Alpha-interferon activated cytotoxic lymphocytes in hairy cell leukemia patients: evaluation of cytotoxic events

To further define the mechanisms responsible for the alpha-interferon (alpha-IFN) efficacy in the treatment of hairy cell leukemia (HCL), experiments were carried out to specify the cytotoxic events taking place following this type of therapy. Although an increased natural killer (NK) activity was demonstrable after alpha-IFN treatment, evidence has been provided that hairy cells were not specifically lysed either by fresh autologous/allogenic NK lymphocytes or by lymphokine activated killer (LAK) cells. This property could not be induced in vitro by alpha-IFN or by interleukin-2 (IL-2). Our data favour the hypothesis that the increase of NK cell activity observed following alpha-IFN therapy has not a direct antineoplastic effect but is likely to be of relevance for a non-specific enhancement of the host immune system. In alpha-IFN treated HCL this latter property may account for the better resistance to infections which usually represents the major cause of mortality in these patients.     

alpha-Interferon inhibits spontaneous and induced DNA synthesis in hairy cell leukemia.

The effect of alpha-interferon (alpha-IFN) on spontaneous or induced proliferation of isolated peripheral blood mononuclear cells from 5 hairy cell leukemia patients was studied. alpha-IFN inhibited the low spontaneous proliferation of B-ly7 positive hairy cells (HCs) and also the proliferation induced by tumour necrosis factor (TNF). Interleukin-2 did not affect HCs, but induced CD4 positive T cells to proliferate, an effect which alpha-IFN antagonized. The stimulatory effect of TNF on the growth of HCs proved to be reversible and was partially blocked with either anti-TNF receptor or anti-lymphotoxin antibodies. Cellular or secreted thymidine kinase levels reflected the proliferative state of HCs in response to different in vitro treatments, as confirmed by thymidine incorporation and cell cycle studies.     

In vitro and in vivo susceptibility of human leukemic cells to lymphokine activated killer activity

The susceptibility of human myeloid and lymphoid leukemic blasts to the lytic action of recombinant interleukin-2 (rIL-2)-generated lymphokine activated killer (LAK) cells was analyzed. With the exception of the K562 cell line, all 9 leukemic cell lines tested were resistant to the natural killer activity of freshly isolated peripheral blood lymphocytes (PBL) from healthy donors but were susceptible to the lytic action of PBL cultured for 3 days in the presence of rIL-2. Of the 32 primary myeloid and lymphoid acute leukemia samples investigated, the great majority were natural killer cell-resistant but were variably sensitive to LAK effectors. Variations in LAK activity were observed according to the donor of PBL, while little or no difference was documented in the capacity to elicit LAK activity of PBL cultured with 100 or 1,000 U of rIL-2/ml. Pretreatment of the leukemic target cells with neuraminidase did not increase substantially their sensitivity to LAK activity. LAK cells generated from the PBL of patients at the onset of the disease or in complete clinicohematological remission lysed Raji cells as efficiently as normal LAK effectors. Finally, LAK cells were capable of abrogating the tumor growth in nude mice of a human leukemic T cell line. These findings demonstrate the susceptibility in vitro and in vivo of human leukemic blasts to the lytic effect of LAK cells and point to a possible clinical exploitment of this new form of adoptive immunotherapy in the management of acute leukemia.     

Membrane-associated Lymphotoxin Expression and Functional Analysis of Lymphokine-activated Killer Cells Derived from Tumor-infiltrating Lymphocytes

