Natural killer cell activity of prostatic cancer patients

Natural killer (NK) cell activity of prostatic cancer patients was compared with that of control groups by the radioactive indium (111In) release assay using the K562 and H494 cells as targets. Patients suffering from advanced prostatic cancer (clinical stages C and D) exhibited significantly lower NK activity against K562 cells (28 +/- 18%) than did the normal group (41 +/- 19%). The lower NK activity of these patients is not related to their age, since patients in the same age range with localized cancer (stage B) or benign prostatic hyperplasia did not show low NK activity (37% +/- 19%). This lower NK activity is not due to a depletion of the NK cell precursor population, since the NK activity of advanced cancer patients improves significantly after in vitro incubation with interferon. The NK activity of normal subjects or patient groups showed wide fluctuations during the 18-month observation period. Because of these interassay variations, it is necessary to use standard control subjects during long-term monitoring of the NK activity of the patients.     

Natural killer and lymphokine-activated killer cell-mediated cytotoxicity in patients with oral cancer

Peripheral blood lymphocytes (PBL) from untreated and treated oral cancer patients, lymph node lymphocytes (LNL) from metastatic (met) and nonmetastatic (non-met) lymph nodes, and tumor infiltrating lymphocytes (TIL) were tested for natural killer (NK) and lymphokine activated killer (LAK) cell cytotoxicity using appropriate targets in a short-term chromium release assay. The results showed that while both NK and LAK functions of PBL from oral cancer patients were comparable to those of normal healthy donors, the NK activity of metastatic and nonmetastatic LNL and TIL was highly compromised. On the other hand, potent LAK activity could be generated from all three lymphoid populations. Individual patients showing low NK activity displayed good LAK cytotoxicity, indicating that endogenous cells with low NK potential have adequate ability to respond to interleukin 2 (IL-2). LAK activity tested on autologous tumour targets revealed that TIL were the best source of LAK cells. followed by PBL and LNL.     

Clinical features and inhibitory activity of regional lymph node cells on the cytotoxicity of autologous killer cells in patients with primary lung cancer

The effect of regional lymph node cells on the cytotoxicity of killer lymphocytes against autologous tumor cells was investigated in 42 patients with primary lung cancer by a 4-h 51Cr-release assay. The cytotoxicities of killer lymphocytes against autologous tumor cells were either significantly inhibited, enhanced, or remained unchanged by the addition of regional lymph node cells in 27, 4 and 11 cases, respectively. Correlation between the inhibitory activity (IA) and the clinical features was studied in terms of age, tumor histologic type, post-surgical TNM stage and chemotherapy. Patients less than 50 years old, those with adenocarcinoma, and those in the N2 stage showed significant inhibition of cytotoxicity, indicating suppressor cell predominance in these cases. Although no significant difference of IA was observed between the stages of lung cancer, T-factor groups, and groups with or without chemotherapy, considerably greater deviation of IA was observed in the chemotherapy group, indicating the possible influence of the drug treatment on the cytotoxicity of lymphocytes.     

Natural killer cell cytotoxicity in the peripheral blood, cervical lymph nodes, and tumor of head and neck cancer patients

This study evaluated peripheral blood lymphocyte and lymph node lymphocyte natural killer (NK) cell activity in 22 patients with head and neck squamous cell carcinoma and eight patients undergoing surgery for nonmalignant conditions who served as controls. A novel mixed-model analysis of variance was used to analyze the results because of the inherent difficulties in data interpretation among heterogeneous groups when several concurrent variables impinge upon the results. The peripheral blood lymphocyte NK activity of cancer patients was significantly less than controls. In contrast, lytic activity from uninvolved draining lymph nodes of cancer patients was comparable to the activity of control nodes. However, if the node contained a small focus of metastatic tumor, NK activity was significantly diminished relative to uninvolved nodes from cancer patients or to control nodes. The mixed-model analysis of variance was particularly helpful in confirming this finding. Finally, NK lysis by tumor-infiltrating lymphocytes, purified from grossly metastatic nodes, was severely depressed. These data indicate that a spectrum of NK suppression exists in draining lymph nodes of head and neck squamous cell carcinoma patients, and that the level of activity depends upon the degree of nodal tumor involvement.     

