Biochemical and biological characterization of the protective Leishmania pifanoi amastigote antigen P-8

Infect Immun. 2001 Nov;69(11):6776-84. doi: 10.1128/IAI.69.11.6776-6784.2001.

Abstract

The Leishmania pifanoi amastigote antigen P-8 has been previously shown to induce protective immunity in a murine model of cutaneous leishmaniasis (L. Soong, S. M. Duboise, P. Kima, and D. McMahon-Pratt, Infect. Immun. 63:3559-3566, 1995). As this antigen is of interest for further vaccine studies, the biochemical characterization of P-8 was undertaken. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western-blot analysis, and gel filtration chromatography revealed that P-8 antigen consisted of two proteoglycolipid complexes. The P-8 epitope is associated with the L. pifanoi amastigote-specific glycolipid components found in the two complexes. The P-8 complex 1 (P-8c1) consists of a 56-kDa serine metalloproteinase, apolipoprotein E (derived from fetal bovine serum), and amastigote-specific glycolipids. The P-8 complex 2 (P-8c2) consists of a 31-kDa cysteine proteinase associated with amastigote glycolipids. Biochemical analyses suggest that the P-8 antigenic glycolipids may be distinct from previously described Leishmania glycolipids (glycosylinositol-phospholipids and sphingoglycolipids). Protective immunity studies revealed that P-8c1 (serine metalloproteinase-glycolipid complex) confers comparable protection against infection as immunopurified P-8. The isolated P-8c2 (cysteine proteinase-glycolipid complex) does not provide significant protection, nor does stimulation with P-8c2 result in significant T-cell activation in P-8- or P-8c2-vaccinated mice. Consequently, the P-8c1 complex appears to be the immunodominant component of P-8.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Protozoan / analysis*
  • Antigens, Protozoan / immunology
  • Female
  • Glycolipids / analysis
  • Glycolipids / immunology
  • Leishmania / immunology*
  • Membrane Proteins / analysis*
  • Membrane Proteins / immunology
  • Mice
  • Mice, Inbred BALB C
  • Proteolipids / analysis
  • Proteolipids / immunology
  • Protozoan Proteins / analysis*
  • Protozoan Proteins / immunology
  • Protozoan Vaccines / immunology

Substances

  • Antigens, Protozoan
  • Glycolipids
  • Membrane Proteins
  • Proteolipids
  • Protozoan Proteins
  • Protozoan Vaccines
  • proteoglycolipids