Lymphoid cells mediating tumor-specific cytotoxicity to carcinoma of the urinary bladder. Separation of the effector population using a surface marker

Applicability of atomic force microscopy to determine cancer-related changes in cells

The determination of mechanical properties of living cells as an indicator of cancer progression has become possible with the development of local measurement techniques such as atomic force microscopy (AFM). Its most important advantage is a nanoscopic character, implying that very local alterations can be quantified. The results gathered from AFM measurements of various cancers show that, for most cancers, individual cells are characterized by the lower apparent Young's modulus, denoting higher cell deformability. The measured value depends on various factors, like the properties of substrates used for cell growth, force loading rate or indentation depth. Despite this, the results proved the AFM capability to recognize mechanically altered cells. This can significantly impact the development of methodological approaches toward the precise identification of pathological cells. This article is part of the theme issue 'Nanocracks in nature and industry'.

Gammadelta T cells: innately adaptive immune cells?

T cells employ a cell surface heterodimeric molecule, the T cell receptor (TCR), to recognize specific antigens (Ags) presented by major histocompatibility complex (MHC) molecules and carry out adaptive immune responses. Most T cells possess a TCR with an α and a β chain. However, a TCR constituted by a γ and a δ chain has been described, defining a novel subset of T cells. γδ TCRs specific for a wide variety of ligands, including bacterial phosphoantigens, nonclassical MHC-I molecules and unprocessed proteins, have been found, greatly expanding the horizons of T cell immune recognition. This review aims to provide background in γδ T cell history and function in mouse and man, as well as to provide a critical view of some of the latest developments on this still enigmatic class of immune cells.

Immunoregulation of human natural killer cells (NK) by corticosteroids: inhibitory effect of culture supernatants

Peripheral blood lymphocytes were separated into HNK-1+ and HNK-1- subpopulations and examined for the effects of prednisolone (PRD) on natural killer cell activities in vitro. Preculture of HNK-1+ lymphocytes with PRD (10(-6) to 10(-8) mol/L) for 72 hours resulted in a significant reduction of cytotoxic functions. When peripheral blood lymphocytes were first precultured with PRD and then separated into HNK-1+ and HNK-1- subpopulations, both could suppress the target binding and lytic activities of fresh large granular lymphocytes with the HNK-1+ cells demonstrating greater inhibition than the HNK-1- cells. Moreover, PRD-treated cells demonstrated greater suppression of target binding and cytotoxicity than identical subpopulations cultured without PRD. Culture supernatants of lymphocytes treated with 10(-6) to 10(-9) mol/L concentrations of PRD contain PRD-induced soluble suppressor factor that significantly inhibited the natural killer activity of allogeneic lymphocytes against different targets. PRD-induced soluble suppressor factor was not cytotoxic itself, and suppression was evident at various effector-to-target cell ratios. These studies indicate that in addition to being directly immunosuppressive, corticosteroids may also induce immunoregulatory lymphocytes to secrete a suppressive lymphokine.

Enhancement of chemically induced bladder carcinoma by cyclosporin A

The effects of cyclosporin A (CsA) on the induction of bladder carcinoma were investigated in Wistar rats using N-butyl-N (4 hydroxybutyl) nitrosamine (BBN) as a known initiator of carcinogenesis. Rats treated with 0.05% BBN + 5 mg/kg per day CsA or 0.05% BBN + 12.5 mg/kg per day CsA developed a dose-dependent (two to fourfold) enhancement of bladder tumor expansion and infiltration as compared to those treated with 0.05% BBN alone. In control rats receiving CsA at doses of 5 mg/kg per day or 12.5 mg/kg per day, no bladder carcinoma occurred. All CsA-treated groups, with or without 0.05% BBN, displayed slight or moderate medullary atrophy of the thymus. The results indicate that immunosuppression with CsA enhances the induction of bladder tumors by BBN. Furthermore, the immunosurveillance theory that effective expression of the immune response may be important in the control of tumor development was confirmed in the carcinogenesis of epithelial cell tumors.

