title: Intrathymic administration of hematopoietic progenitor cells enhances T cell reconstitution in ZAP-70 severe combined immunodeficiency.
abstract: Patients with severe combined immunodeficiency (SCID) present with opportunistic infections that are almost universally fatal in infancy. The mainstay treatment for these patients is allogeneic hematopoietic stem cell (HSC) transplantation, but sustained polyclonal T cell reconstitution is too often unsatisfactory. Although transplantation is conventionally performed by i.v. administration of HSC, we hypothesized that an intrathymic strategy would be superior. Indeed, several progenitor cell populations are incapable of homing to the thymus, the major site of T cell differentiation, and it appears that there are extensive time periods during which the thymus is refractory to progenitor cell import. To test this hypothesis, nonconditioned infant ZAP-70-deficient SCID mice were intrathymically injected with WT bone marrow progenitor cells, a procedure accomplished without surgical intervention. Upon intrathymic HSC injection, there was a more rapid T cell differentiation, with mature thymocytes detected by 4 weeks after transplantation. Intrathymic injection of HSC also resulted in significantly higher numbers of peripheral T cells, increased percentages of naïve T cells, and more diverse T cell receptor repertoires. Moreover, T cell reconstitution after intrathymic transplantation was obtained after injection of 10-fold fewer donor HSC. Thus, this intrathymic transplantation approach may improve the outcome of SCID patients by enhancing T cell reconstitution.
authors.affiliation: Institut de Génétique Moléculaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5535/IFR 122, 34293 Montpellier, France.
authors.forename: Oumeya
authors.initials: O
authors.lastname: Adjali
authors.forename: Rita R
authors.initials: RR
authors.lastname: Vicente
authors.forename: Christophe
authors.initials: C
authors.lastname: Ferrand
authors.forename: Chantal
authors.initials: C
authors.lastname: Jacquet
authors.forename: Cédric
authors.initials: C
authors.lastname: Mongellaz
authors.forename: Pierre
authors.initials: P
authors.lastname: Tiberghien
authors.forename: Karim
authors.initials: K
authors.lastname: Chebli
authors.forename: Valérie S
authors.initials: VS
authors.lastname: Zimmermann
authors.forename: Naomi
authors.initials: N
authors.lastname: Taylor
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D011505:Protein-Tyrosine Kinases / Q000172:deficiency*; D020127:Recovery of Function / Q000276:immunology*; D016511:Severe Combined Immunodeficiency / Q000276:immunology / Q000628:therapy*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D014184:Transplantation, Homologous; D051746:ZAP-70 Protein-Tyrosine Kinase
chemical_list: D011505:Protein-Tyrosine Kinases; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; C497262:Zap70 protein, mouse