Autologous mixed lymphocyte-tumor reaction and autologous mixed lymphocyte reaction. I. Proliferation of two distinct T-cell subsets

In patients with carcinomatous pleural effusions blood T lymphocytes proliferated in vitro in response to autologous, freshly isolated effusion tumor cells in the autologous mixed lymphocyte-tumor culture (AMLTC) and to autologous blood non-T cells in the autologous mixed lymphocyte culture (AMLC). Treatment of the stimulator cells with the anti-HLA-DR monoclonal antibody (MAb) abrogated the stimulatory capacity in AMLC, but not in AMLTC. A subset of T cells that formed rosettes with autologous erythrocytes showed proliferative response to autologous non-malignant cells, whereas this subset did not respond to autologous tumor cells. Non-adherent lymphocytes were fractionated by centrifugation on discontinuous Percoll density gradients. Medium-sized T lymphocytes were excellent responders in AMLC, but were weak responders in AMLTC. Small T lymphocytes proliferated preferentially in AMLTC, but responded poorly in AMLC. Large granular lymphocytes (LGL) did not proliferate in mixed cultures of either type. Instead, LGL suppressed the T-cell proliferation in AMLTC. The same suppressor LGL, however, had no inhibitory effect on AMLC. Elimination of the CD4 subset reduced or abolished proliferative response in AMLC in all cases, whereas it was ineffective in diminishing the reaction in 6 of 8 AMLTC. In contrast, removal of the CD8 subset decreased or eliminated T-cell proliferation in 4 of 8 AMLTC, but in none of the AMLC. These results indicate that the autoreactive T lymphocytes detectable in response to tumor cells and non-malignant non-T cells differ in several characteristics. Thus, the reaction in the AMLTC is not due to contaminating non-malignant cells in the stimulator population and may be a tumor-induced proliferative response.

[Production and function of the monocyte cytotoxic factor (MCF)]

Monocytes lysing a variety of tumor cells were isolated by adhesion to autologous serum-coated plastic surfaces. When the blood monocytes were co-cultured with K562 cells for 3-24 h, the supernatants contained soluble factors, termed monocyte cytotoxic factors (MCF), capable of lysing K562 and other tumor cells in a 48-h microcytotoxicity assay. The production of MCF was mediated by typical monocytes expressing a surface phenotype of CD11 (+), CD16 (-), LeuM1 (+). When target cells were pretreated with actinomycin D, they showed an increase in their susceptibility to lysis by MCF. Addition of the drug to MCF assays also resulted in an enhancement of MCF-mediated lysis. Thus, the lytic activity of MCF was detectable in an 18-h assay. The presence of interferon (IFN)-alpha or -gamma augmented the biological activity of MCF, while pretreatment of target cells with IFN did not enhance MCF activity. The absorption of MCF activity was not elevated by actinomycin D or IFN. MCF lysed target cells that were resistant to tumor necrosis factor (TNF). One result of importance is that MCF lysed autologous and allogeneic freshly isolated human tumor cells. The lysis of fresh human tumor cells by MCF was not inhibited by monoclonal antibodies directed against TNF, lymphotoxin (LT), IFN-alpha, IFN-gamma, or interleukin 1 (IL-1). Furthermore, TNF, LT, IFNs, and IL-1 did not kill fresh human tumor cells. MCF activity was stable at low temperatures but was destroyed by heating. The biological activity of MCF was reduced or abolished by serum, trypsin, chymotrypsin and proteinase K, indicating the proteinaceous nature of MCF. The lytic activity was resistant to protease inhibitors. These data indicate that MCF is a noble cytokine that acts on human fresh tumor cells.

Is the sleeve anastomosis a risky technique?

We report 15 free flap transfers using sleeve vascular anastomoses with minor modifications of the original method. There was partial necrosis of one flap and one other required reoperation due to kinking of the feeding artery and not to the method of anastomosis. We believe that the sleeve anastomosis is reliable in clinical microvascular surgery if proper cases are selected. Indications for the method are discussed.

Growth of bone marrow cells on porous ceramics in vitro

Following the transplantation of bone marrow cells to extra-osseous sites, bone formation occurs in those sites. This osteogenic potential of bone marrow cells might be utilized for filling defects in bone if they could be transported on porous ceramic materials. Before such an approach becomes feasible, it is important to know what happens to the cells in the presence of the ceramics that might be used. In order to investigate the interaction between bone marrow cells and ceramics, in vitro, a system for culturing bone marrow cells on ceramic materials has been developed. Bone marrow cells adhered well to the surface of calcium hydroxyapatite and tricalcium phosphate ceramics, and this was followed by the formation of fibrous tissue on and within the ceramics. These ceramics were compatible with bone marrow cells even in culture conditions in which there was a large surface area of ceramic interfacing with cells. The results support the proposal that calcium hydroxyapatite and tricalcium phosphate are appropriate as bone replacement materials. In contrast, calcium aluminate had an adverse effect on bone marrow cells when there was a high proportion of ceramic to culture medium. However, this effect was not present if the proportion of ceramic to culture medium was low. Therefore, a large amount of biodegradable porous calcium aluminate ceramic should not be used as an alternative to autogeneous bone grafting.

Lysis of autologous tumor cells by high-density lymphocytes is potentiated by the streptococcal preparation OK432 (Picibanil)

In experiments performed with tumor cells isolated from surgical specimens and lymphocytes collected at the time of surgery, tumor cells are often lysed by blood lymphocytes. Some of the effectors are present in the high-density T-cell subset. This population has little or no anti-K562 activity. For the auto-tumor lysis of T cells with high density, CD8-positive cells are mainly responsible. OK432 pretreatment of the effectors potentiates the existing lytic function or induces it in cases in which the cells have no such function. In general, the potentiating effect reflects inherent patterns of cytotoxicity. In contrast to the lysis of autologous tumor cells, cells with low but not high density were induced to lyse K562.

