Recombinant Semliki Forest virus vectors encoding hepatitis B virus small surface and pre-S1 antigens induce broadly reactive neutralizing antibodies.
J Viral Hepat
; 19(9): 664-73, 2012 Sep.
Article
en En
| MEDLINE
| ID: mdl-22863271
ABSTRACT
Most hepatitis B virus (HBV) vaccines consist of viral small surface (S) protein subtype adw2 expressed in yeast cells. In spite of good efficacy, HBV-genotype and subtype differences, escape mutants and insufficient Th1 activation remain potential problems. To address these problems, we generated recombinant Semliki Forest virus (rSFV) vectors encoding S protein, subtype adw2 or ayw2, or a fragment of the large surface protein, amino acids 1-48 of the pre-S1 domain, fused to S (pre-S1.1-48/S). The antigen loop in S protein and the selected pre-S1 sequences are known targets of neutralizing antibodies. BALB/c mice were immunized intravenously with 10(7) rSFV particles and 10(8) rSFV particles 3 weeks later. Antibodies induced by rSFV encoding S proteins reacted preferentially with subtype determinants of yeast-derived S antigen but equally well with patient-derived S antigen. Immunization with rSFV encoding pre-S1.1-48/S resulted in formation of pre-S1- and S-specific immunoglobulin G (IgG), while immunization with the isogenic mutant without S start codon induced pre-S1 antibodies only. Neutralizing antibodies were determined by mixing with plasma-derived HBV/ayw2 and subsequent inoculation of susceptible primary hepatocyte cultures from Tupaia belangeri. S/adw2 antisera neutralized HBV/ayw2 as effectively as antisera raised with S/ayw2. The pre-S1 antibodies also completely neutralized HBV infectivity. The IgG1/IgG2a ratios ranged from 0.28 to 0.88 in the four immunized groups and were lowest for the pre-S1.1-48/S vector, indicating the strongest Th1 response. This vector type may induce subtype-independent and S-escape-resistant neutralizing antibodies against HBV.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Precursores de Proteínas
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Virus de los Bosques Semliki
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Portadores de Fármacos
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Vacunas contra Hepatitis B
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Anticuerpos Neutralizantes
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Vectores Genéticos
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Antígenos de la Hepatitis B
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Antígenos de Superficie de la Hepatitis B
Límite:
Animals
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Female
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Humans
Idioma:
En
Revista:
J Viral Hepat
Asunto de la revista:
GASTROENTEROLOGIA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Alemania