Spontaneous human lymphocyte-mediated cytotoxicity against tumor target cells. IX. The quantitation of natural killer cell activity

Behaviorally conditioned modulation of natural killer cell activity: enhancement of baseline and activated natural killer cell activity

Natural killer (NK) cells comprise a sub-population of lymphocytes functionally defined by their ability to spontaneously lyse select tumor and virally infected cells. NK cell lytic function is sensitive to modulation by cytokines and neuroendocrine mediators. Behavioral conditioning trains an animal to cognitively associate a novel environmental cue (i.e. odor) with a physiologically active agent (i.e. Polylnosinic:PolyCytidilic acid, Poly I:C). Poly I:C induces interferon production resulting in activation of NK cells and enhanced NK cell lytic activity. Subsequent to behavioral conditioning, independent presentation of the odor should elicit similar responses (enhanced NK cell activity). We have shown that animals pre-exposed to the conditioning apparatus or manual restraint prior to behavioral conditioning demonstrate enhanced baseline NK cell activity or no effects respectively. To assess the influence of NK cell activation in conjunction with behavioral conditioning, we have re-presented the odor to animals with activated or baseline NK activity. Lymphocytes were then incubated for five days with IL-2 and cellular cytotoxic activity re-assessed. Behavioral conditioning significantly enhanced baseline and activated NK cell activity in animals previously exposed to the conditioning apparatus. No differences in lytic activity versus NK sensitive targets were observed following IL-2 activation. In contrast, animals manually restrained prior to conditioning showed no differences in baseline or in vivo activated NK activity, but previously non-activated lymphocytes stimulated with IL-2 demonstrated significantly higher lytic activity in conditioned animals re-presented with the odor. These results demonstrate central nervous system (CNS) modulation of NK cell activity and the presence of an interplay between cytokine activation and responsiveness to CNS immunoregulatory signals.

Independent and synergistic effect of interleukin-2 and prolactin on development of T- and NK-derived LAK effectors

We have studied the effect of recombinant (r)-Prl on the in vitro-induced MHC-unrestricted cytotoxicity of NK and T cells. A 4-day treatment with r-Prl in serum-free medium enhanced the cytotoxicity of NK cells to the NK-susceptible cell lines K562 and U937, but did not induce de novo NK cytotoxicity in T lymphocytes. By contrast, development of cytotoxicity against the LAK-susceptible cell lines HL60, Jurkat, Daudi and Supt-1 occurred in both NK and T cells. The effect of r-Prl on NK cells was bi-phasic with peaks at 25 ng/ml (1.2 nM), the upper physiological level, and 200 ng/ml (9.6 nM). By contrast, LAK activation of T cells only occurred at the highest r-Prl concentration. In addition to its intrinsic stimulatory activity, r-Prl was also capable of modulating in a dose-dependent manner distinct stages of the IL2-driven LAK/T differentiation pathway. Physiological concentrations of r-Prl interacted with low doses r-IL2 to significantly enhance generation of NK- and T-LAK activities. By contrast, pathological concentrations had opposite effects on generation of optimal LAK response, depending on the kind of LAK progenitor. The T-derived LAK activity was reversibly inhibited at the effector level, while the mature NK-LAK cells were stimulated. These data confirm our previous findings of a co-operative effect of Prl and IL2 on NK cell proliferation and reinforce the view that the signals conveyed by the two factors may be functionally related.

Behaviorally conditioned modulation of natural killer cell activity: effects of pre-conditioning manual restraint and apparatus exposure

This study investigated behaviorally conditioned modulation of natural killer cell (NK) activity. One and three trial behavioral conditioning training trial designs were examined. In addition, the influence of pre-conditioning exposure to manual restraint and the conditioning apparatus upon behaviorally conditioned natural killer cell responses was assessed. Prior to one trial training, animals were exposed to either the conditioning apparatus, manual restraint, or were undisturbed. The animals were then trained to associate the conditioned stimulus (CS) and the unconditioned stimulus (US), and later re-presented with the CS. Behaviorally conditioned animals demonstrated significantly enhanced NK cell activity, no difference in NK activity, or significantly decreased NK activity, respectively. There was also a significant interaction between the manual restraint and behavioral conditioning interventions. Animals in a three training trial design were either manually restrained daily prior to and during behavioral conditioning or were left undisturbed. In this design behavioral conditioning significantly decreased NK cell activity and manual restraint significantly increased NK cell lytic activity. These data illustrate behaviorally conditioned decreases and increases in NK cell lytic activity dependant upon the experimental design. Behaviorally conditioned NK cell activity is influenced by additional behavioral interventions (i.e. manual restraint and novelty of conditioning environment) inherent within the behavioral conditioning procedures.

Evolutionary conservation of a human function-associated molecule on murine natural killer cells: expression and function

Using a novel anti-natural killer (NK) cell monoclonal antibody (MoAb), we have recently identified an evolutionary conserved function-associated molecule (FAM) present on fish, rat and human NK cells. This molecule is involved in NK cell function as anti-FAM MoAbs inhibit cytotoxicity, stimulate lymphokine secretion and inhibit conjugate formation between effector cells and target cells. We now have examined murine NK cells for the presence of this structure. It was observed by two-colour flow cytometric analysis that the anti-FAM MoAb 5C6 specifically bound to a subpopulation of nylon wool non-adherent splenic lymphocytes (19-20%). The expression of the FAM molecule was restricted to NK cells that expressed the NK1.1 antigen. Neither T cells, B cells, nor macrophages reacted with the anti-FAM MoAb. Analysis of FAM expression in various lymphoid tissues revealed that splenocytes expressed the greatest numbers of MoAb(+) cells. Generation of lymphokine-activated killer (LAK) cells and adherent lymphokine-activated killer (ALAK) cells resulted in higher levels of FAM expression. The anti-FAM MoAb 5C6 also detected the presence of FAM on fresh SCID NK cells. It was demonstrated that the anti-FAM MoAb 5C6 inhibited the lysis of target cells by endogenous NK cells, activated NK cells, 5d LAK cells, ALAK cells and SCID NK cells. Moreover, conjugate assays demonstrated involvement of this molecule in recognition between NK cells and target cells.

Effects of ethanol consumption on enriched natural killer cells from C57BL/6 mice

Ethanol (20% w/v) given to female, C57BL/6 mice in their drinking water was previously shown to suppress natural killer (NK) cell cytolytic activity in a mixed splenocyte population. The present study was designed to examine the hypothesis that ethanol consumption independently results in inhibition of NK cell cytolytic activity. Mice were given 20% w/v ethanol in the drinking water for 2 weeks, and splenic NK cells were enriched up to 88% based on surface expression of NK1.1. Cytolytic activity of these freshly enriched NK cells from ethanol-consuming mice against YAC-1 lymphoma cells was inhibited an average of 41% relative to water-drinking controls. Cytolytic activity of enriched NK cells from ethanol-consuming mice was stimulated to levels equal to control water-drinking mice after 16- to 18-hr incubation in 1000 units/ml recombinant interleukin 2. These data indicate that in vitro cytolytic activity of NK cells from ethanol-consuming mice is inhibited in the absence of other modulatory leukocytes.

Cellular immunity in depressed, conduct disorder, and normal adolescents: role of adverse life events

OBJECTIVE

To determine whether adolescents with major depressive disorder have disturbances in their cellular immunity and to study whether the immunological changes detected are specific to depression or are general responses to stress.

METHOD

Twenty subjects with major depressive disorder, 17 nondepressed subjects with conduct disorder, and 17 normal adolescents were recruited. Subjects were assessed with a clinical interview for DSM-III-R and a modified version of the Coddington Life Events Checklist. Blood samples were drawn for total white blood cells, lymphocytes subsets, natural killer cell activity, lymphocyte proliferation response to phytohemagglutinin, and cortisol plasma levels.

RESULTS

Overall, there were no significant between-group differences in any of the cellular immune measurements. Natural killer cell activity was significantly negatively correlated with past year and lifetime adverse life events across all effector-target cell ratios. Controlling for diagnoses and socioeconomic status yielded similar results. There were no significant effects of age, sex, race, sleep, nutrition, cigarette use, menstrual cycle, or cortisol on any of the immunological variables.

CONCLUSIONS

In this sample of adolescents, we found that independent of the diagnoses and socioeconomic status, increases in adverse life events were associated with low natural killer cell activity.

The in vitro effect of human polymorphonuclear leukocyte azurophil granule components on natural killer cell cytotoxicity

We previously demonstrated that human polymorphonuclear leukocyte (PMN) secretions are capable of activating and inhibiting natural killer cell (NK) cytotoxicity depending on the eliciting PMN stimulus. Serum-opsonized zymosan induced PMN to secrete substances that enhanced NK activity in vitro. Serum-opsonized zymosan stimulates the release of PMN azurophil granules, which contain both human neutrophil peptides (HNPs) and neutral serine proteases (NSPs). When HNPs and NSPs were tested for their ability to activate NK cells in peripheral blood lymphocytes, all but cathepsin G consistently enhanced cytotoxicity above control values. HNP-induced cytotoxicity was significantly enhanced within 12 h, peaking at approximately 24 h. Of the HNPs, HNP-1 was the most potent activator, enhancing NK activity at 1.25 micrograms/ml. Interleukin-2 and interferon-gamma were not involved in this activational process, as antibodies to interleukin-2 and interferon-gamma did not block activation by HNPs and NSPs, and interleukin-2 receptor expression was unaltered after 24 h of incubation. Enzymatically inactivated elastase and cathepsin G produced equivalent activational effects to their active counterparts. Antisera to elastase and cathepsin G decreased but did not eliminate NK activation over untreated peripheral blood lymphocytes. These data suggest that certain PMN azurophil granule components, including HNPs and NSPs directly increase the cytotoxic activity of NK cells.

Lymphokine-activated killer cell function of peripheral blood mononuclear cells, spleen cells and regional lymph node cells in gastric cancer patients

Lymphokine-activated killer (LAK) cells generated by culture of peripheral blood mononuclear cells (PBMC), spleen cells (SPC) and regional lymph node cells (LNC) with IL-2 for 4 days were examined for their functional capabilities in 29 patients with gastric carcinoma. The cytotoxic activity of LAK cells induced from LNC was significantly lower than that from either PBMC or SPC, although there was no difference between PBMC or SPC. The induction of mRNA of interferon-gamma (IFN-gamma) or tumour necrosis factor-alpha (TNF-alpha) and the production of these cytokines in the non-adherent LAK cells from LNC were also significantly reduced compared with those from PBMC or SPC. Further, the LAK cells from LNC secreted significantly lower levels of these cytokines when stimulated with tumour target, Raji cells, although the production of these cytokines was markedly increased by stimulation with the targets in all three cell populations. Phenotypic analysis of each cell population revealed a decreased proportion of the cells mediating natural killer (NK) activity, including CD16+, CD56+, and CD57+ cells in LNC either before or after culture, although OKIa1+ and CD25+ cells were uniformly increased in all cell populations after culture. Changes in subpopulations of CD4+ and CD8+ cells in LNC were not apparently different from PBMC or SPC. These results indicated the differential reactivity of each lymphocyte population to IL-2 and the reduced LAK cell function of LNC compared with PBMC or SPC in patients with gastric carcinoma.

HLA restriction and T-cell-receptor V beta gene expression of cytotoxic T lymphocytes reactive with human squamous-cell carcinoma of the head and neck

A human cytotoxic-T-lymphocyte (CTL) line capable of killing autologous tumor (AuTu) cell targets was established from peripheral-blood lymphocytes of a patient with squamous-cell carcinoma of the tongue. The cultured CTL were CD3+CD8+CD11b-HLA-DR+T cell receptor (TCR) alpha/beta+. When tested in 4-hr 51Cr-release assays against various lines of squamous-cell carcinoma of the head and neck (SCCHN) and a variety of non-squamous human tumor and normal cell targets, the CTL were found to lyse the autologous SCCHN cell line (PCI-50) and 7 allogeneic SCCHN lines: PCI-1, -2, -4A, -4B, -13, -30 and -38. Of these tumor cell lines, PCI-13, -30 and -38 shared HLA-A2 locus with the AuTu, PCI-50, while PCI-4A and -4B shared HLA-B44 with AuTu. Lysis of AuTu (A2+B44+), PCI-13 (A2+B44-) and PCI-4B (A2- B44+) by the CTL was efficiently inhibited by monoclonal antibodies (MAbs) to CD3, CD8, TCR alpha/beta or the major-histocompatibility-complex (MHC)-class-I antigens. MAbs to HLA-A2 antigens inhibited lysis of PCI-50 or PCI-13 targets by the CTL. In cold-target inhibition assays, unlabeled PCI-4B or PCI-13 cells inhibited CTL lysis of AuTu targets. The CTL incubated in the presence of the HLA-A2+ SCCHN PCI-50 or -13, but not an HLA-A2+ gastric carcinoma, produced TNF-alpha, IFN-gamma and GM-CSF. The CTL were tested for their TCR V beta gene expression by polymerase chain reaction (PCR). At week 10 in culture, the time of the highest AuTu cytotoxicity mediated by the CTL line, V beta 6 was expressed by 26% of T cells. Three clones, obtained by limiting dilution from 10-week CTL and selected for high cytotoxicity against AuTu, were found to be V beta6+. Further analysis of the specificity of these clones indicated lytic activity against PCI-13 (A2+B44-), but not PCI-4B (A2-B44+) targets. In 16-week cultures, which retained AuTu cytotoxicity as well as V beta 6 expression, TCR V beta 2 was also expressed at high frequency (29%), and AuTu-reactive clones were found to be V beta 2+. Our results indicate that at least 2 different CTL populations (V beta 6+ and V beta 2+) are able to recognize SCCHN-associated antigen(s) and that the V beta 6+ T cells are HLA-A2 restricted, while V beta 2+ T cells may be HLA-B44 restricted.

Polymorphic Hh genes in the HLA-B(C) region control natural killer cell frequency and activity

We demonstrated earlier that individuals homozygous for conserved major histocompatibility complex (MHC)-extended haplotypes have low natural killer (NK) activity as measured by cytolysis of the K562 tumor cell lines. In the present study, we investigated the segregation and MHC linkage of NK activity in families in which MHC haplotypes of human histocompatibility leukocyte antigens (HLA)-A, -C, and -B, complotype, and DR specificities are known. In two informative families, low activity was inherited as a recessive trait linked to the MHC. By using individuals homozygous for specific fragments of extended haplotypes or for HLA-B alleles, we found that the HLA-C and -B and not the complotype or HLA-DR region contains genes controlling NK activity. The majority of the unrelated individuals with low NK activity were homozygous or doubly heterozygous for HLA-B7 (Cw7), B8 (Cw7), B44 (Cw5), B18, or B57 (Cw6). Thus, these alleles form one complementation group designated NKB1. Another less frequent group, NKB2, was also identified, and consisted of individuals homozygous for B35 (Cw4). NK activity was correlated with the number of circulating NK (CD16+ CD56+) cells. Individuals homozygous for the NKB complementation groups have fewer circulating NK cells than individuals heterozygous for these alleles and alleles of other complementation groups, possibly explaining the low activity of cells in these subjects. These findings suggest that during the maturation of NK cells there is NK cellular deletion in donors homozygous for NKB genes resulting in low NK cell numbers and activity.

Role of enhanced cellular adhesion in IL-6-augmented lymphokine-activated killer-cell function

The authors demonstrated previously that a short-term treatment with IL-6 of lymphokine-activated killer (LAK) cells produces an increase in cytotoxic activity of CD56+/CD3- effector cells generated from human PBL as well as from human thymocytes. In the study described here, the mechanisms by which IL-6 enhances LAK cytotoxicity were examined. Like untreated LAK cells, IL-6-treated LAK cells require Ca++ to initiate cytolysis. However, IL-6 treatment of LAK cells does not alter the rate of programming for lysis. Instead, IL-6 increases target-binding capacity of CD56+/CD3- LAK cells in association with the increased cytotoxicity. Similar to target-binding of untreated LAK cells, the binding between IL-6-treated LAK cells and target cells is dependent on Mg++. Cellular adhesion molecules (CAM), CD11a-c, CD18, CD54, CD56, CD58 and CD2 (T11(1) epitope), are up-regulated in LAK cells by culture with IL-2. Among MoAbs to these CAMs, only Abs to CD11a/CD18 (LFA-1) and CD54 (ICAM-1) decrease both target-binding and cytolysis by LAK cells. IL-6 treatment changes neither the proportion nor the intensity of CAM positive cells. However, MoAbs to CD11a/CD18 and CD54 reduce both target-conjugation and cytotoxicity of IL-6-enhanced LAK cells to the same level as control LAK cells treated with the MoAbs. IL-6-enhanced LAK functions (both target-conjugation and target-lysis) are not abrogated by MoAbs to other CAM which do not inhibit standard LAK functions. These results indicate that IL-6 up-regulates cellular events mediated by CD11a/CD18 and CD54 molecules which are involved in standard LAK functions. These events may result in activation of lytic effector cells, associated with an increase in target-binding and an increase in cytotoxicity.

