Scientists and clinicians at Children's National Medical Center in collaboration with University of Iowa researchers have developed a new anti-tumour vaccine for neuroblastoma and melanoma.
While conducting a study on mice, researchers found that the vaccine uses the tumour's own protein to induce an immune system response, allowing for a personalized approach to treatment.
Developed in the laboratory of Children's National Chief of General and Thoracic Surgery Anthony Sandler, MD, the vaccine and delivery system involves the creation of synthetic microparticles known as "immune stimulatory antigen loaded particles" (ISAPs), that consist of tumour antigens (proteins) from the specific tumour to be targeted, as well as immune stimulatory agents.
The ISAPs are detected and engulfed by specialized immune cells and sensed to be immune-stimulating "foreign bodies."
The study shows that ISAPs are effective at blocking the growth of tumours in mice by inducing activation of immune cells that then stimulate the immune system to specifically target the tumour whose antigens match those that are loaded in the particles - known as tumour specific immunity.
However, the researchers also found that the impact of ISAPs on tumour growth was partially mitigated by an increased presence of regulatory t-cells (T-reg) when ISAPs are introduced into the body.
The researchers believe that T-regs play a key role in how the vaccine impacts tumour growth by suppressing the development of the specific immune cells needed to combat the tumour.
By adding a T-reg suppressor such as cyclosphosphamide or anti-CD25 antibody, the scientists were able to have a greater impact on preventing tumour growth using the ISAP approach.
"For tumours like neuroblastoma, reduction to minimal residual disease with standard therapies like chemotherapy and/or surgical resection and subsequent treatment with this vaccine could quite possibly cure the patient of the disease in the not too distant future," said Sandler, lead author of the study.
"Creation of ISAPs allows us to target our treatments to the specific tumour of interest, a capability that will more effectively combat a wide range of these tumours in a personalized fashion," he added.
The study is published in the October edition of the research journal Cancer Immunology, Immunotherapy.