Cell-mediated cytotoxic activity of spleen cells from patients with gastric carcinoma

The cell-mediated cytotoxic activities of cells from the spleens (SP cells) of patients with gastric carcinoma were assayed in comparison with the activities of peripheral blood mononuclear cells (PBM cells) from the same patients, and from patients with benign lesions. The natural killer cell (NK) activity of the SP cells and their capacity to generate allogeneic cytotoxicity in mixed lymphocyte culture (MLC) were very similar to those of the PBM cells. The cytotoxic activity of SP cells induced by alloactivation in MLC, however, was significantly higher than that of the PBM cells from the same patient as well as from patients with benign lesions. The production of interleukin 2 (IL 2) and the ability to induce cytotoxic cells after activation with IL 2 (LAK) were therefore examined. Both the ability to produce IL 2 and to generate LAK cells were shown to be significantly increased in SP cells when compared to PBM cells. These results indicate that the spleen may be a potential reservoir for the precursors of these activated killer cells in patients with gastric carcinoma. Furthermore, it may play an important role in the defence against tumors in these patients.     

Cell-mediated cytotoxic activity of regional lymph node cells from patients with gastric carcinoma

The cell-mediated cytotoxic activities of cells from the perigastric lymph nodes (LNC) were assayed in patients with gastric carcinoma. These activities were compared with those of the peripheral blood mononuclear cells (PBM), and also with the LNC of patients with benign lesions. The capacity of LNC to be converted to cytotoxic cells in mixed cell culture was significantly impaired in the cancer patients as compared to that of either the PBM from the same patient, or the LNC from patients with benign lesions. The natural killer cell (NK) activity of LNC was significantly lower than that of the PBM in both groups of patients. The cytotoxic activity induced by phytohemagglutinin activation (PAK) in the LNC from patients with carcinoma, as well as from those with benign lesions was also significantly decreased, when compared to that of the PBM, although the ability of LNC to produce interleukin 2 (IL 2) was significantly increased. The ability of these cells to generate cytotoxicity after activation with IL 2 (LAK) was therefore examined, and a decreased capacity in LNC was observed. These results indicated that the ability of T cells in LNC to develop into cytotoxic cells in patients with gastric carcinoma was impaired, and that the nonspecific cytotoxicity, including NK or PAK, as well as LAK activity, was essentially low in the perigastric lymph nodes.     

Cell-mediated cytotoxic activity of regional lymph node cells from patients with gastric carcinoma

The cell-mediated cytotoxic activities of cells from the perigastric lymph nodes (LNC) were assayed in patients with gastric carcinoma. These activities were compared with those of the peripheral blood mononuclear cells (PBM), and also with the LNC of patients with benign lesions. The capacity of LNC to be converted to cytotoxic cells in mixed cell culture was significantly impaired in the cancer patients as compared to that of either the PBM from the same patients, or the LNC from patients with benign lesions. The natural killer cell (NK) activity of LNC was significantly lower than that of the PBM in both groups of patients. The cytotoxic activity induced by phytohemagglutinin activation (PAK) in the LNC from patients with carcinoma, as well as from those with benign lesions was also significantly decreased, when compared to that of the PBM, although the ability of LNC to produce interleukin 2 (IL 2) was significantly increased. The ability of these cells to generate cytotoxicity after activation with IL 2 (LAK) was therefore examined, and a decreased capacity in LNC was observed. These results indicated that the ability of T cells in LNC to develop into cytotoxic cells in patients with gastric carcinoma was impaired, and that the nonspecific cytotoxicity, including NK or PAK, as well as LAK activity, was essentially low in the perigastric lymph nodes.     

