[Recurrence with tumor bleeding in a patient with malignant astrocytoma during the treatment with intracranial injection of lymphokine-activated killer cells--a case report]

A 22-year-old woman harboring recurrent malignant astrocytoma presented with intracranial hypertension by tumor hemorrhage during repeated administration of lymphokine-activated killer (LAK) cells via Ommaya's reservoir. She first suffered from the tumor located at the right occipital lobe at the age of 13. The tumor regressed completely by subtotal removal of the tumor, followed by external irradiation. Nine years later, however, the occipital tumor recurred and was subtotally resected. Pathological diagnosis was astrocytoma grade 3. Postoperatively, LAK cells induced from her peripheral blood lymphocytes incubated with interleukin-2 and anti-CD3 antibody were injected into the tumor cavity via Ommaya's reservoir for eight times. At the end of the LAK therapy, the tumor regrew with massive hemorrhage in the tumor cavity causing intracranial hypertension. At the reoperation, thick granulation tissue covered the surface of the recurrent tumor and dense deposits of clot were noted around the tip of the Ommaya's tube. Histologically the superficial layer of the tumor was infiltrated with macrophages and lymphocytes, mostly CD3-positive T cells, accompanied with capillary hyperplasia. Viable astrocytoma cells were abundant beneath the granulation layer. It should be considered that in local LAK therapy granulation tissue formation with hypervascularization at the surface of the tumor cavity may lead to tumor bleeding as well as resistance to the treatment.

[Clinical observation of immunotherapy in ocular malignant tumors with lymphokine-activated killing (LAK) cell]

In this paper, the authors reported the method of treating ocular malignant tumors with lymphokine-activated killing cells which were induced by rIL-2 in vitro. Among the sixteen cases of ocular tumors, 4 cases of 5 base cell carcinoma (1 case of which was partially extinctive), 4 cases of tarsal gland carcinoma, 2 cases of squamous cell carcinoma and respectively 1 case of retinoblastoma, non-Hodgkin's lymphoma, intraorbital hemangiopericytoma, intraorbital fibrous histiocytomas and hidradenocarcinoma were completely extinctive. The result shows that the immunotherapy method is effective.

[Loco-regional immunotherapy with OK-432 and cultured autologous lymphocytes for patients with metastatic cancer]

Metastases from breast or gastrointestinal cancers have been treated loco-regionally with immunotherapy using OK-432 and cultured autologous lymphocytes since 1983. Response rate for patients with liver, lung, or pleural metastases from breast cancer was 57%, 53%, 90%, respectively, and for those with liver metastases from gastric or colo-rectal cancer was 31% or 29%. Survival of the patients with liver, pleural metastases from breast cancer, or with peritoneal seeding from gastric cancer was prolonged when compared with historical controls. Immunotherapy was one of significant prognostic factor to prolong the survival in patients with pleural effusion from breast cancer, with Stage IV breast cancer, or with peritoneal seeding from gastric cancer. Moreover, concomitant regression of non-treated metastatic sites after the response of treated disease was often observed especially in breast cancer patients with both liver and bone metastases or with Stage IV disease. Thus, loco-regional immunotherapy can show a systemic beneficial effect.

Factors, including transforming growth factor beta, released in the glioblastoma residual cavity, impair activity of adherent lymphokine-activated killer cells

Adherent lymphokine-activated killer (A-LAK) cells were obtained from peripheral blood lymphocytes of patients with recurrent glioblastoma. In vitro features of A-LAK cultures were assessed in comparison to those of non-adherent lymphokine-activated killer (NA-LAK) cells of the same patients with regard to cytotoxic activity, proliferation and surface markers. Only in a minority of cases did A-LAK cells show a markedly higher cytotoxicity on K562, Daudi and allogeneic glioblastoma cells. Nevertheless, A-LAK cells proliferated significantly better than NA-LAK and contained higher percentages of CD16+, CD56+ and CD25+ cells, indicating that A-LAK cells from these patients represent a subpopulation of lymphocytes enriched for activated natural killer cells. We also investigated whether immunosuppressive factor(s) were present in the tumour bed of recurrent gliomas. To this end, samples of glioblastoma cavity fluid (GCF), which accumulates in the cavity of subtotally removed tumour, were recovered and tested for the presence of immunosuppressive activity. All GCF samples analysed were shown to inhibit in vitro proliferation and antitumour cytotoxicity of 1-week-cultured A-LAK cells in a dose-dependent manner. Such GCF activity was effectively antagonized by a transforming growth factor beta (TGF beta) neutralizing antibody, indicating the involvement of TGF beta in lymphocyte inhibition. These results show that in the tumour cavity remaining after subtotal glioblastoma resection a marked immunosuppressive activity, probably due to local release of TGF beta, is present; such activity may negatively influence the therapeutic effectiveness of local cellular immunotherapy.

