The development and biological analysis of cell therapy.

Text . . . After the outbreak of the new coronavirus in 2020, people have become more aware of today's medical methods after such a medical battle.
in the long process of human evolution and the fight against disease, medical methods continue to upgrade, from drug therapy, surgical treatment to a new stage, a new field - cell therapy.
cell therapy as a third generation of medical means, whether it is the use of their own cells to fight cancer "over-the-counter immune cell therapy", or the 10-0most "stem cell therapy", have shown great prospects.
paper summarizes the development of cell therapy and briefly introduces the characteristics of cell therapy products and clinical trial-related tests.
course of the development of
cell therapy is the secondary immunocellular therapy is to remove T cells with anti-cancer ability from the patient's body, proliferate in vitro, and then inject back into the patient's body, so as to achieve the removal of tumor cells.
This treatment is different from conventional radiotherapy and chemotherapy, and the T-cells in the re-injection body are only highly specific to tumor cells and are less damaged to the body, making it a potential and challenging treatment.
scientists have tried to study a number of T-cells, and immunocellular therapy has undergone four technological innovations, see Figure 1.
1 Immune Cell Therapy Technology Update From 1976, when Morgan et al. discovered the amplification effect of leucine 2 (IL-2) on T cells and mass-produced them, scientists used IL-2 to induce LAK cells to treat a variety of malignant tumors, including melanoma and lung cancer.
this is the earliest step-by-step immunocellular therapy.
But LAK cells rely on large doses of IL-2, treatment side effects are larger, the most common and most serious toxic side effects are the emergence of capillaries leakage syndrome (CLS), mainly manifested as systemic edema and multi-organ dysfunction, can cause thoracic abdominal fluid, pulmonary edema and congestive heart failure.
in LAK therapy, Rosenberg et al. isolated TIL cells from tissues near the tumor.
compared with LAK therapy, TIL therapy has a certain tumor specificity, clinical effect is better than LAK therapy, mouse experiments proved that its tumor killing effect is 50-100 times higher than LAK.
TIL technology system is more complex, the training success rate is not high, greatly limiting the clinical application, but with the development of training technology in recent years, I believe that good clinical progress will be made.
1991, the Bone Marrow Transplant Center at Stanford University School of Medicine reported CIC cells with high proliferation and high cytotoxicity.
the emergence of CPK technology, for the first time to get rid of cell culture and re-transmission process of large doses of IL-2 dependence, significantly reducing the clinical side effects of patients.
in China, CIK technology has been vigorously developed, more than 500 hospitals have used CIK and CIK-based cell therapy technology for the treatment of tumor patients, and confirmed that CIK technology can significantly improve the quality of life of patients, prolong the survival of patients with advanced tumors.
The DEndritic Cell vaccine, Sipuleucel-T, approved in April 2010, is the FDA's first therapeutic cancer vaccine, which is an active immune cell stimulated by granulocyte-macrophage cluster stimulation factor (GM-CSF) and prostate acid phosphatase (PAP), an active immune cell that dc fights by stimulating the body's immune function.
, a link between DC and CIC therapy has emerged to build tumor-specific lethal T-cells.
since then, cell therapy has entered a phase of "individualization and precision".
simplifying the interaction between DCs and CIC cells, mature DCs can also interact with NK cells as gene technology develops, and scientists try to transform T cells with viruses as vectors.
T-cells from the patient for in vitro amplification, new genes are inserted into T-cells to enhance their ability to identify attacks on tumor cells.
TCR-T (T-cell receptor engineered T cells) is a "individualized" treatment for differences in tumor antigens in different patients using the patient's own exosychonic blood T cells to transfer the TCR sequence of tumor-related antigens into T-cells through genetic modification.
because TCR-T is a major tissue compatible complex (MHC) restrictive and can only be used for patients' own treatment, this limits the extendability of TCR-T clinical applications.
The principle of CAR therapy that came into being is similar to that of TCR therapy, which enables the patient's T-cells to express the embedded antigen-converted CAR, return the modified T-cells to the patient, and produce a large number of car-T cells specifically identified by the tumor to kill the tumor cells.
CAR-T cells are used to identify tumor cells in a non-MHC-restricted manner.
year, CAR carrier construction has grown to the 4th generation, with better specificity.
3 CAR structural schematic anti-CD19 CAR-T has made remarkable achievements in the study of malignant tumors in the blood system, has been officially listed in Europe and the United States in 2017.
April 21, the CDE website showed that the country's first CD30-targeted in-body CAR-T cell therapy was approved for clinical use.
Figure 4 Globally approved CAR-T therapeutic products today, in addition to CAR-T, many immune cells such as NK cells, gamma T cells and DC are also ideal for the treatment of tumors, and also combined with genetic modification technology to become a new direction of cancer immunocell therapy research.
stem cell therapy began in the 1960s, when Canadian scientists Ernest A. McCulloch and James E. Till first demonstrated the presence of stem cells in the blood, which can be differentiated into multiple cells.
5 The application of hematocyte genealogy and the potential for disease treatment 1967, E. Donnall Thomas completed the first bone marrow transplant to treat hematic dysfunction, a study that won the Nobel Prize in Medicine and Physiology in 1990.
1998, human embryonic stem cells grew and proliferated successfully in-body.
In 1999, Goodell et al. discovered that adult stem cells in mouse muscle tissue can "horizontally differentiate" into blood cells, breaking the limit that stem cells for clinical treatment can only come from embryos or fertilized eggs, providing a new way for stem cells to treat diseases.
1999, the results of research in stem cell and regenerative medicine have been selected 11 times in Science magazine's top ten scientific breakthroughs of the year, highlighting the importance that the scientific community attaches to this field.
addition, in the use of stem cells to build tissues and organs, researchers have used stem cell culture in-body to obtain "micro-organs" to build the liver, brain and kidneys.
