( ( Severity ( of infection ) ) ( ( is ( related ( to ( ( ( the ( cell wall ) ) and ) ( capsule antigens ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Severity)) (PP (IN of) (NP (NN infection)))) (VP (VBZ is) (ADJP (VBN related) (PP (TO to) (NP (NP (DT the) (NN cell) (NN wall)) (CC and) (NP (JJ capsule) (NNS antigens)))))) (. .)))
Severity of infection is related to the cell wall and capsule antigens.
(ROOT (S (NP (DT The) (NN capsule)) (VP (VBZ is) (NP (NP (DT the) (NN layer)) (PP (IN outside) (NP (NP (DT the) (NN cell) (NN wall)) (PP (IN in) (NP (DT a) (NN prokaryote))))))) (. .)))
The capsule is the layer outside the cell wall in a prokaryote.