Humoral and cellular immune responses to glucose regulated protein 78 -- a novel Leishmania donovani antigen.
The recently cloned glucose regulated protein 78 (GRP78) of Leishmania donovani has been suggested as a new and promising Leishmania vaccine candidate. We assessed antibody and T-cell reactivity to GRP78 in an enzyme-linked immunosorbent assay (ELISA) and in lymphoproliferative assays. Serological evaluation of plasma samples obtained in Sudan revealed that 89% of patients with visceral leishmaniasis (VL), 78% with post kala-azar dermal leishmaniasis (PKDL), and 85% with cutaneous leishmaniasis (CL) had antibody reactivity to this Leishmania antigen. Plasma from healthy Sudanese individuals living in an area endemic for malaria but free of leishmaniasis and plasma from healthy Danes was negative in the assay. GRP78 antibody was detected in 10% and 5% of plasma samples from Sudanese and Ghanaian malaria patients, respectively, whereas 35% of plasma samples from otherwise healthy Sudanese individuals with a positive leishmanin skin test showed antibody reactivity to recombinant GRP78 (rGRP78). In lymphoproliferative assays, 9 of 13 isolates of peripheral blood mononuclear cells (PBMC) from individuals previously infected with L. donovani and one of three individuals previously infected with L. major showed a response to rGRP78, whereas PBMC isolates from Danish control individuals did not respond. These findings, in addition to our previous observations in experimental CL (Jensen et al. 2001), confirm GRP78 as a possible vaccine antigen.
Jensen
Anja T R
AT
Centre for Medical Parasitology, Institute for Medical Microbiology and Immunology, University of Copenhagen, Denmark. parasite@biobase.dk
Ismail
Ahmed
A
Gaafar
Ameera
A
El Hassan
Ahmed M
AM
Theander
Thor G
TG
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology*; D000953:Antigens, Protozoan / Q000097:blood / Q000276:immunology*; D002352:Carrier Proteins / Q000097:blood / Q000276:immunology*; D002469:Cell Separation; D003429:Cross Reactions / Q000276:immunology; D019353:Endemic Diseases; D000091342:Endoplasmic Reticulum Chaperone BiP; D004797:Enzyme-Linked Immunosorbent Assay; D005869:Ghana / Q000453:epidemiology; D006360:Heat-Shock Proteins; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007893:Leishmania donovani / Q000276:immunology*; D008288:Malaria / Q000097:blood / Q000453:epidemiology / Q000276:immunology; D018832:Molecular Chaperones / Q000097:blood / Q000276:immunology*; D011994:Recombinant Proteins / Q000097:blood / Q000276:immunology; D013397:Sudan / Q000453:epidemiology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D007074:Immunoglobulin G; D018832:Molecular Chaperones; D011994:Recombinant Proteins