Stem cell therapy is mainly based on 3 theories of adult stem cells: 1) stem cells have unlimited reproductive capacity and the ability to convert to all cells;
The successful results of the 2007 study of induced pluripotent stem cells (iPSCs) by Japanese scientists completely upended the traditional understanding of life and stem cells, bypassed the ethical and legal obstacles that embryonic stem cell research has been facing, became a new hot spot in stem cell research, and formed the fourth theory of stem cell therapy: the use of special means to induce adult cells to reverse into cells with embryonic stem cell differentiation function, iPSC theory.
Clinically more researched stem cell treatment diseases are leukemia, malignant anemia, regenerative disorder anemia, cirrhosis, Crohn's disease, childhood autism, cerebral palsy, Parkinson's disease, Alzheimer's disease, diabetes foot, systemic lupus erythematosus, arthritis, rheumatoid arthritis, transplant anti-host disease, acute myocardial infarction, tumors, etc.
the diversity of treatment for the disease is determined by the complexity of stem cell therapy mechanisms.
Figure 6 The application diversity of stem cell technology is currently approved worldwide 13 kinds of stem cell products approved for market, involving adaptive diseases including knee osteoarthritis, cardiovascular, transplant anti-host disease, Crohn's disease, etc., China's research in the field of stem cells is also in the forefront of the world, especially in the field of interstumined stem cells, although many are still in clinical I, II, but the future can be.
Figure 7 Approved Stem Cell Products (data as of 2020.3) Stem cell clinical research is mainly focused on hematopoietic stem cells (HSCs) and interstumogenic stem cells (MSCs), and neural stem cells (NSCs) and erneernic stem cells (PSCs) are also considered promising prospects in recent years.
There are studies that attempt to obtain neural stem cells through induced differentiation of the aborted fetal brain and their own bone marrow or umbilical cord hemorrhoid stem cells to treat neuro-injury diseases such as glioma, amyotrophy lateral sclerosis (ALS), chronic spinal cord injury and stroke, and the fastest studies are still in Clinical Phase II.
induced errogenic stem cell iPSC due to gene editing is less clinically used.
progress has been made in the currently reported studies of iPSC diagonal repair, heart disease treatment and Parkinson's treatment, but a large number of clinical studies are needed to see the problems.
Hematopoietic stem cell research adaptation is mainly malignant tumors of the blood system, such studies have more adverse reactions, most of which are related to combined chemotherapy and pre-treatment prior to transplantation, and because of the use of allogeneic cells at the time of transplantation, prone to acute and chronic graft anti-host disease (GVHD), and affect the patient's prognosis.
in recent years, there have also been attempts to treat liver and isothermic diseases with self-hematopoietic stem cells, and adverse reactions have been reported relatively rarely.
is the type of stem cell that has carried out the most clinical research in addition to hematopoietic stem cells.
-charged stem cells in animal tests, have good safety and low immunogenicity, no obvious toxic reaction and tumor-like, so widely used.
During the outbreak of neo-crown pneumonia, stem cell therapy was also used for the treatment of severe neo-coronavirus pneumonia, and clinical results have been gratifying, interstitine stem cells on the immune system of the two-way regulation of the acute respiratory distress syndrome (ARDS) in severe patients with neo-crown pneumonia has a positive effect.
many patients are turned from heavy to light or even cured.
gives us a lot of confidence in stem cell therapy.
there is currently no uniform quality standard for stem cell preparations, as the markers on the surface of stem cells are sometimes unstable, making it difficult to identify and classify stem cells.
the number of stem cells used in clinical treatments cannot be amplified indefinitely, as genetic mutations accumulate as the number of amplifications increases, increasing the genetic risk.
In view of this, stem cell-related regulations need to be further improved, the regulatory authorities of various countries, the Fda, as well as China's National Health and Family Planning Commission, the State Food and Drug Administration, have developed corresponding guidelines for stem cell research technology to support the development of the cell therapy industry.
the characteristics of cell therapy products today, the cutting-edge development direction of cell therapy is combined with gene editing technology such as CAR-T, iPSC, so that it not only has the characteristics of cell products but also the characteristics of genetic products.
some products of cell and gene therapy are relatively inexperienced compared to small molecules that have matured.
many of the clinical data in the literature are small samples and single centers, and due to the particularity of the experimental population, there may be considerable uncertainty about the safety that may be associated with specific types of cells and gene therapy products.
In addition, some cell and gene therapy products can last longer in the human body after a single drug is given, or even after the product itself no longer exists, and the effect of the product may change over time.
treatment of cell therapy products can be varied, possibly intravenously, or may require surgery or other invasive operations to reach the target site.
the increased risk of surgery may also be an important part of the overall treatment risk.
addition, there is a possibility of induced immunogenicity for isogenetic cell therapy products, gene therapy vectors, and proteins that may be produced by cells and gene therapy products.
First, antibodies that already exist, or that are produced after giving, may reduce or eliminate positive effects, cause adverse reactions (such as autoimmune syndrome), or affect safety or reduce efficacy when subsequent dossing is possible.
is that for patients who can be treated with cell, tissue, or organ transplants, there may be an exclusive reaction that affects the transplant. bioanalysis of
cell therapy products for cell therapy products may present a variety of molecules on the cell membrane and express a variety of factors (e.g., the International Society for Cell Therapy defines stem cells, requiring more than 95% of cell expression cell surface markers CD105, CD73, CD90, CD44, CD29, the vast majority do not express hematocyte surface markers CD31, CD45, CD34, CD14, CD11b, CD79a and CD19, nor do they express MHCII. class molecules.
these molecules and factors may be affected by the micro-environment and change over time.
cells may differentiate into unwanted cell types in the body. < br.