FilariasisLesional T Cells in Human Bancroftian Biased TCR Repertoire in Infiltrating

To investigate the hypothesis that T cells recognizing specific Ags localize to the site of disease activity in human bancroftian filariasis, we have compared the repertoire of TCR V b gene segments in lesions vs blood in individual patients by RT-PCR ELISA. V b 14 and V b 24 were overrepresented (5% greater in tissue compared with PBMCs and/or tissue/PBMC ratios in the highest 5% of all tissue/PBMC ratios for all V b s for all subjects) in 50% and 40% of study subjects, respectively. Overrepresentation of these two V b s did not occur in any control subject. In comparing three patient groups, the proportion of individuals meeting at least one criterion for V b 14 overrepresentation was shown to increase in tandem with our current concepts of disease progression (asymptomatic filariasis 5 25%; clinical filariasis with active infection 5 60%; clinical filariasis without active infection 5 71%). In 6 of the 10 individuals with V b 14 overrepresentation, V b 14 represented > 20% of the entire lesional V b repertoire. All but one of the 20 study subjects had at least one V b gene segment that was overrepresented in tissue compared with PBMCs. Only a small number of V b s, usually three or less, were overrepresented in any single filariasis patient. However, in the same tissue, no differences between patient groups were found when IFN- g , TNF- a , IL-4, IL-5, and IL-12 mRNA expression were examined. Taken together, these findings suggest that, in principle, in essentially all patients, whether with subclinical or with clinical filariasis, distinct and limited T cell populations are concentrated in affected tissue. The Journal of Immunology, 1999, 162: 1756–1764.