Approaches for the identification of potential excreted/secreted proteins of Leishmania major parasites.
Leishmania parasites are able to survive in host macrophages despite the harsh phagolysosomal vacuoles conditions. This could reflect, in part, their capacity to secrete proteins that may play an essential role in the establishment of infection and serve as targets for cellular immune responses. To characterize Leishmania major proteins excreted/secreted early after promastigote entry into the host macrophage, we have generated antibodies against culture supernatants of stationary-phase promastigotes collected 6 h after incubation in conditions that partially reproduce those prevailing in the parasitophorous vacuole. The screening of an L. major cDNA library with these antibodies led us to isolate 33 different cDNA clones that we report here. Sequence analysis revealed that the corresponding proteins could be classified in 3 groups: 9 proteins have been previously described as excreted/secreted in Leishmania and/or other species; 11 correspond to known proteins already characterized in Leishmania and/or other species although it is unknown whether they are excreted/secreted and 13 code for unknown proteins. Interestingly, the latter are transcribed as shown by RT-PCR and some of them are stage regulated. The L. major excreted/secreted proteins may constitute putative virulence factors, vaccine candidates and/or new drug targets.
Chenik
M
M
WHO Collaborating Center for Research and Training in Leishmaniasis, Laboratoire d'Immunopathologie, Vaccinologie et Génétique Moléculaire, Institut Pasteur de Tunis, 13, Place Pasteur 1002 Tunis-Belvédére, Tunisia. mehdi.chenik@pasteur.rns.tn
Lakhal
S
S
Ben Khalef
N
N
Zribi
L
L
Louzir
H
H
Dellagi
K
K
D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000032:analysis; D015153:Blotting, Western / Q000379:methods; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D020869:Gene Expression Profiling / Q000379:methods; D015723:Gene Library; D006801:Humans; D007158:Immunologic Techniques; D007553:Isotope Labeling; D018320:Leishmania major / Q000502:physiology*; D008969:Molecular Sequence Data; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000145:classification* / Q000302:isolation & purification* / Q000378:metabolism; D011817:Rabbits; D011868:Radioisotopes; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D017931:DNA Primers; D015800:Protozoan Proteins; D011868:Radioisotopes; D019704:Protein Disulfide-Isomerases