The process in which an antigen-presenting cell expresses antigen (peptide or lipid) of exogenous origin on its cell surface in association with an MHC protein complex. [ https://www.worldcat.org/search?q=bn%3A0781735149 http://www.ncbi.nlm.nih.gov/pubmed/15928678 http://www.ncbi.nlm.nih.gov/pubmed/15771591 ]