Decreased natural and antibody-dependent cellular cytotoxic activities in intravenous drug abusers

Peripheral blood lymphocytes from 14 adult male patients admitted to the hospital with complications of intravenous drug abuse (IDA) were examined for natural killer (NK) and antibody-dependent cellular cytotoxic (ADCC) activities, lectin-dependent cellular cytotoxicity, and interferon (IFN)- and interleukin 2 (IL-2)-induced NK activity. Serum was also assayed for circulating interferon levels and soluble factor(s) capable of suppressing the cytotoxic potential of allogeneic lymphocytes from healthy donors. IDA patients demonstrated significantly decreased levels of NK and ADCC activities compared to age- and sex-matched healthy controls. The lectin, phytohemagglutinin, could significantly enhance the cytotoxicity of IDA lymphocytes; however, activity was not completely restored to normal levels. IDA sera demonstrated a significant inhibitory effect on the NK and ADCC activities of normal allogeneic lymphocytes, and these sera contained negligible levels of circulating IFN. Although the NK activity of IDA lymphocytes could not be restored completely to normal levels by either IFN-alpha or IL-2, the percentage enhancement of cytotoxicity was remarkably higher in IDA patients with significantly reduced NK activity than that observed using PBL from patients with near normal NK activity. The ability of IFN or IL-2 to enhance the decreased cytotoxicity of PBL from drug abusers suggests a novel therapeutic approach to the management of the complications of IDA.

Association of decreased T-cell-mediated natural cytotoxicity and interferon production in Down's syndrome

Total peripheral blood lymphocytes (PBL) and isolated subpopulations from children with Down's Syndrome (DS) and age-matched healthy controls were investigated for their (1) natural killer (NK) and antibody-dependent cellular cytotoxic activities, (2) interleukin 2 (IL-2)-induced augmentation of NK activity, (3) lectin-dependent cellular cytotoxicity (LDCC), (4) ability of serum- and culture-derived soluble suppressor factor(s) to inhibit NK activity of normal lymphocytes, and (5) capacity to produce interferon (IFN) against tumor targets in vitro. T lymphocytes from DS patients demonstrated significantly decreased NK activity against K562 target cells compared to controls. DS lymphocytes also demonstrated a significant reduction in LDCC activity and IL-2-induced enhancement of NK activity. Furthermore, the ability of DS lymphocytes to produce IFN in vitro against K562 target cells was also significantly lower than that for normal PBL. Although sera from DS patients showed a significantly greater inhibitory effect on the NK activity of allogeneic normal PBL than normal sera, culture supernates from DS lymphocytes demonstrated suppressive effects comparable to culture supernates from normal PBL. These studies suggest an association between the decreased NK activity of T-cell subpopulations and lower IFN production by PBL from patients with DS.

Effect of histamine and histamine antagonists on natural and antibody-dependent cellular cytotoxicity of human lymphocytes in vitro

The in vitro effect of histamine and its antagonists, cimetidine and clemastine fumarate, on natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities of human lymphocytes was investigated. The histamine 1 (H1) antagonist, clemastine fumarate, and the histamine 2 (H2) antagonist, cimetidine, but not histamine alone, inhibited the NK and ADCC activities of lymphocytes when added directly to the mixture of effector and target cells in a 51Cr-release assay. This inhibition was proportional to the concentration of drugs added and was observed at various effector to target ratios against several targets. H1 and H2 antagonists also inhibited NK activities of T cells as well as Percoll-separated, NK-enriched effector cells. The inhibition was significantly reversed by histamine. In target binding assays, clemastine fumarate and cimetidine also decreased the target binding capacity of effector lymphocytes. Further, PBL precultured with histamine (10(-3)-10(-4) M) for 24 hr showed a significant decrease in their NK and ADCC activities. In coculture experiments, PBL precultured with histamine suppressed the NK activity of normal autologous effector lymphocytes. PBL precultured with histamine showed an increased number of OKT8+ cells, as estimated using monoclonal antibodies. The suppression of cytotoxicity was not due to either direct toxicity, steric hindrance, crowding, or cell death, but by functionally viable suppressor cells. An immunoregulatory role for histamine in NK and ADCC reactions is proposed.

