Sahar Mortezagholi; Davood Rostamzadeh; Maedeh Alinejad; Vahid Younesi; Payam Tabarsi; Mahdi Shabani
Abstract
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly transmits in general population, mainly between health-care workers (HCWs) who are in close contact with patients. Objective: To study the seropositivity of HCWs as a high-risk group compared to general population. Methods: ...
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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly transmits in general population, mainly between health-care workers (HCWs) who are in close contact with patients. Objective: To study the seropositivity of HCWs as a high-risk group compared to general population. Methods: 72 samples were obtained from HCWs working in Masih Daneshvari hospital as one of the main COVID-19 admission centers in Tehran, during April 4 to 6, 2020. Also we collected 2021 blood samples from general population. The SARS-CoV-2 specific IgM, and IgG antibodies in the collected serum specimens were measured by commercial ELISA kits. Results: Based on the clinical manifestations, 25.0%, 47.2%, and 27.8% of HCWs were categorized as symptomatic with typical symptoms, symptomatic with atypical symptoms, and asymptomatic, respectively. Symptomatic individuals with typical and atypical symptoms were 63.2% and 36.8% positive in RT-PCR test, respectively. Anti-SARS-CoV-2 IgM and IgG antibodies were detected in 15.3% and 27.8% of HCWs samples, respectively. Antibody testing in the general population indicated that SARS-CoV-2 specific IgM and IgG were found in (162/2021) 8%, and (290/2021) 14.4%, respectively. The frequency of positive cases of IgM and IgG were significantly increased in HCWs compared to general population (p= 0.028 for IgM and p= 0.002 for IgG). Conclusion: The frequency of SARS-CoV-2 specific antibodies in HCWs was higher than general population indicating a higher viral transmission via close exposure with COVID-19 patients.
Fateme Sadri-Ardalani; Moslem Ahmadi; Azam Hemmati; Shaghayegh Emami; Samira Farid; Mohammad Mehdi Amiri; Mahmood Jeddi-Tehrani; Mahdi Shabani; Fazel Shokri
Volume 14, Issue 2 , June 2017, , Pages 99-110
Abstract
Background: In addition to passive immunotherapy using anti-HER2 monoclonal antibodies, active immunotherapy via HER2 targeting is an interesting approach to inducing specific anti-tumor immune responses. We have recently reported the immunogenicity of HER2 subdomains following DNA immunization and HER2 ...
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Background: In addition to passive immunotherapy using anti-HER2 monoclonal antibodies, active immunotherapy via HER2 targeting is an interesting approach to inducing specific anti-tumor immune responses. We have recently reported the immunogenicity of HER2 subdomains following DNA immunization and HER2 protein boosting. In the present study, we evaluated the immunogenicity of different HER2 extracellular subdomains for the induction of anti-HER2 antibody response in BALB/c mice. Objective: To investigate and characterize antibody responses to human recombinant proteins of HER2 extracellular subdomains in immunized mice. Methods: Four subdomains of HER2 extracellular domain were expressed in E.coli; subsequently, purified recombinant proteins were intraperitoneally injected in BALB/c mice with Freund's adjuvant. The anti-HER2 antibody response was detected by ELISA, immunoblotting and flow cytometry. Results: All the four HER2 subdomains along with the full extracellular domain (fECD) were able to induce specific anti-HER2 antibodies. Although anti-HER2 subdomains antibodies could not react with eukaryotic recombinant fECD protein by ELISA, they were able to recognize this protein by immunoblotting under both reduced and non-reduced conditions. Furthermore, only the sera of mice immunized with fECD protein could recognize native HER2 on HER2 overexpressing tumor cells (>99%) by flow cytometry. Moreover, fECD immunized mice sera inhibited the proliferation of tumor cells by XTT assay. Conclusion: The prokaryotic recombinant proteins of HER2 extracellular subdomains are immunogenic, yet the induced specific antibodies do not react with the native HER2 protein due to the paucity of post-translation modifications and /or distortion of the native conformation of isolated HER2 extracellular subdomains which might be potentially effective for induction of cell mediated immune response against HER2.