Natural killer cells suppress human cutaneous squamous cell carcinoma cancer cell survival and tumor growth

Cutaneous squamous cell carcinoma (CSCC), which develops in response to ultraviolet irradiation exposure, is among the most common cancers. CSCC lesions can be removed by surgical excision, but 4.5% of these cancers reappear as aggressive and therapy-resistant tumors. CSCC tumors display a high mutation burden, and tumor frequency is dramatically increased in immune-suppressed patients, indicating a vital role for the immune system in controlling cancer development. Natural killer cells (NK cells) play a key role in cancer immune surveillance, and recent studies suggest that NK cells from healthy donors can be expanded from peripheral blood for use in therapy. In the present study, we test the ability of ex vivo expanded human NK cells to suppress the CSCC cell cancer phenotype and reduce tumor growth. We expanded human NK cells from multiple healthy donors, in the presence of IL-2, and tested their ability to suppress the CSCC cell cancer phenotype. NK cell treatment produced a dose-dependent reduction in SCC-13 and HaCaT cell spheroid growth and matrigel invasion and induced SCC-13 and HaCaT cell apoptosis as evidenced by increased procaspase 9, procaspase 3, and PARP cleavage. Moreover, two important CSCC cell pro-cancer signaling pathways, YAP1/TAZ/TEAD and MEK1/2-ERK1/2, were markedly reduced. Furthermore, tail-vein injection of NK cells markedly suppressed the growth of SCC-13 xenograft tumors in NSG mice, which was also associated with a reduction in YAP1 and MEK1/2-P levels and enhanced apoptosis. These findings show that NK cell treatment suppresses CSCC cell spheroid formation, invasion, viability, and tumor growth, suggesting NK cell treatment may be a candidate therapy for CSCC.     

Equilibrium between host and cancer caused by effector T cells killing tumor stroma

The growth of solid tumors depends on tumor stroma. A single adoptive transfer of CD8(+) CTLs that recognize tumor antigen-loaded stromal cells, but not the cancer cells because of MHC restriction, caused long-term inhibition of tumor growth. T cells persisted and continuously destroyed CD11b(+) myeloid-derived, F4/80(+) or Gr1(+) stromal cells during homeostasis between host and cancer. Using high-affinity T-cell receptor tetramers, we found that both subpopulations of stromal cells captured tumor antigen from surrounding cancer cells. Epitopes on the captured antigen made these cells targets for antigen-specific T cells. These myeloid stromal cells are immunosuppressive, proangiogenic, and phagocytic. Elimination of these myeloid cells allowed T cells to remain active, prevented neovascularization, and prevented tumor resorption so that tumor size remained stationary. These findings show the effectiveness of adoptive CTL therapy directed against tumor stroma and open a new avenue for cancer treatments.     

Natural killer cell activity in patients with multiple myeloma

The level of natural killer (NK) cell activity was studied in peripheral blood samples from 22 patients with multiple myeloma (13 males, nine females) and a group of age- and sex-matched controls. In a cytostatic assay against K-562 cells the patients showed significantly lower activity than controls (P less than 0.001 for an effector:target ratio = 30:1) and 11 of 22 patients did not reach 50% at this E:T compared with 1 of 18 controls. The percentage of lymphocytes binding to or killing K-562 cells, as judged by a single-cell assay, was not decreased in the patient group, which implies that the decreased cytostatic activity was caused by a functional defect rather than a decline in numbers. In vitro exposure to interferon produced significant (P less than 0.025) stimulation of cytostatic activity in samples from both groups of subjects, but on an individual basis 10 of 22 patients and 4 of 18 controls showed no significant response (P greater than 0.05). This study supports the findings of others of impaired NK cell function in hemopoietic malignancies, which may have implications for the pathophysiology of these disorders.     

