gamma-c gene transfer into SCID X1 patients' B-cell lines restores normal high-affinity interleukin-2 receptor expression and function.
SCID X1 is characterized by faulty T-cell and natural killer cell differentiation caused by mutation of the gamma-c chain gene encoding a number of multiple cytokine receptors (interleukin-2 [IL-2], IL-4, IL-7, IL-9, and IL-15 receptors). To assess the feasibility of inducing long-term expression and function of the gamma-c chain, Epstein-Barr virus (EBV)-transformed B-cell lines from two patients with SCID X1 were transduced with a Moloney-derived retroviral vector containing the gamma-c chain cDNA. The viral LTR was used as the promoter. Immediately after two cycles of coculture with the psi-crip clone producing the MFG(B2)-gamma-c cDNA vector, gamma-c expression, assessed by detection of the mRNA and membrane protein expression, was found in 15% to 20% of cells. The degree of membrane expression was similar to that in control EBV-B cells. Expression increased steadily over 6 months, becoming detectable in 100% of cells, and remained stable thereafter for a total of 9 months, reflecting positive selection of transduced cells. A study of provirus integration sites showed multiple integration. The expressed gamma-c was functional, because it restored high-affinity IL-2 receptor binding, IL-2 endocytosis, and IL-2-triggered phosphorylation of JAK-3 tyrosine kinase. Similar results were obtained with the two B-cell lines. These results show that efficient gamma-c gene transfer into B-cells lacking functional gamma-c is feasible and results in strong and stable expression of a functional gamma-c chain, apparently conferring a selective growth advantage in culture. Further in vitro studies of gamma-c gene transfer into gamma-c- hematopoietic progenitors are being conducted to assess the feasibility of correcting lymphocyte differentiation defects.
Hacein-Bey
H
H
Institut National de la Santé et de la Récherche Medicale U429, Hôpital Necker-Enfants Malades, Paris, France.
Cavazzana-Calvo
M
M
Le Deist
F
F
Dautry-Varsat
A
A
Hivroz
C
C
Rivière
I
I
Danos
O
O
Heard
J M
JM
Sugamura
K
K
Fischer
A
A
De Saint Basile
G
G
D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001483:Base Sequence; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis; D005816:Genetic Complementation Test; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics*; D004854:Herpesvirus 4, Human; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology; D053616:Janus Kinase 3; D008297:Male; D008969:Molecular Sequence Data; D010766:Phosphorylation; D055503:Protein Multimerization; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D016511:Severe Combined Immunodeficiency / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D014162:Transfection; D014960:X Chromosome / Q000235:genetics
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; D011505:Protein-Tyrosine Kinases; C507933:JAK3 protein, human; D053616:Janus Kinase 3