Oral inoculation of the porcine small intestine with live TGE virus has been shown to elicit a local cell-mediated response as well as a peripheral lymphocyte response. This has not been shown to occur following intramuscular (IM) administration of the pathogen. In the research described in this dissertation both a local and a systemic cell-mediated response were induced in response to IM inoculation of a subunit glycoprotein component isolated from pigs which were immunized with a TGEV subunit glycoprotein. The cells were assayed in vitro for a blast transformation response. Reactive lymophocytes were discovered in peripheral blood, Peyer's patches and mesenteric lymph nodes. Little if any reactivity was observed for splenic lymphocytes. Peripheral blood lyphocytes which were sensitized to the glycoprotein derived from the Illinois strain of TGEV responded strongly to the Miller strain glycoprotein. Anti-porcine thymocyte serum plus complement eliminated most of the lymphocyte response;Characterization of the glycoprotein was carried out by PAGE, SDS-PAGE, immunodiffusion, IEF, rocket immunoelectrophoresis and cross immunoelectrophoresis. A molecular weight of 67,000 was revealed for the subunit with SDS-PAGE; a P.I. of 3.86 was determined by isoelectric focusing. Immunodiffusion, rocket immunoelectrophoresis and cross immunoelectrophoresis of the Miller and Illinois glycoprotein demonstrated a similar major antigenic component. Rocket immunoelectrophoresis of the glycoprotein subunit using serum adsorbed with host material revealed that the subunit was a component of the virus and not the host;Colostrum samples from pigs immunized with the glycoprotein contained neutralizing antibodies as revealed by a plaque reduction assay.