Staphylococcal enterotoxin B as DNA vaccine against breast cancer in a murine model

Raheleh Halabian1, Abolfazl Jahangiri1, Hamid Sedighian1

  • 1Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.

Insights

A novel DNA cancer vaccine using the SEB construct shows significant promise for treating breast cancer. This vaccine effectively stimulates immune responses, reduces tumor size, and increases survival time in preclinical models.

Area of Science:

  • Immunology
  • Oncology
  • Biotechnology

Background:

  • Recombinant bacterial toxins and DNA cancer vaccines are emerging strategies for cancer treatment.
  • Cancer vaccines aim to elicit specific, long-lasting immune responses against tumors.
  • Current treatments like chemotherapy and radiation therapy have limitations and side effects.

Purpose of the Study:

  • To evaluate the antitumor efficacy of a novel Staphylococcal Enterotoxin B (SEB) DNA vaccine against breast tumors in vivo.
  • To assess the SEB DNA vaccine's ability to induce specific immune responses and inhibit tumor growth.

Main Methods:

  • A synthetic SEB gene was codon-optimized and cloned into an expression vector.
  • Mice were vaccinated with the SEB construct, SEB alone, or a phosphate-buffered saline (PBS) control.
  • 4T1 breast cancer cells were implanted, and antitumor activity was assessed by measuring cytokine levels (IL-4, IFN-γ), lymphocyte proliferation, tumor size, necrosis, and survival.

Main Results:

  • The SEB DNA vaccine significantly increased Interferon-gamma (IFN-γ) levels and spleen lymphocyte proliferation compared to controls.
  • Significant reductions in tumor size and notable increases in tumor tissue necrosis were observed in the SEB-vaccinated group.
  • The SEB DNA vaccine significantly improved the survival time of the tumor-bearing mice.

Conclusions:

  • The designed SEB DNA gene construct serves as a promising new vaccine model for breast cancer.
  • It effectively induces antitumor immunity, characterized by specific immune responses and tumor necrosis, with a favorable safety profile compared to traditional therapies.
  • The vaccine's slow, long-term release mechanism may enhance immune stimulation and cellular memory for sustained antitumor effects.