1. Human β-Defensin 2 (HBD-2) Displays Oncolytic Activity but Does Not Affect Tumour Cell Migration
Guneet K Bindra, Scott A Williams, Fung T Lay, Amy A Baxter, Ivan K H Poon, Mark D Hulett, Thanh Kha Phan Biomolecules. 2022 Feb 6;12(2):264. doi: 10.3390/biom12020264.
Defensins form an integral part of the cationic host defence peptide (HDP) family, a key component of innate immunity. Apart from their antimicrobial and immunomodulatory activities, many HDPs exert multifaceted effects on tumour cells, notably direct oncolysis and/or inhibition of tumour cell migration. Therefore, HDPs have been explored as promising anticancer therapeutics. Human β-defensin 2 (HBD-2) represents a prominent member of human HDPs, being well-characterised for its potent pathogen-killing, wound-healing, cytokine-inducing and leukocyte-chemoattracting functions. However, its anticancer effects remain largely unknown. Recently, we demonstrated that HBD-2 binds strongly to phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2), a key mediator of defensin-induced cell death and an instructional messenger during cell migration. Hence, in this study, we sought to investigate the lytic and anti-migratory effects of HBD-2 on tumour cells. Using various cell biological assays and confocal microscopy, we showed that HBD-2 killed tumour cells via acute lytic cell death rather than apoptosis. In addition, our data suggested that, despite the reported PI(4,5)P2 interaction, HBD-2 does not affect cytoskeletal-dependent tumour cell migration. Together, our findings provide further insights into defensin biology and informs future defensin-based drug development.
2. Human β-Defensin 2 and Its Postulated Role in Modulation of the Immune Response
Martyna Cieślik, Natalia Bagińska, Andrzej Górski, Ewa Jończyk-Matysiak Cells. 2021 Nov 3;10(11):2991. doi: 10.3390/cells10112991.
Studies described so far suggest that human β-defensin 2 is an important protein of innate immune response which provides protection for the human organism against invading pathogens of bacterial, viral, fungal, as well as parasitical origin. Its pivotal role in enhancing immunity was proved in infants. It may also be considered a marker of inflammation. Its therapeutic administration has been suggested for maintenance of the balance of systemic homeostasis based on the appropriate composition of the microbiota. It has been suggested that it may be an important therapeutic tool for modulating the response of the immune system in many inflammatory diseases, offering new treatment modalities. For this reason, its properties and role in the human body discussed in this review should be studied in more detail.
3. Immunomodulatory effects of β-defensin 2 on macrophages induced immuno-upregulation and their antitumor function in breast cancer
Sonam Agarwal, Anita Chauhan, Khushwant Singh, Kunal Kumar, Rupinder Kaur, Marilyn Masih, Pramod Kumar Gautam BMC Immunol. 2022 Nov 2;23(1):53. doi: 10.1186/s12865-022-00527-y.
Background: Macrophages are mononuclear CD34+ antigen-presenting cells of defense mechanism and play dual roles in tumor burden. The immunomodulatory and their antitumor function of β-defensin 2 is still unclear, despite the accumulating evidence of the response in infection. So, the aim of present study is to elucidate the role of β-defensin 2 on the level of ROS, cytokines, chemokine expression in macrophages and antitumor function in breast cancer. Method: Swiss albino mice were used to harvest PEC macrophages and C127i breast cancer cells line for tumor model was used in this study. Macrophages were harvested and characterized by flow-cytometry using F4/80 and CD11c antibodies. MTT was performed to estimate cytotoxicity and dose optimization of β-defensin 2. Oxidative stress was analyzed by H2O2 and NO estimation followed by iNOS quantified by q-PCR. Cytokines and chemokines estimation was done using q-PCR. Co-culture experiment was performed to study anti-tumor function using PI for cell cycle, Annexin -V and CFSE analysis for cell proliferation. Results: PEC harvested macrophages were characterized by flow-cytometry using F4/80 and CD11c antibodies with the purity of 8% pure population of macrophages. It was found that 99% of cells viable at the maximum dose of 100 ng/ml of β-defensin 2 in MTT. Levels of NO and H2O2 were found to be decreased in β-defensin 2 as compared to control. Expression of cytokines of IFN-γ, IL-1α, TNF-α, TGF-βwas found to be increased while IL-3 was decreased in β-defensin 2 group as compared to control. Levels of chemokines CXCL-1, CXCL-5 and CCL5 increased in treated macrophages while CCL24 and CXCL-15 expression decreased. Adhesion receptor (CD32) and fusion receptor (CD204) were decreased in the β-defensin 2 group as compared to control. Anti-tumor experiment was performed using co-culture experiment apoptosis (Annexin-V) was induced, cell cycle arrest in phage and cell proliferation of C127i cells was decreased. Conclusion: This is the first report of β-defensin 2 modulates macrophage immunomodulatory and their antitumor function in breast cancer. β-defensin 2 as a new therapeutic target for immunotherapy as an adjuvant in vaccines.
