Evaluation of the antitumor properties of melanoma-specifc antibodies and CD8+ T cells of mice immunized with hybrid cells vaccine in the presence or absence of the biological adjuvant Propionibacterium acnes

• Grant number: 19/25960-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2020
• End date: February 28, 2021
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: Ieda Maria Longo Maugéri
• Grantee: Gabriel de Brito Nogueira
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The use of specific immunotherapy as a cancer treatment has been revised in the last decade, especially in patients who no longer respond to conventional treatments. Based on the importance of dendritic cells in antitumor response, immunizations have been proposedcombining these cells with tumors, called hybrid cell vaccines, with thepurpose of better antigen presentation and induction of effector tumoricidal response.Among these vaccines, clinical and experimental studies have been performed withmelanoma. However, despite a new treatment perspective, these vaccines induceresponse that is not sustained, and the use of adjuvants is required.Propionibacterium acnes (P. acnes) bacteria killed by heat or phenol haveAdjuvant properties known for decades, among their effects, we highlightincreased macrophage tumoricidal and phagocytic activity, dendritic cells maturation and proinflammatory cytokine synthesis, polarizing the immune response toTh1, or Th2 acting directly on antigen presenting cells, elevatingthe expression of molecules such as MHCII and MHCI, toll-like receptors and costimulatory molecules.Our group demonstrated that the association of P. acnes with the hybrid vaccine promoted theincreased cytotoxic activity of splenocytes, IFN-³ titres, and B16F10 (murine melanoma) antigen-specific titersHerein we will be to verify the tumoricidal property of immunoglobulinsby promoting complement-independent cellular cytotoxicity (ADCC) as well as the TCD8 + lymphocytes tumoricidal activity specific to melanoma after hibrid vaccine associated with P.acnes immunization.