( ( Once ( ( ( ( a pathogen ) or ) ( other threat ) ) ( is ( ( removed ( from ( the body ) ) ) ( by ( the ( immune system ) ) ) ) ) ) ) ( ( the inflammation ) ( ( must ( be ( switched off ) ) ) . ) ) )
(ROOT (S (SBAR (IN Once) (S (NP (NP (DT a) (NN pathogen)) (CC or) (NP (JJ other) (NN threat))) (VP (VBZ is) (VP (VBN removed) (PP (IN from) (NP (DT the) (NN body))) (PP (IN by) (NP (DT the) (JJ immune) (NN system))))))) (NP (DT the) (NN inflammation)) (VP (MD must) (VP (VB be) (VP (VBN switched) (PRT (RP off))))) (. .)))
Once a pathogen or other threat is removed from the body by the immune system the inflammation must be switched off.
(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)))))))))))) (. .)))