title: Delivery of MUC1 mucin peptide by Poly(d,l-lactic-co-glycolic acid) microspheres induces type 1 T helper immune responses.
abstract: Synthetic peptides corresponding to the variable tandem repeat domain of the cancer-associated antigen MUC1 mucin are candidates for cancer vaccines. In our investigation mice were immunized via subcutaneous injection with poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres containing a MUC1 mucin peptide. It was hypothesized that microencapsulation of the MUC1 mucin peptide would prime for antigen-specific Th1 responses while avoiding the need for traditional adjuvants and carrier proteins. Furthermore, an immunomodulator, monophosphoryl lipid A (MPLA), was incorporated into the peptide-loaded PLGA microspheres based on its ability to enhance Th1 responses. The results revealed T cell specific immune responses. The cytokine secretion profiles of the T cells consisted of high levels of interferon-gamma with undetectable levels of interleukin-4 and interleukin-10. Moreover, incorporation of MPLA in the MUC1 peptide-loaded PLGA microspheres resulted in an increase in interferon-gamma production. The antibody response was negative for IgM and IgG in the absence of MPLA; however, in the presence of MPLA antibody production was negative for IgM with a minimal IgG response consisting of IgG2a, IgG2b, and IgG3. Based on the antibody and cytokine profiles, it was concluded that MUC1 mucin peptide-loaded PLGA microspheres are capable of eliciting specific Th1 responses, which may be enhanced through the use of MPLA.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton Alberta, Canada.
authors.forename: K D
authors.initials: KD
authors.lastname: Newman
authors.forename: D L
authors.initials: DL
authors.lastname: Sosnowski
authors.forename: G S
authors.initials: GS
authors.lastname: Kwon
authors.forename: J
authors.initials: J
authors.lastname: Samuel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004337:Drug Carriers; D016503:Drug Delivery Systems; D005260:Female; D019344:Lactic Acid; D051379:Mice; D008810:Mice, Inbred C57BL; D008863:Microspheres; D008969:Molecular Sequence Data; D018396:Mucin-1; D009842:Oligopeptides / Q000008:administration & dosage* / Q000276:immunology; D010446:Peptide Fragments; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D004337:Drug Carriers; C116055:MUC1 tandem repeat peptide; D018396:Mucin-1; D009842:Oligopeptides; D010446:Peptide Fragments; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid