( ( T cells ) ( ( are ( ( ( ( ( white ( blood cells ) ) , ) ( derived ( from ( the ( thymus gland ) ) ) ) ) , ) ( that ( participate ( in ( ( a variety ) ( of ( cell-mediated ( immune reactions ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP T) (NNS cells)) (VP (VBP are) (NP (NP (JJ white) (NN blood) (NNS cells)) (, ,) (VP (VBN derived) (PP (IN from) (NP (DT the) (JJ thymus) (NN gland)))) (, ,) (SBAR (WHNP (WDT that)) (S (VP (VBP participate) (PP (IN in) (NP (NP (DT a) (NN variety)) (PP (IN of) (NP (JJ cell-mediated) (JJ immune) (NNS reactions)))))))))) (. .)))
T cells are white blood cells, derived from the thymus gland , that participate in a variety of cell-mediated immune reactions.
(ROOT (S (NP (DT The) (NNS thymus) (NN gland)) (VP (VBZ produces) (NP (NN t) (NNS cells))) (. .)))