Lymphokine-activated killer-cell function of lymphocytes from peripheral blood, regional lymph nodes and tumor tissues of patients with oral cancer

Lymphokine-activated killer (LAK) cells, generated from peripheral blood lymphocytes (PBL) from patients with oral cancer or oral leukoplakia and from healthy donors showed comparable lysis of 6 target tumor cell lines, including 3 derived from head and neck and oral cancers. The tumor burden of the host did not appear to influence the systemic LAK activity. LAK activity of lymphocytes infiltrating the tumor tissues (TIL) was also comparable to that of the PBL. Both TIL and PBL showed a parallel increase in proportion of HNK-I+ and CD-25+ cells upon activation with IL-2. The lymph-node lymphocytes (LNL) from metastatic (met) and non-metastatic (non-met) draining lymph nodes, however, showed reduced LAK activity and an increase in CD8+ cells, in addition to CD25+ and HNK-I+ cells, when cultured with IL-2. When IL-2-activated LNL were co-cultured with autologous PBL during IL-2 activation of the latter, a strong suppressive effect was exerted by LNL. In contrast, IL-2-activated PBL did not suppress autologous LAK generation in spite of an increase in CD8+ cells seen after activation with IL-2. Frequency distribution of LAK precursors was significantly lower in LNL than in PBL from oral cancer patients. LAK precursor frequency in TIL was comparable to that of PBL. The results show that, in oral cancer, regional lymph nodes may not have adequate IL-2-inducible cytotoxic potential, due to a reduced number of LAK progenitors and possible activation of suppressor cells. Alternatively, TIL can be a potential source for LAK cell function.     

Preparation and Bioactivity Assay of CD3AK Cell from Lmbilical Cord Blood：—Clinic Report of 10 Tumor Cases

Objective To study the anti-tumor effect of CD3AK cell prepared from umbilical blood,to explore the short-term curative effect on tumor cases and seek better immune index for biotherapy.Methods IL-2 and IL-2 CD3Ab were used to induce LAK cells and CD3AK cells isolated from umbilical blood mononuclear cells(UBMC).The expanding number and bioactivity of LAK cells and CD3AK cells were examined at different time points after culture,the NK activity of peripheral blood mononuclear cells(PBMC)of 10 cases of malignant tumor were determined before and after CD3AK cell adopting immune therapy as well.Results The number and bioactivity(NK killing K562 cell)of LAK and CD3AK cells reached their peaks on 11 th day.The number of LAK and CD3AK cells were 18 folds and 24 folds of that before culture;The NK activities of LAK and CD3AK against K562 were 2.6 folds and 3.2 folds of those before culture respectively.The nK activity for killing K562 cells of malignant tumor patient‘s PBMC was increased from 63%-81% by CD3AK cell transfusing,rising mean 28%.Conclusion (1)The UBMC is a potential and better source of predecessor for LAK and CD3AK;(2)The NK activity of LAK and CD3AK cells from UBMC reached their peaks at 11 th day after culture,and the NK aftivity of CD3AK cells in much greater than that of LAK cells;(3)The NK activity of malignant tumor patient‘s PBMC can be obviously elevated by transfusing CD3AK cell(4)The test of NK activity of PBMC of malignant tumor patient may become an objective immune index for tumor biotherapy.     

In vitro and in vivo antitumor activity of lymphokine-induced cytotoxic cells

The present study demonstrates that LICC possess both in vitro and in vivo antitumor activity. The LICC were generated by culturing normal spleen cells with syngeneic peritoneal cells and indomethacin, or with a conditioned medium containing IL 2 with or without a putative new lymphokine, the CCDF. The LICC thus generated selectively killed the lymphoid or solid tumor targets of different H-2 haplotypes and of different etiological origins. The precursors of LICC were probably NK-like cells. The effectors were neither classical NK nor classical cytotoxic T lymphocytes. The LICC were very effective in preventing growth of both lymphoid and solid tumors in vivo, and Thy I+ cells were essential for the anti-tumor effect. The ability to generate LICC was preserved in the tumor-bearing hosts until the terminal stage of tumor growth, when the generation of suppressor T-cells interfered with LICC induction. LICC seem to play an important role in defense against non-immunogenic tumors.     

