1) Transplantation refers to transferring cells, tissues, or organs from one site to another. A graft is healthy tissue provided by a donor. 2) There are several types of grafts - autografts within the same individual, isografts between genetically identical individuals, allografts between genetically different members of the same species, and xenografts between different species. Autografts and isografts are usually accepted due to genetic identity between graft and host. 3) Allograft rejection shows specificity and memory, mediated by T-cells and the major histocompatibility complex, which causes the immune system to attack foreign agents like allografts from non-

1. IMMUNOLOGICAL BASIS
OF GRAFT REJECTION
Harshita Sharma
MSc. Biotechnology, 3rd Semester
190014155003
BT304

2. Transplantation:
• Transplantation in immunology, refers to the act of transferring cells,
tissues, or organs from one site to another.
• A healthy organ, tissue, cells which is provided by a donor is termed
as a GRAFT.
• The immune system has evolved elaborate and effective mechanisms
to protect the organism from attack by foreign agents, and these
same mechanisms cause rejection of grafts from anyone who is not
genetically identical to the recipient.

3. Type of Grafts:
• Autograft is self-tissue transferred from one body site to another in
the same individual.
• Isograft is tissue transferred between genetically identical individuals.
• Allograft is tissue transferred between genetically different members
of the same species.
• Xenograft is tissue transferred between different species.
• Autografts and isografts are usually accepted, owing to the genetic
identity between graft and host.

4. Allograft
rejection
shows
specificity
and
memory.

5. Rejection due to Memory, Specificity and
T-cells:

6. Role of Major Histocompatibility Complex:

8. RBC and HLA Typing:

9. MICROCYTOTOXICITY
TEST

10. MIXED LYMPHOCYTE REACTION:

11. Cell Mediated Graft Rejection:
1. SENSITIZATION
STAGE

12. 2. EFFECTOR STAGE

14. THANK YOU