T cell receptor V beta expression in patients with allergic asthma before and after repeated low-dose allergen inhalation

The objective of this study was to identify disease-associated T cell subse ts by characterizing the lung and blood T cell receptor (TCR) repertoires i n allergic asthmatics before and after repeated low-dose allergen challenge . Peripheral blood lymphocyte (PBL) and bronchoalveolar lavage (BAL) sample s were obtained from eight patients with allergic asthma before and after a period of repeated low-dose allergen inhalations. RT-PCR followed by South ern blot allowed the quantification of relative VP gene segment usage. Thir teen healthy individuals served as controls at PBL level. PBL as well as BA L T cells of asthmatics displayed a higher usage of V beta3, V beta5.2, and V beta6.1-3 and a lower usage of V beta 16, V beta 18, and V beta 19 compa red to PBL of healthy controls. interestingly, TCR V beta7 and V beta9 usag e was significantly higher in BAL than in PBL in asthmatics before as well as after challenge. TCR repertoire alterations after allergen challenge dif fered between individuals, with relatively mild changes. (C) 2001 Academic Press.