[DNA vaccine of Plasmodium falciparum: immune response of BALB/c mice induced by injection of the recombinant plasmid DNA].
OBJECTIVE
To observe the level of immune responses of BALB/c mice induced by direct injection of the recombinant plasmid DNA and to provide evidence for the application of DNA vaccine of Plasmodium falciparum (P. f.) in animals and humans.


METHODS
The recombinant plasmid pcDNA3-Pf8 encoding the hybrid antigens of PfCMR-MSP1(19) was constructed. The presence of Pf8 plasmid was detected in the muscle, liver, kidney, heart, spleen and lung by PCR. ELISA, T lymphocyte transformation test, inhibitory assay of the growth and development of P. f. in vitro were used to determine the level of humoral and Th-cell responses.


RESULTS
pcDNA3-Pf8 was amplified by PCR technique in the different tissues from BALB/c mice which were injected with pcDNA3-Pf8. The immune serum was specifically recognized by the soluble antigens of P. falciparum (titer: 1:2,560 by ELISA). The specific proliferative response of spleen T cells from immunized mice was remarkably higher than that of control group, the transformation rate being up to 32.82 +/- 3.64%. The immune serum could also inhibit the growth and development of the erythrocytic stages of P. falciparum in vitro.


CONCLUSIONS
Direct injection with the recombinant plasmid pcDNA3-Pf8 specifically elicits BALB/c mice to generate humoral and cell-mediated immune responses, the resulting immune serum being inhibitory to the growth and development of P. f. in vitro.
Li
X
X
Department of Parasitology, Sun Yat-Sen University of Medical Sciences, Guangzhou 510089.
Yu
X
X
Luo
S
S
Xu
J
J
Chen
G
G
D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics; D004274:DNA, Recombinant / Q000276:immunology*; D004912:Erythrocytes / Q000469:parasitology; D005260:Female; D007106:Immune Sera / Q000494:pharmacology; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D010963:Plasmodium falciparum / Q000235:genetics* / Q000254:growth & development; D019444:Vaccines, DNA
D000953:Antigens, Protozoan; D004274:DNA, Recombinant; D007106:Immune Sera; D019444:Vaccines, DNA