Haematologica 2019 Apr 19. Epub 2019 Apr 19.
Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, USA
Respiratory tract infections due to community-acquired respiratory viruses including respiratory syncytial virus, Influenza, parainfluenza virus 3 and human metapneumovirus are detected in up to 40% of allogeneic hematopoietic stem cell transplant recipients in whom they cause severe symptoms including pneumonia and bronchiolitis and can be fatal. Given the lack of effective antivirals and the data from our group demonstrating that adoptively transferred ex vivo-expanded virus-specific T cells can be clinically beneficial for the treatment of both latent (Epstein-Barr virus, cytomegalovirus, BK virus, human herpesvirus 6) and lytic (adenovirus) viruses, we investigated the potential for extending this immunotherapeutic approach to respiratory viruses. We now describe a system that rapidly generates a single preparation of polyclonal (CD4+ and CD8+) virus-specific T cells reactive against 12 antigens derived from 4 viruses (respiratory syncytial virus, Influenza, parainfluenza virus 3 and human metapneumovirus) that commonly cause post-transplant morbidity and mortality. With a single in vitro stimulation we consistently generated Th1-polarized T cell lines that produced multiple effector cytokines and were selectively reactive against viral-expressing targets, with no evidence of 'off target' auto- or allo-reactivity. Finally, we demonstrated the clinical relevance of these virus-specific T cells by measuring responses in transplant recipients who successfully controlled active infections. These results support the clinical importance of T cell immunity in mediating protective antiviral effects against community-acquired respiratory viruses and demonstrate the feasibility of utilizing a broad-spectrum immunotherapeutic in immunocompromised patients with uncontrolled infections.