title: [Protective immune responses induced by a recombinant Listeria monocytogenes delivering HPV16 E7].
abstract: OBJECTIVE
  To investigate specific immune responses elicited by a recombinant Listeria monocytogenes strain LM4 deltahly::E7 and assess protective effect in C57BL/6 mice.
  
  
  METHODS
  C57BL/6 mice were intraperitoneally immunized with LM4 deltahly:: E7 at 1-week intervals. After the second immunization, cellular immunity elicited by this recombinant L. monocytogenes strain was analyzed via an ELISPOT assay, Cytotoxic T lymphocytes (CTL) measurement assay and analysis of effector T cells proportion in the splenocytes. Also, the serum antibodies against HPV16 E7 protein were determined in an ELISA assay. Finally, protective effect was assessed against the challenge with TC-1 tumor cells.
  
  
  RESULTS
  The immune responses elicited by LM4 deltahly::E7 were biased towards Th1 type in the ELISPOT assay. Also, LM4 deltahly::E7 was able to induce E7-specific CTL activity, with average specific lysis of 72%, which was highly significant difference compared with the controls (P<0.01). Moreover, the proportion of effector T cells in the spleens were increased in mice immunized with recombinant L. monocytogenes strain (P<0.05). The titer of E7-specific antibodies in mice immunized with LM4 delta hly::E7 was 1:400 in the ELISA assay. Furthermore, immunization with LM deltahly::E7 protected all mice against the lethal tumor cell challenge.
  
  
  CONCLUSIONS
  The data suggest that attenuated Listeria monocytogenes delivering HPV16 E7 antigen could induce both E7-specific cell mediated immunity and humoral immunity, and had a protective effect against challenge with TC-1 tumor cells.
authors: Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu 225009, China. jiayanyan0120@163.com
authors: Yanyan
authors: Y
authors: Jia
authors: Yuelan
authors: Y
authors: Yin
authors: Weijun
authors: W
authors: Tan
authors: Hong
authors: H
authors: Fu
authors: Xiang
authors: X
authors: Chen
authors: Zhiming
authors: Z
authors: Pan
authors: Xin'an
authors: X
authors: Jiao
mesh_terms: D000818:Animals; D016207:Cytokines / Q000276:immunology; D005260:Female; D052162:Human papillomavirus 16 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007114:Immunization; D008089:Listeria monocytogenes / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D050725:Papillomavirus E7 Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D030361:Papillomavirus Infections / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control
chemical_list: D016207:Cytokines; D050725:Papillomavirus E7 Proteins; C059731:oncogene protein E7, Human papillomavirus type 16