lungs where residual HIV infected cells may be present. These could include headache, seizures, 
coma, shortness of breath and respiratory failure. The HIV-specific lymphocytes have been 
genetically modified to allow us to study the survival of these cells in your body and to provide a 
means of destroying these cells if they cause serious side effects. The genetic modification is the 
result of insertion of a gene into the cells by a special laboratory technique. This involves using a 
virus which cannot grow in the cells to carry the gene into the cells and then selecting the genetically 
modified cells in culture. 
There are some potential risks to this procedure. Even though the virus used to insert the gene into 
your lymphocytes cannot grow and is considered harmless to you, it is possible that events could 
occur within the cell that allow the virus to grow or cause the cell to become cancerous. To 
minimize this possibility, the gene modified lymphocytes will be tested and if any abnormalities are 
found, they will not be used in therapy. However, it is possible the marked cells could become 
abnormal after they have been injected and there is a remote possibility that the altered lymphocytes 
that we administer could cause a tumor. In animal experiments, virus production or the development 
of cancer has not been observed greater than two years after treatment. Finally, the inserted gene 
produces a protein that inactivates certain antibiotics. Several other antibiotics are available that will 
not be inactivated and would be effective in treating bacterial infections. 
The procedure used to genetically modify the HIV-specific lymphocytes is called retroviral -mediated 
gene transfer and has only been used before in very few human patients. Because gene modification 
is relatively new, it is possible that despite our extensive efforts, it may cause some unforeseen 
problems to occur including the possibility that death may occur. 
The HIV-specific T lymphocytes are cultured in sterile media containing human serum to ensure 
optimal cell growth. The serum is obtained from blood donors who are screened and shown to be 
negative for hepatitis and the AIDS virus. Only donors who meet all the requirements to provide red 
blood cell or platelet transfusions to you are used as serum donors, however as with the transfusion of 
any blood products, there is a risk of hepatitis and a theoretical risk of transmitting HIV. The 
cultures of HIV-specific T cells are continuously monitored for contamination with microorganisms 
including your HIV and would be discarded if this occurs. It is still possible that undetected 
pathogens could be administered with the T cells and cause fever, chills, drop in blood pressure 
and/or life threatening infection. 
POTENTIAL BENEFITS 
Bone marrow transplantation enables physicians to use extremely high doses of chemotherapy and irradiation 
that may eradicate the cancer from you. 
Zidovudine (AZT) prevents replication of HIV-1, but does not kill the virus once it has infected a cell. It 
will not necessarily clear the HIV-1 viral infection from the tissues already infected, but will reduce the 
probability of the "new" (donated) immune cells from being infected. 
The HIV-specific lymphocytes are able to kill cells already infected with the virus and it is hoped they will 
provide additional antiviral effects to those observed with AZT. Adoptive immunotherapy is effective therapy 
for many viral diseases in animal models and might provide long-lasting immunity to HIV. 
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Recombinant DNA Research, Volume 15 
