Antigenic cancer cells that escape immune destruction are stimulated by host cells

Cancers induced by UV light in murine skin often regress completely when transplanted into normal syngeneic recipients and grow progressively only in T-cell-deficient hosts. Heritable cancer variants that grow progressively and kill normal mice occasionally evolve in vivo. It is surprising that most of these variants appear to retain their antigenicity and immunogenicity. We have compared three such variants (4102-PRO, 6132A-PRO, and 6134-PRO) with the parental tumors to determine why the variants acquired progressive phenotypes without antigen loss. We found that all three variants grew substantially faster than the parental tumors in T-cell-deficient hosts; one variant, 6132-PRO, also grew faster in vitro. Furthermore, the growth of all of the variants was stimulated by soluble factors released by tumor-induced peritoneal exudate cells, and all attracted more leukocytes than the parental cells. Finally, pretreatment of mice with antigranulocyte antibody reduced the growth of variant but not parental 4102 and 6134A tumor cells. The treatment reduced the growth of both the parental and the variant 6132A lineage cells. We found no evidence for acquired resistance of variant tumors to immune destruction by a host defense mechanism. The parental cells did not grow faster in beige nude mice deficient in natural killer and alpha beta T cells or in SCID mice deficient in B and T cells. The variant parental cells had a similar sensitivity to lysis by polyinosinic-polycytidic acid-induced natural killer cells or thioglycolate- and LPS-induced macrophages. Together, our results are consistent with the notion that these variants escape from immune destruction in vivo by attracting leukocytes that stimulate tumor cell growth.

Synergy between T-cell immunity and inhibition of paracrine stimulation causes tumor rejection

During tumor progression, variants may arise that grow more vigorously. The fate of such variants depends upon the balance between aggressiveness of the variant and the strength of the host immunity. Although enhancing host immunity to cancer is a logical objective, eliminating host factors necessary for aggressive growth of the variant should also be considered. The present study illustrates this concept in the model of a spontaneously occurring, progressively growing variant of an ultraviolet light-induced tumor. The variant produces chemotactic factors that attract host leukocytes and is stimulated in vitro by defined growth factors that can be produced or induced by leukocytes. This study also shows that CD8+ T-cell immunity reduces the rate of tumor growth; however, the variant continues to grow and kills the host. Treatment with a monoclonal anti-granulocyte antibody that counteracts the infiltration of the tumor cell inoculum by non-T-cell leukocytes did not interfere with the CD8+ T-cell-mediated immune response but resulted in rejection of the tumor challenge, indicating a synergy between CD8+ T-cell-mediated immunity and the inhibition of paracrine stimulation.

Cerebral magnetic resonance imaging pathology and cerebro-spinal fluid protein in sporadic amyotrophic lateral sclerosis (sALS)

In 3 out of 20 patients with sporadic amyotrophic lateral sclerosis (sALS), cranial magnetic resonance imaging detected multiple demyelinating lesions. All 3 patients died from definite upper and lower motor neuron degeneration. In all 3 cases total cerebro-spinal fluid (CSF) protein remained within normal ranges, and a blood-CSF barrier dysfunction was not detectable. In one of the patients multifocal CNS demyelination coincided with an intrathecal synthesis of immunoglobulin-G and autochthonous CSF oligoclonal IgG banding (OCB) early in disease. Neither absolute or age-corrected survival nor disease progression differed for patients with and without cerebral MR lesions, or normal vs. elevated CSF total protein. Evaluating the CSF in an extended patient sample (n = 29), we found the total CSF protein elevated in 5 of 16 men and none of 13 women (p < 0.05). The mean age-corrected CSF protein content [practical reference limit = (age x 3.3) + 300 mg/l] was higher in male (465 mg/l +/- 32 SE) than in female (350 mg/l +/- 26 SE) sALS patients (p < 0.01). This coincides with a male preponderance in sALS.

