title: B cell-specific lentiviral gene therapy leads to sustained B-cell functional recovery in a murine model of X-linked agammaglobulinemia.
abstract: The immunodeficiency disorder, X-linked agammaglobulinemia (XLA), results from mutations in the gene encoding Bruton tyrosine kinase (Btk). Btk is required for pre-B cell clonal expansion and B-cell antigen receptor signaling. XLA patients lack mature B cells and immunoglobulin and experience recurrent bacterial infections only partially mitigated by life-long antibody replacement therapy. In pursuit of definitive therapy for XLA, we tested ex vivo gene therapy using a lentiviral vector (LV) containing the immunoglobulin enhancer (Emu) and Igbeta (B29) minimal promoter to drive B lineage-specific human Btk expression in Btk/Tec(-/-) mice, a strain that reproduces the features of human XLA. After transplantation of EmuB29-Btk-LV-transduced stem cells, treated mice showed significant, albeit incomplete, rescue of mature B cells in the bone marrow, peripheral blood, spleen, and peritoneal cavity, and improved responses to T-independent and T-dependent antigens. LV-treated B cells exhibited enhanced B-cell antigen receptor signaling and an in vivo selective advantage in the peripheral versus central B-cell compartment. Secondary transplantation showed sustained Btk expression, viral integration, and partial functional responses, consistent with long-term stem cell marking; and serial transplantation revealed no evidence for cellular or systemic toxicity. These findings strongly support pursuit of B lineage-targeted LV gene therapy in human XLA.
authors.affiliation: Center for Immunity and Immunotherapies, Seattle Children's Research Institute, WA 98101, USA.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Kerns
authors.forename: Byoung Y
authors.initials: BY
authors.lastname: Ryu
authors.forename: Brigid V
authors.initials: BV
authors.lastname: Stirling
authors.forename: Blythe D
authors.initials: BD
authors.lastname: Sather
authors.forename: Alexander
authors.initials: A
authors.lastname: Astrakhan
authors.forename: Stephanie
authors.initials: S
authors.lastname: Humblet-Baron
authors.forename: Denny
authors.initials: D
authors.lastname: Liggitt
authors.forename: David J
authors.initials: DJ
authors.lastname: Rawlings
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D000361:Agammaglobulinemia / Q000503:physiopathology* / Q000628:therapy*; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology*; D001854:Bone Marrow Cells / Q000166:cytology; D016026:Bone Marrow Transplantation; D051925:CD79 Antigens / Q000235:genetics; D002460:Cell Line; D019070:Cell Lineage; D004195:Disease Models, Animal; D040181:Genetic Diseases, X-Linked / Q000503:physiopathology / Q000628:therapy*; D015316:Genetic Therapy / Q000009:adverse effects; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000378:metabolism / Q000627:therapeutic use; D020127:Recovery of Function / Q000502:physiology*
chemical_list: D051925:CD79 Antigens; D007143:Immunoglobulin Heavy Chains; C089848:Tec protein-tyrosine kinase; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; C000625951:Btk protein, mouse