Keyhole-limpet haemocyanin (KLH) immunotherapy of murine transitional cell carcinoma

The antigenicity of transitional cell carcinoma of the bladder has stimulated the search for effective immunotherapeutic agents in the treatment of this disease. Non-specific immunotherapy with local (intravesical/intralesional) and systemic Keyhole Limpet Haemocyanin (KLH) in a FANFT induced murine bladder tumor model was studied. Results showed no difference between control or treated groups in either tumor growth or animal survival.

Expression of the cellular immune response during tumor development in an animal model of bladder cancer

Papillary and solid transitional cell cancers were induced in the bladders of Fischer rats by ingestion of the carcinogen N-[4-(5-nitro-furyl)-2-thiazolyl] formamide. At sequential regular intervals, purified splenic, peripheral blood, regional lymph node, and thymus lymphocytes were harvested from tumor-bearing and age-matched control animals and tested for cytotoxicity against a variety of cell lines. Lymphocytes were also tested in mixed lymphocyte cultures for blastogenesis. Tumor development was accompanied by decreased lymphocyte cytotoxicity against bladder tumor targets at each interval tested. This decrease was in addition to the age-related decrease in cytotoxicity expressed by lymphocytes from control animals. No corresponding differences were seen in lymphocyte subpopulations as determined by immunofluorescence or in lymphocyte blastogenesis. Suppressor cell activity in tumor-bearing animals could not be demonstrated, and no cause-effect relationship between cytotoxicity depression and tumor development in these experiments was apparent.

Effector cells in natural cytotoxicity against human bladder cancer cell lines

Human peripheral blood mononuclear cells obtained by ficoll-hypaque sedimentation were depleted of Fc-receptor-bearing (FcR+) cells. Cytotoxicity (direct killing of target cells by effector cells), tested in a 40 h assay, was significantly decreased against a variety of target cells. Tests in which no FcR+ cells could be detected were also positive for "natural killing" (NK) against a spectrum of target cells from normal donors. NK in this system was mediated by more than one subpopulation of lymphocytes. Monocytes probably did not play a significant role. Decreasing the FcR+ cells in peripheral blood mononuclear cells in patients with bladder cancer and in controls did not reveal specific antitumor activity.

BCG immunotherapy of bladder cancer: inhibition of tumor recurrence and associated immune responses

Fifty-one patients with confirmed bladder cancer have enrolled in a prospective evaluation of BCG immunotherapy. Following resection of existing tumors, patients were stratified according to tumor grade and number of previous recurrences and randomly assigned to control or BCG treatment groups. Immunotherapy consisted of six weekly administrations of Pasteur strain BCG using 120 mg intravesically and 5 mg percutaneously. Immunotherapy side effects were minimal and no patient required postponement of BCG treatments. Eleven control (46%) compared with five (22%) BCG-treated patients had tumor recurrence (P = 0.078, chi 2). Prolongation of the disease-free interval with BCG treatment was significantly at the P = 0.016 level by Wilcoxon analysis. Four control and two BCG-treated patients had multiple recurrences. Comparing total episodes of recurrence, nineteen of 79 (24%) control and eight of 85 (7%) BCG group cystoscopic examinations revealed tumor (P = 0.006, chi 2). Immunologic correlates of response to immunotherapy were not statistically significant since only five BCG-treated patients had tumor recurrence. However, four of these five patients evidenced impaired LIF response to PPD at the time of tumor recurrence, and impairment of skin test reactivity and BCG humoral antibody response were more commonly seen in this subgroup of patients.

Antibody-dependent cellular cytotoxicity in recurrent aphthous ulceration

Antibody-dependent cellular cytotoxicity (ADCC) was investigated as s possible mechanism of pathogenesis in recurrent aphthous ulceration (RAU). ADCC induced by mononuclear cells from patients at various stages of RAU was compared with ADCC induced by mononuclear cells from paired controls. Chicken red blood cells (ChRBC) coated with rabbit anti-ChRBC antibody were used as targets. A significant increase in ADCC (P less than 0.01, paired sample t-test) in patients' samples as compared with controls was found only at the early stage of the disease. No increased cytotoxicity over control values was observed at any other single stage of the disease. The transient increased cytotoxicity observed in the early stage of RAU may reflect a number of possible mechanisms, including an increased number of ADCC effector cells only at the early stage, an increase in Fc receptor avidity, or an increase in efficiency of the existing effector cell population.

