[Enhancement of herpes simplex virus-1 glycoprotein-D DNA vaccine induced specific immune responses by coimmunization with interleukin-2 genetic adjuvant].
OBJECTIVE
To investigate the immune responses and protection from virus challenge, induced by the coinjection of IL-2cDNA with herpes simplex virus type 1 (HSV-1) glycoprotein-D (gD) DNA vaccine.


METHODS
Two DNA vaccines (pgD and pIL-2) were constructed by inserting the gD gene and IL-2 cDNA into the eukaryotic expression vector pcDNA3.1, respectively. The BALB/c mice were inoculated intramuscularly three times at 2-week intervals. Two weeks after the final immunization, mice were bled for antibody assay and spleen cells were separated for Th cell proliferation and cytokine assays. Delayed type hypersensitivity (DTH) response was detected by the pinna-swelling test. Corneal protection under HSV-1 virus challenge was continuously observed with slit-lamp microscope.


RESULTS
IL-2 cDNA coinjection remarkably enhanced the specific IgG2a level when compared with gD plasmid vaccination alone. Th cell proliferation and secretion of cytokines (IL-2 and IFN-gamma) were significantly increased by IL-2 cDNA coinjection. However, the production of IL-10 was inhibited. The DTH response was also enhanced by IL-2 coinjection. When the mice were challenged with HSV-1, the cornea epithelial lesions were significantly alleviated by IL-2 coinjection as compared with gD vaccination alone.


CONCLUSIONS
IL-2 cDNA can enhance both the humoral and cellular immune responses, and thus increase the vaccine potency.
Liu
Xiao-juan
XJ
Department of Biophysics, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China.
Zhu
Ming-zhao
MZ
Song
Guo-xing
GX
Xu
Yu-fei
YF
Liu
Hong-wei
HW
Wang
Sheng
S
Yang
Bao-ling
BL
Dong
Fang-tian
FT
Xu
Xue-mei
XM
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D019556:COS Cells; D049109:Cell Proliferation; D002522:Chlorocebus aethiops; D004247:DNA / Q000235:genetics; D005260:Female; D018259:Herpesvirus 1, Human / Q000472:pathogenicity; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000097:blood; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D011897:Random Allocation; D018417:Th1 Cells / Q000166:cytology; D014162:Transfection; D019444:Vaccines, DNA / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics*; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007376:Interleukin-2; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C039447:glycoprotein D, Human herpesvirus 1; D007371:Interferon-gamma; D004247:DNA