[Effectiveness of treatment with transfer of autologous or allogenic LAK cells combined with rIL-2 in 121 patients with malignant pleural effusion]

Lymphocytes isolated from malignant pleural effusions of patients with advanced lung cancer or from allogenic peripheral blood of healthy donors were induced to become LAK cells after in vitro culture with rIL-2. One hundred and twenty-one patients with malignant effusions were treated by intrapleural administration of autologous or allogenic LAK cells combined with rIL-2. The effusions disappeared in 71 (58.6%) patients and significantly decreased in 45 (36.2%) patients. Five patients did not respond to the treatment. Tumor cells in pleural effusions disappeared or significantly decreased and lymphocytes significantly increased in all responders. Except for transient chill and/or fever in 102 patients, no serious side effect was found. The results indicate that transfer of autologous or allogenic LAK cells combined with rIL-2 in the treatment of patients with malignant pleural effusions due to advanced lung cancer is feasible effective, and safe.

[Study of adoptive immunotherapy for metastatic renal cell carcinoma with lymphokine-activated killer (LAK) cells and interleukin-2. II. Clinical evaluation]

We evaluated adoptive immunotherapy using LAK cells combined with systemic administration of interleukin-2 (IL-2) in 11 patients with metastatic renal cell carcinoma. The LAK cells were generated by incubation in serum-free medium (AIM-V) supplemented with IL-2 (1,000 U/ml) for 4 days and were generally administered twice weekly (4 times/cycle). Daily administration of IL-2 (50 x 10(5) U) was started 3 days prior to the first LAK infusion and continued throughout the cycle. Each course of therapy comprised 1-6 cycles, with the total dose of LAK cells and IL-2 varying from 3.3-52.6 x 10(9) cells and 140-900 x 10(5) U, respectively. Clinical response was evaluated in terms of metastasis to specific organs (lung only: eight cases, lung and brain: one, lung and lymph nodes: one, lung and bone and pleuropericardium: one). The outcome was complete response in one patient, partial response in one, no change in six and disease progression in three. The response rate was 18.8%. This therapy was most effective against pulmonary metastases. Adverse reactions to LAK cell infusion included fever, headache, and chills. Eosinophilia and weight gain due to IL-2 administration were also observed. However, all of these symptoms were transient and no serious side effects occurred. In these patients, the proportion of natural killer (NK) cells (CD16) and cells with IL-2 receptor (CD25) among PBL was increased markedly in the early phase of therapy, and activated T cell (CD3+DR+) and suppressor T cells (CD8+11+) increased significantly at a later phase. It was suggested that the clinical response would be expected in case of increasing of CD16 cells or CD25 cells and augmentation of NK or LAK activity. Our results indicate that this regimen of adoptive immunotherapy shows some promise for the treatment of advanced renal cell carcinoma.

[Study of adoptive immunotherapy with lymphokine-activated killer (LAK) cells and interleukin-2 for metastatic renal cell carcinoma. I. Generation of LAK cells by incubation in serum-free medium]

