CD 47 agonist peptide PKHB 1 induces immunogenic cell death in T‐cell acute lymphoblastic leukemia cells

• Published in: Cancer science 2019-01, Vol.110 (1), p.256-268
• Main Authors: Uscanga‐Palomeque, Ashanti Concepción, Calvillo‐Rodríguez, Kenny Misael, Gómez‐Morales, Luis, Lardé, Eva, Denèfle, Thomas, Caballero‐Hernández, Diana, Merle‐Béral, Hélène, Susin, Santos A., Karoyan, Philippe, Martínez‐Torres, Ana Carolina, Rodríguez‐Padilla, Cristina
• Format: Article
• Language: English
• Subjects: Acute lymphoblastic leukemia; Agonists; Antigens; Apoptosis; Bone marrow; Calcium (mitochondrial); Calreticulin; Cancer; Cancer therapies; Cancer vaccines; Caspase; Cell activation; Cell adhesion & migration; Cell death; Chemoresistance; Chronic lymphocytic leukemia; Flow cytometry; Heat shock proteins; Hematology; Human health and pathology; Immunogenicity; Immunoglobulins; Immunological memory; Immunology; Immunotherapy; Leukemia; Leukocytes; Life Sciences; Lymphatic leukemia; Lymphatic system; Medical prognosis; Membrane potential; Microscopy; Mitochondria; Molting; Peptides; Peripheral blood; Proteins; Spleen; Thrombospondin; Tumor cell lines; Tumor cells; Vaccination; Vaccines; Vaccinology
• ISSN: 1347-9032; 1349-7006
• DOI: 10.1111/cas.13885

T‐cell acute lymphoblastic leukemia (T‐ ALL ) has a poor prognosis derived from its genetic heterogeneity, which translates to a high chemoresistance. Recently, our workgroup designed thrombospondin‐1‐derived CD 47 agonist peptides and demonstrated their ability to induce cell death in chronic lymphocytic leukemia. Encouraged by these promising results, we evaluated cell death induced by PKHB 1 (the first‐described serum‐stable CD 47‐agonist peptide) on CEM and MOLT ‐4 human cell lines (T‐ ALL ) and on one T‐murine tumor lymphoblast cell‐line (L5178Y‐R), also assessing caspase and calcium dependency and mitochondrial membrane potential. Additionally, we evaluated selectivity for cancer cell lines by analyzing cell death and viability of human and murine non‐tumor cells after CD 47 activation. In vivo, we determined that PKHB 1‐treatment in mice bearing the L5178Y‐R cell line increased leukocyte cell count in peripheral blood and lymphoid organs while recruiting leukocytes to the tumor site. To analyze whether CD 47 activation induced immunogenic cell death ( ICD ), we evaluated damage‐associated molecular patterns ( DAMP ) exposure (calreticulin, CRT ) and release ( ATP , heat shock proteins 70 and 90, high‐mobility group box 1, CRT ). Furthermore, we gave prophylactic antitumor vaccination, determining immunological memory. Our data indicate that PKHB 1 induces caspase‐independent and calcium‐dependent cell death in leukemic cells while sparing non‐tumor murine and human cells. Moreover, our results show that PKHB 1 can induce ICD in leukemic cells as it induces CRT exposure and DAMP release in vitro, and prophylactic vaccinations inhibit tumor establishment in vivo. Together, our results improve the knowledge of CD 47 agonist peptides potential as therapeutic tools to treat leukemia.