Local administration of autologous lymphokine-activated killer cells and recombinant interleukin 2 to patients with malignant brain tumors

Lymphokine-activated killer cells (LAK cells) were induced from lymphocytes from patients with malignant glioma by using interleukin 2 (IL-2), and their killing activity was examined. Their LAK activity against Daudi cells was 66.2 +/- 13.1% and 48.7 +/- 12.7% against self glioma cells, 54.4 +/- 10.1% against K562 cells, 43.1 +/- 7.9% against Raji cells, and 33.5 +/- 16.2% against allogeneic glioma cells. The phenotype of these LAK cells was Leu 1 (++), 2a (+/-), 3a (++), 7 (+), and 11 (++). The phenotype of precursor LAK cells, on the other hand, was Leu 1 (-), 2a (-), 3a (+), 7 (-), and 11 (++). Other activated killer cells, including LAK cells, phytohemagglutinin-activated killer cells, autoactivated killer cells, and their precursor LAK cells, were studied serologically in order to identify their phenotypic characteristics. From these data, the LAK cell populations were considered to be polyclonal. Using these LAK cells plus IL-2, local adoptive immunotherapy was undertaken in 23 patients with recurrent malignant glioma. We injected, that is, autologous LAK cells plus IL-2 directly into the cavities of the brain tumors; 1.2 to 324 x 10(8) LAK cells per ml and 0.8 to 5.4 x 10(3) units of IL-2 were directly injected into the brain tumor by using an Ommaya reservoir. Definite tumor regression, improvement of some clinical symptoms, and continuous remission over 6 mo or more were observed in six, nine, and three patients, respectively. There were no marked side effects, except for slight fever and chill, in eight and three patients, respectively. These results suggested the possibility of induction of a sufficient number of LAK cells from the lymphocytes of the patients with recurrent malignant glioma, indicating that local adoptive immunotherapy by direct injections of LAK cells and IL-2 into the brain tumor will prove to be an effective means of immunotherapy. Additional follow-up of the patients will be required before its therapeutic value can be established.     

脐血CD3AK细胞治疗恶性肿瘤的临床应用研究

目的:研究用脐血单个核细胞制备CD3AK细胞的抗肿瘤作用,探讨肿瘤生物治疗近期疗效的免疫指标.方法:分离脐血单个核细胞,分别用IL-2和IL-2 CD3Ab诱导LAK和CD3AK细胞,并测其扩增数量和对K562细胞的杀伤活性;测定肿瘤患者用CD3AK细胞治疗前后外周血T淋巴细胞亚群绝对计数的变化情况和外周血单核细胞(PBMC)的NK杀伤活性.结果:脐血LAK细胞和脐血CD3AK细胞均于培养后11天时扩增倍数最高,分别是培养前的18倍、24倍,对K562的杀伤活性分别是培养前的2.6倍和3.2倍;肿瘤患者输注CD3AK细胞一疗程后,其外周血T淋巴细胞亚群绝对计数有明显升高:总T升高66.0%,Th升高68.0%,Ts升高58.0%;其PBMC的NK杀伤活性由63.0%升高到81.0%,平均升高28.0%.结论:1)脐血单个核细胞是LAK细胞和CD3AK细胞良好的前体细胞.2)LAK和CD3AK细胞的数量和杀伤能力在培养的11天时达高峰,而且CD3AK细胞数量和杀伤活性明显优于LAK细胞.3)CD3AK细胞输注能明显提高肿瘤患者外周血T淋巴细胞亚群绝对计数和PBMC的NK活性.4)肿瘤患者的外周血T淋巴细胞计数和PBMC的NK活性测定可望成为肿瘤生物治疗的一个近期疗效参数.     

Phenotype of syngeneic tumor-specific cytotoxic T-lymphocytes and requirements for their in vitro generation from tumor-bearing host and immune spleens

Cells required for the in vitro generation of syngeneic cytotoxic T-lymphocytes (CTL) against the P815 mastocytoma in the DBA/2 mouse strain were investigated. For both immune and tumor-bearing host spleen cells, CTL effector cells were eliminated by treatment with anti-Thy1.2, anti-Lyt1.1, or anti-Lyt2.1 and C', but were resistant to anti-L3T4 (GK1.5). Thus, CTL effectors (and their precursors) were Lyt1+2+, L3T4-. However, P815-specific CTL could not be generated in the absence of L3T4+ cells, whose function could be replaced with exogenous interleukin-2 (IL-2). When monoclonal antibodies against L3T4 were added to mixed leukocyte tumor cultures, CTL generation was markedly inhibited. Depletion of accessory cells also led to a marked reduction in CTL generation, which could be restored to control levels by adding adherent cells from normal spleens or with exogenous IL-2, but not with IL-1. Thus, accessory cells are apparently required to present the tumor antigens of this Ia-negative tumor to T-helper cells.     

Synergy of interleukin-5 with interleukin-2 in the generation of lymphokine-activated killer-cells

IL-5 synergies with IL-2 to produce increased LAK activity, although IL-5 alone induced little cytotoxic activity. The most dramatic synergy occurred with a suboptimal IL-2 concentration. The kinetics of LAK activity induced by IL-2 plus IL-5 were similar to those induced by IL-2. IL-5 exerted its effects during the late stage of IL-2 induced LAK generation. In the precursor phase, depletion of asialo-GM1+ cells preceding culture eliminated IL-2 plus IL-5 induced LAK activity. In the effector phase, IL-2 plus IL-5 induced LAK activity was eliminated by depletion of Thy1.2+ cells following culture.     

The requirements for successful immunotherapy of intraperitoneal cancer using interleukin-2 and lymphokine-activated killer cells

In a significant proportion of patients with gastrointestinal and ovarian malignancy the peritoneal cavity is a prominent site at which surgical treatment fails. Adjuvant treatments directed at this site should be investigated in an attempt to improve survival in patients with these cancers. In the study reported here, a model of intraperitoneal tumor in the mouse was established and shows the effectiveness of lymphokine activated killer (LAK) cells and exogenous interleukin-2 (IL-2) in the control of intraperitoneal tumor. A standard regimen was used to treat seven different tumors in three different mouse strains. In all seven cases a significant reduction in the intraperitoneal tumor mass was observed when LAK cells plus IL-2 were used as immunotherapy. A prolonged survival was also demonstrated in mice with intraperitoneal tumor. The relevance of these observations to patients with cancer was demonstrated in that allogeneic and syngeneic LAK cells were equally effective, LAK cells generated from normal and from tumor-bearing donors showed equal reactivity, and this treatment was successful in the immuno-compromised host. Both IL-2 derived from an IL-2-producing subline of the EL-4 thymoma and recombinant IL-2 were equally effective in the control of intraperitoneal tumor. The local-regional effects of the intraperitoneal administration of IL-2 were demonstrated by high levels of LAK cell cytotoxicity in peritoneal exudate cells. Intraperitoneal IL-2 or IL-2 plus LAK cell regimens should be investigated in the treatment of malignancy that spreads by implantation onto peritoneal surfaces.     

Effect of macrophages on interleukin-2 (IL-2)- and IL-4-induced murine lymphokine-activated killer activity

The enhancing effect of macrophages on interleukin-2 (IL-2)- and IL-4-induced murine lymphokine-activated killer (LAK) activity was investigated in this study. Peritoneal macrophages significantly enhanced LAK activity generated from accessory cell-depleted splenic lymphocytes in both IL-2 and IL-4 cultures. This effect was dependent on the number of macrophages and was not replaced by a factor derived from macrophages or lymphocytes. Macrophages enhanced IL-2- and IL-4-induced LAK activity against both natural killer (NK)-sensitive (YAC-I, P388D1) and NK-resistant (P815) tumor cells. Negative selection of cells with antibodies and complement showed no differences in surface markers between IL-2 LAK effectors and IL-4 LAK effectors generated in the presence of macrophages. These results suggest that the same LAK effector subsets can be enhanced by macrophages in either IL-2 or IL-4 cultures.     

Cure of murine Ehrlich ascites tumors with chronic oral indomethacin therapy combined with intraperitoneal administration of LAK cells and IL-2

We have shown that prostaglandin E2-(PGE2) mediated inactivation of all killer lineage cells is a common event in the tumor-bearing host, so that chronic indomethacin therapy (CIT) combined with multiple rounds of IL-2 cures spontaneous and experimental metastases of a variety of murine tumors by activating killer cells in situ. Ehrlich ascites tumor (EAT) is fatal for any mouse strain even with a small i.p. inoculum. We compared the therapeutic efficacy of chronic indomethacin therapy (CIT), CIT + interleukin-2 (IL-2), IL-2 + lymphokine activated killer (LAK) cells and CIT + IL-2 + LAK cells on EAT grown in CBA mice. CIT alone retarded tumor growth and stimulated cytotoxic activity in splenocytes as well as tumor-infiltrating lymphocytes against YAC-1 lymphoma and EAT targets but resulted in no cure. The therapeutic efficacy in prolonging the median survival improved in the following order: CIT less than IL-2 + LAK cells less than CIT + IL-2 less than CIT + IL-2 + LAK cells. The last regimen cured 90% of mice and resulted in a short-lasting immunity against a second tumor challenge in some of the animals. Thus, this triple combination therapy may hold promise for eradicating carcinomatous ascites in the human.     

Generation of human lymphokine-activated killer cells following brief exposure to high dose interleukin 2

Current laboratory lymphokine-activated killer (LAK) cell activation procedures require culture of peripheral blood mononuclear cells (PBMC) in the presence of 1000-1500 units/ml of interleukin 2 (IL-2) for 3-7 days. However, we have observed that a brief exposure (15 min-1 h) of PBMC to a high concentration of IL-2 results in the maturation of LAK precursor cells to cytolytic effector cells over the course of 1-3 days. These IL-2-pulsed LAK cells express cytolytic activity comparable to that of nonpulsed PBMC (cultured continuously in IL-2) at 3 days of culture. The acquisition of cytolytic activity followed the same kinetics for both pulsed and nonpulsed mononuclear cells and was maintained when tested at day 7. The pulsed LAK cells were capable of significantly lysing 11 different tumor targets tested and flow cytometric analysis revealed that pulsed LAK cells were phenotypically similar to nonpulsed LAK cells. Serum obtained from cancer patients undergoing IL-2/LAK cell therapy did not inhibit the maturation of the pulsed mononuclear cells into LAK cells. Interestingly, only PBMC obtained from cancer patients receiving in vivo IL-2 infusions could be induced to generate the same levels of cytolytic activity as those in nonpulsed cells using this pulse procedure. PBMC obtained from healthy, normal donors could not be pulsed to the same levels of activation as nonpulsed LAK cultures. Our study demonstrates that for the generation of maximum LAK cell cytolytic activity, LAK cell precursors must be primed in vivo with IL-2. Implementation of this procedure could eliminate the high cost of cell culture which normally accompanies IL-2/LAK cell therapy. Such an approach could make IL-2/LAK cell therapy more accessible for cancer patients.     

Augmentation of interleukin-2 immunotherapeutic effects by lymphokine-activated killer cells and allogeneic stimulation in murine tumor cells

Interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells were used in intraperitoneal and pulmonary tumor models in C57BL/6 mice. To maintain the immunotherapeutic effects of IL-2 plus LAK treatment but reduce its toxicity, ways were sought to augment IL-2 effects. The investigation showed that the adoptive transfer of LAK cells was a prerequisite for successful therapy of intraperitoneal cancer. When LAK cells were given on consecutive days within one course of immunotherapy, antitumor efficacy was augmented with additional doses of LAK cells. However, with the reduction of 1 complete cycle of IL-2 + LAK cells, no further reduction in intraperitoneal tumor was observed as compared to the reduction after 2 or 4 cycles. LAK cells generated from splenocytes of mice that had received an allogeneic tumor challenge 1 week earlier exerted a highly increased cytotoxicity as compared to normal LAK cells. Furthermore, the potentiation effect of an allogeneic response of the host at the tumor site was demonstrated by decreased numbers of lung implants and improved survival in mice given mixtures of syngeneic and allogeneic tumor cell suspensions. An alloimmune response within the microenvironment of tumor tissue markedly enhanced the antitumor effect of IL-2 against the syngeneic tumor. It was concluded that there is a fundamental need to improve the recruitment of adoptively transferred LAK cells or LAK precursors into tumor tissue. This may be the next step required in the further development of IL-2 and LAK immunotherapy.     

脐血CD_3AK细胞的制备、生物活性测定及临床应用初探

 目的　研究用脐血单个核细胞制备CD3 AK细胞的抗肿瘤作用 ,探讨肿瘤生物治疗近期疗效的免疫指标。方法　分离脐血单个核细胞 ,分别用IL 2和IL 2 +CD3 Ab诱导LAK和CD3AK细胞 ,并测其扩增数量和对K5 6 2细胞的杀伤活性 ;测定肿瘤患者用CD3 AK细胞治疗前后外周血单核细胞(PBMC)的NK杀伤活性。结果　脐血LAK细胞和脐血CD3 AK细胞均于培养后第 11天时扩增倍数最高 ,分别是培养前的 18倍、2 4倍 ,对K5 6 2的杀伤活性分别是培养前的 2 .6倍和 3.2倍 ;肿瘤患者输注CD3 AK细胞一疗程后 ,其PBMC的NK杀伤活性由 6 2 %升高到 82 % ,平均升高 32 %。结论　 (1)脐血单个核细胞是LAK细胞和CD3 AK细胞良好的前体细胞。 (2 )LAK和CD3 AK细胞的数量和杀伤能力在培养的第 11天时达高峰 ,而且CD3 AK细胞数量和杀伤活性明显优于LAK细胞。 (3)CD3 AK细胞输注能明显提高肿瘤患者PBMC的NK活性。 (4 )肿瘤病人PBMC的NK活性测定可望成为肿瘤生物治疗的一个近期疗效参数     

Generation of lymphokine-activated killer cells in strain 2 guinea pigs and their use in the therapy of L2C, an acute B-cell leukemia

Lymphokine-activated killer (LAK) cells were induced by incubating strain 2 guinea pig splenocytes or lymph node-derived cells in recombinant human interleukin-2 (IL-2) for 3-5 days. These effector cells had the morphology of lymphoblasts and were able to lyse murine P815 tumor cell targets. Fresh, unstimulated, guinea pig effectors were not capable of lysing these targets. The therapy of the L2C leukemia, an acute B-lymphoblastic leukemia of strain 2 guinea pigs, using LAK cells and recombinant IL-2 was examined. Antitumor effects were demonstrated by premixing LAK and tumor cells prior to intradermal injection in Winn type assays and then measuring the growth of local tumor and survival of the animals. In further experiments i.p. administration of LAK cells, 4 h following tumor cell inoculation by the i.p. route, prolonged the survival of treated animals. The best results in this i.p. therapy model were obtained with a 10-fold excess of LAK cells over tumor cells plus additional treatment with 1000 units of IL-2 for 20 days. This resulted in a 10-day increase in median survival of treated animals. Despite these in vivo antitumor effects, lytic activity of LAK effector populations against L2C targets could not be demonstrated in vitro. The potential synergy between LAK cells, IL-2, and a monoclonal antibody directed against the idiotype of the neoplastic cell surface immunoglobulin was also investigated. In these experiments enhanced survival of the combined treatment group, beyond that of either singly treated group, was not found. This study shows that LAK cells are useful agents in the therapy of a widely disseminated, aggressive, B-cell lymphoblastic leukemia. The use of such effectors, even in cases where in vitro lysis of the target tumor cell cannot be demonstrated, is encouraged by these results.     

Autocytotoxic activity of lymphokine-activated killer cells: characterization of effector cells and susceptible targets

The specificities and surface markers of murine autocytotoxic cells induced by in vitro culture with interleukin 2 (IL2) were studied. Culturing murine spleen cells with recombinant human IL2 resulted in the generation of cytotoxic cells which killed syngeneic lymphoblasts and syngeneic activated macrophages (M phi). Both lectins and protein antigens were capable of inducing lymphoblasts recognized by lymphokine-activated killer (LAK) cells. B-lymphoblasts as well as T-lymphoblasts were sensitive to lysis by these effector cells. In addition, peritoneal M phi activated in vivo with Bacille Calmette-Guérin (BCB), Corynebacterium parvum (C. parvum), thioglycollate (TG) or lipopolysaccharide (LPS) were shown to be susceptible to lysis by LAK cells. In contrast, neither unstimulated T cells nor resident peritoneal M phi were sensitive to lysis by LAK cells, suggesting that normal cells have to be activated in order to be sensitive to lysis by these effector cells. Surface marker analysis indicated that majority of effector cells which killed syngeneic lymphoblasts and activated M phi were Thy1+, asialo GM1+, L3T4-, Ly2-.     

