RESUMEN
Cysteine-cysteine chemokine receptor type 5 (CCR5) is an important co-receptor for human immunodeficiency virus (HIV) infection and CCR5 neutralizing agents have proven efficient in patients suffering from HIV infection. Here, we expressed and purified various CCR5 vaccines named rCCR5, PADRE-rCCR5, GST-C1 and GST-C2 composed of different epitopes of CCR5. Results showed that vaccines containing multiple epitopes (rCCR5 and PADRE-rCCR5) induced stronger immune responses than single-epitope ones (GST-C1 and GST-C2). In addition, the elicited antibodies can specifically bind CCR5(+) U937 but not CCR5(-) Wish cells. These results demonstrate that the CCR5 vaccines are useful for further research, especially for the in vitro preclinical evaluation of their potential as biological CCR5 neutralizing agents.
Asunto(s)
Vacunas contra el SIDA/genética , Vacunas contra el SIDA/uso terapéutico , Infecciones por VIH/prevención & control , VIH-1/inmunología , Receptores CCR5/genética , Receptores CCR5/uso terapéutico , Vacunas contra el SIDA/química , Vacunas contra el SIDA/inmunología , Secuencia de Aminoácidos , Animales , Formación de Anticuerpos , Células 3T3 BALB , Secuencia de Bases , Línea Celular , Clonación Molecular , Epítopos/química , Epítopos/genética , Epítopos/inmunología , Epítopos/uso terapéutico , Escherichia coli/genética , Infecciones por VIH/inmunología , Humanos , Ratones , Datos de Secuencia Molecular , Plásmidos/genética , Receptores CCR5/química , Receptores CCR5/inmunología , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/uso terapéuticoRESUMEN
Cystein-Cystein type chemokine receptor 5 (CCR5) is a seven-transmembrane, G-protein coupled receptor. It is a major coreceptor with CD4 glycoprotein mediating cellular entry of CCR5 strains of HIV-1. A lack of cell-surface expression of CCR5 found in the homozygous Delta32 CCR5 mutation, upregulation of CC chemokines and antibodies to CCR5 are associated with resistance to HIV infection. In addition, CCR5 can be blocked by three CC chemokines and antibodies to three extracellular domains of CCR5. Consequently, CCR5 is considered an attractive therapeutic target against HIV infection. In the current study, we constructed a recombinant vaccine by coupling a T helper epitope AKFVAAWTLKAA (PADRE) to the N terminus of CCR5 extracellular domains (PADRE-CCR5) and expressed this protein in Escherichia coli. We have developed an inexpensive and scalable purification process for the fusion protein from inclusion bodies and the final yields of 6mg purified fusion protein per gram of cell paste was obtained. The immunogenicity of the recombinant vaccine generated was examined in BALB/c mice. Sera from the vaccinated mice demonstrated high-titer specific antibodies to the recombinant vaccine, suggesting that PADRE-rCCR5 may be used as a candidate of active CCR5 vaccine.
