Chinese scientists find new ways to treat AIDS and leukemia!

CCR5-modified HSPCs transplantpicture Source: Lei Xu et alN Engl J Med 2019 DOI: 10.1056/NEJMoa1817426We all know that the genome editing of mammalian cells by the R-Cas9 gene editing tool is now widely used, demonstrating potential clinical use, and researchers are now beginning to use this technology to explore the safety and efficacy of human DISEASE-based treatmentsCCR5 is a protective target for HIV-1 infection in the human body, and CCR5-missing blood cells are often highly resistant to HIV-1 infection; Stemgen cells can be transplanted into allogeneic cells for a long time because CCR5 is a key co-receptor for HIV entering the body, and these cases may increase the possibility that transplanting cells that carry artificial lysering CCR5 may be used as a new way to create cells resistant to HIV-1 infectionprevious study, researchers have created a virus-free CRISPR gene editing system that produces 27% of the human HSPCs that have been destroyed by CCR5; in animal models, these CCR5-modified HSPCs produce a strong immune system that is resistant to HIV-1 infection; in this study, researchers rejected CRISPR-edited CCR5In patients with HIV-1 infection and acute lymphoblastic leukemia (ALL), the researchers found that the patient's ALL was fully relieved (full donor chimeric) and that donor cells with CCR5 were rejected could survive in the patient for more than 19 months, while the patient did not experience adverse reactions associated with gene editingDuring the interruption of patient stort ators, there was a slight increase in the proportion of CD4-T cells with CCR5 rejected, and although the researchers achieved the success and long-term transplantation of CRISPR-edited HSPCs, only about 5% of CCR5 was destroyed in lymphocytes, which required further further study by the researchers2017 Deng Hongkui's team optimized the technology system and was committed to the clinical application of the technology, which has been approved by the ethics committee of the former PLA 307 hospital and registered for clinical research (NCT03164135) on the ClinicalTrials.gov websiteThe patients in this study were diagnosed with HIV-AIDS and ALL (T-cell type) 16 times on May 14 and May 2016, respectively, with a viral load of 8.5 x 106 copies/ml, a CD4 plus cell count of 528 x 106/l, and a random treatment of 300 mg of lamiffin, 300 mg of notoctinavea per day, and lilotovina-to-litre sphilationNavir (400mg lopinavir and 100mg litonavir), after 1 year of treatment, hiv-1 infection in the patient's body is effectively controlled, and the presence of viral RNA cannot be detected in the serum (i.eless than 40 copies/ml); and 0.04%, after 6 courses of micro-residual disease was not detected (less than 0.01%)The donor is a 33-year-old male donor from China's bone marrow donation program, carrying an unmutated CCCR5 gene that perfectly matches the receptor's HLA (tissue-compatible antigen), September 2017The patient received an allogeneic hematopoietic stem progenitor cell transplantthe study, the researchers reported successful allion alsottotransplantation of HSPCs with CCR5 mutations with crispR-Cas9 gene editing, where donor cells were fully embedded and all of patients with HSPCs were fully remissiond for 19 months, during which time The modified CCR5 gene is able to persist, with a range of 5.20%-8.28% of CCR5 mutations in bone marrow cells, and the results demonstrate that researchers can achieve long-term transplantation of allogeneic HSPCs edited by CRISPR, but the response efficiency of the transplanted receptor may not be sufficient to achieve the goal of curing HIV-1 infectionin 19 months of follow-up observations by the researchers, they found that THE CRISPR-mediated CCR5 culling efficiency was 5.20%-8.28% in bone marrow samples, while the researchers observed CRISPR-mediated CCR5 culling in multiple bloodline cells, which indicates that CCR5-rejected/mutated HSPCs can be transplanted into the patient's body for a long time and play a corresponding roleIn particular, cd4-T cells and CCR5 mutants in the patient's body can be continuously produced and released into the patient's peripheral blood, while the number of CD4-T cells in peripheral blood will gradually return to normal levels within 6 months of the patient's transplant, while the patient's treatment for HIV-1 infection can also provide opportunistic protection important aspect of this paper's research is that researchers were able to assess the clinical safety of CRISPR-Cas9-mediated gene therapy, which had previously been less effective because exogenous DNA was randomly integrated into the host genome, sometimes even triggering an acute immune response or tumor In this study, researchers introduced Cas9 ribonucleoprotein swashes through non-viral transfection, effectively avoiding the introduction of exogenous DNA and the long-term presence of Cas9 in target cells, which may be a potential cause of accidental off-target mutations Using high-throughput whole genome sequencing, the researchers analyzed samples before and 15, 12 and 19 months after the patient's transplant, and did not detect any single nucleotide mutations, missing large fragments, and chromosomal rearrangement associated with CRISPR modification; Clinical adverse events brought about by gene editing and off-target effects often provide initial support for the safety of gene editing methods, however, the current inefficient targeting of CCR5 may limit the depth of off-target gene editing analysis; the rate of CCR5 deletion spree increased in patients' organisms after seven months of transplanting HSPCs, and two weeks after the interruption; recent studies have shown that the purity of CCR5-32 mutations is often associated with a decrease in life expectancy in patients, which may highlight the potential lysable effects of CCR5 mutations at the individual level; In summary, this new study by Chinese scientists describes the long-term transplantation of CD34-plus cells edited by CCR5 CRISPR gene after an allogeneic stem cell transplant, which interferes with the genome of circulating bone marrow cells by less than 8% and does not have a off-target effect of gene editing This multi-year work has now confirmed the feasibility and safety of gene-edited hematopoietic stem cells in clinical applications, which will promote and promote the clinical application of the technology in the future In the future, researchers will continue to study in depth ways to optimize gene-edited hematopoietic stem cell transplantation programs to reduce off-target rates and achieve 100% CCR5 knock-out efficiency References: Lei Xu, M.D., Ph.D., Jun Wang, M.D., Ph.D., Yulin Liu, B.S., et al CRISPR-Edited Stem Cells In A Patient HIV and Acute Lymphocytic, Ngl J Med 2019; 381:1240-1247 do: 10.1056/NE616