CD8+ cytolytic T lymphocytes become infected in vitro in the process of killing HIV-1-infected target cells

In the present study the requirements for in vitro infection of antigen-specific CD8⁺ cytotoxic T lymphocytes (CTL) with human immunodeficiency virus –1(HIV-1) were investigated. CD3⁺CD8⁺CD4^? HIV-1 nef-specific CTL become infected with HIV-1 after short-term co-culture with HLA-matched HIV-1-infected CD20⁺ B lymphoblastoid cells (B-LCL) which are specifically killed. Similar results were observed with an allospecific CD8⁺ CTL population. In addition, co-culture experiments showed that once infected with HIV-1, these CD8⁺ CTL could spread the infection further to uninfected CD4⁺ lymphocytes. In contrast, CD8⁺ CTL did not become infected with HIV-1 when co-cultured with HLA-mismatched HIV-1-infected B-LCL which are not killed. These observations in vitro could have relevance in peripheral lymphoid organs contributing to the progressive decrease of HIV-specific CD8⁺ CTL activity that is associated with the progression to AIDS.