The expression of a membrane-associated lymphotoxin molecule (mLT) on lymphokine-activated killer (LAK) cells obtained from 18 patients with malignant tumors and its role in the tumor cell killing mechanisms were investigated. LAK cells from tumor-infiltrating lymphocytes (TIL-LAK cells) were mainly composed of CD3-positive cells, whereas LAK cells from peripheral blood lymphocytes (PBL-LAK cells) were mainly composed of CD16- and CD56-positive cells. However, mLT was found to be expressed on TIL-LAK cells as well as PBL-LAK cells. The degree of mLT expression correlated with the killing activity of LAK cells towards L929 cells (r=0.806, P <0.01, n = 15), but not with that towards Daudi or K562 cells. Although the degree of mLT expression correlated with the amount of secreted lymphotoxin (LT) in the supernatant of LAK cell culture, the secreted LT itself could not account for the tumor cell killing activity of LAK cells. Polyclonal rabbit anti-LT antibody partially inhibited the killing activities of LAK cells towards L929 cells and this inhibition was found in the combination of autologous tumor cells and PBL-LAK cells. These findings suggest the possibility that the mLT-related cytotoxicity is involved in the tumor cell killing mechanisms of TIL-LAK cells as well as PBL-LAK cells.     

Inhibition of colony formation of drug-resistant human tumor cell lines by combinations of interleukin-2-activated killer cells and antitumor drugs

The cytotoxicity of interleukin-2-activated killer (LAK) cells with or without anticancer drugs against cell lines with acquired drug resistance was evaluated in vitro by colony assay. Human non-small cell lung cancer cell lines, PC-9 and PC-14, human leukemia cell line, K-562, and their sublines resistant to cisplatin (CDDP), PC-9/CDDP and PC-14/CDDP, and to adriamycin (ADM), K-562/ADM, were used as target cells. PC-9/CDDP demonstrated a marked increase in susceptibility to killing by both peripheral blood lymphocytes (PBL) and LAK cells, as compared to the parental cell line, PC-9. The cytotoxicity of PBL and LAK cells against PC-14/CDDP and K-562/ADM was similar to that against their parental cell lines. Moreover, the combination of LAK and CDDP had a synergistic effect on PC-14 and PC-14/CDDP.     

Inhibition of Colony Formation of Drug-resistant Human Tumor Cell Lines by Combinations of Interleukin-2-activated Killer Cells and Antitumor Drugs

The cytotoxicity of interleukin-2-activated killer (LAK) cells with or without anticancer drugs against cell lines with acquired drug resistance was evaluated in vitro by colony assay. Human non-small cell lung cancer cell lines, PC-9 and PC-14, human leukemia cell line, K-562, and their sublines resistant to cisplatin (CDDP), PC-9/CDDP and PC-14/CDDP, and to adriamycin (ADM), K-562/ADM, were used as target cells. PC-9/CDDP demonstrated a marked increase in susceptibility to killing by both peripheral blood lymphocytes (PBL) and LAK cells, as compared to the parental cell line, PC-9. The cytotoxicity of PBL and LAK cells against PC-14/CDDP and K-562/ADM was similar to that against their parental cell lines. Moreover, the combination of LAK and CDDP had a synergistic effect on PC-14 and PC-14/CDDP.     

Generation and Characterization of Lymphokine-activated Killer Cells against Fresh Human Leukemia Cells

Lymphokine-activated killer (LAK) cells generated from 15 acute leukemia patients in remission showed significant levels of cytotoxicity against Daudi 1A4, a natural killer-resistant cell line. This indicates that lymphocytes of leukemia patients in remission could respond to interleukin-2 to generate conventional LAK cells. However, LAK cells caused lysis of autologous leukemia cells at considerably lower levels in seven out of the 15 patients, with the exception of one case (48.6% cytolysis). None of the remaining eight patients exhibited LAK activity against autologous leukemia cells. On the other hand, patients' LAK could lyse allogeneic leukemia cells including those resistant to autologous LAK. Thus, patients' LAK seem not to be defective in lysis of leukemia cells. In the cold target competition analysis, the binding of patients' LAK to leukemia cells could be inhibited by autologous and allogeneic leukemia cell competitors, implying that almost all leukemia cells could be recognized by patients' LAK. Most LAK cells from normal donors showed significant lysis of allogeneic leukemia cells, but some leukemia cells were found to be resistant to lysis. LAK cells against both leukemia cells and Daudi 1A4 were phenotypically heterogenous, and were predominantly observed in the T3⁻ fraction in the precursor phase. In the effector phase, whereas LAK activity against leukemia cells was also predominantly shown in the T cell-depleted fraction, similar levels of LAK activity against Daudi 1A4 were found in both the T cell-depleted and -enriched fractions.     

Generation and characterization of lymphokine-activated killer cells against fresh human leukemia cells

Lymphokine-activated killer (LAK) cells generated from 15 acute leukemia patients in remission showed significant levels of cytotoxicity against Daudi 1A4, a natural killer-resistant cell line. This indicates that lymphocytes of leukemia patients in remission could respond to interleukin-2 to generate conventional LAK cells. However, LAK cells caused lysis of autologous leukemia cells at considerably lower levels in seven out of the 15 patients, with the exception of one case (48.6% cytolysis). None of the remaining eight patients exhibited LAK activity against autologous leukemia cells. On the other hand, patients' LAK could lyse allogeneic leukemia cells including those resistant to autologous LAK. Thus, patients' LAK seem not to be defective in lysis of leukemia cells. In the cold target competition analysis, the binding of patients' LAK to leukemia cells could be inhibited by autologous and allogeneic leukemia cell competitors, implying that almost all leukemia cells could be recognized by patients' LAK. Most LAK cells from normal donors showed significant lysis of allogeneic leukemia cells, but some leukemia cells were found to be resistant to lysis. LAK cells against both leukemia cells and Daudi 1A4 were phenotypically heterogenous, and were predominantly observed in the T3- fraction in the precursor phase. In the effector phase, whereas LAK activity against leukemia cells was also predominantly shown in the T cell-depleted fraction, similar levels of LAK activity against Daudi 1A4 were found in both the T cell-depleted and -enriched fractions.     

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.     

Lymphokine-activated killer cells can kill target cells not only by early killing but also by late killing,and the late killing level against autotumor cell line

Generally, lymphokine-activated killer (LAK) cells kill target cells early after the LAK cells adhere to them. In this study, we describe that LAK cells can also kill at a later time, such as 24-96 h. LAK cells were generated from a cancer patient and healthy volunteers. As target cells, the patient's autotumor cell line H41 was used. When LAK cells were added to the target cells in a culture well, the LAK cells killed the target cells by cell-cell adhesion within 1-4 h (early killing), but not all cells were killed. The LAK cells were then removed. However, the remaining cells ultimately died 24-96 h later (late killing). The late killing was different from the early killing because numerous granules and vacuoles appeared in the cytoplasm. The late killing was not induced by adding supernatant of the LAK cell culture, suggesting that LAK-target cell contact may be necessary for the killing. The cell injury was inhibited by 3-methyladenine (lysosome inhibitor). It suggests that the vacuoles may be caused by activated lysosome. The patient's LAK cells induced late killing at high levels. There was a high percentage of CD8(+)CD16(+) cells in the peripheral blood lymphocytes (PBL). This subset induced late killing more effectively than the CD8(-)CD16(+) subset. Killing was more conspicuous against H41 than against allogeneic cell line T98G. This type of killing is noteworthy for understanding of killing mechanism of LAK cells.     

Infiltrative and cytolytic activities of lymphokine-activated killer cells against a human glioma spheroid model

