Supplementary Figures S1-5 from Alternative Splicing of the Inhibitory Immune Checkpoint Receptor SLAMF6 Generates a Dominant Positive Form, Boosting T-cell Effector Functions

Hajaj, Emma; Zisman, Elad; Tzaban, Shay; Merims, Sharon; Cohen, Jonathan; Klein, Shiri; Frankenburg, Shoshana; Sade-Feldman, Moshe; Tabach, Yuval; Yizhak, Keren; Navon, Ami; Stepensky, Polina; Hacohen, Nir; Peretz, Tamar; Veillette, André; Karni, Rotem; Eisenberg, Galit; Lotem, Michal

doi:10.1158/2326-6066.22543437.v1

Supplementary Figures S1-5 from Alternative Splicing of the Inhibitory Immune Checkpoint Receptor SLAMF6 Generates a Dominant Positive Form, Boosting T-cell Effector Functions

journal contribution

posted on 2023-04-04, 01:03 authored by Emma Hajaj, Elad Zisman, Shay Tzaban, Sharon Merims, Jonathan Cohen, Shiri Klein, Shoshana Frankenburg, Moshe Sade-Feldman, Yuval Tabach, Keren Yizhak, Ami Navon, Polina Stepensky, Nir Hacohen, Tamar Peretz, André Veillette, Rotem Karni, Galit Eisenberg, Michal Lotem

Supplementary Figures S1-5

History

ARTICLE ABSTRACT

SLAMF6 is a homotypic receptor of the Ig-superfamily associated with progenitor-exhausted T cells. Here we show that in humans, SLAMF6 has three splice isoforms involving its V-domain. Although the canonical receptor inhibited T-cell activation through SAP recruitment, the short isoform SLAMF6Δ17–65 had a strong agonistic effect. The costimulatory action depended on protein phosphatase SHP1 and led to a cytotoxic molecular profile mediated by the expression of TBX21 and RUNX3. Patients treated with immune checkpoint blockade showed a shift toward SLAMF6Δ17–65 in peripheral blood T cells. We developed splice-switching antisense oligonucleotides (ASO) designed to target the relevant SLAMF6 splice junction. Our ASOs enhanced SLAMF6Δ17–65 expression in human tumor-infiltrating lymphocytes and improved their capacity to inhibit human melanoma in mice. The yin-yang relationship of SLAMF6 splice isoforms may represent a balancing mechanism that could be exploited to improve cancer immunotherapy.