University of Louisville
Insights into the Potent Immunogenicity and Low Toxicity of the Vaccine Adjuvant Monophosphoryl Lipid A
Institution
University of Louisville
Faculty Advisor/ Mentor
Thomas Mitchell
Abstract
The pro-inflammatory cytokine IL-1β is involved in the pathogenesis of several inflammatory diseases and conditions including atherosclerosis, autoimmune arthritis, myocardial infarction, septicemia, stroke, and ulcerative colitis. Synthetic Monophosphoryl Lipid-A (sMLA) containing compounds have been shown to reduce or inhibit such inflammatory events where IL-1β plays a central role. Edgar Ribi discovered in the 1970’s that MLA structures, retained the immunostimulatory properties of its parent biomolecule LPS and was less than 0.10% as toxic. Since Ribi’s discovery much has been learned about MLA-containing compounds, which have been successfully implemented in vaccines as a part of their adjuvant profile. Small changes in the sMLA chemical structure can alter the kinetics and signaling outcomes of the TLR4 receptor complex. TLR4 uses MAL/MyD88 to induce the production of pro-inflammatory cytokines and TRAM/TRIF to induce the production of some immunostimulatory factors. Previously our lab has shown that sMLA like compounds differentially activate the TRAM/TRIF branch of the TLR-4 signalling pathway, leading to high expression of immunostimulatory cytokines, with low inflammatory consequences. This study focuses on characterizing cytokine transcript and protein levels in BM-DC’s during response to sMLA and synthetic diphosphoryl lipid-A, a purified lipid-A subunit of E. coli. We also show that treatment with sMLA leads to the inability of BMDC’s to produce mature IL-1β cytokine. Currently we are using immunofluorescence confocal microscopy in order to gain further insights on IL-1β loss by investigating components of the inflammasome complex responsible for forming mature IL-1β cytokine, as well as IL-1β itself.
Insights into the Potent Immunogenicity and Low Toxicity of the Vaccine Adjuvant Monophosphoryl Lipid A
The pro-inflammatory cytokine IL-1β is involved in the pathogenesis of several inflammatory diseases and conditions including atherosclerosis, autoimmune arthritis, myocardial infarction, septicemia, stroke, and ulcerative colitis. Synthetic Monophosphoryl Lipid-A (sMLA) containing compounds have been shown to reduce or inhibit such inflammatory events where IL-1β plays a central role. Edgar Ribi discovered in the 1970’s that MLA structures, retained the immunostimulatory properties of its parent biomolecule LPS and was less than 0.10% as toxic. Since Ribi’s discovery much has been learned about MLA-containing compounds, which have been successfully implemented in vaccines as a part of their adjuvant profile. Small changes in the sMLA chemical structure can alter the kinetics and signaling outcomes of the TLR4 receptor complex. TLR4 uses MAL/MyD88 to induce the production of pro-inflammatory cytokines and TRAM/TRIF to induce the production of some immunostimulatory factors. Previously our lab has shown that sMLA like compounds differentially activate the TRAM/TRIF branch of the TLR-4 signalling pathway, leading to high expression of immunostimulatory cytokines, with low inflammatory consequences. This study focuses on characterizing cytokine transcript and protein levels in BM-DC’s during response to sMLA and synthetic diphosphoryl lipid-A, a purified lipid-A subunit of E. coli. We also show that treatment with sMLA leads to the inability of BMDC’s to produce mature IL-1β cytokine. Currently we are using immunofluorescence confocal microscopy in order to gain further insights on IL-1β loss by investigating components of the inflammasome complex responsible for forming mature IL-1β cytokine, as well as IL-1β itself.