Type I signal peptidase from Leishmania is a target of the immune response in human cutaneous and visceral leishmaniasis.
The gene encoding type I signal peptidase (Lmjsp) has been cloned from Leishmania major. Lmjsp encodes a protein of 180 amino residues with a predicted molecular mass of 20.5 kDa. Comparison of the protein sequence with those of known type I signal peptidases indicates homology in five conserved domains A-E which are known to be important, or essential, for catalytic activity. Southern blot hybridisation analysis indicates that there is a single copy of the Lmjsp gene. A recombinant SPase protein and a synthetic peptide of the L. major signal peptidase were used to examine the presence of specific antibodies in sera from either recovered or active individuals of both cutaneous and visceral leishmaniasis. This evaluation demonstrated that sera from cutaneous and visceral forms of leishmaniasis are highly reactive to both the recombinant and synthetic signal peptidase antigens. Therefore, the Leishmania signal peptidase, albeit localised intracellularly, is a significant target of the Leishmania specific immune response and highlights its potential use for serodiagnosis of cutaneous and visceral leishmaniasis.
Department of Immunology, Pasteur Institute of Iran, P.O. Box 11365-6699, Tehran, Iran. s_rafat@yahoo.com
Sima
S
Rafati
Ali-Hatef
AH
Salmanian
Tahere
T
Taheri
Slavica
S
Masina
Cedric
C
Schaff
Yasaman
Y
Taslimi
Nicolas
N
Fasel
D000293:Adolescent; D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D020134:Catalytic Domain; D002648:Child; D002675:Child, Preschool; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D018628:Gene Dosage; D017125:Genes, Protozoan; D006801:Humans; D007223:Infant; D018320:Leishmania major / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016773:Leishmaniasis, Cutaneous / Q000175:diagnosis / Q000276:immunology* / Q000469:parasitology; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000276:immunology* / Q000469:parasitology; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D008565:Membrane Proteins; D012697:Serine Endopeptidases; C026515:type I signal peptidase