Comparative study of immune responses induced after immunization with plasmids encoding the HIV-1 Nef protein under the control of the CMV-IE or the muscle-specific desmin promoter.
The objective of this study was to compare immune responses induced against HIV-1 Nef after DNA immunization with Nef encoding plasmids under the control of an ubiquitous or a muscle-specific promoter. To this end, plasmids containing HIV-1 nef under the control of the Cytomegalovirus or the human desmin promoters, specifically expressed in muscle cells, were constructed. Different groups of BALB/c mice were immunized with 10 or 100 microg of both constructs, controls were the pcDNA3 vector or the Nef protein in Freund's adjuvant (Nef-CFA). Our data showed that both plasmids stimulated anti-Nef humoral responses in a dose-dependent manner. The anti-Nef antibody response, however, was earlier and higher with the CMV-IE promoter than with the desmin promoter. We also showed that Nef expressing plasmids induced high titers of anti-Nef antibodies (10(4)), comparable to those obtained in the Nef-CFA group (4x10(4)). Analysis of the specificity of anti-Nef antibodies revealed no influence of the promoter, and in contrast to Nef-CFA, plasmid immunization elicited anti-Nef antibodies directed principally against conformational-dependent epitopes. Data on the lymphoproliferative response showed that the specificity of expression, or the plasmid dose, did not affect the onset-time or the intensity of the response. The predominant IgG2a isotype of anti-Nef antibodies and the cytokine profile, mostly IL-2 and IFN-gamma, produced by Nef-stimulated spleen cells indicated a Th1 response in plasmid-immunized mice, in contrast to mice immunized with Nef-CFA, where a Th2 response was induced. In conclusion, these data indicate that antigen expression by muscle cells is sufficient to stimulate a Th1 immune response.
Cazeaux
Nicolas
N
Université Paul Sabatier, EA 3038, Laboratoire d'Immuno-Virologie, 118 Route de Narbonne, 31062 Toulouse Cedex, France.
Bennasser
Yamina
Y
Vidal
Pierre-Louis
PL
Li
Zhenlin
Z
Paulin
Denise
D
Bahraoui
Elmostafa
E
D016915:AIDS Vaccines / Q000235:genetics*; D000818:Animals; D000918:Antibody Specificity; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D003587:Cytomegalovirus / Q000235:genetics; D003893:Desmin / Q000235:genetics; D005260:Female; D015693:Gene Products, nef / Q000235:genetics* / Q000276:immunology*; D015754:Genes, nef; D015483:HIV Antibodies / Q000096:biosynthesis; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007114:Immunization; D066298:In Vitro Techniques; D007700:Kinetics; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D009132:Muscles / Q000276:immunology; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D019444:Vaccines, DNA / Q000235:genetics; D054311:nef Gene Products, Human Immunodeficiency Virus
D016915:AIDS Vaccines; D016207:Cytokines; D003893:Desmin; D015693:Gene Products, nef; D015483:HIV Antibodies; D019444:Vaccines, DNA; D054311:nef Gene Products, Human Immunodeficiency Virus