In vitro effect of interleukin 2 on depression of cell-mediated immune response after surgery

Effect of exogenous interleukin 2 (IL 2) on the postoperative depression of cell-mediated immune response in vitro was studied in 8 patients with benign lesion and 11 patients with various carcinoma, undergoing major surgical procedures. When peripheral blood mononuclear cells (PBM) were obtained from patients 3 days after surgery, the proliferative response of PBM in mixed lymphocyte culture (MLC) was significantly decreased, as compared to that before operation. The depressed proliferative response was significantly increased and improved to the preoperative level, when exogenous IL 2 was added at a concentration of 50 per cent in culture. The defective generation of cytotoxic cells in MLC 3 days after operation was also significantly augmented and improved to the preoperative range by addition of 25 per cent IL 2 in culture. IL 2 produced minimal increase in these responses when PBM were obtained preoperatively. There was no significant difference between each value in these responses obtained from patients with benign lesion and carcinoma. These results show that PBM from patients who had undergone major surgery were responsive to exogenous IL 2. The postoperative depression of cell-mediated immune response may be reversible with exogenous IL 2.     

In vitro effect of interleukin 2 on depression of cell-mediated immune response after surgery

Effect of exogenous interleukin 2 (IL 2) on the postoperative depression of cell-mediated immune responsein vitro was studied in 8 patients with benign lesion and 11 patients with various carcinoma, undergoing major surgical procedures. When peripheral blood mononuclear cells (PBM) were obtained from patients 3 days after surgery, the proliferative response of PBM in mixed lymphocyte culture (MLC) was significantly decreased, as compared to that before operation. The depressed proliferative response was significantly increased and improved to the preoperative level, when exogenous IL 2 was added at a concentration of 50 per cent in culture. The defective generation of cytotoxic cells in MLC 3 days after operation was also significantly augmented and improved to the preoperative range by addition of 25 per cent IL 2 in culture. IL 2 produced minimal increase in these responses when PBM were obtained preoperatively. There was no significant difference between each value in these responses obtained from patients with benign lesion and carcinoma. These results show that PBM from patients who had undergone major surgery were responsive to exogenous IL 2. The postoperative depression of cell-mediated immune response may be reversible with exogenous IL 2.     

Study on adoptive immunotherapy on patients with renal cell carcinoma. I. Functional characteristics of peripheral blood mononuclear cells and serum immunosuppressive factors in patients with renal cell carcinoma

The immune responses in patients with renal cell carcinoma were evaluated from the production of interleukin-2 (IL-2), the expression of IL-2 receptors and the activity of lymphokine activated killer (LAK) cells. In addition, the effect of the patient's serum on the expression of IL-2 receptors and LAK activity were investigated. The production of IL-2 by peripheral blood mononuclear cells (PBM) from patients with renal cell carcinoma was not suppressed, when compared with that in controls. However, the expression of IL-2 receptors tended to decrease with the progression of clinical stage. The LAK cells generated by PBM of patients with renal cell carcinoma had significant cytotoxic activity against Daudi cells, ACHN cells and autologous tumor cells, while autologous serum suppressed the expression of IL-2 receptors and the induction of LAK cells in patients with renal cell carcinoma. Furthermore, serum from patients with renal cell carcinoma suppressed the cytotoxic activity of LAK cells generated by PBM from a normal volunteer. These results indicated the presence of immunosuppressive factors in the serum of patients with renal cell carcinoma which impaired the clinical effect of treatment using IL-2 or LAK cells.     

Comparison of in vitro glioma cell cytotoxicity of LAK cells from glioma patients and healthy subjects

Peripheral blood mononuclear cells from 11 glioma patients and 11 healthy control subjects were cultured in medium containing recombinant interleukin-2 for a period of 5 days. The cytotoxicity of these lymphokine-activated killer (LAK) cells was tested on chromium-51-labeled freshly prepared allogeneic glioblastoma cells, and on the cell lines K562 (natural killer cell (NK)-sensitive) and Daudi (NK-resistant). Peripheral blood mononuclear cells from all subjects showed high levels of cytotoxicity against these targets. There was no significant difference between the patients and the control group when LAK cytotoxicity was compared. Thus, although glioma patients are known to have depressed immunological reactivity, the cytotoxic capacity of LAK cells derived from glioma patients is similar to that of LAK cells from healthy control subjects. However, the glioma patients had significantly reduced numbers of mononuclear cells in their peripheral blood, possibly due to steroid treatment. Therefore, the volume of blood required to generate the same number of LAK cells was approximately three times larger from the glioma patients than from control subjects.     

