AIDS, also known as acquired immunodeficiency syndrome, is caused by human immunodeficiency virus (HIV) infection. After entering the human body, HIV mainly attacks CD4-positive T lymphocytes, destroying the body's immune system. In the end, patients often suffer from tumors due to the collapse of the immune system or are infected by other pathogens. The study found that HIV-infected T cells need to be mediated by multiple proteins on the cell surface, so blocking the recognition of these proteins and HIV is expected to cure AIDS.
Scientists have accidentally discovered that an HIV patient has lost HIV in his body after undergoing a bone marrow transplant, which means that the patient's AIDS has been cured by bone marrow transplantation. Further studies have found that its bone marrow donor naturally carries the genetic variation of CCR5△32, and the gene prototype CCR5 is one of the key proteins that mediate HIV-infected T cells. This gene mutation blocks the pathway of HIV-infected T cells and gives T cells a special ability to fight HIV. Therefore, by genetic editing, the CCR5 gene of the patient's hematopoietic stem cells can be replaced with CCR5△32, so that the newly formed T cells can acquire the ability to resist HIV. By combining antiviral drugs, AIDS is expected to be cured. After the technology matures, it will completely change the situation.
Hemophilia: gene therapy makes "trauma bleeding" no longer horrible
Common hemophilia (type A and type B hemophilia) is an X-linked recessive genetic disease. Patients have coagulation dysfunction due to defects in the clotting factor gene. The clinical manifestations are long-term bleeding even with minor trauma. There are many kinds of clotting factors, and each clotting factor plays an important role in the process of coagulation. Different clotting factor genes produce different types of hemophilia, but clinical manifestations are coagulopathy.
At present, the clinical treatment of hemophilia is mainly an alternative treatment, that is, the patient is injected with a blood coagulation factor that is lacking in the blood. The drawbacks of this treatment plan are obvious: can not be cured, require lifelong treatment, and the cost of treatment is very expensive. The idea of gene therapy is very clear - use the method of transgenic techniques to supplement the patient's own cells with the missing clotting factor gene. Coagulation factors are mainly produced by hepatocytes, so the target of hemophilia gene therapy is the patient's liver cells. Unlike the treatment of thalassemia and sickle cell anemia, the “ex vivo” gene therapy program does not work in hemophilia and can only be treated in vivo. The viral vector carrying the normal gene is injected into the liver tissue by in situ injection, and the viral vector introduces the normal gene into the liver cell to realize gene compensation and cure hemophilia.
Oncolytic virus: gorgeous transformation from "devil" to "angel"
Oncolytic viruses are another application of gene therapy in the treatment of cancer. Through genetic modification, scientists have given new functions to traditional viruses:
(1). Oncolytic viruses can multiply and lyse tumor cells after infection with tumor cells, but the proliferation of oncolytic viruses is restricted in normal cells, reducing side effects;
(2). The modified oncolytic virus carries certain genes that can inhibit the division of tumor cells. When the virus infects tumor cells, it inhibits the proliferation of tumor cells, thereby achieving tumor control;
(3). By targeting tumor cells, some modified oncolytic viruses further enhance the tumor killing effect and reduce side effects.
Oncolytic virus is currently part of a number of cancer treatment programs, and it is expected to be used alone or in combination with other treatments to improve the curability of the tumor.
Many pharmaceutical and biotechnology companies, Creative Biolabs as one of them, are keeping pace with the development of international technology.