Natural killer cell activity in patients with hepatocellular carcinoma relative to early development and tumor invasion

To evaluate the significance of natural killer (NK) cell activity in the clinical assessment of patients with hepatocellular carcinoma (HCC), 32 patients combined with liver cirrhosis (LC) and HCC, and 29 LC patients were studied. The NK cell activity was markedly decreased in HCC patients and the LC group as compared with the control group, but there was no statistical difference between the NK cell activity of the HCC group and the LC group. The depression of NK cell activity in HCC patients was inversely correlated with the patient's age, and the HCC patients with venous invasion or with both lobes involved had lower NK cell activity. These results suggest that the decreased NK cell activity in HCC patients might be related to the coexistent liver disease, and marked decrease in NK cell activity might be one of the causes for the early development and invasion of HCC.     

Natural killer cell activity and head and neck cancer: a clinical assessment

In 127 patients with squamous cell carcinoma of the upper aerodigestive system, an assessment of natural killer (NK) cell function was performed. The mean lytic unit (LU) value of this cancer population was noted to be less than the mean value of 67 age-matched controls assessed concurrently. The major determinant of cytolytic function was related to the growth pattern of the tumor. Increased NK cell function was observed in patients with lesions that were more locally or regionally aggressive, i.e., that infiltrated surrounding anatomic structures. The magnitude of NK cell response also correlated with increased amounts of circulating IgG immunoglobulin to herpes simplex virus-type 1-associated antigens; elevated IgG levels were also associated with locally aggressive lesions. The clinical significance of NK cell activity in these patients is shown by its relationship to disease-free prognosis. Patients with elevated NK activity followed for a mean of 12 months had an improved disease-free survival as compared to the survival of the remaining population. Furthermore, NK LU values were not reflected in standard staging methods, which suggests that the measurement of NK cell function represents an independent prognostic parameter in the patient with head and neck cancer.     

Natural killer cell activity,phagocytosis, and number of peripheral blood cells in breast cancer patients treated with tamoxifen

Summary The number of leukocytes, proportion and absolute number of granulocytes, lymphocytes, CD4+ cells, CD8+ cells, CD16+ cells, B-lymphocytes, monocytes, natural killer cell (NK) activity, and granulocyte and monocyte phagocytic functions - ingestion and intracellular killing - were determined in a group of 27 patients with ductal invasive breast carcinoma, stage I-III, before and 7 months following postsurgical telecobalt radiotherapy, divided into two subgroups, one of them receiving tamoxifen (TMX group) and the other one not receiving any further therapy (control group). In control group, proportion of all lymphocytes and CD8+ cells as well as absolute number of all lymphocytes, CD4+, CD8+, CD16+ and B lymphocytes were decreased following TCT in comparison to their pre-TCT values, while in TMX group only absolute number of all lymphocytes remained decreased following TCT. Moreover, post-TCT proportions of all and CD8+ lymphocytes as well as absolute numbers of all and CD4+ and CD8+ lymphocytes in TMX patients were significantly increased in comparison to the same parameters in control post-TCT patients, although there was no difference between the two subgroups before TCT. At the other hand, granulocyte ingestion was decreased in post-TCT TMX patients compared to post-TCT values in control patients and NK cell activity showed a similar, although statistically not significant, tendency. It seems that TMX helps recovery of lymphocyte populations decreased by radiotherapy, probably by stimulation of cells carrying estrogen receptors, but its effects on phagocytic functions and probably NK cell activity seemed to be rather inhibitory than stimulatory.     