NMR cross-relaxation investigated by molecular dynamics simulation: a case study of ubiquitin in solution

A one nanosecond molecular dynamics simulation of ubiquitin in solution has been used for the calculation of the total dipolar, the radial and the reorientational correlation functions of 174 interproton NOEs and the 76 peptide chain NH vectors. The NOEs have been classified according to the structural elements they are associated with. Using multiexponential fits of the raw data spectral densities and cross-relaxation rate constants have been determined. Statistical distributions of correlation function parameters are given. On the basis of these data the assumptions underlying the standard method for distance measurement using NOE enhancements have been scrutinized. The separability of elongation and reorientation is verified for the vast majority of NOEs, but the rigid-body assumption is not supported by the simulation results. Relying on a spectral density expression that neither makes use of the product approximation nor neglects spatially restricted motion, a "bias-free" (with regard to molecular motion) distance measurement method is suggested and compared with the standard method. Errors in distances up to 24% and 50% occur due to the neglect of the dispersion of order parameters and correlation times, respectively. The preconditions for a class-specific calibration method have been investigated. Within the framework of the product approximation a method for decomposing the total cross-relaxation rate constant into contributions from radial and angular motion has been developed and applied. In several cases distance fluctuation contributes significantly to cross-relaxation with both amplitude and time behaviour.

Improved event-related potential signs of selective attention after the administration of the cholecystokinin analog ceruletide in healthy persons

Cholecystokinin (CCK) is co-localized with dopamine (DA) in neurons of the mesolimbic-frontocortical dopamine (DA) system, considered essential for the pathology of psychotic behavior and associated attention deficits. The present experiments in 13 healthy men aimed at examining the effects of the CCK analog ceruletide on attention as reflected by event-related brain potentials (ERPs). Subjects were tested according to a double-blind cross-over design on three occasions, following intravenous infusion of placebo, 0.5 microgram ceruletide, and 2.5 micrograms ceruletide. ERPs were recorded during the subject's performance on an auditory selective attention task including the concurrent presentation of frequent standard tones and infrequent deviant tones which the subject had to listen to, or to ignore. The processing negativity (PN) over frontocentral cortical areas, reflecting selective attention, was higher after ceruletide than placebo, this increase being most pronounced after the 2.5 micrograms dose (placebo -1.29 +/- 0.38 microV versus ceruletide -3.02 +/- 0.65 microV, p < .05). ERP signs of a general increase in cortical arousal after ceruletide did not reach significance. Likewise, mismatch negativity, an indicator of preattentive processing of stimulus deviance, was not significantly affected by the peptide. The results indicate that ceruletide affects human brain function primarily by improving selective attention.

[Effectiveness of home ventilation of young children and infants]

BACKGROUND

The home care ventilation of patients with chronic respiratory insufficiency is a well-established method. In treating infants and newborns a lot of problems arise that deal with indication, prognosis and management.

PATIENTS AND METHODS

We investigated 7 newborns and infants with chronic respiratory insufficiency after cervical spine trauma causing "pentaplegia" or due to inherited neuromuscular disorders (spinal muscular atrophy, myopathy) during homecare ventilation.

RESULTS AND DISCUSSION

In contrast to experience with adults the management of the children with "pentaplegia" was relatively harmless. All were tracheostomized primarily, but 1 tracheostomy could be closed, because the patient finally achieved to be ventilated only during night-time in the iron lung. The 3 children with neuromuscular diseases were ventilated noninvasively by specially fitted nasal masks. Despite coming to the frontiers of feasibility, and taking into account the psychological stress for patients, relatives, doctors and nurses, satisfactory results were obtained.

Comparative assessment of saccadic eye movements, psychomotor and cognitive performance in schizophrenics, their first-degree relatives and control subjects

This study is aimed at detecting biological markers for schizophrenia. For this purpose, a total of 70 subjects (21 schizophrenic patients, 27 first-degree relatives and 22 controls) performed a series of tests assessing various attentional, psychomotor and cognitive functions and saccadic eye movements. The schizophrenics performed significantly poorer than both high-risk and control subjects in most of the tests demanding attention, concentration and psychomotor speed (d2 concentration test, reaction times and Stroop test of perceptual interference) as well as cognition (Wechsler intelligence scales). On the other hand, these tests did not differentiate between the high-risk and control subjects. This distinction, however, could be made by two other parameters: hypometria score of saccadic eye movements and ratio of verbal to performance intelligence scores. Both parameters were significantly increased in both the schizophrenic and the high-risk group, distinguishing both from the control group. The relevance of these findings in indicating a schizophrenic disposition is discussed.