Dose-related comparison of antibody-dependent cellular cytotoxicity with chimeric and native murine monoclonal antibody 17-1A. Improved cytolysis of pancreatic cancer cells with chimeric 17-1A

Chimeric 17-1A antibody (IgG1 kappa) was constructed by linking variable region genes of murine monoclonal antibody 17-1A with genes for human kappa light chain and gamma 1 heavy-chain constant regions. This study was undertaken to compare in vitro antibody-dependent cellular cytotoxicity (ADCC) between the chimeric 17-1A (IgG1 kappa) and native murine 17-1A antibody (IgG2a kappa) with human peripheral blood mononuclear cells (PBMNC) against 7 human tumor (1 colon, 6 pancreas) cell lines. ADCC activity was measured by chromium-release assay. When freshly-isolated PBMNC from healthy donors were used for effector cells, significantly higher ADCC activity of chimeric antibody compared to murine antibody at optimal antibody dose (10 micrograms/mL) and lower doses (to 0.6 micrograms/mL) was observed against tumor cells with relatively high 17-1A expression. This high ADCC activity of the chimeric antibody persisted even when freshly-isolated monocyte-depleted PBMNC was used. When interleukin-2 activated PBMNC were used, comparable increases in ADCC were observed with both chimeric and murine antibody. These results suggest that chimeric 17-1A antibody is a more effective mediator of in vitro ADCC activity with human freshly-isolated PBMNC than the native murine antibody and this may be a better choice for clinical cancer trials evaluating possible immunotherapy with monoclonal antibody.

Target-cell sensitivity to natural killer-cell lysis is determined by the expression of a novel antigen in conjunction with major histocompatibility complex class-I molecules

Recently, a panel of monoclonal antibodies (MoAbs) was developed that identified a novel tumour-cell antigen conserved across species (mouse, rat and man). Fluorescence-activated cell sorter (FACS) analysis demonstrated that this antigen was expressed at highest levels on human tumour cell lines sensitive to natural killer (NK)-cell lysis. These MoAbs inhibited NK cell lysis of K562 target cells (by up to 90%), as well as a variety of other NK-sensitive target cells. Biochemical analyses revealed that the MoAbs reacted with a polypeptide of 42 kDaltons, distinct from other known cell surface antigens. Now the expression of this antigen has been analysed further with a panel of 24 tumour cell lines to determine its role in NK cell function. The expression of target cell major histocompatibility complex (MHC) molecules in conjunction with sensitivity to NK cell lysis was examined also. For each of the 24 cell lines it was found that the level of expression of the novel target cell antigen determined the sensitivity of the cell line to NK cell lysis. However, the level of MHC antigen expression could modulate target cell sensitivity to NK cell lysis, in that high levels of MHC class-I molecule expression resulted in a target cell that was insensitive to NK cell lysis regardless of the level of expression of the novel antigen. Thus, for most transformed cell lines, sensitivity to NK cell lysis appeared to be determined by the expression and levels of the novel antigen in association with MHC class-I molecules.

Anti-beta 1 integrin IgG inhibits pulmonary macrometastasis and the size of micrometastases from a murine mammary carcinoma

In the present report, we investigated the possible importance of beta 1 integrins in the growth and metastasis of a murine mammary carcinoma, SP1, and a metastatic variant, SP1-3M in vivo. CBA/J female mice bearing SP1 tumor transplants were injected with anti-beta 1 integrin IgG or control nonimmune IgG (200 micrograms per mouse; i.p.) every two days. Animals received anti-CD4 antibody (100 micrograms per mouse) at time zero to suppress immunity against rabbit IgG. Outgrowth of macroscopic metastases from SP1, but not from SP1-3M primary tumors, was markedly inhibited in animals receiving anti-beta 1 integrin IgG but not nonimmune IgG. To assess the stage(s) in the metastatic cascade affected, we examined the number and diameter of micrometastatic nodules in treated and untreated groups. The diameter of micrometastases was significantly reduced in SP1-tumor-bearing mice treated with anti-beta 1 integrin IgG compared to control IgG, although the number of nodules per cm2 of lung sections examined remained unchanged. No change in the number or size of micrometastases in SP1-3M tumor-bearing mice was observed. No difference in the binding, or complement-mediated and antibody-dependent cell-mediated cytotoxicity of anti-beta 1 integrin IgG with SP1 and SP1-3M cells was detected. The results suggest that under these conditions anti-beta 1 integrin inhibits metastatic tumor growth in lung tissue, but has minimal effect on intravasation, adhesion to target organs and extravasation.

Phase I study of interleukin-2 combined with interferon-alpha and 5-fluorouracil in patients with metastatic renal cell cancer

Interferon-alpha (IFN-alpha) and interleukin-2 (IL-2) each has produced a 15%-20% response in metastatic renal cell cancer. Combining IFN-alpha with either IL-2 or 5-fluorouracil (5-FU) enhanced IFN-alpha activity. We have therefore conducted a Phase I Study combining IL-2, IFN-alpha, and 5-FU. The patients were continuously infused with IL-2 (1-3 x 10(6) u/m2) and 5-FU (600-750 mg/m2) for a 5-day period every 28 days, and IFN-alpha (4-5 x 10(6) u/m2) was injected subcutaneously daily. Lymphokine-activated killer (LAK) and natural killer (NK) cell activity was measured on days 0 and 8. Twenty-one patients received 76 courses. All primary tumors were controlled by surgery (81%) or angioinfarction. Hematologic toxicity was mild; median nadir of platelets was 117 K/microL and of granulocytes was 1.2 K/microL. Dose-limiting toxicity included mucositis, liver damage, and hypotension. No treatment-related death occurred, and only one patient required intensive-care-unit support. Two patients had an objective response, one of which was a complete response. Increased LAK cell and NK cell activity occurred at all IL-2 dose levels. Simultaneous delivery of IL-2, IFN-alpha, and 5-FU is safe and shows antitumor and biologic activity. 5-FU did not appear to suppress IL-2-induced LAK and NK cell activation. Maximum tolerated dose of the three-drug combination is IL-2, 2 x 10(6) u/m2, 5-FU 600 mg/m2, and IFN-alpha, 4 x 10(6) u/m2.

Thymic humoral factor, THF-gamma 2, enhances immunotherapy of murine cytomegalovirus (MCMV) infection by both CD4+ and CD8+ immune T cells

Infection of mice with murine cytomegalovirus (CMV) presents a model for the study of the role of the immune system in the pathogenesis of human CMV. The contribution of the different spleen cell subsets in conferring curative immunocytotherapy to fatally MCMV-infected immunosuppressed mice was assessed using adoptive immunotherapy. It was found that the efficacy of passively transferred immune spleen cells is dose dependent and that the therapeutic effect can be enhanced considerably by treating donor mice with thymic humoral factor (THF-gamma 2). Polymerase chain reaction (PCR) of the donor spleen population was negative, indicating that no MCMV-DNA was transferred with the immune cells. Analysis of the donor mice after THF-gamma 2 treatment showed increased levels of CMV-neutralizing antibodies, while enhancement of natural killer (NK) activity was transient and lasted only during the early phase of the infection. FACS analysis demonstrated that treatment with THF-gamma 2 restored the size of both cell subsets CD4+ and CD8+ that were decreased following MCMV infection. It is shown that both CD4+ and CD8+ T-cell subsets participate in controlling the development of the fatal disease in MCMV-infected immunosuppressed recipients. It is suggested that the enhancement of the immunocompetence of both populations of spleen cells from treated donors is mediated in part by the restoration of Interleukin-2 (IL-2) production by THF-gamma 2.

Effects of virally expressed interleukin-10 on vaccinia virus infection in mice

To investigate the in vivo role of interleukin-10 (IL-10) in viral infection, we compared infections with a recombinant vaccinia virus (VV) expressing IL-10 (VV-IL10) under control of the VV P7.5 promoter and a control virus (VV-beta gal) in normal and severe combined immunodeficient mice. In normal mice, VV-IL10 infection resulted in less natural killer cell activity at 3 days postinfection and less VV-specific cytotoxic T-cell activity at 6 or 7 days postinfection than VV-beta gal infection. However, the use of dermal scarification or intraperitoneal, intranasal, or intracerebral inoculation into immunocompetent mice resulted in no difference between VV-IL10 and VV-beta gal in visible lesions, mortality, protective immunity to a 100-fold lethal VV challenge, or VV-specific antibody response. In the immunodeficient mice, VV-IL10 infection resulted in greater natural killer cell activity and lower virus replication than VV-beta gal infection. These in vivo effects were subtler and more complex than had been anticipated. From the VV-IL10 murine model, the Epstein-Barr virus-encoded homolog of human IL-10, BCRF1, may provide a selective advantage by blunting the early human natural killer cell and cytotoxic T-cell responses so that Epstein-Barr virus can establish a well-contained latent infection in B lymphocytes.

Chemotherapy-induced differential changes in lymphocyte subsets and natural-killer-cell function in patients with advanced breast cancer

To elaborate a rational approach to chemoimmunotherapy in humans, information is required as to how current cytotoxic chemotherapy regimens modulate patients' endogenous immune cells. We have studied a group of 16 advanced breast cancer patients who received cyclical cytotoxic chemotherapy (CMF-cyclophosphamide, methotrexate and 5-fluorouracil) and have documented the progressive differential effects of chemotherapy on endogenous immune cells as judged by changes in immunophenotype and absolute numbers of lymphocyte subsets, together with analysis of natural-killer-cell function. Cells with the immunophenotype of natural killer cells and lymphokine-activated killer cells (NK/LAK cells) were well retained, but their function was suboptimal. Additionally, CD8 T cells were well preserved, but the numbers of CD4 T cells decreased with succeeding cycles of chemotherapy; B-cell numbers decreased rapidly from the first cycle of chemotherapy. These cellular changes in humans indicate defined and precisely timed windows of opportunity for introducing in vivo, simple and direct immune stimulation of the cells modulated by chemotherapy, with the possibility of improving therapy and survival in this disease.

Effect of ASTA-Z 7575 (INN Maphosphamide) on human lymphokine-activated killer cell induction

Recent studies combining chemotherapeutic agents with various biological response modifiers for the treatment of cancer have shown promising results. Cyclophosphamide (Cy) is the most widely used alkylating agent and a major constituent of combination chemotherapy regimens for many neoplastic diseases. It has been reported that Cy is a cytotoxic drug, which becomes immunosuppressive at higher doses. A synthetic metabolite of Cy, ASTA-Z, has recently been produced. ASTA-Z is more active and stable by itself and does not need to be metabolically converted to an active compound. The combined effect of Cy and interleukin-2 (IL-2) on the induction of lymphokine-activated killer (LAK) cells is not known. Therefore, we decided to investigate the effect of ASTA-Z on the induction and function of LAK. The coculture of peripheral blood mononuclear cells (PBMC) with various concentrations of ASTA-Z (0, 10(-6), 10(-5), 10(-4), and 10(-3) dilution) and IL-2 (50 U/ml) for 4 days produced significant suppression of cytotoxicity and lytic ability of the LAK cells against NK-sensitive (K562) and NK-resistant (M14) tumor cell lines. The lower doses of ASTA-Z did not affect the generation of LAK cells, its cytotoxicity and lytic ability of ASTA-Z against both NK-sensitive and NK-resistant tumor cell lines. Furthermore, the ASTA-Z produced dose-dependent suppression of the proliferative response of LAK cells. The significant therapeutic benefit in the cancer patient may be achieved by the low dose regimen of Cy and IL-2 because it has no deleterious effect on the induction and function of LAK cells.

Natural killer and lymphokine-activated killer activity in HLA-B8,DR3-positive subjects

The haplotype HLA-B8,DR3 is over-represented in several autoimmune diseases, implying that genes predisposing people to these disorders are linked to this haplotype. In these diseases, various dysfunctions reflecting an impairment of the immune system have been found. Several reports indicate also that in HLA-B8,DR3-positive healthy subjects similar disorders may be demonstrated. In the present work, we have evaluated NK and LAK activity in these subjects. The study has been performed on monocyte-depleted peripheral blood MNCs by using, the K-562 cell line as a target for NK activity and the HL-60 cell line for as a target LAK activity. LAK cells were obtained by incubating MNCs for 3 days with 100 U/ml of rIL-2. The results of our experiments demonstrate that NK cell activity is significantly decreased in healthy subjects bearing the HLA-B8,DR3 haplotype. Since the number of circulating CD16+ cells is not significantly different between HLA-B8,DR3-positive subjects and negative ones, it is unlikely that this defect is due to a decreased number of NK cells in effector cell preparations. The observation that the treatment with rIL-2 can restore the killer activity of MNCs from these subjects suggests instead that the reduced NK activity may be due at least in part to the imbalance of cytokine network that has been demonstrated in HLA-B8,DR3-positive subjects. Finally, since a decreased NK activity has been reported in the autoimmune diseases linked to this haplotype, our results support the suggestion that immunologic changes observed in autoimmune diseases reflect systemic regulatory disorders that have a genetic basis.

Effects of lovastatin on natural killer cell function and other immunological parameters in man

Suppression of cholesterol synthesis by 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, such as lovastatin, has been shown to inhibit mitogen stimulated proliferation of natural killer (NK) cells and other lymphocytes in vitro. This effect is only partially overcome by provision of exogenous free or lipoprotein cholesterol but is reversed by mevalonate, suggesting that proliferating lymphocytes have a specific requirement for a nonsterol isoprenoid product of mevalonate. The effect of lovastatin (20 mg bid) on a range of immune function parameters was determined in a randomized, placebo-controlled, double-blind ex vivo study in 52 patients with primary hypercholesterolemia. No significant differences (P < 0.05) were found between lovastatin and placebo groups for basal NK or interleukin-2 (IL-2)-induced cell-mediated cytotoxicity, PHA-stimulated lymphocyte proliferation, or relative numbers of T lymphocytes (CD3+), B lymphocytes (CD19+), total NK cells (CD3-, CD16+, CD56+) and CD57+ NK cells or in immunoglobulin levels after 4 or 8 weeks of treatment. In contrast to previous in vitro data, no statistically or clinically significant changes were observed in any parameter of lymphocyte function in patients treated with lovastatin.

Role of a genetic region on chromosome 4 in the regulation of natural killer cell activity in mice

Natural killer cell (NK) activity is regulated by both the H-2 and non-H-2 genes. Using bilineal congenic HW26C and HW13 mice which differ from the background strain C57BL/6By (B6) in a region of chromosome 4, we investigated the role played by a gene/genes in a segment of chromosome 4 of BALB/cBy on NK cell activity. Percoll separated low density spleen cells from young HW26C and HW13 mice showed a 3.5 fold higher NK activity than the B6. We also observed that the increase in NK activity of HW26C was not due to an increase in the number of NK cells. Using five other bilineal congenics containing different regions of chromosome 4 of BALB/cBy, we observed that the putative gene(s) regulating NK activity may be located between b and IFN-alpha/beta genes of chromosome 4. The level of NK activity of (B6xHW26C)F1 ranked between the HW26C and B6 suggesting that the gene product described is inherited in an incompletely dominant fashion.

Association of the p56lck protein tyrosine kinase with the Fc gamma RIIIA/CD16 complex in human natural killer cells

The multimeric Fc gamma RIIIA (CD16) complex is expressed on the surface of natural killer (NK) cells and is composed of a 50-70-kDa transmembrane glycoprotein Fc gamma receptor (CD16), the T cell receptor (TCR)-zeta chain, and the Fc epsilon RI gamma chain. Cross-linking Fc gamma RIIIA initiates the rapid tyrosine phosphorylation of multiple substrates including the zeta subunit and causes subsequent cell activation and antibody-dependent cellular cytotoxicity (ADCC). The subunits of the Fc gamma RIIIA complex lack intrinsic protein tyrosine kinase (PTK) activity, suggesting that receptor-induced tyrosine phosphorylation events are mediated by a nonreceptor PTK. We report here that the human Fc gamma RIIIA is complexed with p56lck, a src-family PTK previously found associated with the CD4 and CD8 receptors on T cells. Upon engagement of the CD16 receptor, p56lck is rapidly (within 30 s) and transiently phosphorylated on tyrosine residues. Several Fc gamma RIIIA-associated proteins are identified in immune complex kinase assays including the TCR-zeta subunit, a p70-90 zeta-associated protein (ZAP), p50a (acidic) and p50b (basic), and p56lck. We demonstrate that the src-family protein tyrosine kinase inhibitor, herbimycin A, blocks increased intracellular calcium levels and ADCC caused by CD16 cross-linking on NK3.3 cells. Likewise cross-linking CD16 with the protein tyrosine phosphatase CD45, abrogates CD16-induced calcium mobilization. These data suggest that p56lck is physically associated with Fc gamma RIIIA (CD16) and functions to mediate signaling events related to the control of NK cellular cytotoxicity.

