[A recurrent case of esophageal cancer in which metastatic skin tumor disappeared after local injection of activated lymphocytes with tumor-pulsed dendritic cells]

We examined the effect of activated lymphocytes stimulated with tumor-pulsed dendritic cells (DC-K), and found that such stimulation enhanced the cytotoxity of the activated lymphocytes. Furthermore, in applying DC-K to a recurrent case of esophageal cancer, the skin tumors disappeared after local injection of DC-K. The only adverse effect of this treatment was pyrexia. Although no general effect was observed, the local effect was satisfactory. This suggests that DC-K might be useful for local treatment or postoperative adjuvant therapy.

The role of possible risk factors for acute and late renal dysfunction after high-dose interleukin-2, interferon alpha and lymphokine-activated killer cells

Renal dysfunction is a frequently encountered adverse event following treatment with high-dose interleukin-2 (IL-2). Information about parameters predicting the severity of IL-2-associated renal function abnormalities is limited. In this study the role of possible risk factors in the development of high-dose IL-2-associated acute and long-term renal dysfunction was investigated. A total of 72 patients, who were treated with a regimen consisting of IL-2 (18 MIU m(-2) day(-1) by continuous infusion), interferon alpha (IFNalpha; 5 MIU m(-2) day(-1), intramuscularly) and lymphokine-activated killer (LAK) lymphocytes, were analysed. Serum creatinine measurements were performed daily during treatment, weekly between courses and monthly during follow-up. Pre-and posttreatment 24-h urine samples were collected for calculation of creatinine clearances. Renal dysfunction was observed in 97% of patients. Grade 1 dysfunction (according to WHO criteria) was observed in 20 patients (28%), grade 2 in 37 (51%), grade 3 in 13 (14%) and grade 4 in 0 (0%). Renal dysfunction was reversible in more than 90% of patients. Only 6 patients (8%) suffered a certain amount of permanent function loss. More severe acute renal dysfunction occurred in patients who were experiencing hypertension prior to treatment, those who suffered sepsis during treatment and in men than in women. Sepsis was also associated with irreversible function loss. Other variables such as age, performance status, diabetes mellitus, interval between nephrectomy and start of IL-2 therapy and hypotension during treatment were not important. In conclusion, with high-dose IL-2, renal dysfunction develops in almost every patient and such abnormalities are mostly reversible. Predictors for severe acute renal dysfunction are pre-existing hypertension, sepsis and sex. A septic episode also carries a risk of permanent damage.

Immunotherapy with effector cells and IL-2 of lymph node metastases of human squamous-cell carcinoma of the head and neck established in nude mice

We have previously reported that immune anti-tumor effector cells, both cytotoxic T lymphocytes (CTLs) and IL-2-activated natural killer (A-NK) cells, are effective at eliminating human head-and-neck cancer (HNC) targets in vitro and in vivo in xenograft models. In this study, these 2 types of human effector cell were compared for the ability to prevent the development of lymph node metastases in a metastasis model of human squamous-cell carcinoma of the head and neck (SCCHN) established in nude mice. A tumor cell line, OSC-19, was injected into the floor of the mouth in nude mice, and the tumor grew progressively and metastasized to cervical lymph nodes by day 21. As effector cells, a human HLA-A2-restricted CTL line recognizing a shared antigen on OSC-19 and human non-MHC-restricted A-NK cells were used. Both types of effector cell mediated high levels of lysis against OSC-19 targets in 4-hr (51)Cr-release assays. Administration of human CTLs or A-NK cells and IL-2 to the site of tumor growth in mice with 7-day OSC-19 tumors resulted in significant reduction of the number of lymph node metastases relative to untreated or sham-operated controls or to mice treated with IL-2 without the effector cells. Our results suggest that in a xenograft model of human SCCHN implanted in the oral cavity of nude mice, the development of lymph node metastases can be successfully controlled by adoptive transfer of human SCCHN-specific CTLs or SCCHN-reactive A-NK cells plus IL-2.

