Lentivector cryptic splicing mediates increase in CD34+ clones expressing truncated HMGA2 in human X-linked severe combined immunodeficiency.

X-linked Severe Combined Immunodeficiency (SCID-X1) due to IL2RG mutations is potentially fatal in infancy where 'emergency' life-saving stem cell transplant may only achieve incomplete immune reconstitution following transplant. Salvage therapy SCID-X1 patients over 2 years old (NCT01306019) is a non-randomized, open-label, phase I/II clinical trial for administration of lentiviral-transduced autologous hematopoietic stem cells following busulfan (6 mg/kg total) conditioning. The primary and secondary objectives assess efficacy in restoring immunity and safety by vector insertion site analysis (VISA).

Hypomorphic Rag mutations can cause destructive midline granulomatous disease.

Destructive midline granulomatous disease characterized by necrotizing granulomas of the head and neck is most commonly caused by Wegener granulomatosis, natural killer/T-cell lymphomas, cocaine abuse, or infections. An adolescent patient with myasthenia gravis treated with thymectomy subsequently developed extensive granulomatous destruction of midface structures, palate, nasal septum, airways, and epiglottis. His lymphocyte numbers, total immunoglobulin G level, and T-cell receptor (TCR) repertoire appeared normal.

Simian immunodeficiency virus lentivector corrects human X-linked chronic granulomatous disease in the NOD/SCID mouse xenograft.

X-linked chronic granulomatous disease (X-CGD) is a primary immunodeficiency caused by mutations in the phagocyte nicotinamide dinucleotide phosphate oxidase catalytic subunit gp91(phox). Gene therapy targeting hematopoietic stem cells (HSCs) can correct CGD, but permanent correction remains a challenge. Lentiviral vectors have become attractive tools for gene transfer, and they may have the potential to transduce very primitive HSCs.

Diprotin A infusion into nonobese diabetic/severe combined immunodeficiency mice markedly enhances engraftment of human mobilized CD34+ peripheral blood cells.

Hematopoietic stem cell (HSC) graft cell dose impacts significantly on allogeneic transplant. Similarly, HSC gene therapy outcome is affected by loss of repopulating cells during culture required for ex vivo retrovirus transduction. Stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 play a central role in marrow trafficking of HSCs, and maneuvers that enhance CXCR4 activation might positively impact outcome in settings of limiting graft dose.

The late dividing population of gamma-retroviral vector transduced human mobilized peripheral blood progenitor cells contributes most to gene-marked cell engraftment in nonobese diabetic/severe combined immunodeficient mice.

We used the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model to assess the repopulation potential of subpopulations of mobilized human CD34+ peripheral blood progenitor cells (PBPC). First, PBPC were transduced with gamma-retrovirus vector RD114-MFGS-CFP, which requires cell division for successful transduction, at 24 hours, 48 hours, and 72 hours to achieve 96% cyan fluorescent protein (CFP)-positive cells. Cells were sorted 12 hours after the last transduction into CFP-positive (divided cells) and CFP-negative populations.