Drug resistance in rat colon cancer cell lines is associated with minor changes in susceptibility to cytotoxic cells

The development of resistance to anticancer drugs urges the search for different treatment modalities. Several investigators have reported the concomitant development of drug resistance and resistance to natural killer (NK), lymphokine-activated killer (LAK) or monocyte/macrophage cell lysis, while others described unchanged or even increased susceptibility. We investigated this subject in the rat colon carcinoma cell line, CC531-PAR, which is intrinsically multidrug-resistant (MDR), and in three sublines derived from this parental cell line: a cell line with an increased MDR phenotype (CC531-COL), a revertant line from CC531-COL (CC531-REV), which demonstrates enhanced sensitivity to anticancer drugs of the MDR phenotype, and an independently developed cisplatin-resistant line (CC531-CIS). In a 4-h 51Cr-release assay we found no difference in susceptibility to NK cell lysis. No significant differences in lysability by adherent LAK (aLAK) cells were observed in a 4-h assay. In a prolonged 20-h 51Cr-release assay an enhanced sensitivity to aLAK-cell-mediated lysis was observed in the revertant, P-glycoprotein-negative cell line and in the cisplatin-resistant cell line (CC531-CIS). None of the cell lines was completely resistant to lysis by aLAK cells. Therefore, a role for immunotherapy in the treatment of drug-resistant tumors remains a realistic option.

Expression of an evolutionarily conserved function associated molecule on sheep, horse and cattle natural killer cells

Natural killer (NK) cells are large granular lymphocytes that lyse a wide variety of transformed and virally-infected target cells without prior exposure to antigen, and without restriction by major histocompatibility complex antigens. Although NK cells have been identified in a variety of mammalian species, how NK cells recognize antigen and trigger lysis is unknown. Recently, monoclonal antibodies made against NK-like cells from teleost fish were shown to react with NK cells from humans and rats, and to inhibit their cytolytic activity. The role of this apparently evolutionarily conserved function-associated molecule (FAM) has been further investigated utilizing a variety of domesticated farm animal species. It was observed that the anti-FAM mAb reacted specifically with peripheral blood lymphocytes isolated from sheep, horses and cattle. Further, the anti-FAM mAb inhibited NK cell lytic activity in each of these species. Finally, the anti-FAM mAb was found to inhibit conjugate formation between NK and target cells, implying that the FAM was involved in antigen recognition by NK cells in each of these species. In conclusion, it appears that NK cell function is mediated by an evolutionarily conserved FAM in a wide variety of species.

Inhibition of tumor growth and enhancement of metastasis after transfection of the gamma-interferon gene

Cells from the spontaneous metastatic TS/A mammary adenocarcinoma of a BALB/c mouse were transfected with the murine gamma-interferon (IFN-gamma) gene. Six clones (IFN-gamma clones) releasing between 2 and 6,000 international units (IU) of IFN-gamma/ml culture medium, were compared to TS/A parental cells (TS/A-pc) and to cells transfected with neomycin resistance gene only (NEO cells). Autocrine IFN-gamma up-regulated membrane expression of H-2 class-I and Ly-6 glycoproteins, but did not alter cellular proliferation in vitro. All IFN-gamma clones gave rise to progressive tumors with a growth rate significantly slower than that of tumors induced by TS/A-pc and NEO cells, and inversely correlated with the amount of IFN-gamma secreted. TS/A-pc and NEO tumors displayed a marginal reactive infiltrate, whereas those formed by IFN-gamma clones were massively infiltrated mostly by macrophages. In T- and NK-deficient mice the growth of tumors formed by IFN-gamma clones was not enhanced. In vitro tests showed that IFN-gamma clone cells were markedly more lysed by macrophages than TS/A-pc and NEO cells, while they remained poorly sensitive to NK and LAK cells. These data as a whole suggest that the development of solid tumors by IFN-gamma clones is primarily hampered by macrophages and not by T-lymphocytes or NK cells. When spontaneous metastatic ability was compared, 2 IFN-gamma clones releasing 2-4 IFN-gamma IU/ml were significantly more metastatic, while most IFN-gamma clones appeared to be as metastatic as NEO cells. By contrast, following intravenous challenge, all IFN-gamma clones produced 5-10 times more experimental metastases than NEO cells. The higher metastatic ability of IFN-gamma clones was attributed to increased resistance to NK cells since, in NK-depleted BALB/c mice, metastatic spread of IFN-gamma clones was not enhanced, whereas a 50-fold increase in the number of metastases was found upon injection of NEO cells.

Large granular lymphoproliferative disease associated with nephrotic syndrome, renal failure and leukoencephalopathy

A 23-year-old black female presented with general malaise, headache, high white cell count (136 x 10(9)/L), thrombocytopenia and nephrotic syndrome. She proved to have large granular lymphoproliferative disease with a natural killer cell phenotype and without a clonal rearrangement of the T-cell receptor genes. Renal biopsy demonstrated focal segmental glomerulosclerosis (FSGS). She developed a monophasic neurological illness, and rapidly became comatose six days after the initiation of high dose prednisone therapy. Computerized tomography of the brain showed marked hypodensity of the subcortical white matter. She regained consciousness subsequently, but died six months after her initial presentation with uncontrolled lymphocytosis and renal failure. Autopsy revealed FSGS with glomerular collapse and microcystic dilatation of the renal tubules, and there was perivascular demyelination in the subcortical white matter of the brain. We speculate that lymphokines released by the natural killer cells may have played an important role in the pathogenesis of both the nephrotic syndrome and leukoencephalopathy.

A phase I study of prolonged continuous infusion of low dose recombinant interleukin-2 in melanoma and renal cell cancer. Part II: Immunological aspects

Previously we described the clinical aspects of a phase I study of prolonged continuous infusion of low-dose recombinant interleukin-2 (rIL-2). In the present paper we report several immunological effects in 13 patients with melanoma and renal cell cancer treated on an out-patient basis with rIL-2 for uninterrupted periods ranging from 5 to 18 weeks. Groups of three patients were treated at following dose levels 0.18, 0.6, 1.8 or 6 x 10(6) IU m-2 24 h-1 and one patient was treated with 3 x 10(6) IU m-2 24 h-1. Prolonged rIL-2 treatment resulted in a dose-dependent and sustained increase in the percentage and absolute number of (CD56+, CD8dim) natural killer cells. Within this population a preferential increase in the CD56bright cells with low expression of CD16 was observed. The CD27 antigen was also upregulated in the CD56bright CD16dim population. This increase of NK cells was accompanied by an enhancement of the cytotoxic capacity of the peripheral lymphocytes. No consistent signs of T cell activation or expansion were noted.

Synergetic effect of interleukin-2 and cellular cytotoxicity against a novel tumor-associated carbohydrate antigen Le(a)/Le(a) (dimeric Le(a)) mediated by monoclonal antibody NCC-ST-421 in adoptive immunization using SCID mice

The murine IgG3 monoclonal antibody NCC-ST-421, raised against a human gastric cancer, shows strong reactivity with dimeric Le(a) (Le(a)/Le(a); V4FucIII4FucLc6Cer) expressed on gastrointestinal cancer cells. ST-421 reacted minimally with non-dimeric or simple Le(a) expressed on normal tissues. ST-421 is capable of mediating both antibody-dependent cellular cytotoxicity (ADCC) with human peripheral blood lymphocytes, and complement-dependent cytotoxicity with human complement. Interleukin-2 (IL-2) modulates the function of immunocytes, in particular inducing lymphokine-activated killer (LAK) cell activity and enhancing ADCC. We therefore employed combination immunotherapy with IL-2, LAK, and ST-421-induced ADCC in vitro and in mice with severe combined immunodeficiency (SCID), using target tumor cells expressing Le(a)/Le(a) antigen. ADCC against human colon cancer cell lines in vitro was enhanced three to four times after preincubation with IL-2. Addition of IL-2 reduced the amount of ST-421 required for efficient ADCC 10- to 100-fold. ADCC was activated by IL-2 earlier (1 day) than the generation of LAK cells (3-4 days), and at lower concentration of IL-2. These effects were specific for ST-421, as demonstrated by experiments with irrelevant antibody or irrelevant target cells. An anti-(Fc receptor) antibody blocked the ADCC but not the LAK activity in vitro. The enhancement of ADCC by IL-2 may be caused by activation of effector cells expressing Fc receptors. In vivo experiments using SCID mice inoculated with human colon cancer showed a significant tumor-growth-suppressive effect after combined therapy using human peripheral blood lymphocytes, LAK, IL-2, and ST-421. In summary, adoptive immunization with human lymphocytes activated by IL-2 and ST-421 effectively suppressed growth of gastrointestinal cancer cells expressing Le(a)/Le(a).

