Evaluating Immunoreactivity of Polyclonal Antibodies Developed against AU-565 Cell Line for Diagnosis and Immunotherapy of Breast Cancer

Abstract

Breast cancer is the most commonly diagnosed cancer type in women and approximately 700 thousand people around the world lose their lives due to breast cancer every year. Mammography and ultrasound are the techniques that are frequently applied for the diagnosis of breast cancer. However they involve several limitations such as low sensitivity and exposing to high radiation. Additionally, false negative and false positive results could be obtained in conventional diagnostic methods for breast cancer. So it is crucial to generate new diagnostic kits which enable rapid and accurate detection of breast cancer. Antibodies created using hybridoma technology can be considered in the diagnostic kits since they are important tools to bind cancer cell antigens. Although monoclonal antibodies are usually utilized in antibody-mediated diagnostic kits and they possess high specificity in diagnosis and treatment, they conversely indicate low avidity to tumor antigens in comparison to polyclonal antibodies because they can only bind to a single epitope region. Therefore, polyclonal antibodies display a pivotal role in recognition of many epitopes of breast cancer cells. The major aim of this study is to create polyclonal antibodies against whole cell lysate of AU-565 cell line by hybridoma technology and examine their diagnostic value by comparing with conventional antibodies. The acquired tumor cell antigens were supplemented with two distinct adjuvants Complete Freund’s Adjuvant (CFA) and Polyoxidonium (PO) while preparing the formulations for immunization. Thus we also evaluated in vivo immunogenic properties of antigen-adjuvant combinations and compared immunostimulatory efficacies of CFA and PO over prepared antigens. The outputs revealed that whole cell antigens reinforced with CFA demonstrated robust immunostimulatory activities, in vivo by enhancing the produced antibody levels in mice excessively. Polyclonal antibodies that were obtained from spleens of mice immunized with AU-565 cell antigens and CFA combinations were highly effective to capture the antigens that were isolated from different breast cancer cell line. It was detected that obtained polyclonal antibodies exhibited stronger immune reactions with breast cancer antigens when compared with conventional antibodies. Consequently, considerable immunostimulatory performance of AU-565 cell antigens and CFA combination was shown as a vaccine candidate and high diagnostic value of polyclonal antibodies produced in response to vaccination with mentioned formulation was established for the first time in the present study.