[Effective mechanisms of BRM, with special reference to induction of autologous tumor cell-killing (ATK) activity by OK-432]

OK-432, a streptococcal preparation, is known to have strong BRM functions and is expected to produce clinical improvement and prolongation of survival in treated cancer patients. In order to clarify the immunopharmacological mechanisms involved with its clinical effectiveness, intrapleural injection of OK-432 was attempted in patients with malignant pleural effusion due to metastasis from lung cancer. About 70-80% of patients thus treated showed clinical improvements with reduction or disappearance of effusion and effusion tumor cells within a week after the therapy. The clinical response was accompanied by an abrogation or reduction of suppressor macrophages and a stimulatory increase of effective cytotoxic cells resulting in an increase of NK and ATK activity. These in vivo effects observed in the OK-432-treated patients were reproducible in vitro by incubating normal or effusion lymphocytes with tumor-associated macrophages. OK-432 was also shown to reduce the locomotor inhibitory activity of macrophages toward LGL, and to augment the production of various sorts of cytokines, such as IL-1 and MCF by macrophages and IL-2 and NKCF by lymphocytes, all of them being exerted upon activation of the anti-tumor immunological mechanism.

Suppression of T-cell response in autologous mixed lymphocyte-tumor culture by large granular lymphocytes

The role of large granular lymphocytes (LGL) in the autologous mixed lymphocyte-tumor culture (MLTC) was studied in cancer patients with malignant pleural effusions. When blood lymphocytes were cocultured in vitro with autologous tumor cells freshly isolated from carcinomatous pleural effusions, [3H]thymidine incorporation was weakly stimulated on day 6 in 6 of 30 samples. Removal of LGL from the responder population by treatment with the Leu-7 or Leu-11b monoclonal antibody plus complement (C') induced or augmented the proliferative response. LGL and small T-lymphocytes were isolated by discontinuous Percoll gradient centrifugation and tested separately for the proliferative response to autologous tumor. T-cells proliferated in 24 of 30 cases, while LGL showed no proliferation. Addition of LGL to autologous mixed T-cell-tumor cultures suppressed the proliferation of T-cells. LGL, however, did not inhibit T-cell proliferation induced by alloantigens and lectins. The suppressive activity of Percoll-purified LGL was not reduced by OKT3 plus C' treatment, but it was totally abrogated by Leu-11b plus C'. Supernatants produced by 24-hour culture of LGL with autologous tumor contained soluble factors that suppressed the autologous MLTC without killing the autologous tumor or T-blasts. The LGL-mediated suppression was not abolished by anti-interferon-alpha or anti-interferon-gamma antibody. Activation of T-cells in the autologous MLTC induced lytic potential restricted to autologous tumor. In the presence of LGL, T-cells failed to develop autotumor killing activity. Once autotumor killer T-cells were generated in autologous MLTC, their cytotoxicity was no longer inhibited by LGL. These results indicate that LGL from patients with carcinomatous pleural effusions suppress the capacity of autotumor-recognizing T-lymphocytes to proliferate and develop autotumor cytotoxicity in the autologous MLTC. This could explain why fresh T-cells have no cytolytic activity to autologous tumor.

Natural cytotoxicity of human blood lymphocytes and monocytes and their cytotoxic factors: effect of interferon on target cell susceptibility

The effect of interferon (IFN) on target cell susceptibility to human natural killer (NK) cells and monocytes was analyzed in direct cell-mediated and their cytotoxic factor-mediated cytotoxicity assays. Treatment of K562 cells with IFN resulted in a decrease in their sensitivity to lysis by nonadherent lymphocytes and Percoll-purified large granular lymphocytes (LGL) when tested in a 4-hour 51Cr release assay. In contrast, the treatment did not affect the target susceptibility to monocytes purified by adherence to autologous serum-coated plastic surfaces. In the target-binding assay with LGL or monocytes the number of conjugates was not altered after IFN treatment of K562. Lymphocytes and monocytes were induced to release soluble cytotoxic factors, termed "natural killer cytotoxic factors (NKCF) and monocyte cytotoxic factors (MCF)," respectively, when co-cultured with K562. Both NKCF and MCF lysed K562 in a 48-hour microcytotoxicity assay or in an 18-hour 51Cr release assay in the presence of dactinomycin. IFN-treated K562 reduced or completely lost their ability to stimulate the release of NKCF, whereas they triggered MCF secretion as effectively as did the untreated K562. When lymphocytes or monocytes were pretreated with IFN, they released NKCF or MCF with augmented lytic activity. In contrast to the sensitivity to NK cell-mediated lysis, IFN pretreatment of K562 induced no change in their susceptibility to NKCF and MCF. When IFN was added to NKCF and MCF assays, the cytotoxicity was enhanced. The addition of IFN to K562 that had been pretreated with NKCF or MCF and washed resulted in no increase in lysis. The capacity of K562 to absorb the lytic activity of NKCF and MCF was not altered by IFN. These results indicate that IFN treatment of target cells can be used to distinguish the two distinct types of blood mononuclear cells with natural cytotoxicity, NK cells and monocytes, and that each effector cell type is stimulated to release cytotoxic factors by the different target determinant after the initial effector-target cell binding.

Use of a combined groin-tensor fasciae latae flap for reconstruction of a full-thickness defect of the abdominal wall

Two cases are presented in whom full-thickness defects of the abdominal wall were repaired by combined groin-tensor fasciae latae flaps nourished only by the superficial circumflex iliac artery. The dissection of the flap is simple and it will probably cover even the upper parts of the flank.

