Development of CD 8 + T cells expressing two distinct receptors specific for MTB and HIV ‐1 peptides

The immune response in individuals co‐infected with M ycobacterium tuberculosis (MTB) and the human immunodeficiency virus (MTB/ HIV ) gradually deteriorates, particularly in the cellular compartment. Adoptive transfer of functional effector T cells can confer protective immunity to immunodeficient MTB/ HIV co‐infected recipients. However, few such effector T cells exist in vivo , and their isolation and amplification to sufficient numbers is difficult. Therefore, enhancing immune responses against both pathogens is critical for treating MTB/ HIV co‐infected patients. One approach is adoptive transfer of T cell receptor ( TCR ) gene‐modified T cells for the treatment of MTB/ HIV co‐infections because lymphocyte numbers and their functional avidity is significantly increased by TCR gene transfer. To generate bispecific CD 8 + T cells, MTB Ag85B 199–207 peptide‐specific TCR s ( MTB / TCR ) and HIV ‐1 Env 120–128 peptide‐specific TCR s ( HIV / TCR ) were isolated and introduced into CD 8 + T cells simultaneously using a retroviral vector. To avoid mispairing among exogenous and endogenous TCR s, and to improve the function and stability of the introduced TCR s, several strategies were employed, including introducing mutations in the MTB / TCR constant (C) regions, substituting part of the HIV / TCR C regions with CD 3ζ, and linking gene segments with three different 2A peptides. Results presented in this report suggest that the engineered T cells possessed peptide‐specific specificity resulting in cytokine production and cytotoxic activity. This is the first report describing the generation of engineered T cells specific for two different pathogens and provides new insights into TCR gene therapy for the treatment of immunocompromised MTB/ HIV co‐infected patients.