Fruit-specific expression of the human immunodeficiency virus type 1 tat gene in tomato plants and its immunogenic potential in mice.
The human immunodeficiency virus type 1 (HIV-1) Tat protein is considered a potential candidate vaccine antigen. In an effort to design a strategy for noninvasive vaccination against HIV-1, we developed transgenic tomatoes expressing the Tat protein. Two independent plants testing positive in transgene detection analysis were selected and grown to maturity. Monoclonal antibodies against Tat recognized a protein of the expected size. Interestingly, expression of Tat seemed to be toxic to the plant, as in all cases the fruit exhibited underdeveloped reproductive structures and no seeds. Nine groups of 10 pathogen-free BALB/c male mice were primed either orally, intraperitoneally, or intramuscularly with 10 mg of tomato fruit extract derived from transgenic or wild-type plants and with 10 microg of Tat86 recombinant protein. Mice were immunized at days 0, 14, and 28, and given boosters after 15 weeks; sera were drawn 7 days after each booster, and the antibody titer was determined by enzyme-linked immunosorbent assay. All three immunization approaches induced the development of a strong anti-Tat immunological response, which increased over time. Isotype subclass determination showed the presence of mucosal (immunoglobulin A) immunity soon after the beginning of the oral immunization protocol, and the data were confirmed by the presence of anti-Tat antibodies in fecal pellets and in vaginal washes. We also demonstrated that sera from immunized mice inhibited with high efficiency recombinant Tat-dependent transactivation of the HIV-1 long terminal repeat promoter. This neutralization activity might be relevant for the suppression of extracellular Tat activities, which play an important role in HIV disease development.
Ramírez
Yuri Jorge Peña
YJ
Departamento de Ingeniería Genética, Cinvestav Campus Guanajuato, Irapuato, Km 9.6 Libramiento norte, Apartado Postal 629, Irapuato, Gto., México 365002.
Tasciotti
Ennio
E
Gutierrez-Ortega
Abel
A
Donayre Torres
Alberto J
AJ
Olivera Flores
María Teresa
MT
Giacca
Mauro
M
Gómez Lim
Miguel Angel
MA
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005638:Fruit / Q000276:immunology / Q000378:metabolism*; D015696:Gene Products, tat; D005982:Glutathione Transferase / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007273:Injections, Intramuscular; D018551:Solanum lycopersicum / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D013047:Specific Pathogen-Free Organisms; D013997:Time Factors; D014611:Vaccination; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D011994:Recombinant Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; D005982:Glutathione Transferase