A mouse model based on replication-competent Tiantan vaccinia expressing luciferase/HIV-1 Gag fusion protein for the evaluation of protective efficacy of HIV vaccine.
BACKGROUND
Developing an effective vaccine against human immunodeficiency virus type 1 (HIV-1) remains a grand challenge after more than two decades of intensive effort. It is partially due to the lack of suitable animal models for screening and prioritizing vaccine candidates. In this study, we aim to develop a mice model to test HIV-1 vaccine efficacy.


METHODS
We constructed a recombinant vaccinia expressing firefly luciferase and HIV-1 Gag fusion protein based on Tiantan strain, an attenuated but replication-competent poxvirus (rTTV-lucgag). By quantifying the luciferase activity as its read out, we defined the biodistribution of Tiantan strain poxvirus in mice inoculated intraperitoneally and attempted to apply this model to evaluate the HIV-1 vaccine efficacy.


RESULTS
Our data demonstrated that the rTTV-lucgag was able to express high level of luciferase (< or = 10(6) relative luciferase units (RLU)/mg protein) and HIV-1 Gag (> 3 folds increase comparing to the control). After intraperitoneal inoculation, this virus had dominant replication in the ovary, uterus, and cervix of mice and the luciferase activities in those organs are significantly correlated with viral titers (r(2) = 0.71, P < 0.01). Pre-immunization with an HIV gag DNA vaccine reduced the luciferase activity in ovary from (6006 +/- 3141) RLU/mg protein in control group to (1538 +/- 463) RLU/mg protein in vaccine group (P = 0.1969).


CONCLUSIONS
The luciferase activity in ovary could represent viral replication in vivo; this rTTV-lucgag/mice model may be suitable to assess the protective efficacy of cytotoxic T-cell responses to HIV Gag with less tedious work and high through-put.
Huang
Yang
Y
National Center for AIDS/STD Control and Prevention, Beijing China.
Qiu
Chao
C
Liu
Lian-xing
LX
Feng
Yan-meng
YM
Zhu
Ting
T
Xu
Jian-qing
JQ
D016915:AIDS Vaccines / Q000235:genetics*; D000818:Animals; D005260:Female; D015658:HIV Infections / Q000276:immunology / Q000517:prevention & control; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D008156:Luciferases / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011212:Poxviridae / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication / Q000235:genetics; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics*
D016915:AIDS Vaccines; D011994:Recombinant Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; D008156:Luciferases