Catecholamines induce alterations of distribution and activity of human natural killer (NK) cells

Catecholamines have been suggested to be responsible for altered cellular immunity after stress. This study was performed to determine the effects of adrenaline and noradrenaline on lymphocyte subpopulations and NK cell functions. Subjects were given a subcutaneous injection of either NaCl, adrenaline (5 micrograms/kg), or noradrenaline (10 micrograms/kg). Catecholamine concentrations, subsets of peripheral blood lymphocytes, NK activity, and antibody-dependent cellular cytotoxicity (ADCC) were analyzed before (baseline) and 5, 15, 30, 60, and 120 min after injection. There were no differences between groups in the distribution of CD2+ and CD8+ lymphocytes over time. However, CD3+ and CD4+ T cells decreased significantly 5 to 60 min after injection of adrenaline. In contrast, NK cell numbers (CD16+, CD56+) increased significantly 5 min after injection of adrenaline and noradrenaline, reached the highest values 15 to 30 min postinjection, and subsequently declined to baseline values 60 (noradrenaline) and 120 (adrenaline) min, respectively, after injection. Similar alterations for NK activity and ADCC were observed after administration of both catecholamines. These data suggest that both sympathetic-adrenal hormones are similarly potent modulators of natural immunity and provide further evidence that catecholamines might be responsible for the observed alterations in immune functions after phases of acute stress.

A novel target cell antigen involved in the NK-like lytic activity of antigen-specific cytotoxic T lymphocytes

Monoclonal antibodies (mAbs) have been derived which identify a target cell antigen involved in human natural killer (NK) cell lysis. The effects of the mAbs on the NK-like cytotoxic activity exhibited by different populations of human cytolytic T cells were examined. The anti-target cell mAbs 1E7 and 18C2 inhibited the lysis of K562 target cells by endogenous NK cells, antigen-specific cytotoxic T lymphocytes (CTL) with NK-like activity, and non-major histocompatibility complex (MHC)-restricted T cells. Cytolysis of K562 target cells was not affected by treatment of the target cells with the anti-class I HLA mAb W6/32. Further, the anti-target cell mAbs had no effect on antigen-specific lysis by the CTL. The mAb W6/32, however, inhibited the antigen-specific killing. Experiments at the single-cell level revealed that the anti-target cell mAbs inhibited the formation of conjugates between the effector cells and K562 tumor cells but had no effect on CTL binding to the antigen-specific target cells. Thus, antigen-specific CTL exhibiting NK-like lytic function appeared to recognize a novel target cell antigen that is distinct from typical MHC antigens and is identical to the target-cell antigen recognized by true NK cells.

Effects of tumour necrosis factor-alpha (TNF-alpha), IL-1 beta and monocytes on lymphokine-activated killer (LAK) induction from natural killer (NK) cells and T lymphocytes

Roles of monocytes and cytokines were investigated on LAK induction from T and NK cells. Monocytes augmented more T-LAK induction than did NK-LAK. Expression of IL-1 beta, TNF-alpha and interferon-gamma (IFN-gamma)-mRNA and their cytokine production were superior in NK cells compared with T cells in parallel with their LAK activities. An increase of TNF-alpha, IL-1 beta and IFN-gamma production was induced by co-culturing NK or T cells with autologous monocytes. The augmentation of T cell cytokine production and T-LAK activity by monocytes was more prominent than that of NK cells. TNF-alpha and IL-1 beta were generated 24 h after IL-2 stimulation, and these cytokines were able to almost substitute for monocytes in LAK induction. Conversely, LAK induction was almost completely suppressed by both anti-IL-1 beta and anti-TNF-alpha antibodies, if they were added within 24 h after the start of the LAK induction. IFN-gamma, which was produced at a later stage, scarcely affected LAK induction in spite of the cooperation with TNF-alpha. The results obtained indicate conclusively that the superiority of NK-LAK depends on their superior productivity of both IL-1 beta and TNF-alpha, and that the up-regulation of LAK induction by monocytes is largely due to the enhanced generation of both cytokines.

Changes in natural immunity during the course of HIV-1 infection

The role of natural killer (NK) and lymphokine-activated killer (LAK) cell-mediated cytotoxicity in AIDS has yet to be established. The objective of this study was to determine inducible LAK cell responses at different stages of HIV-1 infection, and specifically to establish the participation of CD8 lymphocytes in these responses. Peripheral blood lymphocytes (PBL) were isolated from healthy seronegative (CDC-0) subjects and HIV-1+ individuals who were clinically asymptomatic (Centre for Disease Control group 2, CDC-2) or symptomatic (CDC-4) with regard to secondary opportunistic infection (OI). LAK cells were generated upon incubation of PBL with IL-2 and their cytolysis of K562 and U-937 targets was determined using chromium release assays. The role of CD8+ lymphocytes as progenitors and effectors of these LAK cell responses was determined by immunomagnetic depletion of CD8+ cells from precursor PBL and LAK cells, respectively. LAK cell-mediated cytotoxicities in HIV-1-infected individuals were reduced compared with seronegative controls without any corresponding changes in the relative proportions of CD56+ (NK) cells among groups. Depletions of CD8+ subsets from either PBL or LAK cells dramatically reduced total LAK cytotoxic responses and LAK activities per unit CD56+ cell in the OI-/CDC-2 seropositive population. No corresponding changes in LAK activities in seronegative control or HIV+/OI+/CDC-4 groups were observed. Levels of LAK activity against K562 targets in CDC-0/HIV- and CDC-4/HIV+ groups correlated with the percentage of CD56+ LAK cells; corresponding LAK activity in the CDC-2/HIV+ group correlated with the percentage of both CD56+ and CD8+ subsets. These findings suggest that adaptive changes in non-MHC restricted cytotoxic responses occur in HIV-1 individuals at early stages post-HIV infection, before the onset of opportunistic infection.

Increased natural killer cell activity in a model of immunoglobulin A nephropathy secondary to chronic alcohol consumption

We investigated natural killer (NK) cell activity in an animal model of ethanol-induced immunoglobulin A (IgA) nephropathy. Two groups, of 10 rats each, received a continuous intragastric infusion of liquid diet through a permanent cannula for 6 weeks. The alcoholic group was infused additionally with intragastric ethanol, representing from 32% to 40% of the caloric requirement. The group of control rats received an isocaloric diet supplemented with glucose instead of alcohol. IgA nephropathy was observed in all the alcoholic rats but in none of the controls. NK cell activity was investigated in the two groups by measuring the cytotoxicity of spleen cells using the chromium release method. NK cell activity was found to be significantly increased in the alcoholic rats. In view of the known modulation of IgA synthesis by NK cells, we suggest that increased NK cell activity may be a contributing factor to the high levels of circulating IgA seen in IgA nephropathy secondary to chronic alcohol consumption.

Identification and partial characterization of an ectoATPase expressed by human natural killer cells

An extracellular membrane-associated ectoATPase has been identified on the human natural killer cell line NK3.3. The enzyme is distinct from other classes of ATPases, kinases, and phosphatases. NK3.3 ectoATPase demonstrated a Km for ATP of 41 microM and a Vmax of 0.2 mumol/min and required both Ca2+ and Mg2+ for maximal activity. Purine and pyrimidine nucleotides were competitive inhibitors of the catalytic reaction. Inhibition increased with the addition of increasing negative charge of the phosphate side chain and was also dependent on contributions from the nucleoside. NK3.3 ectoATPase activity was inhibited by reaction with the affinity label [p-(fluorosulfonyl)benzoyl]-5'-adenosine (5'-FSBA), which is shown to modify the enzyme at or near the ATP-binding domain. Photoaffinity labeling of intact NK3.3 cells with [alpha-32P]-8-azidoATP demonstrated an ATP-binding protein of 68-80 kDa unique to NK3.3 cells. A positive correlation was observed between the ability of the various nucleotides to block photoincorporation into the 68-80-kDa protein and their ability to inhibit ectoATPase activity. NK3.3 cells which were made ectoATPase-deficient by reaction with 5'-FSBA demonstrated that this enzyme does not have a major role in the protection of this cytolytic effector cell from the possible lytic effects of extracellular ATP.

Phenotypes and lymphokine-activated killer activity of pleural cavity lymphocytes of lung cancer patients without malignant effusion

We examined the phenotypes of lymphocytes in the pleural cavity of 23 lung cancer patients without malignant effusion. The ability of those lymphocytes to develop lymphokine-activated killer (LAK) activity and the regulation of LAK by pleural cavity macrophages were also compared with their counterparts in the peripheral blood. Mononuclear cells (MNC) were obtained simultaneously from the blood and by lavage of the pleural cavity of patients with lung cancer. The proportion of the T-cell subset of HLA-DR+ cells was significantly higher in the pleural cavity than in the peripheral blood, but the proportions of CD3+ and CD8+ cells in the pleural cavity were similar to the corresponding proportions in the blood. The proportions of CD4+ and CD16+ cells were lower in the pleural cavity than in the blood. The LAK activity could be developed by MNC from the pleural cavity following incubation with interleukin 2 (IL-2), but the LAK activity of pleural cavity MNC was significantly less than that of peripheral MNC. Pleural cavity lymphocytes alone also developed LAK activity following incubation with IL-2. Pleural macrophages from the patients were regulated to augment in vitro induction of LAK activity by IL-2 from autologous blood lymphocytes and pleural cavity lymphocytes. Lymphocytes in the pleural cavity without malignant pleural effusion could be developed by LAK activity and this activity was augmented by pleural cavity macrophages. The LAK activity developed by pleural cavity lymphocytes was significantly lower than that developed by peripheral blood lymphocytes. However, they can change their population to include cells with higher activities on exposure to IL-2 against the invasion of lung cancer cells into the pleural cavity. Thus, the population of lymphocytes in the pleural cavity of patients with lung cancer without malignant pleural effusion was different from that in malignant pleural effusion.