Lymphokine-activated killer (LAK) cells from human intestinal mucosa: cytotoxic activity against tumor cell lines and modified self but not autologous and allogeneic colon cancer cells

Patients with colorectal cancer respond poorly to in vivo immunotherapy with lymphokine-activated killer (LAK) cells generated from peripheral blood mononuclear cells (PBMC). We postulated that gut-derived immune cells could be a more relevant source of LAK cells directed against colorectal cancer. Intestinal lamina propria mononuclear cells (LPMC) and colonic adenocarcinoma cells were isolated from operative specimens by combination of mechanical and enzymatic dissociation methods. LAK cells were generated by culturing PBMC and LPMC with recombinant interleukin 2 (IL2), with and without OKT3 monoclonal antibody, in short- (4 days) and long-term (21 days) cultures. Other cultured tumor cells, normal intestinal fibroblasts, and hapten-modified autologous LPMC were used as control targets. Cytotoxicity was measured by a 4-hr 51Cr release assay. Short-term cultured LAK cells exhibited a strong to moderate degree of killing against normal intestinal fibroblasts, hapten-modified self cells, and four different tumor cell lines. Instead, fresh colon cancer cells were resistant to cytotoxicity, regardless of their degree of histologic differentiation and the autologous or allogeneic nature of the LAK cells. Long-term culture with IL2 remarkably increased LAK cell activity against all tumor targets, but not against colonic adenocarcinoma cells. The results of this study, showing that freshly isolated colon cancer cells are intrinsically resistant in vitro to highly activated cytotoxic effector cells, may explain the poor clinical results observed in human trials with in vivo administration of IL2 or LAK cells.     

Crescentic IgA glomerulonephritis following interleukin-2 therapy for hepatocellular carcinoma of the liver.

A patient who developed crescentic IgA nephropathy following treatment with recombinant interleukin-2 (rIL2) and lymphokine-activated killer (LAK) cell therapy for hepatocellular carcinoma was reported. Cessation of rIL2 and LAK cell treatment plus plasmapheresis and steroid therapy was successful in achieving partial improvement and stabilization of renal function. This is the first case report of biopsy-documented glomerulonephritis developing after IL2 and LAK cell therapy. This provides indirect in vivo evidence for the role of IL2 in mediating glomerular injury in IgA nephropathy.     

Immuno-modulatory effects of relaxation training and guided imagery in women with locally advanced breast cancer undergoing multimodality therapy: A randomised controlled trial

Eighty women undergoing multimodality treatment for large (>4 cm) or locally advanced (T3, T4, Tx, N2), breast cancers participated in a randomised controlled trial (RCT) to evaluate the immuno-modulatory effects of relaxation training and guided imagery. Patients underwent chemotherapy followed by surgery, radiotherapy, and hormone therapy. Those in the intervention group were taught relaxation and guided imagery. Patients kept diaries of the frequency of relaxation practice and imagery vividness. On 10 occasions during the 37 weeks following the diagnosis, blood was taken for immunological assays CD phenotyping: T cell subsets (helper, cytotoxic), natural killer (NK) and lymphokine activated killer (LAK) cells, B lymphocytes and monocytes; cytotoxicity: NK and LAK cell activities; cytokines interleukin 1 beta (1β), 2, 4 and 6 and tumour necrosis factor alpha.Significant between-group differences were found in the number of CD25+ (activated T cells) and CD56+ (LAK cell) subsets. The number of CD3+ (mature) T cells was significantly higher following chemotherapy and radiotherapy, in patients randomised to relaxation and guided imagery. Using a median split, women who rated their imagery ratings highly had elevated levels of NK cell activity at the end of chemotherapy and at follow-up. Significant correlations were obtained between imagery ratings and baseline corrected values for NK and LAK cell activity, and IL1β. Relaxation frequency correlated with the number of CD4+ (T helper) cells, the CD4+:8+ (helper:cytotoxic) ratio, and IL1β levels.Relaxation training and guided imagery beneficially altered putative anti-cancer host defences during and after multimodality therapy. Such changes, to the best of our knowledge, have not been previously documented in a RCT.     

