gammac gene transfer in the presence of stem cell factor, FLT-3L, interleukin-7 (IL-7), IL-1, and IL-15 cytokines restores T-cell differentiation from gammac(-) X-linked severe combined immunodeficiency hematopoietic progenitor cells in murine fetal thymic organ cultures.
X-linked severe combined immunodeficiency (SCID-Xl) is a rare human inherited disorder in which early T and natural killer (NK) lymphocyte development is blocked. The genetic disorder results from mutations in the common gammac chain that participates in several cytokine receptors including the interleukin-2 (IL-2), IL-4, IL-7, IL-9, and IL-15 receptors. We have shown in a previous report that gammac gene transfer into SCID-Xl bone marrow (BM) cells restores efficient NK cell differentiation. In this study, we have focused on the introduction of the gammac gene into SCID-Xl hematopoietic stem cells with the goal of obtaining differentiation into mature T cells. For this purpose, we used the in vitro hybrid fetal thymic organ culture (FTOC) system in which a combination of cytokines consisting of stem cell factor (SCF), Flt-3L, IL-7, IL-1, and IL-15 is added concomitantly. In this culture system, CD34(+) marrow cells from two SCID-Xl patients were able to mature into double positive CD4(+) CD8(+) cells and to a lesser degree into CD4(+) TCRbeta+ single positive cells after retroviral-mediated gammac gene transfer. In addition, examination of the output cell population at the TCR DJbeta1 locus exhibited multiple rearrangements. These results indicate that restoration of the gammac/JAK/STAT signaling pathway during the early developmental stages of thymocytes can correct the T-cell differentiation block in SCID-Xl hematopoietic progenitor cells and therefore establishes a basis for further clinical gammac gene transfer studies.
Hacein-Bey
S
S
Institut National de la santé et de la Recherche Médicale U429 et Centre de Transfusion Sanguine, Hôpital Necker-Enfants Malades, Paris Cedex, France.
Basile
G D
GD
Lemerle
J
J
Fischer
A
A
Cavazzana-Calvo
M
M
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D019409:Interleukin-15 / Q000494:pharmacology; D015851:Interleukin-7 / Q000494:pharmacology; D051379:Mice; D009924:Organ Culture Techniques; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics*; D016511:Severe Combined Immunodeficiency / Q000235:genetics* / Q000276:immunology / Q000628:therapy; D019089:Stem Cell Factor / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*
D007375:Interleukin-1; D019409:Interleukin-15; D015851:Interleukin-7; D016692:Receptors, Antigen, T-Cell, gamma-delta; D019089:Stem Cell Factor; C078584:T-cell receptor V(gamma)3