HUMORAL AND CELLULAR IMMUNE-RESPONSES TO THE FIMBRIAE OF PORPHYROMONAS-GINGIVALIS AND THEIR SYNTHETIC PEPTIDES

Subcutaneous injection of fimbriae from Porphylomonas gingivalis strai n 381 in Freund's incomplete adjuvant (FIA) resulted in an excellent s erum anti-fimbrial immunoglobulin G (IgG) response in guinea-pigs and BALB/c mice. Administration of P. gingivalis fimbriae also elicited di stinct cellular immune responses to the fimbriae in terms of ear lobe reaction in BALB/c but not in BALB/c nu/nu mice, and of skin reaction in guineapigs. When the guinea-pigs were given a semi-synthetic adjuva nt GM-53-sodium beta-N-acetylglycosaminyl-(l -t 4)-N- l-L-alanyl-D-iso glutaminyl-(L)-stearoyl-(D)meso-2, 6-diaminopimelic acid-(D)-amide-D-a lanine-and fimbriae in FIA by subcutaneous injection, more enhanced pr oduction of serum anti-fimbrial IgG and stronger cellular immune respo nses were induced in the guinea-pigs than in those given fimbriae alon e. Synthetic peptide FP381(202-221), which corresponds to the amino-ac id residue numbers 202-221 based on the amino-acid sequence of fimbril in from P. gingivalis strain 381, elicited humoral and cellular immune responses in guinea-pigs immunised with the fimbriae or FP381(202-221 ). Furthermore, subcutaneous administration of synthetic peptide FP381 (61-80) with GM-53 induced lesser degrees of humoral and cellular immu ne responses in guineapigs than did FP381(202-221). However, when the fimbriae or FP381(61-80) were administered with bovine serum albumin ( BSA), markedly elevated levels of specific anti-BSA antibody were seen in the serum of BALB/c mice. These results clearly indicated that fim briae from P. gingivalis 381 and their oligopeptide segments induced h umoral and cellular immune responses and exhibited immuno-adjuvant act ivities in guinea-pigs and BALB/c mice.