CpG-ODN from Streptococcus thermophilus as a tool for inducing extrinsic apoptosis via caspase-8 activation in mouse...

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Synthetic oligodeoxynucleotides (ODNs) with unmethylated CpG motifs activate Toll-like receptor 9 (TLR9), leading to immune responses.
• The use of CpG-ODNs for inducing apoptosis is underexplored, especially sequences derived from probiotics.

Purpose of the Study:

• To investigate the potential of a probiotic-derived CpG-ODN, MsST from Streptococcus thermophilus, to induce extrinsic apoptosis.
• To establish a method for controlled apoptosis induction using MsST.

Main Methods:

• Genomic DNA fragmentation assays to detect internucleosomal DNA fragmentation.
• Flow cytometry with annexin V/7-aminoactinomycin D staining to quantify apoptotic cells.
• Western blot analysis to assess the activation of the extrinsic apoptosis pathway via caspase-8 cleavage.

Main Results:

• MsST induced significant internucleosomal DNA fragmentation in mouse splenocytes.
• Flow cytometry confirmed a time-dependent increase in the apoptotic cell population after MsST treatment.
• Western blot analysis showed elevated levels of cleaved caspase-8, indicating activation of the extrinsic apoptosis pathway.

Conclusions:

• MsST, a CpG-ODN from Streptococcus thermophilus, effectively induces extrinsic apoptosis in mouse splenocytes.
• MsST demonstrates distinct apoptosis-inducing characteristics compared to other CpG-ODNs and actinomycin D.
• These findings support MsST as a potential tool for controlled apoptosis induction with applications in cancer immunotherapy and autoimmune/inflammatory disease treatment.