The undefined relationship between tumor antigens and histocompatibility antigens on cancer cells

The data pertaining to the possible relationship between histocompatibility antigens (HA) and tumor-specific transplantation or tumor surface antigen (TSTA or TSA) are reviewed. The HA profiles of certain experimental and human neoplasms have been found to be altered either from the quantitative (increased expression of some antigenic specificities and decreased expression or even lack of other HA) or qualitative point of view (appearance of alien, genetically inappropriate HA). The authors entertain the possibility that the persence of TSTA or TSA on cancer cells may be linked to alterations of the HA profile. Evidence in favour of the idea that tumor antigens may actually to alien MHC products, alien minor HA or modified HA, is reviewed. Findings on structural relationships between TSA and beta2-microglobulin are also summarized. In the authors' opinion, no definitive conclusions can be reached at the present time on the relationship between TSTA or TSA and HA of cancer cells.

Bacillus Calmette-Guerin immunotherapy of superficial bladder cancer

Thirty-seven patients were enrolled in a randomized prospective study to compare standard surgical therapy for superficial bladder cancer to standard therapy plus bacillus Calmette-Guerin (BCG). Side effects of BCG have been tolerated well and include dysuria in 95 per cent of the patients, urinary frequency in 83 per cent, hematuria in 39 per cent, fever in 22 per cent and nausea in 22 per cent. Of 19 control patients 8 (42 per cent) had recurrent tumors in the followup period, compared to 3 of 18 patients (17 per cent) treated with BCG. One patient treated wih BCG had 2 recurrences, yielding a recurrence rate of 22 per cent in the group receiving BCG compared to 42 per cent in controls. When the incidence of recurrent tumors in matched intervals before and after entry into the protocol is compared, no change in the rate of tumor recurrence (p equals 0.726 chi-square) occurred in controls, whereas tumor recurrences were reduced significantly in the group treated with BCG (p equals 0.010 chi-square). The reduction in tumor recurrence in patients treated with BCG compared to controls is statistically significant (p equals 0.029 chi-square). Of 4 patients who presented with new bladder tumors remain free of tumor after BCG therapy, while 2 of 5 comparable control patients developed recurrent tumors. Intravesical and percutaneous BCG immunotherapy appears to decrease the rate of tumor recurrence in patients followed for 1 year.

Antibody-dependent lymphocyte cytotoxicity against basic protein of myelin in multiple sclerosis

An antibody was demonstrated in the serum of 166 out of 200 patients with MS which enabled normal lymphocytes to develop a cytotoxic (ADLC) reaction against MBP. The ADLC correlated with the stage of the process and was positive in 94% of those with active and in 62% of those with inactive disease independent of the type--relapsing or chronic progressive--and of the severity of the disease. Control studies in 200 patients with other organic nervous complaints gave positive findings in patients with carcinoma (7.5%), in rheumatoid arthritis (10-15%) and in syphilis (30%). On the ground of its good specificity and the frequency of positive findings, the reaction may be of diagnostic significance. In 55 of 57 CSF samples investigated in MS, the ADLC was positive. The intensity of the cytotoxicity in serum and CSF is practically identical. This finding supports the pathogenetic significance of the ADLC against MBP although it has no validity as a primary aetiological factor.

In vitro lymphocyte activity: its relation to the stage of gastric cancer

Lymphocyte activity of patients with gastric cancer and its relation to the stage of cancer were studied. PHA response of lymphocytes from patients with gastric cancer was decreased markedly even in early stage of cancer. The PHA-stimulated lympho-cytotoxicity was not impaired in all stages of the disease. Spontaneous lymphocyte-mediated cytotoxicity showed a tendency to decrease as the cancer stage advanced. The cytotoxic activity of the supernatants from lymphocytes cultured without PHA was significantly high in the advanced stage of gastric cancer.

Immunological evaluation of a streptococcal preparation (OK-432) in treatment of bladder carcinoma

When 21 patients with bladder cancer (transitional cell carcinoma) were given local and systemic injections of a streptococcal preparation, OK-432, tumor regression was observed in 3 cases (14.3%). The marked infiltration of lymphocytes observed on histological examination of regressed tumors suggested that a host-mediated action was involved in the antitumor effect of OK-432.

