Review Paper Workshop on a detailed characterization of Trichinella spiralis antigens: a platform for future studies on antigens and antibodies to this parasite M.G.ORTEGA-PIERRES 1 , L.YEPEZ-MULIA 2 , W.HOMAN 3 , H.R.GAMBLE 4 , P.L.LIM 5 , Y.TAKAHASHI 6 , D.L.WASSOM 7 & J.A.APPLETON 8 1 Department of Genetics and Molecular Biology, Center for Research and Advanced Studies, Av. Polite ´cnico Nacional 2508, CP07360, Mexico, DF 2 Infection and Parasitic Disease Unit, Pediatrics Hospital, National Health Center, Mexico 3 Laboratory of Parasitology and Mycology, National Institute of Public Health and Environmental Protection, The Netherlands 4 Parasite Biology and Epidemiology Laboratory, USDA, Agricultural Research Service, USA 5 Clinical Immunology Unit, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 6 Department of Parasitology, Gifu University School of Medicine, Japan 7 Department of Pathology, Colorado State University, USA 8 College of Veterinary Medicine, James A. Baker Institute for Animal Health, USA SUMMARY In order to characterize immunodominant components of T. spiralis a workshop was organized. In this the reactivity of monoclonal and polyclonal antibodies, provided by different research groups, towards total extracts from adult, new born larvae and muscle larvae as well as to excretory/secretory components of muscle larvae were tested by ELISA, Western blot and immunoprecipitation assays. As a result of this work- shop T. spiralis ML antigens have been classified into eight groups (TSL-1–TSL-8) according to their recognition by mono- clonal and polyclonal antibodies. Among them, TSL-1 antigens have been the most extensively characterized both biochemi- cally and immunologically. These antigens are stage specific, originate in the muscle stichosome and are abundant in both E/S and on the larval cuticular surface. The TSL-1 antigens share an immunodominant carbohydrate epitope (tyvelose), which is uniquefor Trichinella and is not associated with phosphorylcho- line. The data collected in this workshop has allowed both the unification of the nomenclature for T. spiralis antigens and their biochemical characterization. It also has provided a platform for further studies on the characterization of other T. spiralis antigens and indeed for other Trichinella species. Keywords Trichinella spiralis, antigens, characterization, classification, monoclonal antibodies AIMS OF THE WORKSHOP Interest in Trichinella spiralis antigens has been focused on the characterization of immunodominant components. As in other helminths, T. spiralis antigens can be divided into three simple and operational compartments: the surface, the excretory/secretory compartment and the residual somatic antigens. The two compartments of greatest immunological interest are the surface and secretions since these provide the interface with the host. All mechanisms of parasite evasion and of host protection must principally concern the mole- cules of these compartments. The surface molecules of T. spiralis are stage specific, with changes in stage frequently coinciding with a move to a new environment. The precise function of these stage specific molecules is undefined, but is likely to include protection against hostile physical, chemical and biological agents and perhaps signal transduction. As functional changes at the host-parasite interface presumably assist survival of the parasite in the face of a vigorous immune response, the study of the genetics and biochemistry of surface molecules is funda- mental to understanding the balance between parasite sur- vival and rejection. A major focus of the 1990 workshop was to collate comparative data on molecular characteristics of surface and secreted molecules/antigens. These were studied by ELISA, Western blot and immunoprecipitation, following the same experimental procedures in at least two different laboratories. Reagents provided by several research groups Parasite Immunology, 1996: 18: 273–284 1996 Blackwell Science Ltd 273 Correspondence: M.G.Ortega-Pierres Received: 1 February 1996 Accepted for publication: 6 February 1996