Investigation of the immunological differences between granulocytes from healthy donors and breast cancer patients, with respect to the cancer testis antigen, CTCFL

Granulocytes or Polymorphonuclear neutrophils (PMNs) are key players in the non-specific immune system against microbial infection as they express surface receptors for the recognition of general antigenic patterns found on pathogens. In addition PMN’s also act as a mediator for the antigen-specific adaptive immunity and T-cells function. However, an anti-tumoral role of the PMN’s was suggested over the recent years beside their well-studied innate function, opening the door for new studies in this area. CTCFL or BORIS (Brother Of the Regulator of the Imprinting Site) is a paralogue protein to a ubiquitously expressed transcription factor, CTCF. The expression of CTCFL was detected exclusively in the spermatocytes. The role of BORIS was then supposed to be linked to the de novo DNA-methylation and re-establishment of methylation markers, however, a full understanding its function calls for further investigations. CTCFL was also recently established as a member of the cancer-testis (CT) gene family as its activation in somatic cells was found to be associated with the development of many types of cancer, including breast cancer. This presents it as an attractive biomarker for cancers dia gnosis/prognosis and therapy target. Interestingly, CTCFL was also detected in PMNs obtained from breast cancer patients while being undetectable in the PMN’s of healthy donors. Again this supports the prospect of using this protein as a biomarker in the early detection of cancer and treatment. In this project we aimed to investigate the effect of CTCFL expression in PMNs of breast cancer patients on the physiological characteristic and immunological functions of these leukocytes. The first part of our experiments assessed phagocytic activity, oxidative burst function, survival and expression of immunity receptors in BORIS-positive PMN cell-line model. The second part investigated the origin of CTCFL activation by the incubation of peripheral human PMN’s with the serum of breast cancer patients or the adenocarcinoma cell lines and observe the possible alteration in CTCFL levels and the corresponding levels of the immune system receptors. Finally, we attempted to manipulate the levels of CTCFL in PMN cell line model (knock down or over-expression) and the effect it may produce on the expression of immune system receptors.