Posted by on February 17, 2018 6:27 pm
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Source: Baidu news search _crispr

    the second stands

    as the saying goes: people red very much. CRISPR-Cas9 gene editing tools security“supremacy”has not yet dispersed, ushered in“a blow in”. According to the British “nature” magazine website reported, recently published papers reveal: the body’s own immune system may be destroyed based on the CRISPR-Cas9 development of gene therapy, and recommended, for the cure of this technology for diseases, scientists need another way in.

    for this study, China animal Research Institute, Li Wei, Dr. 2 on 8 May to accept the science and technology daily reporter interview, said:“the current study results are not equivalent to the body of the Cas9 protein or Cas9-mediated gene therapies to produce an immune response, but can not confirm that these potential immune response will be very serious, in whether to choose a Cas9 protein for clinical gene therapy before, we still need more and more rigorous experiments to assess the associated immune problems.”

    the body of the Cas9 enzyme to produce an immune response.

    CRISPR-Cas9 is a widely present in microorganisms in the original immune system, The system relies on a method called Cas9 enzyme, to a specific RNA sequence to determine the bit point to be cut. Researchers can change this“guide RNA”of the sequence, the Cas9 is directed to a specific DNA fragment, thereby increasing this system to correct certain genetic mutation possibilities. In view of this, it is generally the CRISPR-Cas9 have high hopes that it one day could be used for the human body, treating a variety of diseases.

    but is the so-called as also Xiao defeated also Xiao he, Cas9, etc. exogenous protein capable of eliciting long-lasting immune response, and the molecular biologist, the most cherished of the two Cas9 enzymes version derived from the human body within the common bacteria-Staphylococcus aureus and Streptococcus pyogenes, which can increase some of these proteins produce an immune response of the probability.

    this case has also been experimentally confirmed. By Stanford University Pediatric Hematology expert Matthew·po-tis and Kenneth Weinberg led the research team, analysis of the 22 infants and 12 healthy adult blood samples, the results found that 79%of participants from Staphylococcus aureus Cas9 enzyme that SaCas9 produce the antibody; 65%of participants from the Streptococcus pyogenes Cas9 enzyme SpCas9 produced the antibody. And in another 12 adults participating in the relevant experiment, 46%of people have been targeting SaCas9 T cells, an immune cell, but did not find targeting SpCas9 to the T-cell responses, but the researchers acknowledge that perhaps they used the test method is sensitive enough to detect the immune response.

    researchers noted that if the body’s immune response can destroy the gene therapy, then, people undergoing treatment may also face health risks. Targeting Cas9 T cells may disrupt the expression of this protein in the cells, clear the“already corrected”cells, and potentially on the body’s own tissue to initiate the attack.

    don’t“talk about immune response color change”

    however, for the latest research, Li Wei is not as POU tis as“alarmed”, he explained:“the latest research found that, in human blood for the presence of Cas9 protein or an antibody able to identify the Cas9 antigen of T cells, indicating the body it is possible for the Cas9 protein generates an immune response. Taking into account the clinical trials require very high security, as well as the two kinds of bacteria in the environment are distributed widely, the results of the study for Cas9-mediated gene editing technology for clinical use has important reference significance, the researchers required in the use of CRISPR gene editing technology for clinical trials before, the potential of the immune response and risk for a more adequate assessment.”

    ��Li Wei further pointed out that the study’s in vitro results of the experiment, the current result is not identical to the Cas9 protein into the body can cause severe immune reactions, for Cas9-induced immune response and its security still requires more rigorous experimental evaluation.

    fundamental application prospects remain huge.

    the latest research means that the CRISPR-Cas9 gene therapy will be“on the wrong foot not the Jie body die first”? “Nature” magazine reported that, taking into account the people on this method with great interest and there are plenty of alternative methods to choose from, it’s not too possible.

    treasure tis conceived two ideas: one for the treatment of sickle cell anemia-from a patient to remove hematopoietic cells, using the CRISPR-Cas9 for them to be corrected, then these cells are injected back into the patient’s body, due to contact with Cas9 in vitro occur, and therefore, this method can not be anti-Cas9 immune response to threats. Another possible solution is that the use does not invade or infect humans bacterial development Cas9 system.

    Intellia the Therapeutics company the solution is to develop a short period of time to produce and only in cells occurs within the action of the Cas9 protein of the therapy, they believe that this will potentially limit the production of immune interference probability, even in the body of the cell genome editing, is also true.

    Li Wei said:“in fact, even if the Cas9 protein may cause some patients severe immune response, there are corresponding solutions. First of all, it has now been proved to be effective on human cells for gene editing protein tool more than a dozen, and also in the continuous accumulation. On the other hand, there has been a lot of research for the Cas9 protein can be modified, to achieve a specific purpose of the transformation, such as reducing off-target properties and the like. We can also be of the Cas9 protein can be modified to reduce its immunogenicity.”

    in addition, Li Wei further noted that:“although the CRISPR-Cas9 technology may also exist as to whether or not enough efficient and accurate, as well as some unknown side effects, for now, it is still the most promising medical application prospects of the technology. Moreover, other gene editing techniques but also in research and development, the future we can obtain a more efficient and versatile gene editing system.”

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