( ( The team ) ( ( discovered ( that ( ( ( ( ( an ( immune cell ) ) , ) ( called ( ( ( T cells ) , ) ( activated ( by ( ( the bacterium ) ( that ( causes ( Lyme disease ) ) ) ) ) ) ) ) ) , ) ( ( ( continues ( to ( ( cause ( joint inflammation ) ) ( after ( eradication ( of ( the bacterium ) ) ) ) ) ) ) , ) ( because ( ( these cells ) ( may ( mistake ( ( a ( human protein ) ) ( for ( a ( bacterium protein ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN team)) (VP (VBD discovered) (SBAR (IN that) (S (NP (NP (DT an) (JJ immune) (NN cell)) (, ,) (VP (VBN called) (NP (NP (NNP T) (NNS cells)) (, ,) (VP (VBN activated) (PP (IN by) (NP (NP (DT the) (NN bacterium)) (SBAR (WHNP (WDT that)) (S (VP (VBZ causes) (NP (JJ Lyme) (NN disease)))))))))) (, ,)) (VP (VBZ continues) (S (VP (TO to) (VP (VB cause) (NP (JJ joint) (NN inflammation)) (PP (IN after) (NP (NP (NN eradication)) (PP (IN of) (NP (DT the) (NN bacterium)))))))) (, ,) (SBAR (IN because) (S (NP (DT these) (NNS cells)) (VP (MD may) (VP (VB mistake) (NP (NP (DT a) (JJ human) (NN protein)) (PP (IN for) (NP (DT a) (NN bacterium) (NN protein)))))))))))) (. .)))
The team discovered that an immune cell, called T cells, activated by the bacterium that causes Lyme disease, continues to cause joint inflammation after eradication of the bacterium, because these cells may mistake a human protein for a bacterium protein.
(ROOT (S (NP (JJ Lyme) (NN disease)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NNS bacteria))))) (. .)))
Lyme disease is caused by bacteria.