Endogenous and adoptively transferred A-NK and T-LAK cells continuously accumulate within murine metastases up to 48 h after inoculation

In murine models, therapeutic efficacy of adoptive immunotherapy (AIT) of cancer with lymphokine activated killer (LAK) cells is seen only when applied together with substantial doses of interleukin-2 (IL-2), probably because this cytokine is imperative for both motility and viability of the LAK cells. We wanted to investigate whether IL-2 in addition mediates an immunostimulatory activation and expansion of endogenous effector cells contributing to tumor regression. Using an immunoperoxidase technique, we have been able to longitudinally analyze the accumulation of tumor infiltrating lymphocytes expressing the pan-T cell/activated lymphocyte phenotype (Thy1.2), the natural killer (NK) cell phenotype (AsGM,) as well as the cytotoxic T (CD8) cell phenotype within experimental established B16 pulmonary melanoma metastases in C57BL/6 mice during the first 48 h after high dose IL-2 monotherapy. Whereas a substantial and selective infiltration of AsGM1+ lymphocytes in tumor tissue was seen (262 and 937 cells per sq.mm malignant tissue at 0 and 48 h, respectively), only a minor increase in accumulation of CD8+ cells was seen (106 and 171 cells per sq.mm tumor tissue at 0 and 48 h, respectively). The addition of adoptive transfer with lymphokine-activated adherent NK (A-NK) cells to the high-dose IL-2 treatment resulted in more than a 1.5 fold increase in infiltrating AsGM1+ cells compared to IL-2 therapy alone (1520 compared to 937 AsGM1+ cells per sq.mm malignant tissue). No substantial accumulation of CD8+ cells was observed in this setting either. In contrast, the treatment with high dose IL-2 together with adoptive transfer of mitogen-stimulated, lymphokine-activated T killer (T-LAK) cells increased the infiltration of CD8+ cells 10-fold compared to IL-2 monotherapy (2078 compared to 171 CD8+ cells per sq.mm malignant tissue, respectively). Interestingly, infiltration of both endogenous and exogenous cells continued over time, since the effector-to-tumor cell ratio in metastatic tissue dramatically increased from 1:8 and 1:6 at 16 h to 1:3 and 1:2 at 48 h after adoptive transfer of A-NK and T-LAK cells, respectively. These data underline the longevity of LAK cells in vivo and highlight the importance of IL-2 treatment in recruiting endogenous immune cells to tumor areas.

Allogeneic cell-mediated immunotherapy for eradication of minimal residual disease: comparison of T-cell and IL-2 activated killer (LAK) cell-mediated adoptive immunotherapy in murine models

In the course of allogeneic bone marrow transplantation (BMT), avoiding graft-versus-host disease (GVHD) while retaining the antileukemic effects of the T cells remains a major challenge. T-cell depletion (TCD) reduces the incidence of GVHD but increases the relapse rate after allogeneic BMT. We attempted to develop a regimen that would retain or increase the graft-versus-leukemia effect induced by donor T cells while preventing GVHD. Immunosuppressed mice were given immunocompetent donor cells, i.e., fresh lymphocytes or lymphokine-activated killer (LAK) cells differing from the host in major (MHC) or minor (MiHC) histocompatibility antigens. Engraftment of donor cells was documented by polymerase chain reaction analysis. Administration of MHC- and MiHC-incompatible allogeneic LAK cells, especially in conjunction with recombinant interleukin-2 (rIL-2), increased disease manifestations and mortality associated with GVHD. On the other hand, irradiated LAK cells or TCD-LAK cells prevented GVHD in both mice models studied. Phenotypic analysis of LAK cells demonstrated that CD8(+)-equivalent (Lyt-2) T cells are of significance in aggravation of GVHD. The in vitro cytotoxic capacity of LAK cells against MHC-nonrestricted target cells was not reduced by either irradiation or TCD. These results provide the background for designing improved protocols for immunotherapy of residual disease after BMT. In addition, the data imply that antitumor effects may be retained by irradiated rIL-2-activated allogeneic cells without causing GVHD. Whereas unmodified allogeneic LAK cells can induce more effective graft-versus-leukemia effects at the cost of GVHD, irradiated allogeneic donor LAK cells might play some role in eradication of minimal residual disease following autologous or allogeneic BMT without causing GVHD.

