Recently, I saw an article referencing a young girl’s leukemia being fought by HIV viral transformation. The headline was surprisingly restrained, but the mere mention of HIV (a pathogen surrounded by fear and misinformation, like AIDS denial) risks leaving many readers thinking an HIV infection cured a young girl’s leukemia (not true!). So, I headed to the scientific literature to see if this flashy headline’s mention of HIV was really warranted.
Just as a brief bit of background, it is quite common in cell biology laboratories to introduce genetic sequence into cells via infection of the cells by a virus carrying that genetic sequence. In the case of this new leukemia treatment, the doctors wanted to take the sick patient’s T-cells out of her body and reprogram them via viral infection to attack the cause of her leukemia, her B cells. In some types of leukemia, there is an overproliferation of B cells at the cost of making red blood cells.
To reprogram the T cells, they needed a way to effectively introduce a genetic sequence that would make the T cells able to specifically target and kill B cells. The virus currently most effective at infecting T cells is HIV. The scientists took only the part of the virus’ sequence responsible for effective infection of T cells and replaced the rest with sequence that will enable the cells to specifically target B cells for destruction. When these cells are returned to the body they multiply and go about the business of destroying the over-abundant B cells. These reprogrammed cells will stick around and continue to kill B cells keeping the cancer at bay. These patients will need periodic infusions of healthy B cells but hopefully will not see a resurgence of their cancer.
HIV was involved, but as part of the molecular biology toolkit scientists are using in experiments to reprogram our own immune cells to fight cancer. In the case of the young patient, this was the first time this treatment was effective in producing remission in a child.