Upregulation of surface proteins in Leishmania donovani isolated from patients of post kala-azar dermal leishmaniasis.
Five to fifteen percent of visceral leishmaniasis (VL) patients in India develop post kala-azar dermal leishmaniasis (PKDL), usually 1-2 years after apparent clinical cure. There is evidence pointing to a role played by the host immune responses in the disease pathogenesis, however, the contribution of changes in parasite gene expression has not been explored. Highly sensitive gene expression microarray technology was employed to identify genes that are differentially expressed in Leishmania parasites isolated from PKDL patients in comparison with those from VL. Hybridization on Leishmania donovani genomic microarray comprised of unique clones allowed us to identify 46/2268 (2%) clones that showed statistically significant (P<0.05) changes in expression (1.5-3.5-fold) in parasites of PKDL origin compared to those of VL origin. Sequence analysis of six genomic clones, consistently showing approximately 2-fold higher expression in PKDL parasites, revealed significant homology with gp63, gp46, putative amastin, a putative reductase and a possible calpain-like protein. The gene products showing upregulated expression in PKDL isolates may be candidates playing a role in the altered clinical manifestation in PKDL. Such differentially expressed genes hold the key to understanding the parasite genetic factors that contribute to the persistence after clinical cure of VL.
Molecular Biology Laboratory, Institute of Pathology (ICMR), Safdarjung Hospital Campus, New Delhi, India. salotra@vsnl.com
Poonam
P
Salotra
Robert C
RC
Duncan
Ruchi
R
Singh
B V
BV
Subba Raju
Gannavaram
G
Sreenivas
Hira L
HL
Nakhasi
D000595:Amino Acid Sequence; D000818:Animals; D020869:Gene Expression Profiling; D006790:Host-Parasite Interactions; D006801:Humans; D007194:India / Q000453:epidemiology; D007893:Leishmania donovani / Q000302:isolation & purification* / Q000378:metabolism*; D007898:Leishmaniasis, Visceral / Q000453:epidemiology / Q000469:parasitology*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D008565:Membrane Proteins; D015800:Protozoan Proteins