Heritable translocation study in male mice with trimethyl phosphate

Dominant lethal and heritable translocation studies were performed in male mice receiving a single intraperitoneal injection of trimethyl phosphate (TMP). The germ cell stage investigated was the spermatid. Methyl methanesulfonate (MMS) was used as a positive control in the latter study. A dominant lethal assay gave marked dose-dependent increases in early fetal deaths. Heritable translocations were detected at 1000 or 1500 mg of TMP/kg in F1 male progeny when screening for semi-sterility and cytogenetically analyzing the meiotic or mitotic chromosomes. Translocation induction was higher at the higher TMP dose (14.3%) than at the lower dose (5.3%) and the yield from the higher dose was similar to that induced by 50 mg of MMS/kg (11.0%). Most of the translocation carriers were semi-sterile or sterile. The data confirm conclusions from other dominant lethal studies showing TMP to be capable of causing chromosomal damage in mouse spermatids and show that certain types of damage result in heritable translocations.

Natural cytotoxicity of human blood monocytes and natural killer cells and their cytotoxic factors: discriminating effects of actinomycin D

The effect of actinomycin D on target susceptibility to human blood natural killer (NK) cells and monocytes was analysed in direct cell-mediated and their cytotoxic factor-mediated cytotoxicity assays. Treatment of K562 cells with actinomycin D reduced their susceptibility to lysis by non-adherent lymphocytes and Percoll-purified large granular lymphocytes (LGL) in a 4-hr 51Cr-release assay, without affecting their sensitivity to monocytes purified by adherence to autologous serum-coated plastic surfaces. The drug treatment caused no shift in the kinetics of cytotoxicity. In the target binding assay LGL formed fewer conjugates with actinomycin-D-treated K562 cells than with untreated ones, while the binding of monocytes to targets was not reduced by the drug treatment of K562 cells. The cold target competition assay revealed that actinomycin-D-treated cold K562 cells showed less successful inhibition than untreated cold K562 cells. Lymphocytes and monocytes could be induced to release soluble cytotoxic factors, termed natural killer cytotoxic factors (NKCF) and monocyte cytotoxic factors (MCF), respectively, when co-cultured with K562 cells. Both cytotoxic factors lysed NK-sensitive target cells in a 48-hr assay. Actinomycin-D-treated K562 cells reduced or abolished the ability to stimulate the release of NKCF from lymphocytes, whereas they induced MCF secretion from monocytes as effectively as untreated ones. On the other hand, actinomycin D treatment of K562 cells enhanced their susceptibility to NKCF and MCF. This actinomycin-D-induced augmentation of target sensitivity to the cytotoxic factors was restricted to NK-sensitive target cells (K562 and Molt-4). NK-resistant target cells (Raji, YAC-I, EL4 and T blasts) were not lysed by NKCF and MCF even after they were treated with actinomycin D. The capacity of K562 cells to bind NKCF and MCF was not altered by actinomycin D. Treatment of the adherent cell population with OKMI or Leu-MI plus complement abrogated both cell-mediated cytotoxicity and MCF production, while Leu-IIb plus complement was ineffective. These results suggest that the effect of actinomycin-D treatment can be used to distinguish the two distinct types of blood mononuclear cells with natural cytotoxicity, NK cells and monocytes, and that each effector type recognizes different plasma membrane moieties of NK target cells, although the cytotoxic factors released from each effector cell similarly bind to and lyse the target cells.

Human epidermal cells and squamous carcinoma cells synthesize a cytokine that augments natural killer cell activity

Normal as well as transformed epidermal cells (EC) have recently been reported to produce a cytokine--EC-derived thymocyte-activating factor (ETAF), which according to its biologic as well as biochemical properties is indistinguishable from macrophage-derived interleukin 1 (IL 1). In the present study, the effect of supernatants (SN) derived from normal EC and a human squamous carcinoma cell (SCC) line were tested for their effects on natural killer (NK) cell activity. EC- as well as SCC-derived SN were able to augment in vitro NK cell activity of peripheral blood lymphocytes against K 562 cells. In contrast, adherent cell-derived, IL 1-containing SN did not affect NK cell activity. Upon high-pressure liquid chromatography (HPLC) gel filtration, ETAF and the EC-derived NK cell activity-augmenting factor (ENKAF) exhibited a similar m.w. However, by using reverse-phase HPLC, ETAF and ENKAF eluted as distinct peaks of activity, indicating that SCC cell-derived ENKAF is different from ETAF. Furthermore, ENKAF does not contain interleukin 2 (IL 2) or interferon (IFN) activity. The enhancement of NK cell activity was dose dependent and evident after 20 hr of preincubation of effector cells. Pretreatment of target cells with ENKAF did not affect the susceptibility of the target cells. The NK activity of large granular lymphocytes (LGL) purified by discontinuous Percoll gradient centrifugation and further depleted of high-affinity sheep erythrocyte rosetting cells was enhanced by ENKAF. In contrast, no NK cell activity was expressed by LGL-depleted T cell populations before or after treatment with ENKAF. In a single cell cytotoxicity assay in agarose, the number of lymphocyte binding to K 562 was not affected by ENKAF, but the frequency of dead conjugated target cells and presumably of active killer cells was increased by pretreatment with ENKAF. Additional incubation of LGL with ETAF did not further increase ENKAF-mediated augmentation of NK activity. In contrast to ETAF, ENKAF was not chemotactic for polymorphonuclear leukocytes. These results indicate that normal as well as transformed EC release a unique cytokine--ENKAF--which augments NK cell activity of LGL but is distinct from ETAF, IL 2, and IFN.