Regional transarterial infusion of autologous lymphokine-activated killer (LAK) cells for advanced renal cell carcinoma and its preliminary clinical result

We herein report the preliminary but appreciable results of regional transarterial infusion of 2 gravity subtypes of autologous lymphokine-activated killer (LAK) cells into the metastatic sites in combination with systemic recombinant interleukin-2 (rIL-2) administration in 3 patients with advanced renal cell carcinoma. Leukapheresis was performed once a week and peripheral blood lymphocytes were separated into 2 different subtypes by Percoll gradient centrifugation. These lymphocytes were incubated with rIL-2 for a few days to induce LAK cells. LAK cells were transferred to the metastatic lesions through cannula twice a week. A large iliac bone metastasis disappeared 3 months after the initial LAK cell therapy via a superior gluteal artery. A case of complete disappearance of psoas muscle and para-aortic lymphnode metastasis as well as partial regression of a lumbar bone metastasis was seen after lumbar arterial infusion treatment. Another case with brain metastasis showed a rapid exacerbation of brain edema after one week's LAK therapy. Our treatment modality seems to be worthwhile and promising for treatment of the advanced renal cell carcinoma.     

Operative stress potentiates the inductivity of membrane associated lymphotoxin (mLT) on lymphokine activated killer (LAK) cells in vitro

Membrane-associated lymphotoxin (mLT) is induced in human peripheral blood mononuclear cells when cultured with interleukin 2, in the form of lymphokine-activated killer (LAK) cells. The inductivity of mLT is thought to be dependent upon the differentiation potential of LAK cell precursors, being T cells and natural killer cells. In this study, we investigated the inductivity of mLT on LAK cells from surgical patients. The preoperative values of mLT inductivity were found to be generally higher in malignant than benign cases, and the postoperative time course of mLT inductivity showed a transient decrease immediately after the operation followed by gradual increase over 2 weeks. Moreover, patients with an intraoperative bleeding volume of more than 1,000 ml showed a delay in the postoperative increase of mLT inductivity. These data suggest that operative stress potentiates the inductivity of mLT on LAK cells; however, excess stress may cause a delay in the restoration of mLT inductivity.     

Augmentation of lymphokine-activated killer cell activity in patients with gastrointestinal cancer

Adoptive cellular immunotherapy with lymphokine-(interleukin 2) activated killer (LAK) cells is not as successful in patients with gastrointestinal cancer as with other tumour types. This may be because the cytotoxic capacity of LAK cells from such patients is suboptimal. In this study we have sought to augment this activity by stimulating the lymphocytes with recombinant human interferon-gamma (r-HuIFN-gamma) in addition to interleukin 2 or by depleting the lymphocytes of adherent suppressive mononuclear cells. Both procedures augment LAK activity in gastrointestinal cancer patients but adherent cell depletion results in fewer cells being available for adoptive cellular immunotherapy. No further augmentation of LAK activity of adherent cell depleted cells could be accomplished by addition of r-HuIFN-gamma. Co-stimulation of unfractionated peripheral lymphocytes with r-HuIFN-gamma is the preferable procedure for the generation of LAK cells for adoptive cellular immunotherapy in patients suffering from gastrointestinal cancer.     

