Characterization of humoral and cellular immune responses in mice induced by immunization with HIV-1 Nef regulatory protein encapsulated in poly(DL-lactide-co-glycolide) microparticles.
We have characterized the humoral and cellular immune responses of BALB/c mice immunized with HIV-1 Nef regulatory protein encapsulated in poly(DL-lactide-co-glycolide) PLG particles. Three groups of mice were immunized with Nef PLG, Nef in the presence of complete Freund's adjuvant (CFA) or Nef alone in PBS. When titers were compared 7 months after the last injection, anti-Nef titers in mice immunized with Nef PLG were still close to the maximum, whereas a significant decrease was observed in mice immunized with Nef alone (five times lower) or with Nef in CFA (three times lower). These results indicate that Nef PLG is at least a similar or better vector/adjuvant than Nef in CFA concerning the duration of the humoral immune response. The analysis of cytokine profiles (IL-5 and IL-10) and the isotypic patterns of anti-Nef antibodies (predominantly IgG1), in the three groups of mice, indicated a predominant Th2 immune response. Using synthetic peptides covering the entire sequence of Nef, we identified at least three linear epitopes within sequences 32-64, 118-167 and 185-205 in the sera of mice immunized with Nef PLG or Nef CFA. In contrast, anti-Nef antibodies against Nef alone failed to recognize synthetic peptides, indicating that the majority of anti-Nef antibodies were primarily directed against conformational epitopes. We then examined the ability of Nef PLG to prime for the antigen-specific proliferative responses in vitro. The data obtained indicate the presence of both B-cell and T-cell epitopes in the C-terminal fragment of the protein after immunization of mice with Nef encapsulated in PLG particles.
Moureau
Corinne
C
Laboratoire d'Immuno-virologie, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France.
Vidal
Pierre-Louis
PL
Bennasser
Yamina
Y
Moynier
Marinette
M
Nicaise
Yvan
Y
Aussillous
Muriel
M
Barthelemy
Sophie
S
Montagnier
Luc
L
Bahraoui
Elmostafa
E
D000818:Animals; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D005260:Female; D005620:Freund's Adjuvant / Q000494:pharmacology; D015693:Gene Products, nef / Q000008:administration & dosage / Q000276:immunology*; D015483:HIV Antibodies / Q000096:biosynthesis*; D015488:HIV Antigens / Q000008:administration & dosage / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis; D019344:Lactic Acid / Q000008:administration & dosage*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D011100:Polyglycolic Acid / Q000008:administration & dosage*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000008:administration & dosage*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D054311:nef Gene Products, Human Immunodeficiency Virus
D016207:Cytokines; D018985:Epitopes, B-Lymphocyte; D015693:Gene Products, nef; D015483:HIV Antibodies; D015488:HIV Antigens; D007074:Immunoglobulin G; D011108:Polymers; D054311:nef Gene Products, Human Immunodeficiency Virus; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D005620:Freund's Adjuvant