Anxiolytic effect of progesterone is associated with increases in cortical allopregnanolone and GABAA receptor function

The effects of a SC injection of progesterone (0, 1, or 4 mg) on locomotor behavior and exploration of an elevated plus-maze were examined in ovariectomized rats. At the completion of the behavioral tests, blood serum and cerebral cortical level of the 3 alpha-hydroxy ring-A metabolite of progesterone, 3 alpha-hydroxy-5 alpha-pregnan-20-one (allopregnanolone), was also assessed. GABA-stimulated 36Cl- influx was studied in cortical synaptoneurosomes from a subgroup of ovariectomized females treated with vehicle or 4 mg progesterone. Whereas progesterone treatment did not affect ambulation in a novel arena, significant anxiolytic behavior was detected in the plus-maze 4 h after administration of 1 or 4 mg progesterone. A dose-dependent increase in allopregnanolone level was found in serum and cortical homogenates. Studies of GABA-stimulated Cl- influx demonstrated that progesterone treatment increased the sensitivity of cortical synaptoneurosomes to GABA (i.e., decreased the EC50) and increased the maximal efficacy with which GABA stimulated Cl- transport (i.e., increased the Emax). Together, these data support the hypothesis that the psychotropic effects observed after progesterone administration are due to the bioconversion of progesterone to allopregnanolone, which subsequently augments GABAA receptor-mediated function.

Chemical nature and immunotoxicological properties of arachidonic acid degradation products formed by exposure to ozone

Ozone (O3) exposure in vivo has been reported to degrade arachidonic acid (AA) in the lungs of rodents. The O3-degraded AA products may play a role in the responses to this toxicant. To study the chemical nature and biological activity of O3-exposed AA, we exposed AA in a cell-free, aqueous environment to air, 0.1 ppm O3, or 1.0 ppm O3 for 30-120 min. AA exposed to air was not degraded. All O3 exposures degraded > 98% of the AA to more polar products, which were predominantly aldehydic substances (as determined by reactivity with 2,4-dinitrophenylhydrazine and subsequent separation by HPLC) and hydrogen peroxide. The type and amount of aldehydic substances formed depended on the O3 concentration and exposure duration. A human bronchial epithelial cell line (BEAS-2B, S6 subclone) exposed in vitro to either 0.1 ppm or 1.0 ppm O3 for 1 hr produced AA-derived aldehydic substances, some of which eluted with similar retention times as the aldehydic substances derived from O3 degradation of AA in the cell-free system. In vitro, O3-degraded AA induced an increase in human peripheral blood polymorphonuclear leukocyte (PMN) polarization, decreased human peripheral blood T-lymphocyte proliferation in response to mitogens, and decreased human peripheral blood natural killer cell lysis of K562 target cells. The aldehydic substances, but not hydrogen peroxide, appeared to be the principal active agents responsible for the observed effects. O3-degraded AA may play a role in the PMN influx into lungs and in decreased T-lymphocyte mitogenesis and natural killer cell activity observed in humans and rodents exposed to O3.

Lymphoproliferative disease of "LAK cell" precursor large granular lymphocytes in association with celiac disease

We have investigated a case of lymphoproliferative disease of large granular lymphocytes (LDGL) occurring in association with celiac disease, anemia, neutropenia, and carcinomas of the endometrium, breast, and skin. The large granular lymphocyte (LGL) proliferation was monoclonal, T cell in origin, with T cell receptor beta-chain gene rearrangement, and a CD3+, CD8+, CD16+/- phenotype. In spite of the high frequency of LGL, natural killer (NK) cell activity was absent. Stimulation with interleukin-2 in vitro, however, resulted in high lymphokine-activated killer (LAK) cell activity against NK-resistant targets. The T-cell nature of the LAK precursor cells is in contrast to the majority seen in normal peripheral blood. Therapeutic trials of cyclosporin A, low-dose cyclophosphamide, and levamisole were unsuccessful in reducing transfusion requirements. This case is unique in the association of LDGL with celiac disease. It is also unique in that the patient had been followed for several years prior to the onset of the LDGL. The case extends the list of lymphoproliferative disorders documented to be associated with celiac disease and, conversely, adds to our knowledge of lymphoproliferative disorder of LGL and its "dysimmune" manifestations.

Usage of T-cell receptor V beta chain genes in fresh and cultured tumor-infiltrating lymphocytes from human melanoma

Tumor-infiltrating lymphocytes (TIL) freshly obtained from human malignant melanomas as well as the same TIL grown in the presence of interleukin 2 (IL2) were studied for gene expression of the T-cell receptor (TCR) variable beta regions (V beta). To perform the TCR-V beta analysis, total RNA was isolated from TIL and reverse-transcribed into cDNA, which was then amplified by PCR using 22 different 5' primers specifically recognizing the sequences of 20 V beta gene families and a 3' primer annealing to the constant region of the beta chain. The TCR-alpha constant region (C alpha) gene was co-amplified as a standard for the calculation of the percentage of each TCR-V beta gene expressed. The frequency of individual V beta regions expressed on TIL was computed from the ratio of cpm V beta to cpm C alpha for each V beta region in relation to the total of all 22 ratios. With fresh TIL obtained from 8 different melanomas, oligoclonal distribution of V beta genes expressed on TIL was observed, in comparison with a broader and unrestricted distribution seen with peripheral-blood T cells of 8 normal individuals. The oligoclonal patterns of V beta-gene expression in fresh melanoma TIL were distinct in every tumor. Several of the V beta-genes usually expressed in normal PBL were not expressed in fresh TIL in melanoma TIL cultured in the presence of IL2 and IL4 and in the absence of autologous tumor (AuTu) or antigen-presenting cells for 23 to 65 days, selection of T-cell lines expressing a restricted number of V beta genes occurred. Although in 4/5 TIL cultures this selection involved the V beta 7 gene, no relationship could be established between V beta gene expression in fresh TIL and that in T-cell lines outgrowing in long-term cultures. Selection in culture of CD3+CD8+ T-cell lines with V beta-gene expression restricted to 1 or 2 V beta families did not correlate with the presence or level of AuTu cytotoxicity mediated by these T cells. The results indicate that in TIL cultures random selection of T-cell lines with reactivity not relevant to AuTu may account for poor expression or loss of AuTu cytotoxicity by most TIL cultured long-term in the presence of cytokines and in the absence of specific antigenic stimulation.

Expression of a novel function-associated molecule on cells mediating spontaneous cytolysis in swine

In the present study, we have analyzed the effects of the anti-FAM mAb 5C6, on endogenous NK cell and lymphokine-activated killer (LAK) cell activity of swine. We report that the anti-FAM mAb 5C6 binds to fresh and cultured lymphocytes with spontaneous cytotoxic activity from swine peripheral blood. In conjunction, the anti-FAM mAb 5C6 inhibits swine cytolysis against K562 target cells. Inhibition was found to be mediated by blocking of conjugate formation. The level of spontaneous killing and mAb inhibition was correlated with the number of swine cells staining positive with the mAb 5C6 as assessed by flow cytometry.

Clinical and immunologic studies in reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin

BACKGROUND

Little is understood about reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin.

OBJECTIVE

Our purpose was to define reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin further with focus on immunologic studies.

METHODS

In patients with reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin, we measured circulating immune complexes before, during, and after therapy. We examined natural killer cells in a functional assay; we performed direct immunofluorescence and T- and B-cell marker studies in skin biopsy specimens.

RESULTS

The infiltrate in reticular erythematous mucinosis is composed of helper T cells. Circulating immune complexes are increased in both reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin and decrease with hydroxychloroquine therapy and clinical clearing. Natural killer cell function is decreased in reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin.

CONCLUSION

Changes in circulating immune complex titers accompanying therapy with hydroxychloroquine and clinical clearing, with recurrence of the condition and increase in circulating immune complexes on discontinuation of treatment, point to a possible relation between these events.

