Monoclonal antibodies against nucleoside triphosphate hydrolase-II can reduce the replication of Toxoplasma gondii.
Nucleoside triphosphate hydrolase (NTPase) is an abundant protein secreted by the obligate protozoan parasite Toxoplasma gondii, which has a wide specificity toward NTP. In the present study, two monoclonal antibodies (mAbs, MNT1 and MNT2) against recombinant T. gondii NTPase-II (rTgNTPase-II) were developed. Western blot analysis displayed that these two mAbs can recognize specifically rTgNTPase-II as well as a 63kDa molecule in tachyzoites soluble antigens that corresponded to native NTPase-II. T. gondii tachyzoites pretreated with two mAbs were observed under Confocal Laser Microscope and a specific reaction was displayed on tachyzoites after indirect fluorescence antibody test (IFAT). When COS-7 cells were co-cultured with tachyzoites pretreated with two mAbs, the number of intracellular parasites per infected cell was significantly decreased compared with the control. Furthermore, incubation of T. gondii tachyzoites with two mAbs can inhibit NTPase activity in the presence of dithiothreitol, which hinted that the reduction of tachyzoite replication might be owing to the inhibition of NTPase-II by the mAbs. The passive immunization test indicated that the transferred mAbs can significantly prolong the survival time of challenge infected mice. Taken together, we concluded that the mAbs against NTPase-II can reduce the replication of T. gondii and have a crucial effect on the protection of host from T. gondii infection.
Tan
Feng
F
Department of Parasitology, School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, PR China.
Hu
Xin
X
Pan
Chang-Wang
CW
Ding
Jie-Qiong
JQ
Chen
Xiao-Guang
XG
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000276:immunology*; D019556:COS Cells; D002522:Chlorocebus aethiops; D005260:Female; D007116:Immunization, Passive; D051379:Mice; D008807:Mice, Inbred BALB C; D043583:Nucleoside-Triphosphatase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014122:Toxoplasma / Q000201:enzymology / Q000254:growth & development* / Q000276:immunology / Q000472:pathogenicity; D014124:Toxoplasmosis, Animal / Q000276:immunology* / Q000401:mortality* / Q000469:parasitology
D000911:Antibodies, Monoclonal; D011994:Recombinant Proteins; D043583:Nucleoside-Triphosphatase