xenotransplantation

1. Xenotransplantatio
n

2. Shoolini Institute of Life Sciences
And Business Management
Presented By:-
Neerja Kumari (5794)
Rohit Kumar (5798)
Tanvi Sharma (5810)
M.Sc. Biotechnology 3rd sem.

3. Xenotransplantation
• What is Xenotransplantation ?
• Why do we need it ?
• Why is not an option yet ?
• How can we overcome the problems ?
• Where are we in this process ?
• What can you do ?

4. INTRODUCTION
 Xenotransplantation is the transplantation of the
cells , tissue and organs from one species to another.
 Mainly from pig to human
 Highly controversial topic in medicine
 It was formulated to overcome shortage of donor
organ
+ ?=

5. NEED OF
XENOTRANSPLANTATION
i. Transplantation – leading form of
treatment for many forms of end-
stage organ failure
ii. 1990- 20,000 waiting for transplant
iii. Today-100,000 men , women &
children need life-saving
transplants
iv. Every 12 minute another name is
added to the National Organ
Transplant waiting list

6. HISTORY
 Alexis carrel is known as the founding father of experimental
organ transplantation (1904-1906).
The first experiments in transplanting chimpanzee kidneys into
human were conducted in 1963 and 1964.
An American infant girl known as "Baby Fae" with hypoplastic
left heart syndrome was the first infant recipient of a
xenotransplantation, when she received a baboon heart in 1984.
In 1997. Professor Robin Weiss found ,the PERV in pigs.

7. Advantages
 It saves human lives.
 There is always a vast supply of organs.
 It is thought to be easier to achieve tolerance with
Xenotransplantation than with traditional organ
transplants.
 Transplanted animal cells to be used for
haemophilia , diabetes , Alzheimer's and
Parkinson's disease.
 Also gave a way of delivering genes of therapeutic
importance.
 To expand the range of treatment.

8. Why isn’t it an option yet ?
Problems:-
1. Ensuring correct functioning across species
barriers
2. Rejection –
 Antibodies rejection
 T-cell mediated rejection
 Chronic rejection
3. Fear of zoonosis

9. Types ofrejection
 Hyper acute rejection:- response results due to preformed natural
antibodies , known as XNAs. This rapid and violent type of rejection
occurs within minutes to hours from the time of the transplant.
 Acute rejection:- also known as delayed xenoactive rejection. The
response is characterized by an inflammatory infiltrate of mostly
macrophages and natural killer cells (with small numbers of T cells),
intravascular thrombosis, and fibroid necrosis of vessel walls.
 Cellular rejection :-is based on cellular immunity, and is mediated by:
1. Natural killer cells, which accumulate in and damage the
xenograft; and
2. T-lymphocytes - which are activated by MHC molecules.
 Chronic rejection:-the major cause of chronic rejection is
arteriosclerosis. Lymphocytes, which were previously activated by
antigens in the vessel wall of the graft, activate macrophages to
secrete smooth muscle growth factors.

10. *Overcoming Antibody rejection
a) Elimination of xenoreactive natural antibodies that bind to
endothelial cells of pig organ
b) Transgenic pigs with this protein have been produced and organs
from these pigs usually do not undergo antibody rejection
*Overcoming T-cell rejection
a) Main immunological barrier to successful xenotransplantation
b) Immunosuppression- greater organ survival time
c) Further genetic engineering of animal- number of genes may
suppress the inflammatory response that causes this type of
rejection
*Overcoming Chronic Rejection
a) Can still be rejected months or year later
b) Not well understood in any transplantation

11. Fear of zoonosis
potentialfor infectiousdisease to spread from donor
animalto recipient , is calledXenozoonosis.
Eg- one porcine endogenous
retroviruses(PERVs) which are viruses
within the pigs that pigs are immune to,
but can infect humans.

12. Where are we in this process?
i. First xenotransplants performed between 1963-
1964
ii. Several attempts to transplant hearts,never
surviving more than 21 days
iii. 3 liver transplants attempted with longest survival
70 days
iv. Thousand of people has received living pig tissue
v. Held back by stem cell research
vi. Not enough research to move forward
vii. May not be permanent organs but could provide
temporary treatment
viii. Research in xenotransplantation=greater
knowledge in allotransplantation

13. FUTURE PERSPECTIVES
• Xenotransplantation will Open up a new
treatment strategy, including the direction of the
future development of medical application of a
variety of gene transfer strategy modification of
donor organs.
• Due to some ethical issue related to the animal
rights researchers concluded preference of stem
cells over organ transplants.
• Tissue engineering- today’s approach.
• immunosuppressive protocols .
• Strategies to diagnose PERV in the recipient of an
organ.

14. What can you do ?
 Be an advocate for xenotransplantation
 More advocates = greater push for research and
progress
 Be an organ donor and advocate your
decision

15. Thank you