{HEAD ~ An antibody} targeted to an antigen is brought into {TAIL ~ contact} with a body component in situ 
{ HEAD ~ An antibody } targeted to an antigen is brought into { TAIL ~ contact } with a body component in situ
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH