Interview with experts
Dr. Cui Jun, Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of
Biocontrol, School of Life Sciences, Sun Yat-sen University.
Dr. Xia Xiaojun, State Key Laboratory of Oncology in South China
Q1: How is CAR-T therapy doing in clinical?
Dr. Cui Jun (referred as C hereafter): CAR-T is the future of Immunology and tumor treatment.
Accordingly, the Noble Prize in Physiology or Medicine of this year goes to CAR-T therapy, concerning the great developments made in
this field. It is strongly indicated that CAR-T and adoptive T-cell therapy are the hotspot of follo wing researches. These days, the
application of CD19 in clinical and FDA's approval of it both show that CAR-T is feasible in practical operation. And there still remains a lot of improvements could be made in the future, like broader applications, slighter side-
effects, and more effective function.
Dr. Xia Xiaojun (referred as X hereafter)：CAR-T has achieved good results in hematological tumors, but almost no result has been achieved in solid
tumors.
Q2: How is CAR-T operated in clinical?
C: The patient needs a Lymphatic clearance before given CAR-T treatment. And his immune system will be rebuilt after. This whole
process has to be done in an gem-free room, considering the patient's vulnerable condition.
Actually, you can call CAR-T a personalized treatment, since different patients with different
conditions need to be given different treatments. So, more attempt and exploration are required.
Q3: What is the potential side-effect of CAR-T therapy?
C: The modified immune system will kill tumor cells efficiently with substantial cytokines released, which leads to a disastrous cytokine storm. Because CAR-T therapy targets on antigens, normal organs expressing the
same antigen as the tumor will be friendly-fired by CAR-T. So, CAR-T therapy will possibly cause
tissue-specific damage.
X: The excessive immune response of CAR-T causes cytokine storms, and excessive inflammatory
reactions can also put the patient's life at risk. In addition, Off-target effect is dangerous.
For example, HER2 was used as a target. HER2 CAR-T cells not only kill tumor cells with high expression of HER2, but also damages
cardiomyocytes expressing HER2, resulting in patients' myocarditis. We try to achieve the goal that the target of CAR-T is not
expressed in cells other than tumor cells. Recently, Nature Medicine reported the emergence of
CAR-cancer cells, which acquired the genes of CAR during CAR-T preparation, leading to
treatment failure.
Q4: Which side-effect is the most terrible one in currently CAR-T therapy?
C: Cytokine Storm, I shall say. Cytokine can activate immune responses on one hand, and its too
high or too long expression could also be harmful on the other hand. Terrible ones will lead to patients’ organ damage. In fact,
there exists a lot of negative regulation system in human body, however, cytokine storm caused by CAR-T therapy cannot simply be
regulated by that. So this is a tough problem facing CAR-T therapy and its patients.
Q5: Is there ways to inhibit the side-effect of CAR-T therapy now？
C: At present, we try to fix cytokine storm from its source, that is to stop the over-
production of cytokines in T cells. However,when cytokine storm is already established, little can we do but to interfere it with
antibodies. And antibody interference is expensive, cytokine-
specific, and potentially poisonous itself. As for single cytokine with definite toxicity, antibody interference is very
effective. While in a cytokine storm, it's hard to find the notably toxic ones among a great amount of cytokines. So the inhibition
of cytokine storm by antibody interference cannot be achieved unless we could lock the most toxic one.
X: It is not too difficult to solve if nothing but cytokine storm exists. Initially, some doctors use
glucocorticoids to completely suppress inflammation. But glucocorticoids will definitely affect
the therapeutic effect. Doctors just have to use this method and sacrifice efficacy.
After we know the most important toxic cytokines, we will be able to use some specific cytokine
blocking antibodies. Although it also inhibits part of the immune response and has a slower rate, it is superior to the
overall inhibition.
In addition, some companies in the United States, such as cellectis and bellicum, have similar
ideas to yours. They want to use a switch to let CAR-T work as expected.
Q6: Will the high cost of treatment hinder the popularizing of CAR-T?
C: As for me, the high cost will not be a problem in the future. With the development of bio-technology, the price of CAR-T treatment
will be definitely decreasing. Inevitably, as a research hotspot, CAR-T can attract more and
more researchers to find new ways to lower its cost. For now, as a kind of cancer treatment, the price of CAR-T is
acceptable relatively.
Q7: A viral protein (has been checked in) is involved in our project. In your opinion, what kind of safety problems will it bring?
