RECOMBINANT CHOLERA-TOXIN-B SUBUNIT ACTS AS AN ADJUVANT FOR THE MUCOSAL AND SYSTEMIC RESPONSES OF MICE TO MUCOSALLY CO-ADMINISTERED BOVINE SERUM-ALBUMIN

We examined the mucosal adjuvant activity of recombinant cholera toxin B subunit (rCTB) produced by Bacillus brevis carrying pNU212-CTB by i ntranasal or oral co-administration of bovine serum albumin (BSA), Int ranasal administration stimulated a high level of BSA-specific serum I gG antibody response and BSA-specific IgA antibody responses in the na sal and pulmonary lavages. Oral administration induced a moderate leve l of BSA-specific serum Ige antibody and a low level of BSA-specific I gA antibody in the large intestinal washes, These results show that CT B alone can act as an intranasal or-oral delivery carrier; it also has strong adjuvant proper-ties for stimulating serum Ige and mucosal IgA immune responses to unrelated non-coupled antigens after intranasal o r oral co-immunization. (C) 1997 Elsevier Science Ltd, All rights rese rved.