Increased vascular permeability in organs mediated by the systemic administration of lymphokine-activated killer cells and recombinant interleukin-2 in mice

Significant tumor regressions in mice with established carcinomas, sarcomas, and melanomas and in humans with advanced cancers have been observed following immunotherapy with lymphokine-activated killer (LAK) cells and recombinant interleukin-2 (IL-2). However, dose escalations of LAK cells and IL-2 have been prevented by the development of a vascular leak syndrome (VLS). Although IL-2 alone can produce this VLS, we investigated the role of transferred LAK cells, generated by the incubation of syngeneic splenocytes in IL-2, in mediating this phenomenon. We used a murine model to quantitate the vascular leak by measuring the extravasation of iv injected 125I-bovine serum albumin. A permeability index (PI) was calculated by dividing the mean cpm of tissues from treated mice by those from control animals. The systemic transfer of LAK cells and IL-2 produced a significantly greater extravasation of albumin in the lungs, liver, and kidneys than after Hanks' balanced salt solution, IL-2, or LAK cells alone (in the lungs, for example, PI = 4.7, 1.4, and 1.6 after LAK cells and IL-2, LAK cells alone, and IL-2 alone, respectively). To eliminate the contribution to the leak by host lymphocytes, we irradiated mice before cell transfer. As compared to controls, LAK cells and IL-2 resulted in higher extravasation in the lungs, liver, kidneys, and spleen. However, a similar vascular leak was not observed in the lungs, liver, and kidneys after treatment with IL-2 plus fresh or cultured (without IL-2) splenocytes. Moreover, the combination of IL-2 excipient and LAK cells or IL-2 and irradiated LAK cells did not produce a fluid leak. The development of the VLS by LAK cells was directly related to the dose of concurrently administered IL-2 and the number of injected cells. Depletion of Thy 1.2-positive lymphocytes using antibody and complement prior to generating the LAK cells used in adoptive transfer did not abrogate the VLS in any of the organs tested. Similarly, depletion of L3T4 and Lyt-2 positive cells in vivo using monoclonal antibodies prior to harvesting spleens for generation of LAK cells also had no impact on the VLS. In contrast, in vitro treatment of LAK precursor cells with antibody to asialo-GM-1 plus complement completely eliminated the VLS when the depleted cells were cultured in IL-2 and subsequently transferred.(ABSTRACT TRUNCATED AT 400 WORDS)     

Lymphokine-activated killer cells: lysis of fresh syngeneic natural killer-resistant murine tumor cells by lymphocytes cultured in interleukin 2

Normal splenocytes that are cultured in the lymphokine, interleukin 2 (IL-2), for as short as 2 days develop lytic activity for fresh syngeneic natural killer-resistant tumor cells as well as natural killer-sensitive YAC cells in a 4-hr 51Cr release assay. Lymphokine-activated killer (LAK) cells do not lyse syngeneic fresh lymphocytes but do lyse syngeneic concanavalin A-induced lymphocyte blasts. Lysis is not due to the presence of lectin or xenogeneic serum and appears to be an intrinsic property of lymphocytes activated in IL-2. The activation appears universal in that lymphocytes from all strains of mice activated in this manner exhibited similar patterns of lysis for fresh tumor target cells. To characterize the cells responsible for this lysis, we analyzed the phenotypic expression of surface markers on these cells with depletion techniques using monoclonal antibody and complement. These studies indicate that the precursor of the LAK cell is Thy-1+ and nonadherent to plastic or nylon wool. Lysis of syngeneic tumor was inhibited when LAK cells were treated with an anti-Thy-1.2, or anti-Lyt-2.2 monoclonal antibody and complement but not with anti-Lyt-1.2 monoclonal antibody and complement, indicating that the observed lytic activity was due to a Thy-1+ Lyt-1-2+ cell. Furthermore, LAK cell-mediated lysis could be inhibited by the addition of anti-Lyt-2 or LFA-1 monoclonal antibody to cytotoxicity assays. Cold target inhibition analysis revealed that the syngeneic tumor cells were lysed by recognition of a determinant not present on normal lymphocytes or lymphocyte blasts. This lysis of fresh solid tumor cells by lymphoid cells grown in IL-2 may be of value in the study of tumor-host immunological interactions. The biological significance of tumor lysis by IL-2-activated cells requires further study.     

