Iscom and iscom-matrix enhance by intranasal route the IgA responses to OVA and rCTB in local and remote mucosal secretions

Iscoms, with rCTB incorporated via the GM1 receptor, enhanced in mice the m ucosal immunogenicity of rCTB as antigen after intranasal (i.n.) administra tion both by inducing IgA response in the remote intestinal tract mucosa an d by a 100-fold increase of the specific IgA locally in the lungs. Iscom-ma trix as a separate entity mixed with rCTB enhanced the rCTB-IgA response si milarly. While OVA in iscoms induced high mucosal IgA responses, iscom-matr ix co-administered with OVA induced low or no mucosal IEA response to OVA. A synergism between iscoms and rCTB could only be seen as an adjuvant targe ting effect enhancing the IgA response to OVA in the remote genital tract m ucosa. In serum, the immunomodulatory effect of iscoms after i.n. administr ation was seen as an enhanced serum IgG2a response. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.