In the present study, we investigated not only the cytotoxic effects of lymphokine-activated killer (LAK) cells on a tumor mass but also the ultrastructural cell-to-cell interaction between LAK effector cells and tumor cells during the cytolytic process within a three-dimensional solid tumor. A multicellular tumor spheroid of a human glioma cell line (U-251MG) was utilized as a solid tumor model. LAK cells were generated from peripheral blood lymphocytes of a healthy donor after stimulation by interleukin 2. Multicellular tumor spheroids with diameters of 500 microns were cocultivated with either LAK cells or nonactivated peripheral blood lymphocytes at the effector:target cell ratio of 20:1, and then time-sequential kinetic, morphological, and ultrastructural analyses were carried out. Morphological and kinetic studies showed that LAK cells directly infiltrated toward the inner areas of multicellular tumor spheroids and caused a progressive tumor destruction. In contrast, peripheral blood lymphocytes hardly exhibited such activities. Ultrastructurally, it was found that the infiltrating LAK effector cells were composed of heterogeneous subpopulations, T-like cells, and large granular lymphocyte-like cells. Both types of lymphocytes tightly adhered to the tumor cells and showed typical morphological features of killing them.     

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     

健康人和骨肉瘤病人来源的LAK细胞体外抗瘤作用

采用５１Ｃｒ释放试验对健康人和骨肉瘤病人外周血单个核细胞（ＰＢＭ）在重组白细胞介素－２（ｒＩＬ－２）条件下，ＬＡＫ细胞的诱导形成及对４种传代瘤细胞的体外杀伤活性进行探讨。实验结果表明：２种来源ＬＡＫ细胞对Ｋ５６２（人慢性髓样红白血病细胞系）、ＳＭＭＣ７７２１（人肝癌细胞系）、ＬＡＸ（人肺腺癌细胞系）的杀伤活性均在５５％以上（按效靶比例５０：１），而对ＯＳ细胞（人骨肉瘤细胞系）的活性普遍低下，杀伤率低于３５％。结果证实：１）健康人和骨肉瘤病人的ＰＢＭ均能在ｒＩＬ－２条件下诱导形成具有广谱抗瘤活性的ＬＡＫ细胞群，二者的杀伤格局和效力相近。２）骨肉瘤细胞本身对ＬＡＫ细胞的杀伤作用存在强烈抗性。     

Cytotoxic in vitro function in patients with metastatic renal cell carcinoma before and after alpha-2b-interferon therapy. Effects of activation with recombinant interleukin-2.

In this study the characteristics of the cytotoxic function in a series of patients with metastatic renal cell carcinoma (RCC) were analyzed and the possibility of modulating this capacity in vitro with the use of biologic response modifiers (BMR) such as alpha-interferon (alpha-IFN) and recombinant interleukin-2 (rIL-2) was verified, with the ultimate goal of providing a rationale for a therapeutic approach to this disease with these molecules. Peripheral blood mononuclear cells (PBMC) of patients with advanced RCC were tested for natural killer (NK) and lymphokine-activated killer (LAK) activity both before and after alpha-IFN therapy. In addition, surface markers of unstimulated and stimulated cells were analyzed and in vitro assays were performed to determine the proliferative capacity in response to the stimulus with rIL-2. During an evaluation before treatment, defective NK activity was observed that could be corrected by incubating the cells with rIL-2. In these subjects, LAK cells could be consistently generated after PBMC were activated with this cytokine in vitro. No changes in NK and LAK activity were found after alpha-IFN therapy. In contrast, treatment with alpha-IFN affected the proliferative response of PBMC to rIL-2, and a significant decrease in this in vitro capacity was observed during follow-up. The ability to restore NK activity and obtain an adequate LAK cytotoxicity from the PBMC of patients with RCC supports a therapeutic approach with BRM. However, the fact that this type of treatment affects the proliferative response of PBMC to rIL-2 must be considered when clinical trials are designed for patients with RCC.     

