title: An endogenous superantigen in the rat gut lumen as a model to study the role of human protein-Fv.
abstract: Protein-Fv (pFv) is a human B superantigen which can bind the variable domain (VH) of the heavy chain of immunoglobulins (Igs) and enhance the effector functions of secretory antibodies in the gut lumen. This study describes a rat molecule related to pFv by a similar specificity to the human VH3 domain. Investigation of the content of different gut segments shows that the rat pFv is usually hidden by its binding to local Igs to form macromolecular complexes similar to the immune fortresses described in normal humans. Furthermore, the pFv level generally increases from the jejunum to the colon in parallel with the decreasing water dilution, and finally a discontinuous presence can occur along the digestive tract. Detection of this molecule in the fetus proves its non-microbial origin. Variations of the release of pFv, according to the breeding and to littermating, suggest the influence of external factors. This animal model allows the development of a study of the functions of pFv in vivo using a current laboratory species and has already provided evidence that the synthesis of this important molecule of the secretory immune system is regulated by environmental factors.
authors.affiliation: Unité d'Immunocytochimie, Institut Pasteur, Paris, France.
authors.forename: A I
authors.initials: AI
authors.lastname: Guihard
authors.forename: R
authors.initials: R
authors.lastname: Pires
authors.forename: J P
authors.initials: JP
authors.lastname: Bouvet
mesh_terms: D000818:Animals; D002432:Cecum / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D005314:Embryonic and Fetal Development / Q000276:immunology; D005260:Female; D006801:Humans; D007128:Immunoglobulin Fragments / Q000502:physiology*; D007422:Intestines / Q000737:chemistry / Q000276:immunology*; D008222:Lymphokines / Q000502:physiology*; D008297:Male; D018448:Models, Immunological; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012149:Restraint, Physical; D012795:Sialoglycoproteins / Q000502:physiology*; D013312:Stress, Physiological / Q000276:immunology; D018089:Superantigens / Q000032:analysis*
chemical_list: C089422:Fv protein, human; D007128:Immunoglobulin Fragments; D008222:Lymphokines; D012795:Sialoglycoproteins; D018089:Superantigens