Effect of combined adoptive immunotherapy and radiotherapy on tumor growth

Advanced squamous cell carcinomas of the head and neck are difficult to control despite optimal surgery, radiotherapy and/or chemotherapy, and the tumors are usually not immunogenic. Because of the anatomic accessibility of the tumors, local adoptive immunotherapy of these tumors is feasible and may interact with radiotherapy to retard tumor growth. It is hypothesized that antigens released from tumor cells injured by radiation may stimulate, in the presence of interleukin-2, an enhanced immunocytodestruction of live tumor cells by adoptively transferred lymphokine activated killer cells and recruited tumor cytotoxic cells. DBA/2 mice were injected subcutaneously with 5 x 10(5) syngeneic squamous cell carcinoma cells in the thigh and the resulting tumors were treated for two weeks with daily peritumoral injections of interleukin-2 (1,000 International Units) or saline, four radiation treatments of 625 cGy each, and four peritumoral injections of 10(7) lymphokine activated killer cells. The results suggested that radiotherapy combined with peritumoral injection of lymphokine activated killer cells and interleukin-2 resulted in a significant reduction (P < 0.01) of tumor size whereas radiation alone, at the same dose, failed to produce a significant effect. Such results may have direct clinical application in enhancing the response of tumors to radiotherapy and in reducing the incidence of tumor recurrence.

The role of LY49 NK cell subsets in the regulation of murine cytomegalovirus infections

The distributions and functions of NK cell subsets, as defined by the expression of Ly49 NK cell receptors, were examined in murine CMV (MCMV)-infected mice. MCMV induced a reduction in NK1.1+ cell number in the spleen and an increase in the peritoneal exudate cells. Within the splenic NK1.1+ population, proportional increases in Ly49A+ and Ly49G2+ cells but decreases in Ly49C+ and Ly49D+ cells were observed 3 days post-MCMV infection, but within the peritoneal NK1.1+ cell populations there were proportional decreases in Ly49A+ cells and increases in Ly49C+, Ly49D+, and Ly49G2+ cells. Lymphocytic choriomeningitis virus did not elicit a comparable NK cell subset distribution. Lymphokine-activated killer cells were sorted into different Ly49 NK cell subsets and adoptively transferred into C57BL/6 suckling mice. Regulation of MCMV synthesis in these suckling mice was shown to be an IFN-gamma-dependent, perforin- and Cmv-1-independent process, and each NK cell subset mediated anti-viral activity. In adult C57BL/6 mice, the control of MCMV in the spleen is mediated by a perforin-dependent mechanism, regulated in part by the Cmv-1 gene, which maps closely to the Ly49 family. In vivo depletions of either one or two of the Ly49 subsets in adult mice did not affect the ability of the residual NK cells to regulate MCMV synthesis. These data provide evidence of NK cell subset distribution and function in MCMV infection, but no individual subset was required for the Cmv-1-like regulation of MCMV synthesis.

Effective treatment of high-grade lymphoproliferative disorder after renal transplantation using autologous lymphocyte activated killer cell therapy

Posttransplantation lymphoproliferative disorders (PTLD) is not uncommon and can occur in 2% to 5% of solid organ recipients on immunosuppression. Epstein-Barr virus (EBV) infection or reactivation and intensive anti-T lymphocyte treatment are important pathogenetic factors for a large proportion of these disorders. Nonclonal lesions with polymorphous histology have a potential for regressing when the immunosuppressants are reduced or stopped. Clonal tumors with a monomorphous histology carry a poor prognosis, and the mortality rate for monoclonal lymphoma has been reported as high as 80%. We report a renal transplant recipient who developed high-grade monoclonal lymphoma only 4 months after a live-donor transplantation. The tumor was EBV positive. Reduction of immunosuppressants resulted in minimal regression of the tumor. The patient was treated with adoptive immunotherapy using ex vivo generation of autologous lymphocyte activated killer (LAK) cells. She had leukapheresis, and autologous peripheral blood mononuclear cells were obtained and cultured in interleukin-2 (IL-2)-rich medium for 9 to 10 days. The IL-2-activated LAK cells were reinfused into the patient without any systemic administration of IL-2. The patient experienced no side effects during the infusion. There was no rejection episode, and the renal function of the patient remained stable after treatment. Computed tomography scan performed 2 months after the infusion showed marked regression of the lesions in the liver and spleen. Five months later, magnetic resonance imaging showed complete resolution of the tumor lesions. Ultrasonography 13 months after the LAK cell infusion showed no lesion. The allograft function was not affected after treatment. Adoptive immunotherapy using IL-2-activated autologous LAK cells was effective in treating this renal transplant patient with EBV-positive high-grade lymphoma. The patient's kidney allograft functioned well without any rejection.

