T cell receptor Vβ 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 subsets by characterizing the lung and blood T cell receptor (TCR) repertoires in allergic asthmatics before and after repeated low-dose allergen challenge. Peripheral blood lymphocyte (PBL) and bronchoalveolar lavage (BAL) samples were obtained from eight patients with allergic asthma before and after a period of repeated low-dose allergen inhalations. RT-PCR followed by Southern blot allowed the quantification of relative VP gene segment usage. Thirteen healthy individuals served as controls at PBL level. PBL as well as BAL 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 compared to PBL of healthy controls. interestingly, TCR V beta7 and V beta9 usage was significantly higher in BAL than in PBL in asthmatics before as well as after challenge. TCR repertoire alterations after allergen challenge differed between individuals, with relatively mild changes. (C) 2001 Academic Press.