Human epidermal cells and squamous carcinoma cells synthesize a cytokine that augments natural killer cell activity

Normal as well as transformed epidermal cells (EC) have recently been reported to produce a cytokine--EC-derived thymocyte-activating factor (ETAF), which according to its biologic as well as biochemical properties is indistinguishable from macrophage-derived interleukin 1 (IL 1). In the present study, the effect of supernatants (SN) derived from normal EC and a human squamous carcinoma cell (SCC) line were tested for their effects on natural killer (NK) cell activity. EC- as well as SCC-derived SN were able to augment in vitro NK cell activity of peripheral blood lymphocytes against K 562 cells. In contrast, adherent cell-derived, IL 1-containing SN did not affect NK cell activity. Upon high-pressure liquid chromatography (HPLC) gel filtration, ETAF and the EC-derived NK cell activity-augmenting factor (ENKAF) exhibited a similar m.w. However, by using reverse-phase HPLC, ETAF and ENKAF eluted as distinct peaks of activity, indicating that SCC cell-derived ENKAF is different from ETAF. Furthermore, ENKAF does not contain interleukin 2 (IL 2) or interferon (IFN) activity. The enhancement of NK cell activity was dose dependent and evident after 20 hr of preincubation of effector cells. Pretreatment of target cells with ENKAF did not affect the susceptibility of the target cells. The NK activity of large granular lymphocytes (LGL) purified by discontinuous Percoll gradient centrifugation and further depleted of high-affinity sheep erythrocyte rosetting cells was enhanced by ENKAF. In contrast, no NK cell activity was expressed by LGL-depleted T cell populations before or after treatment with ENKAF. In a single cell cytotoxicity assay in agarose, the number of lymphocyte binding to K 562 was not affected by ENKAF, but the frequency of dead conjugated target cells and presumably of active killer cells was increased by pretreatment with ENKAF. Additional incubation of LGL with ETAF did not further increase ENKAF-mediated augmentation of NK activity. In contrast to ETAF, ENKAF was not chemotactic for polymorphonuclear leukocytes. These results indicate that normal as well as transformed EC release a unique cytokine--ENKAF--which augments NK cell activity of LGL but is distinct from ETAF, IL 2, and IFN.

Lysis of fresh human tumour cells by autologous tumour-associated lymphocytes: two distinct types of autologous tumour killer cells induced by co-culture with autologous tumour

The specific and natural killer (NK)-restricted nature of auto-tumour cytotoxicity of tumour-associated lymphocytes was studied in cancer patients with malignant pleural effusions. Large granular lymphocytes (LGL) and small T lymphocytes were isolated from carcinomatous pleural effusions by centrifugation on discontinuous Percoll gradients. Tumour cells freshly isolated from pleural effusions were classified according to their susceptibility to lysis by Percoll-purified LGL from the blood of normal donors in a 4-h 51Cr release assay. Of 12 NK-sensitive tumour samples, 11 were killed by autologous fresh effusion LGL, whereas only 2 were lysed by autologous T cells. Neither LGL nor T cells were cytotoxic to NK-resistant autologous tumour cells. T cells and LGL were each cultured in vitro with autologous tumour cells for 6 days. Effusion LGL maintained their auto-tumour killing activity in 10 of 12 autologous mixed lymphocyte-tumour cultures (MLTC) with NK-sensitive tumour, while LGL lost the activity when cultured alone. Removal of high-affinity sheep erythrocyte-rosetting cells from Percoll-purified LGL enriched effector cells. Autologous MLTC-derived LGL could also kill NK-sensitive allogeneic effusion tumour cells and K562 cells, as did fresh LGL. In autologous MLTC LGL failed to acquire lytic function to NK-resistant autologous tumour cells. In contrast, in vitro activation of effusion T cells with autologous tumour cells induced auto-tumour killer cells in 9 of 12 NK-sensitive tumour samples and 3 of 6 NK-resistant tumour cases. However, cultured T cells were incapable of killing allogeneic tumour cells and K562 cells. In the autologous MLTC effusion T cells proliferated vigorously in response to autologous tumour cells, whereas LGL showed no proliferation. The enrichment of blasts from cultured T cells on discontinuous Percoll gradients resulted in an enhancement of auto-tumour cytotoxicity, with no reactions recorded in blast-depleted, small, resting T cells. These results indicate that two distinct types of auto-tumour-recognising lymphocytes, LGL and T cells, are present in carcinomatous pleural effusions of cancer patients and that each effector type recognises different membrane moieties of autologous effusion tumour cells.

Bone ingrowth into three different porous ceramics implanted into the tibia of rats and rabbits

Three different porous ceramics--calcium aluminate, calcium hydroxyapatite, and tricalcium phosphate--were implanted into the proximal tibia in rats and rabbits to study the interactions between these ceramics and a bony site that is abundant in bone marrow. New bone was consistently formed within the bone marrow surrounding and adjacent to all three types of ceramics. Calcium hydroxyapatite and tricalcium phosphate ceramics permitted bone ingrowth into their pores. The newly formed bone was found only in the part of the ceramic intruding into the bone, not in the portion protruding in the soft tissues outside the tibia. Partial replacement of the new bone opposite the medullary portion by new hemopoietic marrow occurred with longer implantation times. In contrast, no bone was seen within the pores of any of the calcium aluminate implants.

Autologous tumor killing and natural cytotoxic activity of tumor-associated macrophages in cancer patients

Tumor-associated macrophages (TAM) isolated from pleural effusions and ascites fluids of cancer patients were tested for cytotoxicity against freshly isolated autologous tumor cells and K562 in a 4-h 51Cr-release assay, and in vitro effects of OK432 (a streptococcal preparation) and partially purified human leukocyte interferon (IFN) on their cytotoxicities were examined. Positive cytotoxicities against K562 were recorded for TAM samples from 2 of 23 pleural effusions and 3 of 10 ascites specimens. Tumor-associated macrophages were not cytotoxic to autologous tumor cells, while low but significant lysis was observed with tumor-associated lymphocytes (TAL) samples from 2 of 13 pleural effusions and 1 of 6 ascites specimens. In vitro treatment with OK432 resulted in an enhancement of natural cytotoxicity in 4 of 13 TAM and 10 of 15 TAL samples. An induction or augmentation of autologous tumor killing activity by OK432 was observed in 2 of 10 TAM and 8 of 11 TAL samples. In contrast, IFN failed to induce autologous tumor killing activity, although IFN-enhanced lysis of K562 was detected in 1 of 7 TAM and 2 of 9 TAL samples. These results indicated that autologous tumor killing and natural cytotoxic activities were defective in macrophages and lymphocytes at the site of the tumor growth, and both activities were strongly enhanced by OK432 rather than IFN.

