Application of Electroblotting Technique to Studies of the Intestinal Antibody Response to Extractable Fecal Antigens

Abstract

Water-soluble and sodium dodecyl sulfate (SDS)-extractable fractions were prepared from feces of four patients with inflammatory and six with non-inflammatory bowel disease. Both types of fractions were run on polyacrylamide gel electrophoresis, followed by electroblotting on nitrocellulose sheets of the separated components. The antibody reactivities in serum and in the intestinal wall against the extracted and separated fecal components were investigated. A striking lack of reactivity was observed when serum was used as antibody source against the fecal extracts both in patients with inflamed and in those with non-inflamed intestinal mucosa. The locally produced gut-associated IgG reacted more intensely with SDS-extractable fecal components than with water-soluble components. A strong reaction between intestinal-wall IgG extracts and a water-soluble antigen of 46-48 kD in the feces of two colitis patients was, however, observed. No clear correlation between the single bands and the occurrence of inflammatory bowel disease could be established because of the small number of patients.

Key Words:

• Electroblotting
• intestinal antigens
• mucosal antibodies
• ulcerative colitis