Use of cellular and cytokine adjuvants in the immunotherapy of cancer

Cellular and cytokine adjuvants, often immune effector cells and soluble factors, respectively, are supplemental and/or follow-up treatments of human origin for cancer patients who have unsatisfactory clinical responses to conventional chemotherapy, radiotherapy, and surgery. Since many human studies with these reagents are in their infancy, extensive data collection is only now being performed to determine which strategy provides the greatest therapeutic benefit. Research published in the literature since the genesis of this approach to cancer treatment is summarized in this report. Methodologies attempting to generate anticancer responses by provoking or enhancing the patient's own immune system are new compared with the other standard types of cancer treatment. Although a few encouraging human studies can be discussed, many of the most promising techniques are only now being transferred from the laboratory to the clinic. The administration of immune effector cells in combination with immunomodulators, such as interferons or interleukins, often enhances clinical outcome. The literature cited in this report indicate that immune-cell- and cytokine-based therapies hold promise in our attempts to improve the quality and duration of life in those with cancer. With each report reaching the literature, more effective clinical trials are being designed and implemented.

Adoptive immunotherapy of patients with metastatic renal cell cancer using lymphokine-activated killer cells, interleukin-2 and cyclophosphamide: long-term results

BACKGROUND

Initial results of adoptive immunotherapy using lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) appeared to offer promise for treating renal cell cancer (RCC). However, lower response rates were seen in subsequent trials, and the long-term results of this treatment method have not been fully reported. In this study, we examine long-term results of adoptive immunotherapy using LAK cells, IL-2, and cyclophosphamide (LAK/IL-2/CPM therapy).

METHODS

We administered 10 courses of therapy to 9 patients with advanced RCC. One patient had liver and para-aortic lymph node metastases; the others had only lung metastases. The clinical effects were initially evaluated 4 weeks after therapy and follow-up was continued for periods of 43 to 76 months.

RESULTS

The 4-week evaluation revealed 3 complete responses (CR), 3 partial responses (PR), 1 minor response (MR), 1 patient with no change in disease status (NC), and 2 patients whose disease progressed (PD). One CR patient remained apparently free of disease for 43 months. After tumors recurred in the lung of another CR patient further disease progression was suppressed by IL-2 administration until the patient died from other causes at 46 months. The third CR patient showed tumor recurrence in the lung and was re-treated with the same LAK/CPM/IL-2 therapy. Lung tumors decreased in size (PR), but the patient died due to brain metastasis 2 months after the second round of treatment. The 2 initial PR patients, as well as the MR and NC patients, developed regrowth or new metastatic lesions within 2 to 15 months following therapy. The 2 PD patients died 2 and 9 months after therapy.

CONCLUSION

Long-term effects of LAK/IL-2/CPM therapy were not correlated with the maximal response observed 4 weeks after therapy. Although LAK/IL-2/CPM therapy appears suitable for use as induction therapy in RCC, our data suggest that long-term suppression will require surgical removal of remnant tumors or more intensive maintenance therapy.

Metastatic renal cell carcinoma: long-term survival after therapy with high-dose continuous-infusion interleukin-2

PURPOSE

This article undertakes to define the response rate, long-term survival, and toxicity in patients with metastatic renal cell carcinoma (MRCC) treated with high-dose continuous intravenous infusion (CIV) recombinant interleukin-2 (rIL-2) with or without lymphokine-activated killer (LAK) cells.

PATIENTS AND METHODS

One hundred twenty-three consecutive patients received CIV rIL-2 (18-22 MIU/m2/day on days 1-5, and 6-8 MIU/m2/day on days 10-19) on one of five sequential protocols at the University of Washington between 1988 and 1995. The first 76 patients received LAK cells. The median age was 55 years (range, 32-76 years), and 71% had undergone prior nephrectomy.