Activation of human blood lymphocytes and monocytes by the streptococcal preparation OK432: enhanced generation of soluble cytotoxic factors

The streptococcal preparation OK432 augments natural cytotoxicity of human blood lymphocytes and monocytes. It also enhanced the production of natural killer soluble cytotoxic factors (NKCF) when the effector cells interact with K562 cells. There was a good correlation between the OK432-induced enhancement of NK cell-mediated cytotoxicity and the released NKCF activity. OK432-pretreated monocytes secreted higher amounts of monocyte cytotoxic factors (MCF) than the untreated monocytes. With the monocytes the enhanced generation of MCF was not always accompanied by the increase in direct cell-mediated lysis of K562. OK432 treatment alone did not induce NKCF release from lymphocytes, and the presence of K562 in the culture was necessary. In contrast, monocytes generated MCF when exposed to OK432. In the supernatants of cocultures of OK432-activated effectors and K562 the NKCF and MCF activity was elevated two- to ten-fold. The OK432-induced augmentation of natural cytotoxicity exerted by lymphocytes and monocytes may be mediated through an increase in the synthesis, activation and/or release of NKCF and MCF.

Lysis of fresh human tumor cells by autologous large granular lymphocytes and T-lymphocytes: two distinct killing activities induced by coculture with autologous tumor

The specific and natural killer (NK)-restricted nature of autologous tumor killing by blood lymphocytes was studied in patients with carcinomatous pleural effusions. Large granular lymphocytes (LGL) and small T-lymphocytes were isolated by centrifugation on discontinuous Percoll density gradients. Tumor cells freshly isolated from pleural effusions of cancer patients were classified according to their susceptibility to purified LGL from normal donors in a 4-hour 51Cr release assay. Of 15 NK-sensitive tumors, 14 were lysed by fresh autologous LGL, whereas only 2 were killed by T-cells. Neither LGL nor T-cells were cytotoxic to NK-resistant autologous tumor. LGL and T-cells were then cultured in vitro with autologous tumor cells for 6 days. In 13 of 15 autologous mixed lymphocyte-tumor cultures (MLTC) NK-sensitive tumor-cultured LGL maintained their autotumor killing activity, whereas LGL cultured alone lost the activity. Depletion of high-affinity sheep erythrocyte-rosetting cells from Percoll-purified LGL resulted in an enrichment of effector cells. LGL from autologous MLTC were able to kill NK-susceptible allogeneic effusion tumor and K562 as were fresh LGL. No lysis of NK-resistant autologous tumor was observed with cultured LGL. In contrast, activation of T-cells in autologous MLTC resulted in the generation of autotumor killer cells in 10 of 15 NK-sensitive and 3 of 6 NK-resistant tumor samples. However, cultured T-cells were incapable of killing allogeneic tumor and K562. In autologous MLTC T-cells proliferated in response to autologous tumor, whereas no proliferation was observed in the culture of LGL. The enrichment of blasts from cultured T-cells on discontinuous Percoll gradients induced an augmentation of autotumor cytotoxicity, with no reactivity in blast-depleted, small, resting T-lymphocytes. These results indicated that 2 distinct types of autotumor-recognizing lymphocytes, LGL and T-cells, are present in the peripheral blood of cancer patients.

Natural killer cell activity and autologous tumor killing activity in cancer patients: overlapping involvement of effector cells as determined in two-target conjugate cytotoxicity assay

The relationship between natural killer (NK) cell activity and autologous tumor killing activity was examined in patients with carcinomatous pleural effusions (PE) by means of a two-target conjugate cytotoxicity assay. Enrichment of large granular lymphocyte(s) (LGL) by discontinuous Percoll gradient centrifugation resulted in an augmentation of cytotoxicity against both K562 cells and tumor cells freshly isolated from PE of the same patients in a 4-hour 51Cr release cytotoxicity assay. At the single-cell level, the LGL-enriched fraction contained an increased number of effector cells that bound to autologous tumor cells and to K562 cells, as well as an increased frequency of cells cytotoxic to these target cells. In the two-target conjugate cytotoxicity assay, a single lymphocyte in the LGL population simultaneously bound to both a fluorescein-labeled K562 cell and a nonfluorescent autologous tumor cell. A significant number of lymphocytes in these mixed two-target conjugates lysed both autologous tumor cells and K562 cells after 6 hours' incubation, although overall lysis of K562 cells was higher than that of autologous tumor cells. These results indicate that a single LGL is involved in the lysis of both autologous tumor cells and K562 cells and thus provide direct evidence of involvement of subsets of NK cells in autologous tumor cell killing.

