Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 18 5 2019 10 23 501 510 EN Leila Siavoshinia Department of Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Mostafa Jamalan Abadan Faculty of Medical Sciences, Abadan, Iran Majid Zeinali Biotechnology Research Center, Research Institute of Petroleum Industry (RIPI), Tehran, Iran Ghorban Mohammadzadeh Department of Clinical Biochemistry, Hyperlipidemia Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2018 07 28 2019 05 11 Targeting of cancerous cells with a high level of human epidermal growth factor receptor 2 (HER2) expressions by drug immunoconjugates is a new approach for specific delivery of chemotherapeutic agents. Our previous work indicated that idarubicin-ZHER2 affibody conjugate has a great potential for the treatment of HER2-overexpressing malignant cell lines but possible induced immune response against constructed conjugate was not addressed. In the current study, the possibility of induction of humoral and cellular immune responses against idarubicin-ZHER2 affibody conjugate in BALB/c mice was investigated. For assessment of the induced immune response, prepared and qualified idarubicin-ZHER2 affibody conjugate was administrated intravenously to BALB/c mice and the induced cellular immune response was evaluated by measuring secretion levels of interferon gamma (IFN-γ) and interleukin 10 (IL-10) cytokines by the splenocytes. Humoral response of treated mice was also assessed by measuring total immunoglobulin G (IgG) titer in mice sera. The obtained results showed that idarubicin-ZHER2 affibody conjugate at any examined concentrations could not induce secretion of IFN-γ as a pro-inflammatory cytokine. A mild increase in the level of regulatory IL-10 cytokine was seen in the treated mice although no dose dependency in the level of IL-10 production was observed. Furthermore, results showed that idarubicin-ZHER2 conjugate could not induce IgG production in the treated mice. Based on these findings, the idarubicin-ZHER2 conjugate can be considered as a candidate for the development of new therapeutics against HER2-overexpressing cancers although further in vivo studies are needed. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/2075