Cytokine gene expression during the generation of human lymphokine-activated killer cells: early induction of interleukin 1 beta by interleukin 2

Culture of human peripheral blood leukocytes with interleukin 2 (IL-2) stimulates their differentiation into lymphokine-activated killer (LAK) cells, with a broad range of cytotoxicity against fresh tumor cells and tumor cell lines (Grimm et al., J. Exp. Med., 155: 1823-1841, 1982). We chose to utilize a molecular approach to determine whether IL-2 stimulates the expression of cytokine genes by the mixed cell population which may be involved in the generation or regulation of lytic activity. Northern blot analysis performed with total cellular RNA from LAK cells cultured for varying periods of time with IL-2 revealed that the genes which code for cytokines [interleukin 1 (IL-1)alpha and beta, gamma-interferon, tumor necrosis factor alpha, and lymphotoxin] were not spontaneously expressed. As soon as 2 h after IL-2 treatment, IL-1 alpha and IL-1 beta mRNAs were expressed. Both nonadherent and adherent populations of LAK cells express IL-1 beta mRNA; however, the adherent population produced more IL-1 beta mRNA and maintained its expression for a prolonged period of time. Other cytokine mRNAs (gamma-interferon, tumor necrosis factor alpha, and lymphotoxin) were expressed later than the IL-1 mRNAs with maximal levels between Days 2 through 7. Our results indicate that LAK cell populations can generate a variety of cytokines which may be involved in the generation of lytic activity.     

In vivo requirement for asialo GM1 and Thy1 positive leukocytes for antitumor effect of rIL-2 +/- rIFN-gamma

Localized treatment with recombinant human interleukin-2 (rIL-2) +/- recombinant murine interferon-gamma (rIFN-gamma) results in regression of early B16 melanomas in normal C57BL/6 (B6) mice, but not in syngeneic beige mice, which have defective natural killer (NK) cells. Injection of antibodies to asialo GM1 (a-AGM1) or Thy1 abolishes the tymoricidal effects of rIL-1 +/- rIFN-gamma. Thus, cells activated by these cytokines must be either NK-like cells that are AGM1+ Thy1+, or NK-like cells (AGM1+) cooperating with T lymphocytes (Thy1+), since either antibody (a-AGM1 or a-Thy1) independently abrogates the in vivo antitumor effect.     

Adoptive immunotherapy of human cancer using low-dose recombinant interleukin 2 and lymphokine-activated killer cells

The adoptive transfer of recombinant-methionyl human interleukin 2 (rIL-2)-activated autologous peripheral blood mononuclear lymphokine-activated killer (LAK) cells to cancer patients is being evaluated as an alternative to conventional cancer therapy. We have independently developed an alternative regimen to previously reported adoptive immunotherapy protocols using rIL-2 and LAK cells which features the prolonged administration of low-dose rIL-2 (30,000 units/kg) and an automated, entirely enclosed system of peripheral blood cell procurement, culture, harvest, and reinfusion of activated cells. The cell culture system was tested with a murine tumor model in which LAK cells generated in plastic culture bags were reinfused into tumor-bearing mice. Tumor regression was as effective with cells activated in the bags as in conventional culture flasks. Twenty-eight cancer patients were treated for 5 consecutive days with low-dose rIL-2, followed by leukapheresis, infusion of LAK cells, and prolonged IL-2 administration. At least 50% tumor regression was observed in 46% of all patients treated. These data imply that human peripheral blood mononuclear cells retain fully their capacity for rIL-2-induced activation and effector cell function under this alternative approach, and further, that a low-dose rIL-2 regimen with markedly reduced toxicities can be as effective as high-dose rIL-2 regimens if low-dose rIL-2 is given for a prolonged period of time following LAK cell infusion.