Selective decrease in antibody-dependent cell-mediated cytotoxicity in systemic lupus erythematosus and progressive systemic sclerosis

With the use of two target cells (chicken erythrocytes and Chang cells), the antibody-dependent cell-mediated cytotoxicity (ADCMC) of peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE) and progressive systemic sclerosis (PSS) was studied. Patients with active SLE had a significant reduction in ADCMC against Chang cells whereas cytotoxicity against chicken erythrocytes did not differ significantly from that of a control population. Similarly, a group of PSS patients with positive anti-DNP antibodies demonstrated a selective reduction in ADCMC against Chang cells. These findings support the concept that different effector cells mediate ADCMC against chicken erythrocytes and Chang cells, and indicate that in some patients with SLE and PSS there is a selective reduction or blockade of the ADCMC effector cell active against Chang cells.

Heterogeneity of human lymphocyte Fc receptors. II. Relationship to antibody-dependent, cell-mediated cytotoxicity

Human peripheral blood lymphocytes (PBL) were incubated (stripped) with pronase or papain and compared with unstripped lymphocytes for their ability to mediate antibody-dependent, cell-mediated cytotoxicity (ADCC). Despite marked removal or inactivation of receptors for heat-aggregated IgG (aggG) by proteolytic digestion, and pronounced changes in the percentages of cells rosetting with IgG-sensitized erythrocytes (EA) (decreased by papain, increased by pronase), stripped PBL functioned normally in ADCC.

Stripped and unstripped lymphocytes were pre-treated with aggG to determine the role of aggG receptors in ADCC. AggG almost totally abolished ADCC by unstripped PBL, but inhibited ADCC by enzyme-stripped lymphocytes relatively poorly. Neither untreated nor stripped PBL were able to induce cytotoxicity of chicken erythrocyte (CRBC) target cells sensitized with the Fab'₂ fragment of anti-CRBC IgG antibody (CRBC-A).

Exposure of PBL to EA monolayers composed of CRBC-A or of sheep erythrocytes (SRBC) sensitized with rabbit anti-SRBC IgG antibody (SRBC-A) depleted PBL of cells that rosetted with CRBC-A and with human Rh-positive, type O erythrocytes sensitized with the human anti-Rh serum Ripley (HRBC-A Ripley). Non-adherent cells were incapable of binding aggG and had markedly diminished cytotoxicity in ADCC. Similarly, exposure of PBL to HRBC-A Ripley monolayers resulted in non-adherent cells that were incapable of rosette formation with HRBC-A or CRBC-A, failed to bind aggG, and exhibited significantly diminished ADCC activity.

These studies indicated that: (1) cytotoxic effector PBL active in ADCC (K cells) have receptors for aggG and for EA; (2) PBL deficient in functional aggG receptors (enzymatically inactivated or removed) are capable of inducing normal levels of ADCC; (3) aggG and EA receptors appear to be closely associated on native K-cell membranes; (4) there is no clear-cut relationship in a given lymphocyte population between the presence of either aggG or EA receptors and ADCC activity; and (5) populations of PBL binding HRBC-A Ripley overlap with, and may be identical to, those binding aggG and other types of EA complexes.

Ultrastructure, karyology and immunology of a cell line originated from a human transitional-cell carcinoma

A cell line (J82) was derived from a poorly differentiated, invasive, transitional-cell carcinoma, Stage T3. The cells have been propagated in vitro for 5 years and showed 100% aneuploidy and a mixed epithelial-fibroblastic morphology. The majority of cells contained 2Y chromosomes and several distinctive markers. Peripheral-blood lymphocytes from the donor of the J82 cells were tested sequentially for cytotoxicity toward autologous and allogeneic tumour cells. Autologous cytotoxicity was detected against J82 cells in early in vitro passage. Allogeneic lymphocytes from some patients with transitional-cell carcinoma were also cytotoxic to J82 cells in primary culture. However, selective cytotoxicity by lymphoid cells from bladder-carcinoma patients was not detected against J82 cells in long-term tissue culture.