Impact of IL-2 and IL-2R SNPs on Proliferation and Tumorkilling Activity of Lymphokine-Activated Killer Cells from Healthy Chinese Blood Donors

One of the goals of tumor immunotherapy is to generate immune cells with potent anti-tumor activity throughin vitro techniques using peripheral blood collected from patients. However, cancer patients generally havepoor immunological function. Thus using patient T cells, which have reduced in vitro proliferative capabilitiesand less tumor cell killing activity to generate lymphokine-activated killer (LAK) cells, fails to achieve optimalclinical efficacy. Interleukin-2 (IL-2) is a potent activating cytokine for both T cells and natural killer cells.Thus, this study aimed to identify optimal donors for allogeneic LAK cell immunotherapy based on singlenucleotide polymorphisms (SNP) in the IL-2 and IL-2R genes. IL-2 and IL-2R SNPs were analyzed using HRMPCR.LAK cells were derived from peripheral blood mononuclear cells by culturing with IL-2. The frequencyand tumor-killing activity of LAK cells in each group were analyzed by flow cytometry and tumor cell killingassays, respectively. Regarding polymorphisms at IL-2-330 (rs2069762) T/G, LAK cells from GG donors hadsignificantly greater proliferation, tumor-killing activity, and IFN-γ production than LAK cells from TT donors(P<0.05). Regarding polymorphisms at IL-2R rs2104286 A/G, LAK cell proliferation and tumor cell killing weresignificantly greater in LAK cells from AA donors than GG donors (P<0.05). These data suggest that either IL-2-330(rs2069762)T/G GG donors or IL-2R rs2104286 A/G AA donors are excellent candidates for allogeneicLAK cell immunotherapy.     

Natural killer and lymphokine-activated killer activities in stomach cancer patients with special emphasis on the effect of 5-fluorouracil, adriamycin and mitomycin-C chemotherapy

The cytotoxicities of peripheral blood lymphocytes (PBL) and lymphokine-activated killer (LAK) cells were studied to evaluate the effect of chemotherapy on cellular immunity, in 18 patients with unresectable stomach cancer before and after chemotherapy with 5-fluorouracil, adriamycin and mitomycin-C (FAM), and in 21 healthy volunteers. LAK cells were generated in vitro by culturing PBL with 100 U recombinant human interleukin-2 (rH-IL-2)/ml for 72 h. K562 (human myelogenous leukemia), MKN-45 (human stomach adenocarcinoma) and PC-14 (human pulmonary adenocarcinoma) were used as target cells. The cytotoxicity of PBL to K562 and MKN-45 was suppressed in patients with stomach cancer before chemotherapy, compared with that in healthy volunteers (P less than 0.05). The cytotoxicity of LAK cells was significantly higher to all three cell lines tested than that of PBL in both the healthy volunteers and stomach cancer patients (P less than 0.01); however, a lower level of LAK activity was generated in patients with cancer compared to that in the healthy volunteers. FAM therapy did not suppress the cytotoxicities of PBL and LAK cells. The surface markers of PBL and LAK cells were measured, demonstrating that there was no significant change in the percentage of lymphocytes with CD3+, CD4+, CD8+, CD16+ or CD19+ after chemotherapy. The ratios of CD4+ to CD8+ cells in PBL and LAK cells were also not significantly changed after chemotherapy. In the present study, we have demonstrated that the PBL of stomach cancer were defective in generating LAK activity compared to those of controls, but the LAK activity generated from PBL receiving chemotherapy was similar to that from PBL without chemotherapy in stomach cancer patients.     

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.     

Lymphokine activated killer (LAK) cell mediated killing of human glioma: Effect of pretreating glioma with various membrane modifying agents

The killing of human glioma by lymphokine activated killer (LAK) cells was studied. LAK cells generated by culturing recombinant interleukin-2 (ILr2) with human peripheral blood lymphocytes (PBL) obtained from normal volunteers markedly lysed allogeneic glioma grown in tissue culture. Susceptibility of glioma to lysis by LAK cells was abrogated by pretreating the glioma cells with trypsin or chymotrypsin, but was unaffected by pretreatment with hydrocortisone, neuraminidase, glycosidases or sodium periodate. These results suggest that the cell surface determinant on human glioma cells responsible for its tumor selective lysis by LAK is a protein sensitive to trypsin and chymotrypsin.