C: There's no doubt that virus proteins are kind of risky, potentially or visibly. Actually, it
is quite a common experiment to transfect with viral vectors in our lab. I think, when we have to use virus, safety modifying of
viral vectors is prerequisite. And we also need to pay attention to its potential danger in the
human body.
X: U24 is a protein derived from herpes virus. It is necessary to verify whether the foreign
protein itself has side effects or neurotoxicity. We need to verify that U24 is expressed only in the target cells and will not
secreted extracellularly. In addition, the tet-on system is used to control the expression of U24, and attention should also be paid
to the leakage of the tet-on system.There is also some basal level of expression in tet-on
without DOX induction. Whether low levels of U24 will affect the efficiency of CAR, whether it
will be cytotoxic, is also problems that need to be verified.
Q8: If we can obtain the desirable result, what role will it play in the optimization of CAR-T treatment?
C: From my perspective, the innovation of your project is to regulate the activity and function of CAR-T cells
without killing them.In practice, there needs to be appropriate amount of CAR-T cells in
patient's body. Too few or too many CAR-T cells will both cause serious problems. But if there exists a switch to
regulate the activity of CAR-T cells, then we no longer need to consider the number
of CAR-T cells injected into the patient's body. Thus, it may help a lot in the suppression of
cytokine storm.
X: Control of CAR-T is a problem that almost every practitioner will pay attention to. Your project is also an attempt. Based on
clinical experience and reports and results statistics, coupled with close monitoring during treatment,
pre-administration of cytokine storms can be achieved in advance
to prevent cytokine storms.
Q9: Any comments on our project?
X: Many companies are studying the control of CAR-T therapy. Some of their highlights are ‘fast’, so the
timeliness of this system is more important. What are the pros and cons of
toxicity and production costs between the small molecules used by other companies
and the DOX you use should be noticed.
In addition, the premise of this project is that the CAR-T reaction is too strong. However,
only the CD19 CAR-T has strong effects,
but there are still many types of CAR-T that do not have sufficient reaction intensity.
Moreover, in the current CAR-T treatment, the patient's recurrence rate during the subsequent time is still relatively high, which
may be because the CAR-T cells are not maintained in the body for a sufficient period of time.
Therefore, your system cannot prevent the maintenance of CAR-T cells in the body.
If clinical application is desired, the system needs to be validated in normal human peripheral blood,
primary T cells.
Q10: How fast should our system's response be to become clinically meaningful?
C: Of course as fast as possible. But the delay definitely exists, youdd better control it
within hours. That is to say, sensitive molecular switches should be preferred. I think that
you can make more combinations of different molecular switches and adjust them according to
various situations. For example, CAR-T can cause tissue-specific damage due to the same antigen expression of tumor cells and normal
cells. If you can design a molecular switch based on a gene specifically expressed in that certain
tissue, then the tissue damage may be avoided, which also broadens the choice of antigens involved in the CAR-T therapy.
Interview with Dr. Cui Jun
Interview with Dr. Xia Xiaojun
Survey about CAR-T Therapy
PART 1. Educational background of informants
Figure 1. Pie Chart of Education Background Information
Figure 2. Pie Chart of Information about Majors among informants.
These two pie charts above show that our informants are mostly well-educated, with 89% of them being undergraduate. And we got a
sample mostly majored in Sciences (74%), especially Biology, Physiology and Medicine (45%). It's a good news to know that our sample
also includes people engaged in different majors other than the related ones. And our informants cover all ages, while people aged
20-30 account for the majority.
Part 2 How well do our informants know about cancer and CAR-T therapy?
Q1: Are you familiar with cancer and its treatment?
Figure 3. Pie Chart of Familiarity of cancer among Informants.
Q2: Are you familiar with CAR-T therapy?
Figure 4. Pie Chart of Familiarity of CAR-T therapy among Informants.
Roughly half of the participants were familiar with cancer (52%). However, only one-third of them are familiar with CAR-T therapy
(35%). What's more, 43% of the informants have never heard about CAR-T. Due to this great contrast and the role CAR-T plays in
current cancer treatment, we considered it high time to introduce more about CAR-T Therapy to the public.
Q3: What is the range of cancer treatment price that you can undertake?
Figure 5. Pie Chart of price range that Informants can undertake.