Differences in pathological characteristics and prognosis of clinical A2 prostatic cancer from A1 and B disease

A retrospective study was done of 53 cases of clinical stages A1 to B2 prostatic carcinomas staged by pelvic lymphadenectomy. The study compared the histologic differentiation, degree of lymphocytic infiltration, incidence of lymph node metastases and type of cellular response of clinical stage A2 to stages A1 and B disease. The available data pertaining to the incidence and survival of patients with stage A2 prostatic carcinoma were analyzed. Our study indicates that 1 of every 3 unsuspected carcinomas is of clinical stage A2. The stage A2 tumors are diffused, with a higher degree of undifferentiation and a higher incidence of lymph node metastases than tumors classified clinically as stages A1 and B1. Also the survival of patients with clinical stage A2 tumors is lower than the survival of patients with clinical stage B1 disease. Clinical stage A2 tumors are more advanced biologically than clinical stage B1 tumors.

Lymphocyte response to transitional cell carcinoma: peripheral cytotoxicity and local tumor infiltration

The cytotoxicity of peripheral lymphocytes from patients with transitional cell carcinoma was evaluated and the results were compared to the degree of local lymphocytic infiltration in the bed of the primary tumor. Although a clear correlation was not established local lymphocytic infiltration was associated more commonly with tumor-related peripheral lymphocyte cytotoxicity.

Lymphocyte function and response to chemo-immunotherapy in patients with metastatic melanoma

Thirty-eight patients with metastatic melanoma were investigated for lymphocyte function immediately prior to chemo-immunotherapy. The pre-treatment immune tests were compared with normal control values and with response to therapy. The "non-responder" group (but not "responder") had significantly reduced values for lymphocyte, null-cell and E-rosette-cell counts compared with controls. Lymphocytoxicity ( using a Chang target cell) showed the same pattern, with depression of direct and K-cell cytotoxic capacity in non-responders compared with controls. Eight patients were studied sequentially whilst on treatment, and demonstrated considerable change (not statistically significant) in lymphocytotoxicity, an untreated "control" patient showed little variation. "Recall"-antigen skin testing showed no statistically significant difference between the patient groups. The data indicate that "non-T-cell activity" may be associated with response to chemo-immunotherapy.

Detection of carcinoembryonic-like antigen on melanoma cells by leucocyte-dependent-antibody assays

CEA-like antigen has been detected on the surface of some melanoma cells using a rabbit antiserum raised against CEA antigen in 51Cr-release leucocyte-dependent cytotoxic-antibody (LDA) assays. The CEA antigen used for production of the antiserum was shown to be immunologically pure by immunoelectrophoresis procedures and reacted with a reference serum to CEA. The specificity of the CEA antiserum for CEA on the melanoma cells was further shown by removal of reactivity to melanoma cells after absorption on CEA affinity columns. LDA activity to CEA was also shown in a serum taken during pregnancy. No CEA LDA activity was found in several melanoma sera. These findings suggest that CEA may have biological significance in tumour rejection, and that CEA assays may be of value in monitoring disease activity in melanoma patients.

Lack of specificity of lymphocyte-mediated cytotoxicity against the bladder cancer cell line, T24

We evaluated in vitro lymphocyte-mediated cytotoxicity against the T24 transitional carcinoma cell line and a control melanoma cell line (H894) in a double-blind study involving 25 bladder cancer patients, 19 patients with non-transitional carcinoma and 9 patients with benign conditions using a tritiated proline-labeled tumor cell assay. We found selective reactivity against T24 cells in 16 per cent of bladder cancer patients, 11 per cent of patients with non-transitional cell tumors and 22 per cent of patients with benign conditions. We found no significant differences with respect to the patterns of cytotoxic reactivity among the various patient groups. The use of different methods of lymphocyte purification and different lymphocyte to target cell ratios did not enhance the degree of specificity observed. Prior exposure to alloantigens did not account for the lack of specificity.

Cryopreservation of immunological memory and other lymphoid cell functions

The following components of the immune response by mouse spleen cells were retained after cryopreservation at --110 degrees C: direct and indirect plaque formation, avidity of antibody secreted by plaque forming cells, and induction of primary or secondary adoptive transfer responses. Human peripheral blood lymphocytes retained the capacity to mediate antibody-dependent cytotoxicity and cell mediated immunity to tumor in vitro.