RESULTS

Nine patients achieved a complete response (7.3%) and 14 patients achieved a partial response (11.4%) for an overall response rate of 19% (95% confidence interval, 12%-26%). The median survival was 19 months, and the 5-year survival was 20%. Seven of nine complete responders (78%) remain in continuing complete response at 43+ to 109+ months. Intensive care unit and vasopressor support were required in 42% and 23% of patients, respectively, who received rIL-2 + LAK cells, and in 18% and 4% of those who received rIL-2 alone. There was one treatment-related death.

CONCLUSION

We report the largest single-institution experience and the longest survival for patients with MRCC treated with CIV rIL-2. The administration of rIL-2 by CIV is associated with less frequent intensive care unit and vasopressor support than with high-dose intravenous bolus regimens, and hence may enhance the therapeutic index in patients with MRCC.

[The observation on treatment effects of local adoptive immunotherapy in 33 cases with head and neck cancer]

OBJECTIVE

To evaluate treatment effects of local adoptive immunotherapy in 33 cases with head and neck cancer.

METHODS

IL-2 1 x 10(5)-2 x 10(5) U per day was injected into tumor for 10 days; during the 4th-8th day LAK cells 1.0 x 10(8)-5.0 x 10(8) per day were combined with IL-2 injection. Then we analysized clinical effect, immunopathology, side effects, etc.

RESULTS

CR was seen in 1 case; PR in 6, MR in 20 cases, and SD in 6 cases. The one-, two- and three-year survival rate was 96.3%, 83.3% or 75.0% respectively. The results of histopathology showed that there were large amount of T lymphocytes (CD3+/4+) infiltrating in the tumor area after immunotherapy. No serious side effects were found during the course of the treatment.

CONCLUSION

Local injection of IL-2/LAK can be used as immunotherapy for head and neck cancer.

[Our experience with lymphocytes activated against cancer: CTL cells]

Our group, thanks to the considerable help offered by prof. S. Fujimoto, Chief of the Immunologic Oncology Department of the Kochi Medical School (Japan), developed a method of "in vitro" activation of cytotoxic T lymphocytes (CTL), which are directed against tumour-specific antigens MHC-linked of the tumor cells. A protocol of specific immunotherapy based on the use of the CTL cells appropriately manipulated as therapeutic agents is our goal. The protocol recognizes five essential points: 1) retrieve and culture of tumor cells; 2) retrieve of T Lymphocytes; 3) induction of CTL cells; 4) assay of CTL activity; 5) reinfusion of the activated CTL cells to the patient.

Treatment of malignant melanoma with interleukin-2

Treatment of metastatic malignant melanoma with recombinant interleukin-2 (rIL-2) represents one of the earliest attempts at systemic immunomodulation as a therapy for cancer. Initial reports showed objective response rates with single-agent rIL-2 therapy in the range of 15% to 20% with some durable responses; however, the overall response rates were lower than originally anticipated. In addition, in contrast to animal models, it appears that coadministration of lymphokine-activated killer (LAK) cells, generated ex vivo with rIL-2, does not enhance the response rates achieved with single-agent rIL-2. Despite a multitude of studies with various rIL-2 regimens, with and without coadministration of LAK cells or tumor-infiltrating lymphocytes, the optimum dose and treatment schedule for rIL-2-based therapy in metastatic melanoma remains a topic of controversy. To date, there are also no clear immunologic parameters that can predict biologic response to rIL-2-based therapy.

Activated allogeneic cell therapy (allo-ACT) for relapsed chronic myelogenous leukemia (CML) refractory to buffy coat transfusions post-allogeneic bone marrow transplantation

We describe a 17-year-old male patient with chronic myelogenous leukemia (CML) in hematologic and cytogenetic relapse 4 months post-non-T cell-depleted allogeneic bone marrow transplantation for accelerated CML. Two sequential buffy coat transfusion with donor peripheral blood cells (8.9 and 4.8 x 10(7) cells/kg), the second transfusion in combination with in vivo activation of donor cells by human recombinant interleukin-2 (rIL-2) 6 x 10(6) IU/m2 subcutaneously for 3 days, failed to induce remission . The patient responded to an infusion of donor peripheral blood lymphocytes (3.4 x 10(7) cells/kg) pre-activated in vivo with rIL-2 and additionally activated in vivo with rIL-2, 6 x 10(6) IU/m2/day subcutaneously for 3 days. Elimination of the Philadelphia (Ph) clone was confirmed by cytogenetic analysis showing a normal male karyotype and by disappearance of the bcr/abl transcript, using the polymerase chain reaction (PCR). At present, the patient is 26 months post-treatment with no evidence of disease, but with chronic graft-versus-host disease. Our data indicate that allogeneic activated cell therapy (allo-ACT) may provide antitumor effector cells that successfully induce graft-versus-leukemia (GVL) effects even when cell therapy with donor buffy coats was insufficient.