Most informants (54%) stated that they could only undertake cancer therapy less than 200,000 RMB (nearly $30,000), and another 26% of
them stated that less than 500,000RMB (nearly$72,000) would be affordable. However, the average cost of cancer treatment is around
500,000RMB. That is to say, only 20% of our informants are willing to pay the price. So, this leave a space for CAR-T, as a
prospering therapy, to knock a better market which targets on lower-budget patients.
Q4: Where do you think that we should make a breakthrough in cancer treatment at present? (Multiple Selection)
Figure 6. Histogram of expected breakthrough to be made in cancer therapy.
It's quite surprising to find that only half of our sample (93 out of 201) think that reducing risks is a breakthrough point in
cancer therapy. Cancer therapies have long been at high risks because people don't necessarily know how a therapy could be more
effective, so there exists a lot of experimental treatments. Perhaps for this reason, a large number of people think that the risk of
treatment is not worth mentioning when fronting costs and curative effect.
Part 3 CAR-T therapy's potential in cancer treatment.
Q5: Do you agree that CAR-T is a therapy with more advantages over traditional ones?
Figure 7. Pie chart of informants' recognition of CAR-T's advantage over traditional therapies
Clearly, most informants (52%) haven't got enough understanding of CAR-T therapy to decide whether it is better than traditional ones
or not. Only 8% informants have clear-cut stands. And the left 40% take a midst stand to wait and see. Therefore, the popularity of
CAR-T therapy is not high in the public's opinion. CAR-T needs a little bit of promotion.
Q6: What's your major concern about CAR-T therapy?
Figure 8. Pie chart of informants' concern of CAR-T therapy.
Q7: What kind of shortages do you think that CAR-T therapy has at present? (Multiple Selection)
Figure 9. Histogram of 4 shortages that informants think CAR-T therapy has at present
Q8: As a new treatment, there is certain risks in CAR-T therapy. So, under what circumstances will you choose CAR-T therapy? (Multiple Selection)
Figure 10. Histogram of circumstances that informants will choose CAR-T since it is a risking treatment
In Figure 10. we can see that only few people define CAR-T as definitely their top choice (16 out of 201) or definitely never their
choice (9 out of 201). Most people still consider curative effect as the most important factor, followed by concerns of price and
risks. And this coincides with Figure 8. and Figure 9.
CAR-T as a new cancer treatment has shown some side-effects, while our work is precisely aimed at reduce that risks. So, the
importance of our work is once again confirmed indirectly.
Part 4 Recognition of our work.
Q9: Do you consider our work meaningful? (We try to reversibly control CAR-T cell activities by regulating the CAR receptor on the cell surface, so that the side effect of CAR-T therapy could be reduced or even eliminated.)
Figure 11. Pie chart of informants' recognition of our work.
To our delight, most people consider our work to be meaningful. After these questions above, our informants had a better
understanding of the CAR-T as a whole. Therefore, we deserve a great recognition of work as shown in Figure 11. This also proves that
the choice of our subjects has indeed captured the urge need of the public about CAR-T therapy and even cancer treatment.
Q10: A virus-derived protein will be used in our work to improve the therapy. Do you agree that virus-derived protein is suitable for treatment-use?
Figure 12. Pie chart of informants' recognition of the use of a virus-derived protein.
This question is made for informants majored in Biology, Physiology and Medicine, since others may not possess a thorough
understanding of virus and its protein. And we found that our peers have a rather high acceptance (74%) in our choice of the viral
protein.
Q11: To what degree should the viral protein be controlled, in order to make people feel enough safety?
Figure 13. Histogram of viral protein controlled
Integrated Human Practices
Most of the integrated human practices have been shown above, and here is a conclusion.
1. What attitude do public have towards CAR-T therapy?
We tried and finally found out the fact that it's really difficult to popularize CAR-T therapy to people who only have common sense.
So, it can be found that most of the people who completed our questionnaire are undergraduates (our schoolmates). We didn’t have
interviews with patients, which seems to be what should be done, because we don’t think it's a good thing to give patients
unrealistic hope, and our project is just an idea now.
A college student, Wei Zexi, was dead in 2016. He searched the Internet for cancer treatment to cure himself, and he chose a hospital
for immunotherapy, which was a swindle. Immunotherapy can be easily suggestive of swindle in China for a long time, and even the
Nobel Prize couldn't completely eliminate this shadow. This makes our popularizing more difficult.