The role of autologous tumor cells in preventing lymphokine-activated killer cell induction in vitro

Peripheral blood lymphocytes (PBL), when cultured in vitro in the presence of autologous irradiated tumor and interleukin-2 (IL-2), become more restricted in the spectrum of their cytotoxicity. The cells continue to exhibit cytotoxicity for autologous tumor cells and major histocompatibility complex (MHC)-concordant allogeneic tumor cells of similar histologic type but not for the natural killer target cell line, K562. Furthermore, the addition of autologous tumor at different time points after the initiation with IL-2 alone of conventional lymphokine-activated killer cell cultures modifies both the specificity and the degree of cytotoxicity of these lymphocytes for tumor targets. By varying the culture conditions it may be possible to generate killer cells that will exhibit similarly enhanced and more restricted antitumor effects in vivo.     

Inhibition of effector cell functions in natural killer cell activity (NK) and antibody-dependent cellular cytotoxicity (ADCC) in mice by normal and cancer sera

Effector cells mediating natural killer (NK) cell activity and antibody-dependent cellular cytotoxicity (ADCC) have been receiving considerable interest recently as they may represent an additional cellular defense mechanism against maglinancy. Spleen cells from normal young C3H (MTV+) female mice were found to have relatively high natural killer (NK) activities toward RL 1 and YAC-1 tumor cell lines and high antibody-dependent cell-mediated cytotoxicity (ADCC) activities toward chicken RBC and SB tumor targets. Serum inhibition of NK and ADCC activities was either not demonstrable or only seen at low levels in the young mice. Following injection of a transplantable mammary adenocarcinoma that grew progressively in these mice, both NK and ADCC activities decreased and serummediated inhibition of both NK and ADCC increased as the tumors grew. NK and ADCC activities declined with age in C3H (MTV+) mice, and the serum inhibition of NK and ADCC activities of young mice increased with age. Aging mice, however, which had developed spontaneous mammary adenocarcinoma, although having increased levels of inhibitor against both NK and ADCC activities and decreased NK and ADCC activities of their spleen cells as compared to young normal mice, did not have different levels from those of aging mice which had not developed the mammary tumor. Correlation was poor between the amount of serum inhibitor(s) on NK and ADCC activities. NK versus RL 1 and ADCC for chicken RBC were not correlated, but NK versus YAC-1 and ADCC for the tumor cell line SB appeared to be correlated. Decreasing NK and ADCC and increasing serum inhibitory activity toward these functions appeared to correlate with tumor progression. Sera from transplantable tumor-bearing young C3H mice contained increased amounts of circulating immune complexes, but the amount of circulating immune complexes was only weakly correlated with the serum inhibition of NK activity of spleen cells from young animals by sera from tumor-bearing young mice. These findings indicate that a serum blocking factor(s) that can inhibit natural cell-mediated cytotoxicity or antibody-mediated cytotoxicity in vitro must be considered in analyzing host resistance to tumor growth.     

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-.     

Lymphokine-activated killer cells in rats: analysis of progenitor and effector cell phenotype and relationship to natural killer cells