Soluble IL-6 receptors (sIL-6R) in hematological patients receiving immunotherapy with IL-2/IFN-alpha or donor lymphocytes following bone marrow transplantation

Soluble interleukin-6 receptor (sIL-6R) has previously been shown to potentiate the activity of interleukin-6 (IL-6) which may display antitumor activity. Therefore, we evaluated sIL-6R levels in the sera of 15 patients who received cytokine-mediated immunotherapy with (IL-2/IFN-alpha), and 15 patients who received cell-mediated immunotherapy post-BMT, in an attempt to reduce the relapse rate. sIL-6R levels were evaluated pre-, during and post-cytokine or cell-mediated immunotherapy, using IL-6R-specific monoclonal antibodies (McAb) and double-sandwich ELISA. In normal controls, sIL-6R levels were found to be 20 +/- 3 ng/ml. sIL-6R levels increased significantly during IL-2/IFN-alpha immunotherapy in comparison to pre- or post-immunotherapy levels (74 +/- 9 ng/ml vs 46 +/- 6 ng/ml, and 50 +/- 9 ng/ml, respectively) (n = 15) (P < 0.05). sIL-6R levels also significantly increased following donor lymphokine activated killer (LAK) cells, given in addition to IL-2, in comparison to base line levels (87 +/- 3 ng/ml vs 60 +/- 2 ng/ml) (n = 6) (P < 0.05). Increased levels of sIL-6R were observed in BMT patients treated with immunotherapy.

[Regional adoptive immunotherapy using activated lymphocytes]

The antitumor effect of PSK was analysed with the "double grafted tumor system" in which BALB/c mice received simultaneous intradermal inoculations of Meth-A in the right (10(6) cells) and left (2 x 10(5) cells) flanks and were then injected with PSK in the right tumor on day 3. PSK inhibited the growth of not only the right but also the left, non-treated tumor. Immunized spleen cells were taken from mice which had been cured by intratumoral administration of 5 mg of PSK. On day 3, one hour after intravenous injection of cyclophosphamide, immunized spleen cells (2 x 10(7) cells/mouse) were injected into the Meth-A tumor. Adoptive transfer of PSK immunized spleen cells caused the complete regression of Meth-A tumors. However, the intravenous administration of spleen cells showed no antitumor effect. Expansion of peripheral blood lymphocytes was stimulated with immobilized anti CD3 antibody plus IL-2 for use in adoptive immunotherapy. gamma delta T cells proliferated in response to immobilized anti CD3. About 5 x 10(9) BRM-activated killer (BAK) cells were treated in cancer patients who gave their informed consent. One patient with colon cancer and metastatic cancer of the liver was treated with BAK cells by transcatheter arterial infusion without side effect. During the course of BAK treatment, serum IAP CIAE (crossed immunoaffino electrophoresis) pattern of patient changed tumor IAP pattern to normal IAP pattern. Two patients with malignant tumor in maxillary sinus were treated with BAK cells and OK-432 intratumorally. BAK treatment induced more infiltration of T cells, M phi and granulocytes in the tumor than OK-432 treatment alone and showed an antitumor effect with extensive necrosis.

Antibody-targeted lymphokine-activated killer cells inhibit liver micrometastases in severe combined immunodeficient mice

BACKGROUND & AIMS

Animal models for hepatic metastases can facilitate the investigation of lymphokine-activated killer (LAK) cell-based immunotherapy. The aim of this study was to investigate the efficacy of ccM4 antibody-targeted LAK cells in inhibiting hepatic micrometastases.

