14 
Dr. Levine said he would prefer Dr. Murphy be permitted to use BL2 contairment. 
He moved that BL2 be recommended as the contairment level for Dr. Murphy's 
three requests, and that this language be reccmrrended for approval by the 
working group. This motion would permit Dr. Murphy to produce enough material 
to test toxicity. Dr. Fbrmal seconded this motion. 
Dr. Collier re-emphasized that the toxicity of the Sph l fragment is not kncwn. 
rte offered a friendly amendment to Dr. Levine's motion; the modified motion 
would specify BL3 containment conditions for Dr. Murphy's three proposals. 
Dr. Levine accepted this modification. 
Dr. Martin suggested the working group specify BL2 contairment plus BL3 prac- 
tices for Dr. Murphy's proposals. A negatively pressurized room is the only 
difference between BL3 contairment and BL2 containment plus BL3 procedures. 
He did not think a negatively pressurized rocm offered any additional safety 
factor for Dr. Murphy's proposed experiments. 
Dr. Levine modified his motion to require BL2 containment plus BL3 practices 
for Dr. Murphy's three requests. 
Dr. Gill suggested additional language be added to the motion to indicate 
the working group wished to permit Dr. Murphy the opportunity to acquire better 
toxicity data on the purified protein with the implication containment could 
be further lowered on the basis of these data. 
Dr. Levine accepted Dr. Gill's proposed amendment. 
By a vote of six in favor, none opposed, and no abstentions, the working group 
approved of Dr. Levine's motion. 
Proposal to Construct a IL-2-Diphthena Toxin Hybrid Protein 
Dr. Gottesman said m this proposal. Dr. John Murphy of the University Hospital 
of the Boston University Medical Center requests permission to construct a 
hybrid gene composed of the gene coding for interleukin-2 (IL-2) and the Sph l 
segment of the diphtheria toxin gene. The hybrid gene would be cloned in E. 
coll K-12 host-vector systems. 
The long-term goal of this research is to develcp no/el IL-2 receptor- targeted 
cytotoxic agents to combat organ rejection and to create a state of graft 
"tolerance" in organ transplantation. Same of the products may have therapeutic 
potential for treating leukemia and lymphcma. 
Dr. Gottesman said the primary difference between the a-MSH-diphtheria toxin 
hybrid molecule proposal and the IL-2-diphtheria toxin hybrid molecule proposal 
is the type of cell postulated to be sensitive to the conjugate protein. 
Dr. John Williams of Beth Israel Hospital said IL-2 receptors are found on 
proliferating, antigen-activated T cells anl to a lesser o<tent on activated B 
cells. These cells would be the targets of the IL-2-diphthena toxin hybrid 
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