title: The adjuvant PCEP induces recruitment of myeloid and lymphoid cells at the injection site and draining lymph node.
abstract: Poly[di(sodiumcarboxylatoethylphenoxy)phosphazene] (PCEP) has shown great potential as a vaccine adjuvant, but the mechanisms that mediate its adjuvant activity have not been investigated. Previously, we had reported the potential of PCEP to induce cytokines and chemokines at the site of injection. Hence, we hypothesized that PCEP creates strong immuno-competent environment leading to recruitment of immune cells at the injection site. Intramuscular injection of mice with PCEP induced significant recruitment of neutrophils, macrophages, monocytes, dendritic cells (DCs), and lymphocytes at the site of injection as well as in the draining lymph nodes. Flow cytometric analysis showed that the majority of the recruited immune cells took up and/or were associated with PCEP at the injection site, with lymphocytes taking up PCEP in lesser quantity. Further, confocal analysis revealed intracytoplasmic lysosomal localization of PCEP in recruited immune cells. These observations suggest that recruitment of distinct immune cells to the site of injection site may be an important mechanism by which PCEP potentiates immune responses to antigens.
authors.affiliation: Vaccinology and Immunotherapeutics, School of Public Health, 107 Wiggins Road University of Saskatchewan, Canada; Vaccine and Infectious Disease Organization-International Vaccine Centre, 120 Veterinary Road, University of Saskatchewan, Saskatoon, S7N 5E3, Canada.
authors.forename: Sunita
authors.initials: S
authors.lastname: Awate
authors.affiliation: Vaccine and Infectious Disease Organization-International Vaccine Centre, 120 Veterinary Road, University of Saskatchewan, Saskatoon, S7N 5E3, Canada.
authors.forename: Heather L
authors.initials: HL
authors.lastname: Wilson
authors.affiliation: Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine University of Saskatchewan, S7N 5E5, Canada.
authors.forename: Baljit
authors.initials: B
authors.lastname: Singh
authors.affiliation: University of Alberta, 3-7 University Hall, Edmonton, AB, T6G 2J9, Canada.
authors.forename: Lorne A
authors.initials: LA
authors.lastname: Babiuk
authors.affiliation: Vaccinology and Immunotherapeutics, School of Public Health, 107 Wiggins Road University of Saskatchewan, Canada; Vaccine and Infectious Disease Organization-International Vaccine Centre, 120 Veterinary Road, University of Saskatchewan, Saskatoon, S7N 5E3, Canada. Electronic address: george.mutwiri@usask.ca.
authors.forename: George
authors.initials: G
authors.lastname: Mutwiri
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D007273:Injections, Intramuscular; D008198:Lymph Nodes / Q000166:cytology* / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000276:immunology; D018482:Muscle, Skeletal / Q000166:cytology* / Q000276:immunology; D022423:Myeloid Cells / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D010666:Phenylpropionates / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D010666:Phenylpropionates; D011108:Polymers; C508285:poly(bis(carboxylatoethylphenoxy)phosphazene)
keywords: Adjuvants; Draining lymph nodes; Mechanisms; Myeloid cells; PCEP; Polyphosphazenes; Recruitment