Usefulness and limitation of immunotherapy of metastatic renal cell carcinoma with autologous lymphokine-activated killer cells and interleukin 2

Fourteen patients with metastatic renal cell carcinoma (RCC) were treated by systemic administration of autologous lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2). Pulmonary metastases alone were found in 9 cases, pulmonary and mediastinal nodal metastases in 3, and pulmonary and bone metastases in 2. LAK cells, generated by incubation in 2 units/ml of IL 2 for 3-4 days, were intravenously administered once or twice a week. In addition, beginning on the day of the first LAK cell infusion, 1000 units of IL 2 diluted in normal saline were intravenously infused once or twice a day with occasional supplementation of 1000 units of IL-2 on each day of LAK cell infusion. The total number of LAK cells and total amount of IL-2 administered per patient in this study ranged from 0.8 x 10(10) to 6.9 x 10(10) cells and from 3.3 x 10(4) to 21.4 x 10(4) units, respectively. As toxic effects caused by the infusion of LAK cells, headache, shaking chills, fever and leukocytosis were found in all 14 cases. Side effects possibly induced by IL-2 infusion were tolerable fever, fluid retention (body weight gain of 2-3 kg) and eosinophilia. No objective regression of mediastinal nodal or bone metastases was observed. In regard to lung metastases, however, partial and minor responses were observed in 3 and 2 cases, respectively. One of the 3 patients with a partial response was clinically free of disease after undergoing a thoracotomy for resection of residual lesions, but a brain metastasis was detected 10 months after the thoracotomy. The remaining 2 patients are being closely followed up at present. In 3 of 11 patients who showed a minor response, no change or progressive disease, brain metastases were observed during or after the immunotherapy. Furthermore, we examined the possibility of selection of suitable candidates for this therapy on the basis of the degree of in vitro LAK activity against autologous cultured tumor cells in 6 patients, but there was no significant correlation between in vitro autologous tumor cell lysis by LAK cells and the clinical response to immunotherapy. In conclusion, although a complete response could not be obtained, it can be said that this immunotherapy may be effective against RCC, in particular lung metastases, since a partial response was achieved in 3 of 14 patients. However, it should be taken into consideration that this immunotherapeutic approach may have a risk of increasing the frequency of brain metastases.     

The effect of recombinant interleukin 2 in combination with mitomycin C on advanced cancer

We recently discovered that the ability of cancer patients to generate lymphokine-activated killer (LAK) cells became remarkably augmented after mitomycin C (MMC) administration. Based on our clinical findings, we designed a treatment regimen comprised of MMC 12 mg/m2 given intravenously on day 1 and recombinant interleukin 2 (rIL 2) 700 U/m2 given intravenously every 12 hr from day 4 through day 8, when the generation of LAK cells had been shown to be markedly increased. Ten patients with various advanced carcinomas for which standard therapy had failed or no standard therapy was available, were treated with this regimen. Of these ten, three had a partial response and three others had a minor response. Fevers were common and anemia occurred in four patients, but nevertheless, severe toxicity was not encountered. These results indicated that rIL 2 in combination with MMC might be effective against advanced carcinoma without causing severe toxicity when these drugs are used in an appropriate combination.     

Bacillus-Calmette-Guérin (BCG) and 3D tumors: an in vitro model for the study of adhesion and invasion.

