Immunogenicity of the Lyme disease antigen OspA, particleized by cobalt porphyrin-phospholipid liposomes

Vaccine. 2020 Jan 22;38(4):942-950. doi: 10.1016/j.vaccine.2019.10.073. Epub 2019 Nov 11.


Outer surface protein A (OspA) is a Borrelia lipoprotein and an established Lyme disease vaccine target. Admixing non-lipidated, recombinant B. burgdorferi OspA with liposomes containing cobalt porphyrin-phospholipid (CoPoP) resulted in rapid, particulate surface display of the conformationally intact antigen. Particleization was serum-stable and led to enhanced antigen uptake in murine macrophages in vitro. Mouse immunization using CoPoP liposomes that also contained a synthetic monophosphoryl lipid A (PHAD) elicited a Th1-biased OspA antibody response with higher IgG production compared to other vaccine adjuvants. Antibodies were reactive with intact B. burgdorferi spirochetes and Borrelia lysates, and induced complement-mediated borreliacidal activity in vitro. One year after initial immunization, mice maintained high levels of circulating borreliacidal antibodies capable of blocking B. burgdorferi transmission from infected ticks to human blood in a feeding chamber.

Keywords: Adjuvant; Liposomes; Lyme disease; OspA; Particle vaccine.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antibody Formation / immunology
  • Antigens, Surface / immunology*
  • Bacterial Outer Membrane Proteins / immunology*
  • Bacterial Vaccines / immunology*
  • Cobalt / chemistry
  • Female
  • Immunogenicity, Vaccine
  • Lipoproteins / immunology*
  • Liposomes
  • Lyme Disease / immunology
  • Lyme Disease / prevention & control*
  • Lyme Disease Vaccines / administration & dosage*
  • Lyme Disease Vaccines / immunology
  • Macrophages / immunology
  • Mice
  • Mice, Inbred ICR
  • Phospholipids / chemistry
  • Porphyrins / chemistry
  • Time Factors
  • Vaccination*


  • Antigens, Surface
  • Bacterial Outer Membrane Proteins
  • Bacterial Vaccines
  • Lipoproteins
  • Liposomes
  • Lyme Disease Vaccines
  • OspA protein
  • Phospholipids
  • Porphyrins
  • Cobalt