GM1 binding-deficient exotoxin is a potent noninflammatory broad spectrum intradermal immunoadjuvant.
Intradermal (i.d.) immunization is a promising route of vaccine administration. Suitable i.d. adjuvants are important to increase vaccine efficacy in poorly responding populations such as the elderly or for dose-sparing strategies in the face of vaccine shortages. Bacterial exotoxins, such as Escherichia coli heat-labile enterotoxin (LT), exert strong immunostimulatory effects through binding to monosialoganglioside (GM1) cell surface receptors; however, injection is hampered by local inflammation. We demonstrate that the injection of LT formulations deficient in GM1 binding by mutation (LT(G33D)) or in vitro ligand coupling does not cause localized edema and inflammation in mice, yet these formulations retain potent adjuvant activity by enhancing functional Ab and cellular immune responses to coadministered Ags. Complete protection against in vivo lethal tetanus toxin challenge and the induction of Ag-specific CTL responses capable of killing target cells in vivo indicated in vivo efficacy of the induced immune responses. LT(G33D) proved superior to standard alum adjuvant regarding the magnitude and breadth of the induced immune responses. Immunizations in complex ganglioside knockout mice revealed a GM1-independent pathway of LT adjuvanticity. Immunostimulation by i.d. LT(G33D) is explained by its ability to induce migration of activated APCs to the proximal draining lymph nodes. LT(G33D) is a promising candidate adjuvant for human trials of parenteral vaccines in general and for current i.d. vaccine development in particular.
Zoeteweij
J Paul
JP
Iomai Corporation, 20 Firstfield Road, Gaithersburg, MD 20878, USA. pzoet@iomai.com
Epperson
Diane E
DE
Porter
Jackie D
JD
Zhang
Chen X
CX
Frolova
Olga Y
OY
Constantinides
Anita P
AP
Fuhrmann
Steven R
SR
El-Amine
Moustapha
M
Tian
Jing-Hui
JH
Ellingsworth
Larry R
LR
Glenn
Gregory M
GM
D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000378:metabolism; D000534:Alum Compounds / Q000008:administration & dosage / Q000378:metabolism; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology; D001427:Bacterial Toxins / Q000008:administration & dosage; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D004768:Enterotoxins / Q000008:administration & dosage; D029968:Escherichia coli Proteins / Q000008:administration & dosage; D005098:Exotoxins / Q000008:administration & dosage* / Q000378:metabolism; D005260:Female; D005677:G(M1) Ganglioside / Q000378:metabolism; D007249:Inflammation / Q000276:immunology / Q000517:prevention & control; D007271:Injections, Intradermal; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008546:Melanoma, Experimental; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017350:N-Acetylgalactosaminyltransferases / Q000172:deficiency / Q000235:genetics; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D013742:Tetanus / Q000235:genetics / Q000276:immunology / Q000517:prevention & control; D013745:Tetanus Toxoid / Q000008:administration & dosage / Q000276:immunology / Q000378:metabolism
D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D005098:Exotoxins; D013745:Tetanus Toxoid; C041524:aluminum sulfate; D005677:G(M1) Ganglioside; C027538:heat-labile enterotoxin, E coli; D017350:N-Acetylgalactosaminyltransferases; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase