Foetal bovine serum (fbs)

Isolated T-cells were cultured in a 25 cm² plastic flask containing advanced Roswell park memorial institute (RPMI) 1640 media (Thermo Fisher Scientific, Waltham, MA, USA), supplemented with 10% foetal bovine serum (Thermo Fisher Scientific) and 1% penicillin/streptomycin (Thermo Fisher Scientific), at a density of 1 × 10⁶ cells/mL at 37 °C in a humidified 5% CO₂ atmosphere with daily monitoring. The cells were also supplemented with DynaBeads Human T-Activator CD3/CD28 (Thermo Fisher Scientific) at a 1:10 beads to cell ratio and 50 U/mL of interleukin 2 (IL-2) (PeproTech, Rocky Hill, NJ, USA) in order to induce T-cell activation and expansion. SK-BR-3 (SKBR3) breast cancer cell line (ATCC HTB-30, Manassas, VA, USA) were cultured in a 25 cm² plastic flask containing advanced RPMI 1640 media, 10% foetal bovine serum, and 1% penicillin/streptomycin at a seeding density of 1 × 10⁵ cells/mL at 37 °C in a humidified 5% CO₂ atmosphere. Once the cells reached confluence, they were detached using 0.25% trypsin-EDTA (Thermo Fisher Scientific) and sub-cultured into new flasks at a similar cell density for maintaining culture.

HEK293T-hACE2 [20 (link)] cells were cultured at 37 °C under 5 % CO₂ and grown in Dulbecco’s modified Eagle medium (DMEM; Sigma-Aldrich, Taufkirchen, Germany) supplemented with 10 % foetal bovine serum (Sigma-Aldrich, Taufkirchen, Germany), 5 % l-glutamine (200 mM; Lonza, Verviers, Belgium), and 1 % penicillin/streptavidin (Fisher Scientific, Schwerte, Germany). Vero cells (ATCC CCL-81) and Huh7 cells (CSC-C9441L) were cultured in DMEM supplemented with 10 % foetal bovine serum and 1 % l-glutamine. SARS-CoV-2 (isolate MUC-IMB-1) was a kind gift of G. Dobler, Bundeswehr Institute for Microbiology, Germany. MERS-CoV strain EMC/2012 was provided by Ron Fouchier (Erasmus University, Rotterdam, The Netherlands [21 (link)];) and SARS-CoV strain Frankfurt-1 by Christian Drosten (Institute of Virology, Charite, Berlin, Germany [22 (link)]). Epigallocatechin gallate (EGCG) and epicatechin (EC) were purchased from Sigma-Aldrich (Taufkirchen, Germany).

Cells were maintained at 37 °C in 5% CO_2. LNCaPs were maintained in RPMI medium with 10% foetal bovine serum (First Link, Wolverhampton, UK) (ATCC CRL-1740). LNCaP/PHB^cDNA and LNCaP/PHB^siRNA cells^{5 (link)} were maintained in RPMI medium with 10% doxycycline-free foetal bovine serum (Clontech, Palo Alto, CA, USA), 12 μg/ml blasticidin (Sigma, Dorset, UK), 0.3 mg/ml zeocin (ThermoFisher, Waltham, MA, USA) and 500 μg/ml G418 (Sigma). COS-7 cells (ECACC 87021302), PC3 cells (ATCC CRL-1435) and VCaP (ATCC CRL-2876) were maintained in Dulbecco’s modified Eagle's medium with 10% foetal bovine serum. Media were supplemented with 2 mMl-glutamine, 100 U/ml penicillin and 100 mg/ml streptomycin (Sigma). Seventy-two hours before androgen exposure, the medium was replaced with the ‘starvation medium’ consisting of phenol red-free RPMI medium (or Dulbecco’s modified Eagle's medium), supplemented with 5% charcoal-stripped foetal bovine serum (First Link).

The L929 mouse fibroblast (ATTC^® CCL-1^™, Manassas, VA) was routinely maintained in RPMI 1640 media (R8758, Sigma-Aldrich, Suffolk, UK), supplemented with 10% Foetal Bovine Serum (Foetal Bovine Serum, ATCC^® 30–2020^™), 100 I.U./mL penicillin and 100 µg/mL streptomycin (Penicillin-Streptomycin Solution ATCC^® 30–2300^™). Cells were trypsinised (Trypsin-EDTA Solution, 1X ATCC^® 30–2101™) twice a week and seeded at a density of 1 × 10⁶ per T25 cell culture flask and incubated at 37 °C and 10% CO₂ to achieve a confluent monolayer.

The human benign prostatic epithelial RWPE1 cell line (ATCC CRL-11609) was cultivated in a Keratinocyte serum-free medium (Cat. No. 17005–042) supplemented with BPE (bovine pituitary extract) and EGF (epidermal growth factor) provided with the medium and antibiotics (penicillin 100 U·mL⁻¹, streptomycin 100 μg·mL⁻¹). The human prostate carcinoma 22Rv1 cell line (ATCC CRL-2505) was cultured in an ATCC-formulated Roswell Park Memorial Institute (RPMI)-1640 medium (ATCC 30–2001) supplemented with 10% exosome-depleted foetal bovine serum (A2720801) and antibiotics (penicillin 100 U·mL⁻¹, streptomycin 100 μg·mL⁻¹). Cell lines were purchased from the American Type of Culture Collection (ATCC, Manassas, VA, USA). The cells were maintained at 37 °C in a humidified atmosphere of 5% CO₂. The culture media, foetal bovine serum (FBS), antibiotics and other chemicals used for cell cultivation were purchased from GIBCO (Thermo Fisher Scientific, Waltham, MA, USA).

Cells were maintained at 37 °C in 5% CO₂. LNCaP cells were maintained in RPMI medium with 10% foetal bovine serum (First Link, Wolverhampton, UK) (ATCC CRL-1740). LNCaP/Luc/PHB^cDNA and LNCaP/Luc/PHB^siRNA cells were maintained in RPMI medium with 10% doxycycline-free foetal bovine serum (Clontech, Palo Alto, CA, USA), 12 μg/mL blasticidin (Sigma, Dorset, UK), 0.3 mg/mL Zeocin (ThermoFisher, Waltham, MA, USA) and 500 μg/mL G418 (Sigma). HeLa (ATCC CCL-2) and PC3 (ATCC CRL-1435) were maintained in Dulbecco’s modified Eagle’s medium with 10% foetal bovine serum. Media were supplemented with 2 mM L-glutamine, 100 U/mL penicillin and 100 mg/mL streptomycin (Sigma). Seventy-two hours prior to androgen exposure, the medium was replaced with the ‘starvation medium’ consisting of phenol-red-free RPMI medium (or Dulbecco’s modified Eagle’s medium), supplemented with 5% charcoal-stripped foetal bovine serum (First Link).