E. coli heat-labile toxin, LT |
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Vaxjo ID |
78 |
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Vaccine Adjuvant Name |
E. coli heat-labile toxin, LT |
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Alternative Names |
LT-OA or LT Oral Adjuvant |
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Adjuvant VO ID |
VO_0001322
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Description |
For inducing mucosal and systemic immunity (both humoral [including IgA and IgG2, isotypes] and cell-mediated) to killed microorganisms or peptide antigens mixed with it in neutral non-phosphate buffered saline, with/ without sodium bicarbonate (Vogel and Powell, 1995). |
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Stage of Development |
Clinical Trial |
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Components |
E. coli heat-labile toxin |
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Structure |
Polypeptide consisting of one 28 kD A subunit (toxic component consisting of the A, chain of 21 kD and the A2 chain of 7 kD) and five 11.6 kD B subunits (binding component) (Vogel and Powell, 1995). |
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Molecular Weight |
84,000 to 94,000 |
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Appearance |
White, odorless powder. |
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Storage |
Store lyophilized solid at -20° C. Solutions of LT-OA at 1 mg/ mL at pH 7.5 in non-phosphate buffers may be stored at 5° C for 1-2 years (Vogel and Powell, 1995). |
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Function |
E. coli heat-labile toxin (LT) has been found to affect several steps in the induction of a mucosal immune response, which alone or in combination might explain its strong adjuvant action after oral immunisation. These effects include: (a) increased permeability of the intestinal epithelium leading to enhanced uptake of co-administered antigen; (b) enhanced antigen presentation by a variety of cell types; (c) promotion of isotype differentiation in B cells leading to increased IgA formation; and (d) complex stimulatory as well as inhibitory effects on T-cell proliferation and cytokine production (Holmgren et al., 2003). |
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Safety |
Non-toxic at adjuvant active doses in mouse, rabbit and monkey (Vogel and Powell, 1995). |
| Related Vaccine(s) |
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| References |
Holmgren et al., 2003: Holmgren J, Czerkinsky C, Eriksson K, Mharandi A. Mucosal immunisation and adjuvants: a brief overview of recent advances and challenges. Vaccine. 2003; 21 Suppl 2; S89-95. [PubMed: 12763689].
Vogel and Powell, 1995: Vogel FR, Powell MF. A compendium of vaccine adjuvants and excipients. Pharmaceutical biotechnology. 1995; 6; 141-228. [PubMed: 7551218].
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