In vitro modulation of human natural killer cell activity by interferon: generation of adherent suppressor cells

The in vivo and in vitro effects of human alpha-interferon (IFN) on blood natural killer (NK) cell activity were studied in patients with malignant melanoma. The initial response to an i.m. injection of IFN was a depression of blood NK cell activity, being detectable at 4 h and reaching a nadir at 12 h. Blood NK cell activity returned to or exceeded pretreatment levels within 24 h. The frequency of large granular lymphocytes among peripheral blood lymphocytes (PBL), however, remained unchanged during the first 24 h of IFN treatment. In a single cell cytotoxicity assay in agarose the number of lymphocytes forming conjugates with K562 target cells was not affected at 12-h points of IFN treatment, while the frequency of lytic conjugates with dead target cells was decreased by 12 h. Thus, the number of active NK cells was reduced by IFN administration. While in vitro exposure to IFN resulted in an augmentation of NK cell activity of PBL from untreated patients, IFN failed to enhance the activity of PBL obtained 12 h post IFN injection. When PBL obtained 12 h after IFN injection were cultured overnight, they recovered their responsiveness to NK-boosting effects of IFN. Blood monocytes obtained at 12-h points from IFN-treated patients suppressed IFN-induced enhancement of NK cell activity, although these monocytes did not inhibit the base line level of NK cell activity. In contrast, the streptococcal preparation OK432 was able to augment NK cell activity of PBL obtained 12 h post IFN administration and of control PBL even in the presence of suppressor monocytes. PBL obtained 24 h post IFN injection expressing enhanced NK cell activity were also unresponsive to IFN in vitro. However, monocytes obtained 24 h after IFN injection were no longer able to inhibit IFN-induced augmentation of NK cell activity. These results indicate that in vivo administration of IFN-alpha to cancer patients results in rapid and transient generation of suppressor monocytes capable of inhibiting IFN-dependent development of functional NK cell activity, which could be responsible for the initial and transient decline in blood NK cell activity.

Strong natural killer (NK) cell activity in bone marrow of myeloma patients: accelerated maturation of bone marrow NK cells and their interaction with other bone marrow cells

Bone marrow natural killer (NK) cell activity was studied in patients with multiple myeloma. Bone marrow mononuclear cells from myeloma patients expressed considerable levels of cytotoxicity against K562 in a 4 h 51Cr-release assay, which was comparable to that of blood lymphocytes. In contrast, NK-cell activity was markedly low or absent in bone marrow of normal donors and control patients. Fractionation of bone marrow cells from myeloma patients on linear bovine serum albumin gradients enriched NK effector cells in the upper, lymphocyte-enriched fraction, with no reactivity in the middle fraction containing mainly myeloma cells. Treatment with either Leu-7 or OKMI monoclonal antibody plus complement reduced or abrogated bone marrow NK-cell activity of myeloma patients as well as blood NK-cell activity. However, OKMI plus complement failed to reduce control bone marrow NK-cell activity, although the activity was reduced by Leu-7 plus complement. Overnight exposure to interferon (IFN) of bone marrow cells resulted in an augmentation of NK-cell activity in myeloma patients, but not in controls. Furthermore, adherent bone marrow cells from controls suppressed IFN-induced enhancement of NK-cell activity of blood lymphocytes, whereas bone marrow of myeloma patients did not contain such suppressor cells. No cytotoxicity was induced in control bone marrow cells by cocultivation with bone marrow myeloma cells. Bone marrow NK cells from myeloma patients were able to lyse control bone marrow cells in a 18 h assay and their lytic activity was augmented by IFN treatment. However, neither bone marrow cells nor blood lymphocytes were cytotoxic to autologous and allogeneic fresh myeloma cells even after activation with IFN. These results suggest that NK precursor cells differentiate into HNK-I- and OKMI-positive mature NK cells in bone marrow of myeloma patients, but not in control bone marrow, and that these functional bone marrow NK cells may interact with other bone marrow elements.

The use of ceramics for bone replacement. A comparative study of three different porous ceramics

Ceramics have many properties which might make them suitable alternatives to bone grafts. This present study was done to find a suitable biodegradable porous ceramic for human bone replacement. Three different porous ceramics (calcium aluminate, calcium hydroxyapatite and tricalcium phosphate), with interlinked pores of two size ranges (150 to 210 micron), were implanted into the skulls of rats and rabbits for up to six months; the interaction with surrounding bone, which is virtually devoid of bone marrow, was then assessed. The ceramics caused no adverse biological response. Tissue ingrowth into pores throughout the implant was seen in all three types and in both pore sizes of ceramic, but the density of the penetrating tissue was far less for calcium aluminate than for calcium hydroxyapatite or tricalcium phosphate. For each type of ceramic, the soft-tissue ingrowth was more dense with the larger pore size, and with a longer period of implantation. Bone ingrowth was not usually seen within the pores of any ceramic. There were no differences in the histological findings between the rats and the rabbits. The results demonstrate that it is possible to produce ceramic materials with a porous structure which allows ingrowth of tissue and biological fluids.

Natural cytotoxicity of lymphocytes and monocytes and its augmentation by OK432 in melanoma patients

Lymphocytes and monocytes from the peripheral blood of 30 patients with malignant melanoma were tested for natural cytotoxicity against K562 cells in a 3-h 51Cr-release assay, and the effects of OK432 (a streptococcal preparation) on the cytotoxicity were examined. The lymphocyte cytotoxicity of melanoma patients was similar to that of normal donors and control patients with benign skin disease. Furthermore, the lymphocyte cytotoxicity of melanoma patients was not correlated to the stage of the disease. Similarly, lysis of K562 cells by monocytes isolated by adherence to autologous serum-coated plastic dishes in melanoma patients was comparable to that of controls and not associated with the stage of the disease. Positive monocyte reactions were recorded in 10 of 30 (33%) melanoma patients, seven of 21 (33%) normal donors and three of 10 (30%) control patients. There was no correlation between lymphocyte cytotoxicity and monocyte cytotoxicity. Overnight treatment of monocytes and lymphocytes with OK432 resulted in an increase in cytotoxicity. Significant augmentation of cytotoxicity by OK432 was observed in 28% of the monocyte samples and 86% of the lymphocyte samples, while partially purified human interferon augmented cytotoxicity in 63% of the monocyte samples and all the lymphocyte samples. These results suggest that neither lymphocyte nor monocyte cytotoxicities are depressed in melanoma patients as compared with normal donors and patients with benign disease and that OK432 has a stronger stimulatory effect on lymphocytes than on monocytes.