Pulmonary macrophages suppress the proliferation and cytotoxicity of tumor-infiltrating lymphocytes

Adoptive immunotherapy with interleukin-2 and tumor-infiltrating lymphocytes (TIL) is rarely effective in primary lung cancer. We hypothesize that pulmonary macrophages (PM), which are increased substantially in the lungs of smokers, might suppress TIL function. The addition of PM into the TIL cytotoxicity assay produced a concentration-dependent suppression of TIL cytotoxicity with up to 71% inhibition of autologous tumor killing at the 1:1 PM:TIL ratio. Inhibition was not target-specific, as killing of NK-sensitive (K562), NK-resistant (M14), and autologous tumor targets were equally suppressed. Nor was inhibition specific for lung TIL, as similar inhibition was observed with melanoma and renal TIL. Using a model system, we demonstrated that both CD3+ antigen-specific and CD56+ nonspecific lymphocytes are susceptible to the suppressive effects of the PM. Direct co-incubation of PM and TIL for 4 to 44 h resulted in progressive suppression of TIL proliferation and cytotoxicity. TIL cytotoxicity remained suppressed even if PM were removed from the co-culture after 24 h, but was restored if the separated TIL were re-incubated in interleukin-2. These results suggest that PM may locally regulate the proliferative and cytotoxic function of adoptively transferred TIL.

Importance of hypothalamic function to stressor-induced responsiveness of the GABAA receptor in the cerebral cortex: a non-corticosterone influence

Catecholamine terminals in the paraventricular nucleus (PVN) of the hypothalamus of 60-day-old rats were destroyed by the stereotaxic injection of 6-hydroxydopamine into the PVN (6-OHDA; 9 micrograms/1.5 microliters bilaterally), and the rats were tested 2 weeks later. Lesions led to a 70% reduction of norepinephrine in the hypothalamus and a loss of dopamine-beta-hydroxylase immunoreactivity in the PVN. Furthermore, 6-OHDA lesions in the hypothalamus disrupted stressor-induced (15 min of restraint) changes in GABAA receptor function in the cerebral cortex (assessed by measuring chloride-facilitated benzodiazepine binding) but did not alter stressor-induced increases in plasma corticosterone levels. Additionally, the lesion did not change the responsiveness of the GABAA receptor to the corticosterone metabolite, allotetrahydrodeoxycorticosterone. These results indicate that stressor-induced changes in cortical GABAA receptor function are not driven by the stressor-induced release of corticosterone. A separate group of animals were tested for behavioral responses to challenge, and while 6-OHDA-induced lesions did not alter total scores in the test of environment-specific social interaction, the lesions did induce a change in composition of the behavior. Lesioned animals demonstrated increased physical (vigorous contact) interactions, similar to behavior previously observed in younger rats. The results of the behavioral study support a role for the GABAA receptor in the cerebral cortex in mediating appropriate behavioral responses to challenge in the adult rat. Thus, a hypothalamic lesion that prevented challenge-induced changes in GABAA receptor function in the cortex (with no change in the corticosterone response to the stressor) also led to altered behavioral responses to challenge.

Effect of monoclonal antibody 17-1A and GM-CSF in patients with advanced colorectal carcinoma--long-lasting, complete remissions can be induced

Antibody-dependent cellular cytotoxicity (ADCC) is considered to be one of the effector functions of unconjugated monoclonal antibodies (MAbs) in tumor therapy. The antitumor activity of MAbs might therefore be augmented if the cytotoxic capability of the effector cells could be increased. In an in vitro system, the killing capacity of MAb was significantly enhanced by pre-treatment of the effector cells with granulocyte-macrophage colony-stimulating factor (GM-CSF). Based on these findings, the therapeutic effect of the combination of mouse MAb 17-1A (IgG2a) and GM-CSF was evaluated in 20 patients with metastatic colorectal carcinoma (CRC). The patients received GM-CSF for 10 days and a single i.v. infusion of MAb 17-1A on day 3 of the cycle. Four cycles were given at 1-monthly intervals. There was a continuous increase in blood monocytes and lymphocytes during all 4 GM-CSF cycles. Neutrophils and eosinophils were also significantly augmented but in a biphasic manner and the cell counts on day 10 of cycle IV were significantly lower than in cycles I and II. GM-CSF-related side-effects were of no major clinical importance. During the third cycle, an immediate-type allergic reaction (ITAR) against MAb 17-1A occurred in most patients, necessitating reduction of the MAb dose as well as of the infusion rate. Two patients achieved complete remission. One patient had a minor response, and 3 other patients were considered to have stable disease > 3 months.

Changes of natural killer cells during acute psychological stress

Emotional stress is often followed by increased susceptibility to infections. One major role in the immediate immune response to infection is played by natural killer (NK) cells. This study was designed to establish whether acute psychological stress influences cellular immune functions and to elucidate the role of endocrine parameters as potent mediators of stress induced alterations of the immune system. Forty-five first-time tandem parachutists were examined continuously for their plasma concentrations of cortisol and catecholamines from 120 min before to 60 min after jumping. Lymphocyte subsets, NK activity, and ADCC were determined 2 hr before, immediately after, and 1 hr after jumping. There was a significant increase in sympathetic-adrenal hormones during (adrenaline, noradrenaline) and shortly after jumping (cortisol). Lymphocyte subsets and the functional capacity of NK cells revealed an increase immediately after jumping followed by a decrease significantly below starting values 1 hr later. These changes were significantly correlated to plasma concentrations of noradrenaline. Thus, quick mobilization of NK cells is suggested as one major mechanism for this effective adaptation of the immune system to stress situations.

Alcohol consumption suppresses metastasis of B16-BL6 melanoma in mice

Female C57BL/6 mice were fed a defined, pelleted diet and given 10% w/v or 20% w/v ethanol in their drinking water. Natural killer (NK) cell cytolytic activity was compared between water-drinking and ethanol-consuming mice and in mice that were also treated with polyinosinic-polycytidylic acid (poly I:C) to augment NK cell activity or with anti-NK1.1 antibody to decrease activity. NK cell cytolytic activity was not altered in mice given 10% ethanol, but was decreased in mice given 20% ethanol compared to water-drinking mice. Poly I:C treatment increased and anti-NK1.1 antibody treatment decreased NK cell activity in both water-drinking and 20% ethanol-consuming mice. Experimental and spontaneous metastases of B16-BL6 melanoma were evaluated as a function of the duration of ethanol consumption before tumor inoculation and as a function of altered NK cell activity. Experimental metastasis was inhibited after 4 and also after 6.5 weeks of ethanol exposure. Poly I:C treatment inhibited tumor lung colonization irrespective of ethanol consumption. Anti-NK1.1 antibody treatment increased metastasis, although to a lesser degree in mice consuming 10% ethanol. Spontaneous metastasis was inhibited in mice consuming 10% ethanol for 4 weeks, and in mice consuming 20% ethanol for 1 and 4 weeks before melanoma inoculation.

Effect of anti-CD3/anti-CD28/interleukin-2 stimulation of mononuclear cells on transforming growth factor beta inhibition of lymphokine-activated killer cell generation

After simultaneous stimulation with anti-CD3 monoclonal antibody (mAb) at 10 ng/ml, anti-CD28 mAb at 125 ng/ml, and interleukin-2 (IL-2) at 20 U/ml, peripheral blood mononuclear cells (PBMC) were partially resistant to immunosuppression by transforming growth factor-beta (TGF beta 2). The doses of TGF beta 2 that inhibit cytotoxicity of IL-2 stimulated cells by 60%-70% were much less effective when the same cells were stimulated with anti-CD3/anti-CD28/IL-2. This favorable stimulation a generated a cell population characterized by high lytic activity, excellent expansion, and a greater resistance to immunosuppressive action of TGF beta 2. The secretion of secondary cytokines important for LAK generation is considered a crucial event, at least partially responsible for the antagonization of TGF beta immunosuppression.

Interleukin-2-responsive wound-infiltrating lymphocytes in surgical adjuvant cancer immunotherapy

Wound-infiltrating lymphocytes (WIL) were assessed in murine models of localized sarcoma and carcinoma to evaluate the role of interleukin-2 (IL-2)-responsive lymphocytes in adjuvant immunotherapy. Following tumor resection, IL-2 or diluent was injected at the surgical site for 6 days. Surgical site tissues were harvested and digested in a triple enzyme mixture, and single cell suspensions were prepared. Thy 1.2+ lymphocytes were isolated by incubating cells with monoclonal anti-Thy 1.2 antibody-coated magnetic beads. Lymphocyte-bead complexes were extracted with a magnet and cultured in medium containing IL-2 (100 units/ml) for 1-3 weeks. Perioperative IL-2 immunotherapy led to a three- to four-fold increase in WIL yield. WIL from IL-2-treated mice also demonstrated enhanced cytolysis of the autologous tumor and bound to activated endothelial cells with greater avidity than did the controls. We conclude that perioperative IL-2 therapy augments the yield, as well as the cytolytic and adhesive properties, of wound-infiltrating lymphocytes.