T cell receptors for the HIV KK10 epitope from patients with differential immunologic control are functionally indistinguishable

Abstract

HIV controllers (HCs) are individuals who can naturally control HIV infection, partially due to potent HIV-specific CD8+ T cell responses. Here, we examined the hypothesis that superior function of CD8+ T cells from HCs is encoded by their T cell receptors (TCRs). We compared the functional properties of immunodominant HIV-specific TCRs obtained from HLA-B*2705 HCs and chronic progressors (CPs) following expression in primary T cells. T cells transduced with TCRs from HCs and CPs showed equivalent induction of epitope-specific cytotoxicity, cytokine secretion, and antigen-binding properties. Transduced T cells comparably, albeit modestly, also suppressed HIV infection in vitro and in humanized mice. We also performed extensive molecular dynamics simulations that provided a structural basis for similarities in cytotoxicity and epitope cross-reactivity. These results demonstrate that the differential abilities of HIV-specific CD8+ T cells from HCs and CPs are not genetically encoded in the TCRs alone and must depend on additional factors.

T Cell Receptor Immunotherapy Drives Human Immunodeficiency Virus Evolution in Humanized Mice

“…However, some studies have shown reduced recognition of L6M by KK10-specific T cells (Chen et al, 2012; Iglesias et al, 2011; Xia et al, 2014). In our previous study, L6M mutation did not affect cytotoxicity when target cells were pulsed with saturating amounts of the peptide (Joglekar et al, 2018). Cytotoxicity assays using GXR-B27 cells infected with wildtype or L6M mutant viruses showed attenuated recognition of L6M (Fig 4B).…”

“…Two B*27:05-KK10-specific TCRs, EC27 and EC5.5 (referred to as FC5.5 previously), isolated from HIV controllers were used for immunotherapy (Joglekar et al, 2018). The TCRs were cloned into lentiviral vectors and linked to a cell surface marker, LNGFR, using 2A peptide sequences.…”

“…Upon confirming development of engineered T cells, ex vivo assays were performed to test their function. Previously described co-culture assays were used to measure KK10-specific cytotoxicity (Joglekar et al, 2018). GXR-B27 cells that express HLA-B*27:05 and express GFP upon HIV infection were used as target cells.…”

“…Lentiviral vectors expressing EC27 and EC5.5 TCRs along with LNGFR were constructed, packaged, and concentrated as described previously (Joglekar et al, 2018). Briefly, HEK-293T cells were plated on poly-L-Lysine-coated 15 cm plates (Corning; 430599) at 15×10 6 cells per plate.…”

“…The KK10 epitope is also hypothesized to be more structurally constrained as compared to the SL9 epitope (Schneidewind et al, 2008). Therefore, we tested if two B27-KK10-specific TCRs, EC27 and EC5.5, that we previously isolated from HIV controllers (Joglekar et al, 2018) could be used for HSPC-based immunotherapy. Immunocompromised mice were engrafted with CD34+ HSPCs enriched from G-CSF mobilized peripheral blood from HLA-B*27:05+ healthy donors.…”