Release of the soluble co-receptor (protein Fv) of secretory immunoglobulins after colonization of axenic rats by the human gut microflora.
The presence of protein Fv (pFv), a soluble co-receptor of human gut antibodies, was investigated in heteroxenic rats as a function of the presence of the human digestive microflora. This endogenous molecule was not detected in the stools of axenic rats but was found in those of heteroxenic animals. The release was delayed for 1 week after colonization and found to be independent from the kinetics of bacteria-induced short-chain fatty acids issued from the catabolism of carbohydrates and of proteins. The similar bacterial composition of pFv-positive and of pFv-negative stools, and the lack of induction by different dominant bacterial genera, suggest that non-dominant species must be involved. These results indicate that human colonic flora is a major inducer of pFv and thus participates in increasing the efficiency of the intestinal immunity by this additional mechanism known to maintain and augment the polymeric status of secretory immunoglobulin (Ig)A.
Andrieux
C
C
Unité d'Ecologie et de Physiologie du Système Digestif, Institut National de la Recherche Agronomique, Jouy en Josas, France.
Pires
R
R
Moreau
M C
MC
Bouvet
J P
JP
D000818:Animals; D005856:Germ-Free Life; D006801:Humans; D007128:Immunoglobulin Fragments / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000382:microbiology*; D008222:Lymphokines / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D012795:Sialoglycoproteins / Q000378:metabolism*; D013997:Time Factors
C089422:Fv protein, human; D007128:Immunoglobulin Fragments; D008222:Lymphokines; D012795:Sialoglycoproteins