Blocking factors against leucocyte-dependent melanoma antibody in the sera of melanoma patients

Previous studies, using plasmapheresis to remove blocking factors of cell-mediated cytotoxicity to melanoma cells from the circulation of melanoma patients, suggested that leucocyte-dependent antibody to melanoma cells may also be blocked by factors in their sera. The present study confirms these findings, by showing that most patients with disseminated melanoma had melanoma LDA activity in the IgG fraction when this was separated from their sera. This also applied to a high percentage of patients with primary melanoma. Evidence that the blocking factors may be immune complexes was shown by experiments in which LDA activity to melanoma cells was revealed after acidification of melanoma sera to dissociate immune complexes, followed by ultrafiltration through membranes retaining molecules of size greater than 100,000 daltons. Blocking of LDA activity in the retentate recurred when the retentate was recombined with the filtrate. Further studies indicated that the blocking activity showed affinity for the target cell and not the effector cell. Preliminary analysis of the specificity of the blocking suggests that this was similar to that of melanoma antisera. These results appear to show that blocking of LDA activity to melanoma cells is common in melanoma patients and that the assay system may provide a quantitative method for their analysis that may yield information of biological importance in the management of melanoma patients.

Commentary on the immunobiology of bladder cancer

This review is an attempt to integrate the conflicting studies that constitute the literature on immunobiology of bladder cancer and to indicate areas that need further investigation. It is clear that immune reactivity directed at antigens expressed on bladder cancer cells and general host immunologic competence decline with progressive tumor growth. This immunodepression correlates with patient prognosis, even within a given stage of disease. The mechanisms underlying this decline in host immune reactivity are poorly understood. A better understanding of these mechanisms may provide fundamental insight into the host-tumor relationship that possibly could be exploited for preventive, diagnostic and therapeutic purposes.

Influence of surgery and dexamethasone on cell-mediated immune responses in patients with meningiomas

Cell-mediated cytotoxicity (CTX) was studied in meningioma patients before and within 2 weeks of complete excision of the tumour, using the [3H]-prolin- microcytotoxicity test. Three of 7 patients tested before surgery showed specific CTX, 2 revealed a "non-specific" (tumour-unrelated) response, and 2 were non-reactive. After surgery, CTX decreased from 84 to 50% in one patient and became negative in 2 others previously positive. One of 2 patients showing "non-specific" CTX preoperatively became positive, while the other remained unchanged. All patients were receiving dexamethasone (DXM) at the time they were tested. Lymphocyte responses to PHA were not significantly different before or after surgery (i.e. after prolonged treatment with DXM), from healthy controls. Blocking activity could be detected in the sera of all 3 patients before surgery. This activity was not specific for meningiomas. Paradoxically, the same sera did not inhibit the proliferative response to PHA. Serum from only one patient consistently suppressed the blastogenic response of homologous lymphocytes to PHA. Inhibitory activity was associated with the IgG fraction of his serum.

A 51chromium isotope release assay for detecting cytotoxicity to human bladder carcinoma

A 51chromium isotope release assay is described for measuring in vitro cytotoxicity reactions against allogenetic target cells. Lymphoid cells from some patients with localized transitional cell carcinoma (TCC) were shown to selectively lyse targets derived from two long-term cell lines of TCC. The effector cells in this reaction did not form E rosettes. Cytotoxicity was successfully recovered after cryopreservation.

Evaluation of the effect of ammonium chloride treatment on the activity of human effector cells in antibody-dependent and spontaneous cell-mediated cytotoxicity

The effect of ammonium chloride treatment, used to eliminate contaminating red blood cells from lymphoid cell preparations, on the cytotoxic activity of human effector cells in antibody-dependent and spontaneous cell-mediated cytotoxicity was quantitatively determined. No significant difference between the cytotoxic efficiency of treated and untreated cell preparations was observed.

A cell line from an anaplastic transitional cell carcinoma of human urinary bladder

A cell line, TCCSUP, derived from an undifferentiated, Grade IV transitional cell carcinoma is described. The karyotype showed an abnormal distribution of chromosomes, with no obvious modal number. Distinct marker chromosomes were observed in both early and late in vitro passages. These cells have been subcultured over 50 times during a 20-month period. TCCSUP differs in certain morphological and immunological features from other cell lines from transitional cell carcinomas.