Investigation into the clinical application of LAK cells for treating renal cell carcinoma was carried out. LAK cells were induced from peripheral blood mononuclear cells of healthy adults or renal cell carcinoma patients by incubation of peripheral blood mononuclear cells in complete medium (RMPI1640 containing 10% heat-inactivated human AB serum) or serum-free medium (AIM-V) supplemented with IL-2. Then the characteristics of the LAK cells thus produced were studied. When cultured in complete medium, peripheral blood mononuclear cells isolated from healthy adults, recovered to 60% of the initial level on day 4 of incubation. Both NK and LAK activity were markedly enhanced before day 4. On day 4, a similar number of peripheral blood mononuclear blood cells and a similar cytotoxicity were observed in serum-free culture. The cells with a high growth rate during the 4 days of incubation were CD25, HLA-DR, CD3, CD16 cells in both cultures. The supernatant of LAK generation cultures had detectable levels of interferon (IFN)-gamma, interleukin (IL)-1 beta, and tumor necrosis factor (TNF)-alpha on day 4. IFN-gamma and IL-1 beta both showed significant concentrations in the LAK culture supernatant, which increased progressively with further culture. TNF-alpha was not produced by LAK cells alone. IFN-gamma and IL-beta production by the LAK cells was enhanced by stimulation with the Caki-1, ACHN and K-562 tumor cell lines, while TNF-alpha production was stimulated by Caki-1 and K-562 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective randomized trial of high-dose interleukin-2 alone or in conjunction with lymphokine-activated killer cells for the treatment of patients with advanced cancer

BACKGROUND

Treatment using interleukin-2 (IL-2) alone or in conjunction with lymphokine-activated killer (LAK) cells has been shown to mediate disease regression in selected patients with advanced cancer.

PURPOSE

This prospective randomized trial was designed to determine whether the administration of LAK cells in conjunction with high-dose IL-2 alters response and survival rates, compared with those for IL-2 alone, in patients with advanced cancer.

METHODS

The 181 patients who had metastatic cancer that had failed to respond to standard therapy or who had disease for which no effective therapy existed received treatment with high-dose IL-2 alone or with LAK cells plus IL-2. Both treatment groups were to receive the same dose of IL-2 administered according to the same schedule. IL-2 doses were omitted depending on the tolerance of the patient. Of the 181 patients, 97 had renal cell cancer and 54 had melanoma.

RESULTS

Median potential follow-up was 63.2 months. There were 10 complete responses among the 85 assessable patients who received IL-2 plus LAK cells, compared with four among the 79 who received IL-2 alone. There were 14 and 12 partial responses, respectively. Complete response continues in seven patients at 50-66 months. The 36-month actuarial survival with IL-2 plus LAK cells was 31%, compared with 17% with IL-2 alone (two-sided P value [P2] = .089). A trend toward improved survival was seen for patients with melanoma who received IL-2 plus LAK cells, compared with those who received IL-2 alone (24-month survival: 32% versus 15%; 48-month survival: 18% versus 4%; P2 = .064 [corrected]). None of 26 patients with melanoma who received IL-2 alone are alive; five of 28 who received IL-2 plus LAK cells are alive, and three continue in complete response. No difference in survival was seen in patients with renal cell cancer in the two treatment groups. There were six treatment-related deaths (3.3%); three were due to myocardial infarction. Other toxic effects resolved by discontinuation of IL-2. Many toxic effects were related to increased vascular permeability induced by IL-2.

CONCLUSIONS

Some patients with metastatic cancer have prolonged remission when they are treated with high-dose IL-2 alone or in conjunction with LAK cells. Our results suggest a trend toward increased survival when IL-2 is given with LAK cells in patients with melanoma, but no trend was observed for patients with renal cell cancer.

IMPLICATIONS

As these studies continue, efforts are underway to develop improved immunotherapies using tumor-infiltrating lymphocytes (TIL) and gene-modified TIL.

T cells migrate to tumour sites after extracorporeal interleukin 2 stimulation and reinfusion in a patient with metastatic melanoma

Peripheral blood mononuclear cells (PBMC) were taken by leukapheresis from a patient with melanoma skin metastases and stimulated in vitro using 1000 IU recombinant interleukin 2 (IL-2)/ml to generate lymphokine-activated killer cells (LAK cells). Two-colour immunofluorescence analysis demonstrated an IL-2-induced up-regulation of CD25 on natural killer cells (CD56+) as well as on T lymphocytes (CD3+). After radiolabelling with indium-111, the cells were reinfused. Gamma-camera imaging revealed an enrichment at the tumour sites. Immunostaining of tumour tissue taken before and after scintigraphy demonstrated CD25+ T lymphocytes (CD2+, CD3+), but no natural killer cells (CD16+, CD56+) infiltrating the metastases. LAK cell enrichment at melanoma metastases in vivo did not involve natural killer cells, but was characterized by increased numbers of activated T lymphocytes in this patient.

