( ( ( ( ( ( The ( first lines ) ) ( of defense ) ) , ) ( often ( called ( the ( innate ( immune system ) ) ) ) ) ) , ) ( ( try ( to ( ( keep invaders ) ( from ( ( entering ( the body ) ) ( in ( the ( first place ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ first) (NNS lines)) (PP (IN of) (NP (NN defense))) (, ,) (VP (ADVP (RB often)) (VBN called) (NP (DT the) (JJ innate) (JJ immune) (NN system))) (, ,)) (VP (VBP try) (S (VP (TO to) (VP (VB keep) (NP (NNS invaders)) (PP (IN from) (S (VP (VBG entering) (NP (DT the) (NN body)) (PP (IN in) (NP (DT the) (JJ first) (NN place)))))))))) (. .)))
The first lines of defense, often called the innate immune system, try to keep invaders from entering the body in the first place.
(ROOT (S (NP (DT The) (JJ innate) (JJ immune) (NN system)) (VP (VBZ serves) (PP (IN as) (NP (NP (DT a) (JJ first) (NN responder)) (PP (TO to) (NP (NP (JJ pathogenic) (NNS threats)) (SBAR (WHNP (WDT that)) (S (VP (VB bypass) (NP (NP (JJ natural) (ADJP (NN physical) (CC and) (NN chemical)) (NNS barriers)) (PP (IN of) (NP (DT the) (NN body)))))))))))) (. .)))