Natural cytotoxicity of human blood monocytes: production of monocyte cytotoxic factors (MCF) during interaction with tumor cells

Human blood monocytes obtained by EDTA-reversible adherence to autologous serum-coated plastic dishes expressed natural cytotoxicity against NK-sensitive K562 cells in a 4-h 51Cr release assay. These monocytes released soluble cytotoxic factors, termed monocyte cytotoxic factors (MCF), when cultured with target cells. In contrast, blood monocytes obtained by adherence to fetal calf serum-coated plastic surfaces failed to kill K562 cells and to produce MCF. Although some lysis could be detected at 18 h, optimal lysis of K562 cells by MCF was observed after 48 h incubation in a microcytotoxicity assay using trypan blue dye exclusion. The addition of actinomycin D to the cytotoxicity assay enhanced the sensitivity and then NCF activity was detectable in a 18-h Cr release assay. Neither supernatants produced by culture of monocytes alone nor lysates of monocytes were cytotoxic. In addition, cytochalasin A inhibited both direct cell-mediated lysis and generation of MCF. Optimal production of MCF occurred after 6-24 h of interaction with K562 cells, although significant activity was already present by 3 h. Treatment of monocytes with OKM1 monoclonal antibody plus complement abrogated both cell-mediated lysis and MCF generation, whereas Leu-11b plus complement were ineffective. These results indicate that human blood monocytes can release MCF during interaction with tumor cells and that this may be involved in the lytic mechanism of monocyte-mediated natural cytotoxicity.

Suppression of natural killer cell activity by adherent effusion cells of cancer patients. Suppression of motility, binding capacity and lethal hit of NK cells

Adherent cells from carcinomatous pleural effusions of lung cancer patients were tested for their ability to suppress natural killer (NK) cell activity, and the mechanism involved in the suppression of NK cell activity was determined. Adherent effusion cells (AEC) were isolated from malignant pleural effusions of patients by centrifugation discontinuous Ficoll-Hypaque gradients and adherence to serum-coated plastic dishes, and large granular lymphocytes (LGL) were purified from the peripheral blood of normal individuals by centrifugation on discontinuous Percoll gradients and further depletion of high-affinity sheep erythrocyte rosette formation. LGL-mediated lysis of K562 cells was suppressed when LGL were cultured with AEC for 20 h, then washed and tested in a 4-h 51Cr release assay. More profound suppression of NK cell activity was observed when cytotoxicity was assayed in flat-bottomed wells rather than in round-bottomed wells. Cytotoxicity assays conducted at the single cell level in agarose revealed that the frequency of LGL binding to K562 cells and of dead conjugated target cells was reduced after overnight contact with AEC. In agarose microdroplet assays, functional LGL from normal donors exhibited definitive motility, expressing polarized shape. In contrast, a small number of LGL with non-polarized configuration migrated from the agarose droplet after overnight culture with AEC. These results indicate that functionally suppressed NK cells lose their motility, binding capacity and killing activity, which could be responsible for the suppression of NK cell activity by AEC.

Intrapleural administration of OK432 in cancer patients: augmentation of autologous tumor killing activity of tumor-associated large granular lymphocytes

Ten patients with carcinomatous pleural effusions were treated with single intrapleural (i.pl.) injections of the streptococcal preparation OK432 on day 0 and the effects of i.pl. OK432 on the lysis of fresh or cryopreserved autologous tumor cells isolated from the pleural effusions were observed on day 7. In eight patients tumor cells in the effusions had decreased or disappeared by day 7. The other two patients, however, had no clinical evidence of therapeutic benefit from i.pl. OK432. Effusion tumor cells were relatively resistant to lysis by autologous lymphocytes when tested in a 4-h 51Cr-release assay. Positive reactions were recorded for blood and effusion lymphocytes in two of ten untreated patients. Injection of OK432 i.pl. resulted in an induction or augmentation of cytotoxicity against autologous tumor cells and K562 in the effusions of seven of ten subjects by day 7. In contrast, autologous tumor killing activity of blood lymphocytes was not always modified by i.pl. OK432. Purification of large granular lymphocytes (LGL) by discontinuous Percoll gradient centrifugation enriched autologous tumor killing activity, with no reactivity in LGL-depleted, small T lymphocytes. Significant lysis of autologous tumor cells was observed with effusion LGL from seven of ten untreated patients. Seven days after i.pl. OK432 injection, effusion LGL expressed enhanced cytotoxicity against autologous effusion tumor cells, whereas T cells were still not cytotoxic to autologous tumor cells on day 7. The frequency of LGL among effusion lymphocytes was not altered by i.pl. OK432. Adherent effusion cells were not involved in lysis of autologous effusion tumor cells in either untreated or OK432-treated patients. In vitro treatment of blood and effusion lymphocytes with OK432 induced an enhancement of autologous tumor-killing activity in patients who subsequently responded to i.pl. OK432 treatment. OK432 augmented in vitro autologous tumor killing activity of LGL, whereas T cells failed to lyse autologous tumor cells even after in vitro activation with OK432. These results indicate that i.pl. administration of OK432 to cancer patients will result in an augmentation of autologous tumor killing activity of LGL in the pleural effusions, and that this could be responsible for the antitumor activity of i.pl. OK432 therapy.

