Evaluation of blocking mechanisms against immunological responses in patients with laryngeal carcinoma.

The specific tumor-induced leukocyte inhibition factor (LIF) production in laryngeal cancer patients has been investigated before and after the removal of adherent cells in order to evaluate the existence of a suppressor activity; 20 patients served as subject. The LIF production, after challenging the lymphocytes with 3MKC1 autologous tumor extracts, was significant in 12 patients and showed a further significant increase after the removal of adherent cells. In 3 patients with no previous significant LIF production, there was a conversion to significance when the adherent cells were removed. The other patients did not show any significant variation. These data seem to suggest the existence of a suppressor activity exerted by adherent cells in laryngeal cancer patients on LIF production.

Natural killer-mediated cytotoxicity in patients with laryngeal carcinoma.

Natural killer (NK)-mediated cytotoxicity against the K562 cell line was evaluated in normal subjects and in patients with laryngeal cancer. Results showed reduced lymphocyte cytotoxicity in patients with neoplastic disease and further reduction in NK activity following postoperative radiation therapy. The authors discuss the possibility of using this test in the immunological monitoring of patients with laryngeal carcinoma.

Specific LIF production in laryngeal cancer patients: evidence of suppressor activity exerted by adherent cells.

The specific tumor-induced LIF production in 30 laryngeal cancer patients has been investigated before and after the removal of adherent cells to evaluate the existence of a suppressor activity. LIF production, after challenging lymphocytes with 3 M KCI autologous tumor extracts, was significant in 16 patients and showed a further significant increase after removal of adherent cells. A conversion to significance when the adherent cells were removed was shown in 6 patients, with no previous significant LIF production. These data suggest the existence of a suppressor activity exerted by adherent cells on LIF production in laryngeal cancer patients.

Evaluation of the immune responsiveness in laryngeal cancer patients with specific and aspecific tests: first results of follow-up in 80 cases.

We have evaluated in 80 patients suffering with laryngeal carcinoma their specific and aspecific immune responsiveness. We used the E rosette-test, the PHA-induced in vitro stimulation and the in vitro specific LIF production. We chose to use the LIF production test both for its marked sensitivity and because the lymphokines--which are soluble mediators--act as a "bridge" between the different fields of the immune response. Furthermore in our previous research, we observed that the specific LIF production was influenced in a negative way by adherent cells of the peripheral blood that could behave as blocking factors. For what attains the autologous LIF production, before and after the removal of adherent cells, our results show that the patients suffering with a cancer staged as T3T4N1N2N3 exhibit much more marked blocking phenomena than the patients with a cancer staged as T1T2T3N0. In fact the results demonstrate that in this second group only 62% of the cases, after the removal of the adherent cells, showed an increase of LIF production, while this percentage rose to 83% for the patients with a more advanced disease. A similar pattern was found in those patients who showed a recurrence two of three years after the primary disease.

Production of leukocyte migration inhibition factor by lymphocytes of larynx cancer patients stimulated by laryngeal carcinoma solubilized membrane antigens.

The production of leukocyte migration inhibition factor (LIF) from lymphocytes after stimulation with 3 M KCl soluble tumor and normal mucosa extracts was investigated in 30 patients with laryngeal carcinoma at different development stages and in 30 normal donors. The experiments were performed in heterologous and autologous systems. In heterologous systems 3 M KCl tumor extracts induced LIF production by heterologous lymphocytes from patients in 91% of the cases, and normal mucosa extracts induced LIF production by heterologous lymphocytes from patients in 73% of the cases and from normal donors in 90% of the cases. In autologous systems 3 M KCl tumor extracts induced LIF production by autologous lymphocytes from the same patients in 65% of the cases, whereas the normal laryngeal mucosa extracts induced LIF production by the same autologous lymphocytes in the 6% of the cases. The high positivity percentage of the test in heterologous systems could be related to differences in the major histocompatibility complex. The 65% test positivity in autologous systems using tumor extracts could be related to the presence of tumor associated antigens.

Evidence of suppressor activity mediated by concanavalin-A stimulated cells towards aspecific LIF production.

Since the T-suppressor subpopulation is known to have a peculiar sensitivity to the mitogenic activity of Concanavalin-A we decided to verify whether in normal subjects it was possible to induce, by using the Con-A as a mitogenic factor, the proliferation of cells--possibly T-suppressor--which: a) had the property of adherence and b) show inhibitory activity toward LIF production. The statistical analysis of the results of our experimental patterns show that even if a difference between the suppression exerted on LIF production by Con-A stimulated versus not stimulated cells is present at any dilution, the level of significance rises from P less than 0.005 to P less than 0.0001 for the range of dilution 1:1/4 to 1:132, thus revealing that these experimental conditions are optimal for eliciting the blocking effect. The researches that are currently in progress in our laboratory seem to suggest that this experimental approach is of some value in characterizing the immunity pattern of laryngeal cancer patients and its evolution through the course of disease.

Effect of the cryopreservation on the production of leukocyte migration inhibition factor (LIF) by lymphocytes from normal volunteers and patients with laryngeal carcinomas.

The present paper reports the results of an investigation on the influence of cryopreservation methods of human lymphocytes on the leukocyte migration inhibition factor (LIF) production following PHA stimulation. The optimal freezing and thawing procedures, fetal calf serum and dimethyl sulphoxide concentrations are reported.