Antibody response to HER2 extracellular domain and subdomains in mouse following DNA immunization.
Human epidermal growth factor receptor 2 (HER2) is overexpressed in 15-20 % of breast cancer patients and is an appropriate target for immunotherapy in these patients. Monoclonal antibodies (mAbs) specific to HER2 are currently applied to treat breast cancer patients with HER2 overexpression. Active immunization with HER2 DNA or protein has been considered as a suitable alternative. The aim of this study is to evaluate anti-HER2 antibody response in serum of mice immunized with DNA constructs containing full extracellular domain (fECD) or subdomains of human HER2. Four extracellular subdomains and also fECD of HER2 were cloned into pCMV6-Neo vector. Different groups of Balb/C mice were immunized with HER2 DNA constructs and boosted with HER2 recombinant protein. The anti-HER2 antibody was subsequently determined by ELISA, flow cytometry, and immunohistochemistry. Anti-HER2 antibody was detected only in serum of mice immunized with fECD DNA. None of HER2 extracellular subdomains induced appreciable levels of anti-HER2 antibody. However, boosting with fECD or extracellular subdomain III (DIII) recombinant protein resulted in enhanced anti-HER2 fECD as well as anti-HER2 subdomain antibody responses. In this regard, almost all (99 %) of HER2-overexpressing BT474 cells could be detected by serum antibody from mice immunized with HER2 subdomain DNA and boosted with recombinant HER2 protein by flow cytometry. Similarly, serum of mice immunized with DIII DNA construct and boosted with recombinant DIII protein could also recognize these cells, but to a lesser extent (50 %). Our findings suggest that combination of HER2 DNA and protein immunization could effectively induce anti-HER2 antibody response in Balb/C mice.
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.|Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Fateme
F
Sadri-Ardalani
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. m.shabani@avicenna.ac.ir.
Mahdi
M
Shabani
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
Mohammad Mehdi
MM
Amiri
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
Motahareh
M
Bahadori
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
Shaghayegh
S
Emami
Department of Pathology, Khatam Al Anbia Hospital, Tehran, Iran.
Ali Reza
AR
Sarrafzadeh
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
Farzaneh
F
Noutash-Haghighat
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
Mahmood
M
Jeddi-Tehrani
Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. fshokri@tums.ac.ir.|Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. fshokri@tums.ac.ir.
Fazel
F
Shokri
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation; D001943:Breast Neoplasms / Q000276:immunology / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology*; D017931:DNA Primers / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D005822:Genetic Vectors; D006801:Humans; D007150:Immunohistochemistry; D007167:Immunotherapy / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D000072417:Protein Domains; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*
D000911:Antibodies, Monoclonal; D019496:Cancer Vaccines; D017931:DNA Primers; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins; D019444:Vaccines, DNA; C508053:ERBB2 protein, human
Breast cancer; DNA immunization; Extracellular domains; HER2; Immunotherapy; Recombinant protein