[Effect of lymphokine-activated killer cells of head and neck tumors in vitro and in nude mice]

Human lymphokine-activated killer (LAK) cells were prepared by culturing normal peripheral blood mononuclear cells (PBMC) for 4 days with or without added recombinant interleukin 2 (rIL-2) and assayed for anti-tumor activity against established squamous cell carcinoma lines of the head and neck (SCCHN) in vitro and in nude mice. The results showed that LAK cells had a stronger cytotoxicity than control cells to different SCCHN in vitro. In vivo, LAK cells almost completely inhibited the growth of HEP-2 tumor in nude mice and resulted in an inhibition rate of 81.6% (P < 0.01 with control cells). Our data indicate that LAK cells may be useful in the treatment of patients with head and neck tumors.

[Lymphokine-activated killer (LAK) therapy for advanced renal cell carcinoma: clinical study on arterial LAK therapy and experimental study on LAK cell activity]

Experimental and clinical studies were conducted on lymphokine-activated killer (LAK) cell therapy for advanced renal cell carcinoma (RCC). The traffic assay using radiolabeled LAK cells indicated short-term but appreciable accumulation of LAK cells in the tumor site when trans-arterially infused. By contrast, systemically infused LAK cells were localized not to the tumor tissue but to the lung. Therefore, we began treatment of the patients with extrapulmonary metastases by means of regional arterial administration of LAK cells and those who had pulmonary metastases by a systemic LAK therapy. Regimen of Interleukin-2 (IL-2) administration was bolus infusion of 5 x 10 U IL-2 twice daily. Frequency of LAK cell administration varied from one to three times a week depending upon the patient's condition. Eight out of 16 metastases, such as bone, muscle, and lymph node metastases, in 9 patients treated by arterial LAK therapy showed regression. Side effects during LAK therapy were not serious. Past history of having chemotherapy was an unfavorable factor that could reduce the sensitivity to LAK therapy. Our laboratory study showed the production of Interferon (IFN)-gamma and Tumor Necrosis Factor (TNF)-alpha by LAK cells when preincubated with RCC cells, which may indicate the mechanism of LAK cell-mediated antitumor activity in vivo. The study also showed that LAK cells as well as monocytes preincubated with the supernatant of LAK cells damaged normal endothelial cells in vitro, which suggested the possibility that LAK therapy risks increasing the frequency of brain metastasis by damaging the blood-brain barrier.(ABSTRACT TRUNCATED AT 250 WORDS)

[Lymphokine-activated killer (LAK) therapy for metastatic renal cell carcinoma]

Fifteen patients with metastatic renal cell carcinoma (RCC) were treated by administration of autologous lymphokine-activated killer (LAK) cells given together with systemic administration of interleukin-2 (IL-2). Pulmonary metastases alone were found in 10 cases, pulmonary and mediastinal nodal metastases in 3, and pulmonary and bone metastases in 2. LAK cells, generated by incubation in 700 units/ml of IL-2 for 3-4 days, were intravenously administered once a week. In addition, beginning on the day of the first LAK cell infusion, 3.5 x 10(5) units of IL-2 were intravenously infused once or twice a day with occasional supplementation of 3.5 x 10(5) 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 10.2 x 10(6) to 74.9 x 10(6) units, respectively. As toxic effects caused by the infusion of LAK cells, headache, shaking chills, fever and leukocytosis were found in all cases. Side effects possibly induced by IL-2 infusion were tolerable fever, fluid retention (body weight gain of 2-3 kg) and eosinophilia. Out of 15 patients, a partial response was observed in 4 patients who had pulmonary metastases alone. One of the 4 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 3 patients are being closely followed up at present.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic therapy in disseminated melanoma

There is no standard treatment for advanced melanoma. As long as metastases are satellites or in-transit metastases localized in a leg or arm, the prospects for curative treatment by isolation perfusion are good. But as soon as metastases have spread via the circulation, curative treatment with cytotoxic agents becomes virtually impossible. When the tumor burden is not too extensive, however, palliative treatment can be of clinical value. Some combinations of cytotoxic agents or combinations of biologic response modifiers have been shown to induce worthwhile remissions. Toxicity remains a problem, however. The advantages of the newer immunological approaches, especially with interleukin-2 (IL-2) and T-cell lymphocytes, is that treatment for a short period may result in good remissions at an early stage. Much clinical research is still needed to improve these costly approaches.

Surgical resection following interleukin 2 therapy for metastatic renal cell carcinoma prolongs remission

Records of 399 patients with metastatic renal cell carcinoma treated with interleukin 2 with or without lymphokine-activated killer cell immunotherapy enrolled in 14 separate clinical trials from multiple institutions were reviewed to determine whether patients with a partial response to interleukin 2 therapy would benefit from surgical resection of residual tumor. Sixty-two patients demonstrated objective responses (15.5%), 18 (4.5%) complete and 44 (11.0%) partial. Eleven patients underwent resection of residual tumor in the lung, kidney, retroperitoneum, or pelvis so that they had "surgically no evidence of disease" (SNED). Of these, 10 had partial responses, and one patient with progressive disease had a complete response. Comparison of response duration showed no difference between the complete response and SNED groups, but there was a significant difference between each of these groups and the partial response group. At this writing, all 11 patients in the SNED group remained alive without evidence of disease (median follow-up, 21 months). In contrast, only 14 patients (76%) with complete responses and 15 patients (35%) with partial responses remained free of disease progression. Enhanced survival of the complete response and SNED groups compared with the partial response group borders on significance and awaits longer follow-up. These data suggest that surgical resection, if technically feasible, may benefit patients who show a partial response to interleukin 2 treatment for metastatic renal cell carcinoma.

[A study to increase the therapeutic effects of adoptive immunotherapy in vivo. Influence on the generation of lymphokine activated killer (LAK) cells and therapeutic effects of LAK cells with anti-tumor drug (cyclophosphamide)]

To enhance the effect of adoptive immunotherapy (AIT), we investigated the induction and characteristics of lymphokine activated killer (LAK) cells and also analyzed the combined effects of AIT with an antitumor drug (cyclophosphamide: CPA) in mice models. LAK cells were generated from C57/BL/6 (B6) spleen cells. The spleen cells were passed through a nylon wool column and cultured in RPMI-1640 medium containing 10% FCS and 2 x 10(3) units of human recombinant IL-2 (hr IL-2) for up to 14 days. During this period, the time kinetic analyses of the LAK cells' cytotoxicity and motility were performed. The cytotoxicities against Lewis Lung Carcinoma (3LL), evaluated by standard 51Cr release assay, gradually increased during the cultured period, and the motilities, determined by a modified version of the Boyden chamber method, greatly increased within the first 7 days' incubation. Based on these in vitro findings, we examined the efficacy of AIT alone or in combination with chemotherapy (CPA) in in vivo studies. AIT was performed in the following way: LAK cells were intravenously infused and rIL-2 was intraperitoneally administered for 5 consecutive days following LAK cell administration. CPA was intraperitoneally administered. The therapy protocols were as follows. There were seven experimental groups. Group I; the mice were infused with 3-day cultured LAK cells (3DLAKs) on the second day after tumor inoculation (day 2). Group II; the mice were infused with 3DLAKs on day 5. Group III; 10-day cultured LAK cells (10DLAKs) on day 2. Group IV; 10DLAKs on day 5. Group V (AIT and CPA combination); AIT (10DLAKs) was started on day 5 followed by CPA on day 10. Group VI; CPA was performed on day 5 followed by AIT (10DLAKs) on day 10. Group VII; CPA was performed on day 5 without AIT. Each group consisted on 15 mice. The therapeutic efficacies were evaluated by calculating the median survival time of each group. The results of these experiments were as follows (mean +/- SD); Group I's median survival time was 16.8 +/- 3.2 days, Group II 15.1 +/- 2.1 days, Group III 19.2 +/- 5.4 days, Group IV 16.1 +/- 4.8 days, Group V 23 +/- 6.3 days, Group VI 32 +/- 8.4 days and Group VII 22 +/- 5.1 days. These results suggested that the efficacy of AIT is closely related to the LAK cells' cytotoxicity and motility. Although AIT alone in the advanced tumor bearing host had a limited effect, combination with CPA improved it's efficacy.(ABSTRACT TRUNCATED AT 400 WORDS)

Use of human leukocyte antigen-mismatched allogeneic lymphokine-activated killer cells and interleukin-2 in the adoptive immunotherapy of patients with malignancies

Clinical effects and side effects were investigated in the adoptive immunotherapy of patients bearing malignant diseases using human leukocyte antigen (HLA)-mismatched allogeneic lymphokine-activated killer (LAK) cells. Allogeneic LAK cells were induced from peripheral blood lymphocytes (PBL) of healthy donors with the same blood types as those of patients. Recently we succeeded in increasing the proliferation rate and enhancing the cytotoxic activity of LAK cells by means of initial stimulation with pokeweed mitogen (PWM, PWM-LAK cells). Five of 12 patients applied in the adoptive immunotherapy showed clinical effects such as partial or complete regression of pulmonary metastases and pleural effusion. All pulmonary metastatic lesions were eliminated in one case by this adoptive immunotherapy combined with chemotherapy. Toxic effects were chillness, fever and general fatigue which were reversible, and no allergic side effects occurred even though allogeneic LAK cells were injected frequently. In the patients who received more than 10(11) of allogeneic LAK cells, anti-HLA class I antibodies appeared without any evidence of autoantibody. However, immunological side effects were never experienced after injection of allogeneic LAK cells even when the anti-HLA class I antibodies existed in the patients; this phenomenon suggests the safety of the adoptive immunotherapy using allogeneic LAK cells. Taken together, allogeneic LAK cells could be considered as alternative therapy for patients with malignancies who could not supply sufficient materials of autologous LAK cells. Recently, LAK cells, particularly PWM-LAK cells were found to obtain significantly potent and prompt lectin-dependent cell-mediated cytotoxicity (LDCC). All tumor cells confluent in microtest plate well could be annihilated by PWM-LAK cells plus PWM less than 8 hours. New immunotherapy using PWM-LAK cells or lectin-stimulated LAK cells with PWM or other lectins is discussed.

[Adoptive immunotherapy using immobilized anti-CD3 mAb-activated autologous lymphocytes: the strong cytotoxicity was supported by CD16+ cells which proliferated in prolonged cultures]

Inflammatory cytokines are able to facilitate the homing of transferred lymphocytes, tumor cell lysis through induction of adhesion molecules, also able to reduce tumor cell susceptibility to LAK cells by increasing tumor cell class I antigen. Investigation with 12 cell lines suggested that promotion of lysis by ICAM-1 was more responsible than protection by (allogeneic) class I Ags (Fig. 1). PBMC were cultured in anti-CD3 coated flasks with rIL-2. CD3+ cells dominated until day 7, decreased thereafter with CD4+. CD8+ and CD16+ increased (Fig. 2). Strong cytotoxicity obtained in some cultures correlated well with CD16+, contributing exclusively among several variables to the activity estimation in multiple regression analysis (Fig. 4). Among 6 cases, in which 2 or more cycles of transfer was done, 1 was prophylaxis of recurrence, in 2 of 3 advanced metastasis cases in which cells were transferred as BRM in the course of chemotherapy, survival of half a year was obtained in good QOL with suppressed disease and adequate level of PBL number. In 2 other cases, inflammation eliciting local treatments were combined. In the case 4, three large liver metastasis from colon cancer which resisted topical ethanol injection and chemotherapy, responded to the transfer with reduced lesions to 1/8 (Fig. 8). In the case 5, abdominal metastasis from colon cancer were removed, liver metastasis were injected of ethanol, and cells were transferred. Responses were obtained to immunotherapy in a certain degree, while never to any chemotherapy.

[Lymphokine-activated killer cell adoptive immunotherapy for cancer treatment and its significance]

New culture system, CDCS-T1, was developed for clinical conduction of lymphokine-activated killer (LAK) cell adoptive immunotherapy (AIT). Advanced or recurrent cancer patients of digestive tract were treated with AIT with LAK cells generated by CDCS-T1 in combination with plasma exchange. Partial responses were shown in 10 to 20% of patients treated. Long survival was found in some responders, indicating the significance of LAK therapy for cancer treatment. AIT with LAK cell transfer was also conducted in patients with esophageal cancer as postoperative adjuvant therapy. Better restoration of postoperative depression of immunological parameters was found in patients with postoperative LAK cell transfer. It is suggested that postoperative LAK cell transfer is a good candidate for adjuvant immunotherapy for cancer treatment.