PURPOSE: To study adhesion, penetration and internalization of BCG and effector-cells to and into three-dimensional in vitro cell aggregates from benign and malignant urothelial origin mimicking small in vitro tumors. MATERIALS AND METHODS: Multicellular spheroids (MCS) were generated by "liquid-overlay" technique. Adhesion and penetration of viable FITC-labelled BCG into MCS from urothelial cancer cell lines and normal urothelial cells was studied by electron microscopy (TEM) and fluorescence microscopy. Spheroid growth during BCG-co-incubation was determined by light microscopy. Peripheral blood mononuclear cells (PBMC) were stimulated with BCG to generate BCG-activated-killer (BAK) cells. The infiltration of these effectors and of lymphokine-activated killer (LAK) cells into MCS was examined at different intervals by means of immunohistochemistry. The resulting cytotoxicity was judged in a 3H-l-methionine release assay. RESULTS: BCG adhered to MCS from tumor cells but not to benign cell MCS. Intracellular internalization of the bacteria was detectable in superficial tumor cell-layers (1-5) whereas BCG was not found in deeper layers. Proliferation of malignant MCS was reduced in the presence of BCG. Benign MCS showed contact inhibition growth arrest, which was not altered by BCG. BAK and LAK effector cells both infiltrated tumor cell MCS as opposed to unstimulated PBMC. In contrast to LAK cells, BAK cells did not infiltrate into benign cell MCS and were not cytotoxic towards them. CONCLUSION: With regard to the clinical situation the selective adhesion and internalization of BCG to malignant cells might explain why BCG has been rarely found in follow-up biopsies in tumor free patients. More interestingly, the selective adhesion of BCG to and infiltration of BAK effector cells into malignant cell spheroids suggests a selective mode of action of BCG.     

Study on adoptive immunotherapy in patients with renal cell carcinoma. II. Plasmapheresis with adoptive immunotherapy using LAK cells and IL-2

The existence of immunosuppressive factors which impair the clinical effect of treatment using IL-2 or lymphokine activated killer (LAK) cells has been reported in the serum of patients with renal cell carcinoma. For the purpose of eliminating these immunosuppressive factors, plasmapheresis combined with adoptive immunotherapy using LAK cells was performed in ten patients with stage IV renal cell carcinoma. Immunological examinations revealed that the number of peripheral blood lymphocytes, NK activity and the ratio of Leu 11 positive cells were increased during the treatment. Of the 9 evaluable patients, one has a partial response, 5 showed no change and 3 had progressive disease. In addition to the one partial response, the size of some metastatic lesions in the lungs decreased in 2 patients during the treatment. As serious side effects, brain edema progressed in 2 patients with brain metastases and acute hepatitis due to plasmapheresis was noted in one patient. Moreover, transient and reversible renal dysfunction developed in most patients. These results indicated that plasmapheresis combined with adoptive immunotherapy using LAK cells is a useful therapy for patients with advanced renal cell carcinoma.     

Antitumor activity against established intracerebral gliomas exhibited by cytotoxic T lymphocytes, but not by lymphokine-activated killer cells.

Specific immune responses against malignant brain tumors have been difficult to demonstrate. Moreover, immunotherapy has met with little success, despite using lymphocytes with high levels of cytotoxicity against brain tumor cells. Lymphokine-activated killer (LAK) cells that nonspecifically kill brain tumor cells are produced by stimulating resting precursors with high concentrations of interleukin-2 (IL-2). Cytotoxic T lymphocytes that specifically kill brain tumor cells are produced by stimulating antigen receptor-positive immune-cell precursors with tumor cells. In an attempt to gain insight into immune cell function against brain tumors, the present study compared the in vitro and in vivo activities of LAK cells and cytotoxic T lymphocytes produced against RT2, a fast-growing rat glioma cell line. Lymphokine-activated killer cells were produced by stimulating normal rat spleen cells with 1000 units of IL-2, and RT2-specific cytotoxic T lymphocytes were produced by priming them in vivo with RT2 and Corynebacterium parvum and restimulating primed spleen cells with RT2 in vitro. Lymphokine-activated killer cells were highly cytotoxic for a panel of syngeneic and allogeneic brain tumor and non-brain tumor target cells, including RT2, as measured in a 4-hour 51Cr release assay. Cytotoxic T lymphocytes were highly cytotoxic only for syngeneic brain tumor target cells. Lymphokine-activated killer cells and cytotoxic T lymphocytes were tested for in vivo antitumor activity against intracerebral RT2 by intravenous adoptive transfer of activated lymphocytes. Untreated rats died in approximately 2 weeks. Lymphokine-activated killer cells plus IL-2 failed to affect survival when treatment was initiated as early as 1 day following tumor inoculation. Cytotoxic T lymphocytes and IL-2 administered as late as Day 5 rejected progressing intracerebral tumor. Thus, although both cytotoxic T lymphocytes and LAK cells exhibited high levels of in vitro killing of glioma cells, only cytotoxic T lymphocytes rejected progressing intracerebral tumors.     

