Efficient secretion of a modified E7 protein from human papilloma virus type-16 by Lactococcus lactis.
OBJECTIVE
To create and provide a strain of the food-grade bacterium Lactococcus lactis able to efficiently secrete a modified form of the E7 protein from the human papilloma virus (HPV) type-16.


RESULTS
We cloned the coding sequence of a modified E7 (E7m) from the HPV-16 in a plasmid regulated by the strong expression promoter p59. Secretion of the E7m was made by the signal peptide of the usp45 gene. The E7m was detected by Western blot in the cell-free-medium fraction, showing no degradation or aberrant forms.


CONCLUSIONS
We constructed a strain of L. lactis able to secrete efficiently a HPV-16 E7 modified protein with diminished transforming activity.


CONCLUSIONS
Human papilloma virus infection is associated with more than 99% of cervical cancers. Immunotherapy targeting E7 to treat HPV-associated cervical malignancies has been demonstrated to be highly efficient. However, native E7 maintains transforming activity. We present this new strain of a food-grade bacterium able to efficiently secrete a HPV-16 E7-modified protein with diminished transforming activity. This new strain could be used as a live vaccine to deliver E7 at a mucosal level and generate antitumour immune responses against HPV-associated tumours.
Quistián-Martínez
D
D
Departamento de Bioquímica, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León (UANL), San Nicolás de los Garza, N.L. México  
Villatoro-Hernández
J
J
Loera-Arias
M J
MJ
Rangel-Colmenero
B R
BR
Zavala-Flores
L M
LM
Sepúlveda-Saavedra
J
J
Guzmán-López
S
S
Elizondo-Omaña
R E
RE
Montes-de-Oca-Luna
R
R
Saucedo-Cárdenas
O
O
D000970:Antineoplastic Agents / Q000378:metabolism*; D015153:Blotting, Western; D005260:Female; D005786:Gene Expression Regulation; D052162:Human papillomavirus 16 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D013294:Lactococcus lactis / Q000235:genetics / Q000378:metabolism*; D050725:Papillomavirus E7 Proteins / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals
D000970:Antineoplastic Agents; D050725:Papillomavirus E7 Proteins; D021382:Protein Sorting Signals; C059731:oncogene protein E7, Human papillomavirus type 16