|SOUZA, CLEVERSON - Washington State University|
|BROWN, WENDY - Washington State University|
|HWANG, JULIANNE - Washington State University|
|LAWS, ELISABETH - Washington State University|
|ZIAEI, PARISA - Washington State University|
|NORTON, M - Washington State University|
|ABDELLREZEQ, GABER - Washington State University|
|DAVIS, WILLIAM - Washington State University|
|EREN, MEAGHAN - Washington State University|
|CARDIERI, MARIA CLARA - Washington State University|
Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2017
Publication Date: 5/14/2017
Citation: Souza, C.D., Bannantine, J.P., Brown, W., Hwang, J.K., Laws, E., Ziaei, P., Norton, M.G., Abdellrezeq, G.S., Davis, W.C., Eren, M., Cardieri, M.D. 2017. A nano particle vector comprised of poly lactic-co-glycolic acid and monophosphoryl lipid A and recombinant Mycobacterium avium subsp paratuberculosis peptides stimulate a pro-immune profile in bovine macrophages. Journal of Applied Microbiology. 123(1):54-65. https://doi.org/10.1111/jam.13491.
Interpretive Summary: Some vaccines show poor protection against disease, not because of the protective antigens mixed together, but because of the adjuvant or stability of the vaccine formulation. As a result, we explored the use of nanoparticles to deliver antigens of Mycobacterium avium subspecies paratuberculosis (which causes Johne's disease in cattle and sheep) to cultured immune cells, called macrophages. These nanoparticles, which are small spherical objects that can encase proteins, are readily taken up by macrophages and then we can monitor the proteins (cytokines) produced by the macrophages to gauge how the nanoparticles affect those cells. We discovered that some cytokines that promote inflammation are produced at significantly higher than normal levels. Although preliminary, these experiments form the foundation of using nanoparticle vaccine formulations in cattle to protect them from Johne's disease.
Technical Abstract: Current research and development of antigens for vaccination often center on purified recombinant proteins, viral vectored subunits, and synthetic peptides, most of which suffer from poor immunogenicity and are subject to degradation. For these reasons, efficient delivery systems and potent immunostimulants are necessary for vaccine enhancement. In this study, model antigen peptides derived from Mycobacterium avium subsp paratuberculosis (Map) and the immunostimulant monophosphoryl lipid A (MPLA) were incorporated in polymeric nanoparticles (NPs) based on poly (D,L-lactide-co-glycolide) (PLGA). These PLGA NP carriers were incubated with bovine macrophages and their effects were subsequently investigated. PLGA NP are spherical in shape, varying from 431 to 1218 nm in size, negatively charged and had peptide and MPLA encapsulation efficiencies varying from 50.13% to 108.5% and 37.2% to 98.41%, respectively. Our results showed that PLGA/MPLA NPs containing Map peptides are promptly and efficiently phagocytized by bovine macrophages. Incorporation of MPLA to the formulation of PLGA NP strongly stimulated expression of TNFa and IL12p40, with lesser amounts of IL10 expression, along with increased expression of MHC class II by bovine macrophages. T cell proliferation studies using the model peptide from the outer membrane of Anaplasma marginale provided further support for the use of antigens encapsulated by PLGA/MPLA in cattle studies. These findings can be extrapolated to demonstrate that co-delivery of peptides and MPLA in PLGA NPs represents a suitable strategy to increase immune protection against Map.