27 
Dr. Martin asked whether the carboxyl -terminal of the diphtheria toxin 
fragment had been modified other than by addition of the a-MSH ligand. 
Dr. Murphy said the carboxyl terminal end was modified; linker nucleotides 
were ligated to the diphtheria toxin fragment before the a-MSH ligand 
was added. 
Dr. Martin suggested RAC might permit Dr. Murphy to test the toxicity of 
the diphtheria toxin fragment under BL2 containment; containment might 
then be lowered to BL2 for the fusion protein if the diphtheria toxin 
fragment is not toxic. Dr. Handy felt some questions would still remain 
unanswered; e.g. , the fusion protein oould be more easily processed 
than the toxin fragment alone. He felt enough was known new to permit 
the experiment to proceed. 
Dr. Collier did not think containment higher them BL3 would be appropriate 
for procedures involving this hybrid toxin gene. He pointed out that the 
gene for Pseudomonas aeruginosa exotoxin A, a toxin only ten to fifty 
times less toxic than diphtheria toxin but with the same mode of action, 
may be cloned under ELI containment conditions. 
Dr. Collier noted that the Working Group on Toxins had suggested the use 
of BL2 containment with BL3 practices for studies involving the a-MSH- 
diphtheria toxin fusion gene. Dr. Rapp said he preferred to designate 
either BL2 or BL3 containment rather than RL2 containment with BL3 practices. 
Dr. Gottesman said she would offer a motion but would abstain during the 
vote because she had discovered that investigators within her laboratory 
are working with IL-2. She moved that the request described in the 
August 19, 1985, Federal Register be permitted under BL3 conditions using 
E. coli K-12 hosts and poorly rrobilizable plasmid vectors such as EK2 
certified plasmids. There was no second to the motion. 
Dr. Davis moved to substitute BL2 containment conditions plus BL3 practices 
in the motion offered by Dr. Gottesman. Dr. Clcwes seconded the motion. 
Dr. Walters felt the RAC appeared to be following a more liberal approach 
than the working group. He asked how a more restricted approach would 
affect the progress of the research. 
Dr. Murphy said at present there is no functional BL3 laboratory in the 
city of Boston. If RAC reccrtmends BL3 containment, a BL3 laboratory would 
have to be built. 
Dr. Davis said RAC is responsible for promoting the public welfare by 
protecting the interests of patients as well as protecting society 
against hazard. He said: 
[409] 