A reappraisal of the effects of monoclonal antibodies directed at T cell differentiation antigens

We examined the effects of monoclonal antibodies (Abs) directed at T3 antigen (expressed on most post-thymic T cells), T4 antigen (helper/inducer subset) and T8 antigen (suppressor/cytotoxic subset). Anti-T3 induced interleukin-2 production and proliferation of peripheral blood mononuclear cells (PBM). Anti-T4 or T8 did not exhibit such properties. Addition of methylprednisolone (MP) or cyclosporine (CsA) to PBM activated with anti-T3 resulted in 79% and 88% suppression of proliferation, respectively. Neither anti-T4 nor anti-T8 mediated significant inhibition of anti-T3-induced proliferation. Primary mixed lymphocyte cultures (MLC) were variably affected by Abs. Anti-T3 augmented proliferation found in primary MLCs at 48 hr and had an inconsistent effect on the proliferative response found at 120-136 hr of culture. Primary cytotoxic T lymphocyte (CTL) generation was consistently suppressed by anti-T3, while natural killer (NK)-cell-like activity was augmented at 72 hr and suppressed after 136 hr of culture. Anti-T4 mediated a dose-dependent suppression of proliferation and CTL generation in the primary MLC and had minimal effect on the induction of NK-cell-like activity. At high concentrations (5000-1000 ng/ml), anti-T8 mediated modest inhibition of proliferation and of the induction of cytolytic activity. Alloimmune memory cells, generated in long-term primary MLCs, were activated by anti-T3 to exhibit specific secondary cytolytic activity and NK-cell-like activity in the absence of the original priming stimulus. Neither anti-T4 nor anti-T8, under identical experimental conditions, activated memory cells. When interrelated, our experimental findings indicated that: (1) the ultimate immunity elicited by anti-T3-T3 antigen interaction is critically dependent upon the immune potential of the cell assessed; (2) MP or CsA can inhibit PBM activation by anti-T3; and (3) anti-T4 might have a role as an immunosuppressant in renal graft recipients.     

Induction of cytotoxicity from human lymphocytes coated with bispecific antibody against human glioma cells

A bifunctional hetero-F (ab') 2 fragment containing the Fab portions from anti-CD3 and anti-glioma monoclonal antibodies was prepared. The antibody simultaneously recognized two different molecules, the CD3 complex on effector T cells and human glioma-associated antigens on target glioma cells. This bispecific F (ab') 2 fragment induced peripheral blood lymphocytes (PBLs) from healthy donors to lyse cells of the human glioma cell line, U251MG, that is resistant to natural killer cell-mediated cytolysis. Compared with lymphokine-activated killer (LAK) activity which is obtained by exposure to interleukin (IL)-2 for more than 3 days, the maximum bispecific antibody-dependent cytotoxicity can be generated only after 24 hour exposure to IL-2. And cytotoxicity of lymphocytes triggered by the bispecific antibody was dependent upon the concentration of IL-2 in the culture medium. The effect of the bispecific antibody on LAK cells was tested in patients suffering from malignant glioma. One patient who received specific targeting therapy (LAK plus bispecific antibody) showed the disappearance of high density tumor mass from CT scan. But the patient who received only LAK therapy showed the recurrence of tumor one year after LAK treatment. These are preliminary data, but may be a promising approach in cancer immunotherapy.