The progenitor and effector cell phenotype of lymphokine-activated killer (LAK) cells generated in F344 rats by recombinant human interleukin 2 (IL-2) (rIL-2) were analyzed. Highly purified populations of peripheral blood large granular lymphocytes (LGL) exhaustively depleted of T-cells were fully capable of generating high levels of LAK activity by 3 to 5 days in culture while purified populations of resting T-cells devoid of LGL could not generate LAK activity. This pure population of LGL expressed surface markers characteristic of rat natural killer (NK) cells [i.e., OX8+, asialomonoganglioside (asialo-GM1+), laminin+, OX19-, R1-3B3-, W3/25-, Ia-, surface immunoglobulin negative (SIg-)]. Further evidence that NK cells were the progenitors of cells with LAK activity was obtained by treatment of spleen or peripheral blood lymphocytes with anti-laminin or anti-asialo-GM1 antibodies plus complement or with the lysosomotropic agent L-leucine methyl ester. These treatments effectively depleted LGL/NK cell activity and the subsequent generation of rIL-2-induced LAK activity. Analysis of the LAK effector phenotype by cell sorting demonstrated that the majority of cells with LAK activity were OX8+, asialo-GM1+, laminin+, OX6+, OX19-, R1-3B3-, W3/25-, and SIg-. Furthermore, treatment of LAK cells with L-leucine methyl ester also significantly reduced their cytolytic activity. Thus, the LAK effector cells were also LGL and expressed surface marker characteristic of activated NK cells and not those of mature T- or B-cells. The proliferative response of rat spleen or blood lymphocytes to rIL-2 appeared to be primarily associated with LGL/NK cells since depletion of NK cells by anti-asialo-GM1 or anti-laminin antibody plus complement or by L-leucine methyl ester significantly (P less than 0.001) reduced the incorporation of [3H]thymidine into DNA. In contrast, depletion of T-cells (by anti-T-cell antibody plus complement) did not significantly affect rIL-2-induced proliferation. Similarly, T-cell-depleted, highly purified populations of LGL gave substantial proliferative responses to rIL-2. These studies clearly indicate that in the rat, the major cell population activated by rIL-2 is the LGL/NK cell and these cells appear to represent the major population of cells in blood or spleen which generate broad antitumor (LAK) cytotoxicity.     

APOPTOSIS OF TUMOR CELLS IN LECTIN－DEPENDENTLYMPHOKINE－ACTIVATED KILLER CELLMEDIATED CYTOTOXICITY

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Delayed cutaneous hypersensitivity to autologous tumor cells in colorectal cancer patients immunized with an autologous tumor cell: Bacillus Calmette-Guérin vaccine

The principles and procedures of active specific immunotherapy developed from studies with the inbred guinea pig hepatocarcinoma model were used as the basis of a randomized, controlled prospective trial of active specific immunotherapy of colorectal cancer patients. The goal was to determine whether colorectal cancer patients treated with vaccines made of autologous tumor cells plus Bacillus Calmette-Guérin as adjuvant would have an increased reaction to their autologous tumor cells as measured by delayed-type cutaneous hypersensitivity (DCH) responses. Our results demonstrate that the active specific immunotherapy significantly increased the DCH responses to autologous tumor cells in 16 of 24 patients (67%). The DCH response of immunized patients to autologous normal mucosa, used as a normal tissue control, did not increase significantly. Furthermore, no significant DCH responses against autologous tumor or mucosa cells were detected in a group of nonimmunized control patients. The induced DCH responses were not correlated with other factors, such as the presence of bacteria in the cell preparation or the protein concentration of the cell preparations. The qualitative and quantitative differences in DCH responses to tumor cells and to normal mucosa cells suggest that the immunizations are targeted mainly to tumor-associated antigens with tissue-associated antigens playing a secondary role.     

Liver as a tumor cell killing organ: Kupffer cells and natural killers

Sinusoidal rat liver cells spontaneously kill tumor cells in vitro. They have the same preferences as do spleen cells for certain types of tumor cells, YAC-1, P815, BSP73Asml, BSP73As, EB, EsB, and L5222. Metastasizing tumor cells are less sensitive than their nonmetastasizing counterparts. Not all effector cells are Kupffer cells. These nonmacrophage killer cells share some features with classical natural killers: (a) fast reactions (4 h); (b) high toxicity against YAC-1 cells; (c) sensitivity to anti-asialo GM1 globulin; (d) similar age dependency; (e) short biological halflife (approximately 1 day) (deduced from radiation experiments); (b) silica particle insensitivity; and (g) nonadherence. The natural killing potency of the liver is higher than that of the spleen. The reduction of tumoricidal capacity of the liver in germ-free animals suggests environmental influences. Tumoricidal capacity (organ capacity) is increased in rats chronically fed thioacetamide, carbon tetrachloride (CC14), dimethylaminoazobenzene, and N-nitrosomorpholin.