Faculty Bibliography

Purine metabolism and phosphoribosylpyrophosphate content of lymphocytes and erythrocytes were studied in an immunocompetent black male child with a total deficiency of erythrocyte and partial deficiency of lymphocyte adenosine deaminase. The partial genetic deficiency of adenosine deaminase was demonstrated in intact lymphocytes, and was approximately one third of the deaminating activity of control lymphocytes. Intact lymphocytes of the patient did not incorporate adenosine at a faster rate than those of control lymphocytes. The patient's erythrocytes deaminating activity was low and adenine ribonucleotide synthesis from adenosine was increased several fold, while adenine incorporation into purine ribonucleotides was comparable to that of control erythrocytes. Transfusion with packed erythrocytes temporarily improved the deaminating capacity of circulating erythrocytes, but did not reduce the elevated incorporation of adenosine into purine ribonucleotides. Phosphoribosylpyrophosphate content of the patient's lymphocytes and erythrocytes was not diminished. Incubation of erythrocytes with adenosine lowered phosphoribosylpyrophosphate content while incubation with phosphate increased phosphoribosylpyrophosphate content to the same extent in mutant and control erythrocytes

Human blood lymphocytes activated in vitro with antigen to which the donor is reactive are capable of suppressing the secondary proliferative response of autochthonous fresh cells to antigen. Both antigen-specific and antigen-nonspecific suppression can be detected in each experiment. These suppressor cells act by decreasing the number of lymphocytes entering the proliferative response rather than by slowing or otherwise inhibiting ongoing proliferation. The suppressor cells must be added soon after fresh cells are stimulated with antigen to be effective, but the suppressor cells themselves need not proliferate to exert their effect. Suppressor cells are optimally effective when added in numbers equal to those of the responding population, but still exert a significant effect at one-eighth that number