US researchers have used HIV (Human Immunodeficiency Virus) to develop gene therapy that cured 8 infantswho were treated at St. Jude and at UCSF Benioff Children’s Hospital, San Francisco of a rare combined immunodeficiency disease termed as “bubble boy” disorder.
i. Results of the research were developed at St. JudeChildren’s Research Hospital, Memphis, Tennessee hospital and were published in the New England Journal of Medicine.
ii. The disorder is termed as “bubble boy” after David Vetter born in 1971 had to live in a sterile plastic bubble because the disease made him extremely vulnerable to infectious diseases outside the bubble. He died at age 12 after a failed bone marrow transplant.
iii. Previously, untreated babies with this disorder had to live in completely sterile conditions and died as infants.
What is the “Bubble boy” syndrome?
“Bubble boy” or SCID (Severe combined immunodeficiency) is also known as alymphocytosis, Glanzmann–Riniker syndrome, severe mixed immunodeficiency syndrome, and thymic alymphoplasia.
How is it caused?
SCID is caused by a mutation in the ‘Interleukin-2 receptor Subunit Gamma Gene’ (IL2RG) that produces a protein which is crucial for normal immune-system development.
i. The disease affects 1 in 200,000 newborns, mostly males and without any treatment, it often kills the child in the first 2 years of life.
i. The gene-therapy treatment first collects the baby’s bone marrow, then replaces the mutated gene ‘IL2RG’ with a corrected copy by inserting the “correct” gene into an altered version of one of HIV virus.
ii. Thus, with this treatment, the babies born with ‘SCID-X’ with very little immune protection, now have fully functional immune systems including T (thymus cells) and B(bone marrow- or bursa-derived cells) cells and natural killer (NK) cells after gene therapy treatment.