Open AccessImmunogenicity of chloroplast‐derived HIV‐1 p24 and a p24‐Nef fusion protein following subcutaneous and oral administration in mice
Author(s) -
GonzalezRabade Nuria,
McGowan Edward G.,
Zhou Fei,
McCabe Matthew S.,
Bock Ralph,
Dix Philip J.,
Gray John C.,
Ma Julian KC.
Publication year - 2011
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2011.00609.x
Subject(s) - immunogenicity , biology , fusion protein , antigen , cholera toxin , protein subunit , virology , escherichia coli , microbiology and biotechnology , immunology , recombinant dna , biochemistry , gene
Summary High‐level expression of foreign proteins in chloroplasts of transplastomic plants provides excellent opportunities for the development of oral vaccines against a range of debilitating or fatal diseases. The HIV‐1 capsid protein p24 and a fusion of p24 with the negative regulatory protein Nef (p24‐Nef) accumulate to ∼4% and ∼40% of the total soluble protein of leaves of transplastomic tobacco ( Nicotiana tabacum L.) plants. This study has investigated the immunogenicity in mice of these two HIV‐1 proteins, using cholera toxin B subunit as an adjuvant. Subcutaneous immunization with purified chloroplast‐derived p24 elicited a strong antigen‐specific serum IgG response, comparable to that produced by Escherichia coli ‐derived p24. Oral administration of a partially purified preparation of chloroplast‐derived p24‐Nef fusion protein, used as a booster after subcutaneous injection with either p24 or Nef, also elicited strong antigen‐specific serum IgG responses. Both IgG1 and IgG2a subtypes, associated with cell‐mediated Th1 and humoral Th2 responses, respectively, were found in sera after subcutaneous and oral administration. These results indicate that chloroplast‐derived HIV‐1 p24‐Nef is a promising candidate as a component of a subunit vaccine delivered by oral boosting, after subcutaneous priming by injection of p24 and/or Nef.