So, we chose another direction. We asked people what do they thought that we should make a breakthrough in cancer treatment at
present and what’s their major concern about CAR-T therapy, etc.
From figure 7-9 of Survey of CAR-T Therapy, we can easily find that most people are not optimistic about CAR-T therapy now, and
expect its future development. What is concerned about now is the recovery rate, risk and side-effect, and the price is still
exceeding expectations. Our project is aimed to help to solve problems including side-effect and high prices, which are also
mentioned by experts we interviewed.
2. How and why we chose this idea?
After 3 brainstorms with our teammates, we had more than 10 ideas. Professor Huang Junjiu and Professor Liu Feng helped us to pick
out the final idea. Vice Dean of School of Life Sciences, Professor Xiang Hui, thought that we should prove the significance of our
project, so we visited many professors to evaluate it. The professors we visited include: Laurent Coscoy, professor from Berkeley,
did lots of works in the research of U24 protein; Huang Shengfeng, professor from our school, taught us immunology course and have
interests in CAR-T therapy; Cui Jun, professor from our school, taught us introduction to immunology course.
It is a pity that we didn’t record full of our conversations with professors because of some reasons, and we were not completely
sure about the choice of this project at that time. Part of the conversations were recorded in the Interview with experts page.
Professor Huang Shengfeng told us about the clinical treatment methods, risks and side effects of CAR-T. Professor Cui Jun pointed
out that cytokine storm might be the most important side effect. Professor Laurent Coscoy introduced the key protein, U24, to us.
These professors brought us deeper review of CAR-T therapies and helped us a lot in the project approval process.
3. Is it safe enough to use U24?
In Interview with experts page, Q7 and Q9 are focusing on the safety of U24.
Q7: A viral protein (has been checked in) is involved in our project. In your opinion, what kind of safety problems will it bring?
Q9: Any comments on our project?
Dr. Cui Jun thinks that U24 is allowed to be used, but attention should be paid to test its potential danger in human body.
Dr. Xiao Xiaojun thinks that we need to test the leakage of Tet-On system and the side effect of U24( even with a low level
expression)
In Survey of CAR-T Therapy page, Q10 and Q11 are focusing on the safety of U24
Q10: A virus-derived protein will be used in our work to improve the therapy. Do you agree that virus-derived protein is suitable for
treatment-use?
Q11: To what degree should the viral protein be controlled, in order to make people feel enough safety?
It's beyond our expectations that there is a rather high acceptance (74%) in our choice of the viral protein. At the same time, most
of the people thinks that U24 shouldn't do harm to human body. More than quarter of people thinks that the expression of U24 should
be regulated by foreign medicine, U24's expression pathway should be able to be blocked, and U24 should be degraded very fast in
vivo.
We design experiments to test Protein Half-Life of U24 , leakage of Tet-On system(can be seen in Determination of Optimal Concentration of Dox ), and The potential toxicity of U24 . And the results are shown in Demonstrate page.
4. The Timeliness.
In Interview with experts page, Q8-10 are focusing on the timeliness of our design.
Q8: If we can obtain the desirable result, what role will it play in the optimization of CAR-T treatment?
Q9: Any comments on our project?
Q10: How fast should our system’s response be to become clinically meaningful?
Dr. Xiao Xiaojun thinks that the timeliness of this system is very important, and Dr. Cui Jun thinks that the system's response time
should be as fast as possible, and would be better to be within hours.
Based on experimental data, our model is for prediction of the response of Tet-On system.
Experimental data is shown in the Demonstrate page, and the prediction is shown in the Modeling Page.
5. Applied Design and Future Works.
The interviews with experts also provided inspiration for our product design and future works.
"The innovation of your project is to regulate the activity and function of CAR-T cells without killing them. It may help a lot in
the suppression of cytokine storm." Said Dr. Cui.
Dr. Xia provide us a more specific method to control cytokine storm with our system. He said:"Based on clinical experience and
reports and results statistics, coupled with close monitoring during treatment, pre-administration of cytokine storms
can be achieved
in advance to prevent cytokine storms ."
He also pointed out that if clinical application is desired, the system needs to be validated in normal human peripheral blood,
primary T cells.
Dr. Cui also gave us inspiration of the future works."you can make more combinations of different molecular switches
and adjust
them according to various situations" It is a very "Synthetic" and "iGEM" idea , and we hope to do some work on it (see more in Applied Design Page).