Natural cytotoxicity of lymphocytes from lymph nodes draining breast carcinoma and its augmentation by interferon and OK432

Lymphocytes isolated from axillary lymph nodes draining breast carcinoma were tested for natural killer (NK) activity against K562 in a 4-h 51Cr-release assay, and the in vitro effects of interferon (IFN) and OK432 (a streptococcal preparation) on their cytotoxicity were examined in comparison with NK activity of autologous peripheral blood lymphocytes (PBL). The levels of NK activity were lower in lymph node lymphocytes (LNL) than in PBL of the same patients. Significant levels of LNL-mediated lysis were recorded in 14 of 42 (33%) lymph node samples and in nine of 14 (64%) patients. Purification of large granular lymphocytes (LGL) from lymph node cells by discontinuous Percoll density gradient centrifugation resulted in an induction or enhancement of cytotoxic activity, with no reactivity in LGL-depleted, small T-lymphocyte populations. Positive reactions were observed with 10 of 13 (77%) LGL samples. The low reactivity of LNL was not attributable to coexistent suppressor cells for NK function, since lymph node cells failed to suppress NK activity of normal PBL. Partially purified human IFN and OK432 augmented NK activity of patients' PBL in approximately 70% and 90% of the cases, respectively, while LNL-mediated lysis was augmented in only 7% and 36% of the lymph node samples by IFN and OK432, respectively. These results indicate that K562-reactive NK cells and/or their precursors may frequently be present at subthreshold levels in the lymph nodes draining breast carcinoma, and that the augmentation of LNL-mediated cytotoxicity by OK432 might provide a local potentiation of natural immune function at the host-tumor interface rather than IFN.

Lysis of fresh human tumor cells by autologous peripheral blood lymphocytes and pleural effusion lymphocytes activated by OK432

Lymphocytes from peripheral blood (PBL) and from pleural effusions (PEL) of cancer patients were tested for cytotoxicity against tumor cells freshly isolated from carcinomatous pleural effusion of the same patient. Significant lysis of autologous tumor cells was recorded for 4 of 28 PBL samples and for 5 of 28 PEL cases when investigated in a 4-hour 51Cr release assay. In vitro treatment of lymphocytes for 20 hours with the streptococcal preparation OK432 resulted in an induction or augmentation of cytotoxicity against autologous tumor cells in 21 of 28 PBL and PEL specimens. OK432-induced cytotoxicity required active cell metabolism, RNA and protein syntheses, but not DNA synthesis of lymphocytes. Supernatants of OK432-stimulated lymphocytes, and interferon and interleukin 2 failed to induce autologous tumor killing. Nylon wool-nonadherent lymphocytes were involved in both spontaneous and OK432-induced lysis of fresh autologous tumor cells. OK432-activated lymphocytes from normal donors and cancer patients caused lysis of fresh allogeneic tumor cells and also K562 cells.

Lysis of fresh human tumor cells by autologous large granular lymphocytes from peripheral blood and pleural effusions

Human lymphocytes and their subpopulations from the peripheral blood and pleural effusions of cancer patients were tested for cytotoxicity against fresh tumor cells isolated from carcinomatous pleural effusions of the same patients. Fresh tumor cells were relatively resistant to lysis by autologous unseparated lymphocytes in a 4 h Cr-release assay. Positive reactions were recorded in 10 of 38 blood samples and 10 of 37 effusion specimens. Purification of large granular lymphocytes (LGL) by discontinuous Percoll gradient centrifugation resulted in enhancement of cytotoxic activity against autologous tumor cells and K562 cells, with no reactivity in LGL-depleted small T-lymphocyte populations. Significant lysis of effusion tumor cells by autologous LGL was observed in 15 of 22 blood specimens and 15 of 21 effusion samples. Further depletion of high-affinity sheep erythrocyte rosetting cells from Percoll-purified LGL populations gave an increase in autologous tumor-killing activity. Depletion of LGL/K562 conjugates from LGL populations decreased lysis of autologous tumor cells and K562 cells. Effusion tumor cells that were susceptible to lysis by allogeneic normal LGL were also killed by autologous LGL, and effusion tumor cells resistant to lysis by allogeneic NK cells were not lysed by autologous LGL. In a single-cell cytotoxicity assay in agarose, 4-26% LGL bound autologous tumor cells and 0.2-5% LGL killed these target cells, while 12-45% LGL bound K562 cells and 2-20% LGL lysed them. These results indicate that cytotoxic potential for autologous effusion tumor cells is present in the peripheral blood and pleural effusions of cancer patients; it is strongly associated with a minor proportion of LGL and restricted to the cell population that can lyse NK-sensitive K562 cells.

Intrapleural administration of OK432 in cancer patients: activation of NK cells and reduction of suppressor cells

Twelve patients with carcinomatous pleural effusions were treated with single intrapleural (i.pl.) administration of OK432 on day 0 and the effects of i.pl. OK432 on natural killer (NK) cell activity were followed on day 7. Two patients showed no clinical evidence of therapeutic benefit from i.pl. OK432. In the other 10 patients, pleural effusions and/or tumor cells in the effusions had decreased or disappeared by day 7. NK cell activity was markedly low or absent in pleural effusions of untreated patients due to the presence of adherent effusion cells capable of suppressing the maintenance and interferon-induced augmentation of NK cell activity. I.pl. injection of OK432 resulted in enhancement of NK cell activity and abrogation of NK suppressor cell activity in the effusions. On the other hand, blood NK cell activity was not consistently altered by i.pl. OK432. In vitro treatment of effusion mononuclear cells from untreated patients with OK432, but not with interferon, augmented NK cell activity. In addition, adherent effusion cells of untreated patients lost their NK suppressor function following in vitro OK432 treatment. These results suggest that i.pl. administration of OK432 will result in augmentation of NK cell activity and reduction of NK suppressor cell activity in pleural effusions, which could be responsible for the antitumor activity of i.pl. OK432.

Distribution of ultraviolet light irradiated mitochondrial genomes during meiosis in yeast

Clones derived from ascospores from ultraviolet irradiated diploid cells were examined for the genetic determinants or respiratory properties. Approximately 10% of the cells produced petites of mitochondrial origin at the dose applied. Among 13 asci which produced mitochondrial petites with high frequencies, 6 asci of uniparental type, 0 grandes : 4 petites, were observed. Furthermore, most of the petite spore clones from each individual uniparental ascus showed similar levels of suppressiveness and of mitochondrial gene retention. From these results it is suggested that a single mitochondrial genome participates meiosis in yeast.