Phage display selection of non-glycosylated recombinant human antibodies against TIM-3, PD-1 and LAG-3 immune checkpoints, and their characterization as antitumor and antiviral therapeutic molecules

• Grant number: 23/01816-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: August 01, 2023
• End date: March 31, 2027
• Field of knowledge: Health Sciences - Collective Health - Public Health
• Principal Investigator: Daniela Luz Hessel da Cunha
• Grantee: Gabriel Correia Lima
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated scholarship(s): 24/01723-0 - Isolation of anti-TIM-3 antibodies from combinatorial libraries expressed in the cytoplasm of Escherichia coli., BE.EP.DD

Abstract

Immune checkpoints are negative regulatory receptors expressed on immune cells and under normal physiological conditions, serve as brakes for the immune system, maintaining self-tolerance and preventing tissue damage. However, these molecules also participate in escape mechanisms for the immune system, causing dysfunctions in T cell populations in a variety of diseases such as cancer and viral infections, including that caused by the SARS-CoV-2 virus. The blockade of these inhibitory receptors with monoclonal antibodies is used in therapies that aim to rescue the activity of chronically exhausted effector cells, in order to restore the immune system response. Currently, there are six immune control points involved with viral infection and with a history of antitumor immunotherapy, among which stand out PD-1, LAG-3 and TIM-3. In this context, this project proposes to obtain and characterize recombinant monoclonal antibodies against PD-1, TIM-3 and LAG-3 immune checkpoint blockers, based on phage display selection, using a synthetic human antibody library, and its subsequent prokaryotic expression in an E. coli SHuffle strain, genetically adapted for cytoplasmic expression of non-glycosylated monoclonal antibodies. After characterizing their sensitivity and specificity, such antibodies will be tested alone or together, as therapeutic alternatives for activating T lymphocytes in diseases such as cancer and chronic viral infections such as long-term COVID-19. The transcriptomic profile of effector cells used in functional assays will be used to choose candidate antibodies with greater capacity to prevent the development of resistance in patients and induce cytotoxicity to tumor cell lines. The innovation in producing antibodies in bacteria opens up new therapeutic possibilities. This proposal is already in progress in the form of a master's project (FAPESP n 2021/04307-0) and due to its innovative capacity and the promising preliminary results obtained, it was expanded and is being presented as a PhD project. (AU)