Transfer factor in vitro abrogation of blocking factors and amplification of immunoreactivity directed to soluble tumor associated antigens in the leukocyte adherence inhibition assay

Abstract

26 breast cancer patients with recurrent disease were studied in order to evaluate whether transfer factor (TF) could abrogate serum blocking factors (SBF) and transfer or amplify immune reactivity directed to tumor-associated antigens (TAA) by using the leukocyte adherence inhibition assay (LAI). When 11 leukocyte samples obtained from patients reactive to cancer extract were preincubated with autologous blocking sera in the presence of PBS, nonspecific TF, or specific TF, leukocytes from these patients gained reactivity against breast cancer extract in none out of 11, one out of 11, and nine out of 11 experiments, respectively. Specific TF was obtained from donors with positive LAI breast cancer extract. Mean percentage LAI differences between control extract and breast cancer extract were −4.5±2.6, 0.5±1.7, and 15.5±2.4. The results of specific TF were significantly different from those of nonspecific TF (P<0.005). When nine leukocyte samples obtained from patients unreactive to cancer extract were preincubated with autologous blocking sera in the presence of PBS, nonspecific TF, or specific TF, leukocytes from these patients gained reactivity against breast cancer extract in none out of nine, one out of nine, and seven out of nine experiments, respectively. Mean percentage LAI differences between control extract and breast cancer extract were −4.6±2.0, 0.6±2.3, and 11.8±3.5. The results of specific TF were again significantly different from those of nonspecific TF (P<0.005). When allogeneic blocking sera were utilized, similar results were obtained. When specific TF was administered in two doses, 1 week apart subcutaneously to six breast cancer patients who were unreactive to breast cancer extracts, four patients gained reactivity against breast cancer extracts. Our in vitro experiments support the presence of a specific component in transfer factor extract which can transfer or amplify cell-mediated reactivity with abrogation of SBF directed at TAA.