner in unfractionated, @entity404 +, and @entity405 + T cells in BAL fluids before ragweed challenge, as indicated by a few predominant junctional region lengths. The majority of these V gene families became polyclonal after challenge, compatible with polyclonal T-cell influx during @entity32 immediately after ragweed challenge. However, some V gene families became oligoclonal or developed a new oligoclonal pattern of junctional region lengths in BAL T cells after ragweed challenge. Surprisingly, this occurred in both @entity404 + and @entity405 + T cells. In one of these instances, DNA sequencing of Vbeta21 junctional regions in @entity405 + T cells confirmed a change from polyclonal to oligoclonal expression after ragweed challenge. These findings show that ragweed challenge is associated with polyclonal influx and oligoclonal activation of both @entity404 + and @entity405 + T cells in the lungs.

T-Cell repertoire in the blood and lungs of XXXX before and after ragweed challenge.

@entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation'] @entity404 :: ('920', 'Gene') :: ['CD4'] @entity565 :: ('MESH:D001249', 'Disease') :: ['asthma'] @entity1097 :: ('MESH:C566404', 'Disease') :: ['atopic asthmatics'] @entity377 :: ('CHEBI:36976', 'Chemical') :: ['nucleotide'] @entity405 :: ('925', 'Gene') :: ['CD8']
@entity1097 :: (MESH:C566404,Disease) :: ['atopic asthmatics']