[Augmentation of therapeutic effect of adoptive immunotherapy through a synergy between transferred killer cells and host's fresh lymphocytes]

Among several approaches to augment the therapeutic effect of adoptive immunotherapy, we focused the antitumor synergy between transferred killer cells and host's fresh lymphocytes. Immunotherapy models using murine tumors or clinical experiments revealed that preadministration of immunostimulator such as OK-432, followed by chemotherapeutic agents such as cyclophosphamide, can induce host's non-cytotoxic fresh lymphocytes that act synergistically with cultured killer cells against autologous tumor cells. Immuno-chemo-lymphocytotherapy (a sequential treatment with OK-432, chemotherapy and adoptive immunotherapy) is useful to treat the patients with advanced cancer even if the number of transferred lymphocytes is limited.

[Augmentation of LAK cell-accumulation in tumor tissue and its therapeutic effect after chemotherapy]

We investigated the therapeutic effects of a combination of chemotherapy with adoptive immunotherapy on BMT-11 fibrosarcoma in C57BL/6 mice. Although no significant therapeutic effects were brought about by CY alone or LAK.rIL-2 alone, CY plus LAK/rIL-2 brought about significant therapeutic effects such as a reduced proportion of dead mice (63%) and prolongation of the mean survival times of dead mice (64.4 days). We transferred radioactive 111In-labeled effector cells into untreated and CY-treated tumor bearing mice. LAK cell-accumulation (% dose/g) at the tumor site was only 2.7% in untreated mice and 19.7 in CY-treated mice. On the other hand, CTL.rIL-2 therapy exhibited significant therapeutic effects by itself. The accumulation of CTL was 9.1% in untreated tumors and only slightly enhanced by CY-chemotherapy. These results suggest that the therapeutic effects of adoptive immunotherapy depend on the accumulation of transferred effector cells at the tumor site and are augmented by the enhanced accumulation of effector cells after chemotherapy.

[Studies on lymphokine-activated killer (LAK) cell: accumulation in tumor tissue and the therapeutic effects of adoptive immunotherapy]

We studied the therapeutic effects of adoptive immunotherapy with lymphokine-activated killer (LAK) cells combined with chemotherapy on BMT-11 fibrosarcoma in C57BL/6 mice. Compared with the untreated group, no significant therapeutic effect was brought about by CY therapy alone or LAK.rIL-2 alone and all mice belonging to these three groups died with a mean survival time (MST) of 45.3, 51.8 and 45.9 days respectively. CY plus LAK.rIL-2 brought about complete cures in 3 out of 8 mice (37.5%) and a significant prolongation of MST of mice which died (64.4 days) and the accumulation of LAK cells (% Dose/g) at tumor sites was enhanced more than 7-fold by combination with CY. On the other hand, the therapeutic effects of cytotoxic T lymphocytes (CTLs) was sufficiently high even in the CTL.rIL-2 alone and were only slightly enhanced by combination with CY compared with LAK cells. Also, we detected LAK-attractant activity in the conditioned medium (CM) of CY-treated tumor tissues but not in that of untreated tumor tissues, and peak activity was reached 5 days after CY-treatment. This attractant activity was located in two major 10,000-50,000 M. W. fractions of CM. We then observed that LAK-attractant was produced in CM of host reactive cell enriched fractions from CY-treated tumor tissues, but not in that of tumor cell enriched fractions. The above findings imply that the effects of adoptive immunotherapy depend upon the accumulation of transferred effector cells at tumor sites, and we believe that the production of LAK-attractant by tumor tissue, facilitated by chemotherapy, is one of the mechanisms responsible for enhanced LAK-cell-accumulation at tumor sites. We performed a preliminary clinical trial with adriamycin, autologous spleen-LAK cells and rIL-2 on 30 hepatocellular carcinoma patients after radical resection on the basis of the experimental results above. There were no significant therapeutic effects after adoptive immunotherapy during the postoperative course but tendency for temporary inhibition of recurrence. Thus it is shown that this method has probable value as effective adjuvant postoperative therapy.