METHODS

Hepatic micrometastases were generated after the intrasplenic injection of HM7 colon carcinoma cells. TAG72 expression was detected in these hepatic micrometastases using ccM4 antibody. The ccM4 antibody was conjugated onto LAK cells by treatment with 17.5% polyethylene glycol 8000. After the intrasplenic injection of HM7 cells, severe combined immunodeficient mice were randomized into five groups (i-v) and received either 10(7) ccM4-LAK cells plus 1000 U interleukin 2 (IL-2; group i), LAK cells plus 50 micrograms ccM4 and IL-2 (group ii), LAK cells plus IL-2 (group iii), IL-2 alone (group iv), or only phosphate-buffered saline (group v).

RESULTS

The ccM4-LAK cells retained cytolytic activity and acquired TAG72-binding reactivity. The results showed that group i had significantly fewer hepatic metastases compared with group ii or group iii (P < 0.05) and even fewer hepatic metastases compared with group iv or group v (P < 0.001).

CONCLUSIONS

These results show that ccM4 antibody-targeted LAK cells significantly inhibited tumor growth in vivo; thus, they can be potentially useful in treatment of hepatic micrometastases.

Immunotherapy with IL-2-stimulated splenocytes reduces in vitro the level of Leishmania donovani infection in peritoneal macrophages

A study was done in vitro to determine if IL-2-stimulated lymphocytes (LAK cells) would activate infected macrophages to reduce their burden of Leishmania donovani. Macrophage-depleted splenocytes from normal or infected C57BL/6 (H-2b; LshS) mice, stimulated in vitro by the IL-2-containing supernatant of the MLA 144 cell line or by rIL-2, significantly reduced the number of syngeneic resting peritoneal macrophages infected by L. donovani; LAK cells from infected animals were significantly more effective in reducing the numbers of infected cells. Supernatants of MLA 144-stimulated spleen cells and rIL-2-stimulated splenocytes isolated in Millipore chambers also induced a significant reduction of the infection in vitro. Anti-Thy 1.2 eliminated the ability of the supernatant of MLA 144 to induce an activating function in C57BL/6 splenocytes; monoclonal anti-IL-2 abolished the ability of rIL-2 and of the MLA 144 supernatant to stimulate the splenocytes. Infected resting peritoneal macrophages of C57L (H-2b; LshR) mice were more responsive to activation than those of the C57BL/6 animals, irrespective of the phenotype of the stimulating LAK cells. Lymphokine stimulation reverses the immunological anergy induced in T lymphocytes by Leishmania donovani; IL-2-stimulated LAK splenocytes are highly effective in reducing the intensity of experimental visceral leishmaniasis in vitro in peritoneal macrophages.

[Combined immunotherapy using interferon-alpha, interleukin-2 and lymphokine-activated killer cells--improvement of quality of life in patients with advanced renal cell carcinoma]

The goal of any treatment strategy for cancer is to improve not only patient survival but also quality of that survival. Between March 1990 and February 1993, we treated 10 patients with advanced RCC (9 men and 1 woman) by combined immunotherapy using natural interferon-alpha (IFN-alpha), recombinant interleukin-2 (rIL-2) and lymphokine-activated killer (LAK) cells, and resulting the quality of life (QOL) issues examined. The ages of the patients ranged from 36 to 78 years (mean: 60.2) and the performance status (PS) ranged from 30 to 100% (mean: 77%). There were 8 lung, 3 bone, 2 brain and 1 neck and para-aortic lymph node metastases. We could evaluate 8 patients, 2 patients dropped out because of bone fracture and acute pneumonia. The protocol was as follows; 1 x 10(6) IU of rIL-2 as an intravenous infusion and 6 x 10(6) IU of IFN-alpha intramuscularly on days 1-7 and 15-21. In additions LAK cells obtained from the patients were given on days 14, 21, 28, and 35 intravenously. This protocol was repeated for more than three cycles (mean: 4.13 cycles) in each patient. The maintenance therapy on outpatient basis were performed in 4 patients after confirmation of the safety of the combined immunotherapy. This outpatient regimen was composed of 1 x 10(6) IU of rIL-2 intravenously, 6 x 10(6) IU of IFN-alpha intramuscularly on days, 1, 8, 15, 22, and 29, plus LAK cells on days 15 and 29. We repeated this protocol for 3-5 cycles (mean: 4.25 cycles).(ABSTRACT TRUNCATED AT 250 WORDS)