Transfer of the immunologically competent T-lymphocytes from a donor into host expression different MHC antigens can have severe consequences, causing a fatal syndrome known as graft versus host disease (GVH). The following table explores a ran model of GVH, it displays the minimum number of parental strain t- cells which cause fatal GVH in sevearl treatment groups of F1 hybrid off spring derived from mating of two MHC different strain, a and b.
|
|
Minimum number of A or B strain t- cells which cause lethal GVH in the AxB F1 106 |
|
Group |
(A X B) F1 hosts age and treatment |
Strain A T cells |
Strain B t cells |
1 |
Intreated new born F1 |
5 |
5 |
2 |
Untreated adult f1 |
1000 |
1000 |
3 |
Adult F1 given 300 rad irradiation or an anti – proliferative drug |
5 |
5 |
4 |
Adult F1 immunized with 10 of the strain parental t – cells and then irradiated as in group 3 |
1000 |
5 |
5 |
Adult F1 immunized with 107 a strain t- cells taken from donors that had previously been made tolerant to MHC of B, and then irradiated as in group 3. |
5 |
5 |
Give a mechanistic explanation for finding which is consistent with all the data. Describe your answer with reasoning.