Changes in ascorbate peroxidase activities during fruit ripening in Capsicum annum

The ascorbate peroxidase (APX) system was studied in Capsicum annum during fruit ripening. A large increase in organelle APX activity was found during chloroplast-chromoplast transition whereas only a slight difference was detected in total fruit extracts. On native gels, four different isoforms were found in total fruit extracts but the patterns for red and green fruit were quite different. In isolated organelles, six isozymes were found and a comparison of the patterns showed significant differences. A cDNA encoding a cytosolic APX was cloned and sequenced. The corresponding transcript was shown to increase 3-4-fold during fruit ripening.

A unique tumor antigen produced by a single amino acid substitution

Mice immunized against a cancer recognize antigens unique to that cancer, but the molecular structures of such antigens are unknown. We isolated CD4+ T cell clones recognizing an antigen uniquely expressed on the UV-induced tumor 6132A; some clones inhibited the growth of tumors bearing the specific antigen. A T cell hybridoma was used to purify this antigen from nuclear extracts by RP-HPLC and SDS-PAGE using T cell immunoblot assays. A partial amino acid sequence was nearly identical to a sequence in ribosomal protein L9. The cDNA sequence of L9 from 6132A PRO cells differed from the normal sequence at one nucleotide; this mutation encoded histidine instead of leucine at position 47. A synthetic peptide containing this mutation was over 1000-fold more stimulatory of T cells than was the wild-type peptide. These results indicate that this unique tumor antigen is derived from a single amino acid substitution in a cellular protein.

Inhibition of tumor growth by elimination of granulocytes

As observed for many types of cancers, heritable variants of ultraviolet light-induced tumors often grow more aggressively than the parental tumors. The aggressive growth of some variants is due to the loss of a T cell-recognized tumor-specific antigen; however, other variants retain such antigens. We have analyzed an antigen retention variant and found that the variant tumor cells grow at the same rate as the parental tumor cells in vitro, but grew more rapidly than the parental cells in the T cell-deficient host. The growth of the variant cells was stimulated in vitro by factors released from tumor-induced leukocytes and by several defined growth factors. In addition, the variant cancer cells actually attracted more leukocytes in vitro than the parental cells. Furthermore, elimination of granulocytes in vivo in nude mice by a specific antigranulocyte antibody inhibited the growth of the variant cancer, indicating that this tumor requires granulocytes for rapid growth.

Inhibition of tumor growth by elimination of granulocytes

As observed for many types of cancers, heritable variants of ultraviolet light-induced tumors often grow more aggressively than the parental tumors. The aggressive growth of some variants is due to the loss of a T cell-recognized tumor-specific antigen; however, other variants retain such antigens. We have analyzed an antigen retention variant and found that the variant tumor cells grow at the same rate as the parental tumor cells in vitro, but grew more rapidly than the parental cells in the T cell-deficient host. The growth of the variant cells was stimulated in vitro by factors released from tumor-induced leukocytes and by several defined growth factors. In addition, the variant cancer cells actually attracted more leukocytes in vitro than the parental cells. Furthermore, elimination of granulocytes in vivo in nude mice by a specific antigranulocyte antibody inhibited the growth of the variant cancer, indicating that this tumor requires granulocytes for rapid growth.

Scalp recorded direct current potential shifts associated with the transition to sleep in man

Cortical direct current (DC) potentials are considered to reflect the state of cortical excitability which may change characteristically from wakefulness to sleep. The present experiments examined changes in the scalp recorded DC potential in 10 healthy humans at the transition from wakefulness to nocturnal sleep. For each subject, DC recordings obtained from Cz were evaluated for a 15 min pre-sleep onset interval and for a 20 min post-sleep onset interval, on 2 separate nights. Sleep stages were determined from standard sleep recordings. The transition from wakefulness to sleep coincided with a significant (P < 0.05) shift in the DC potential of negative polarity. Maximum negative potentials of (mean +/- S.E.M.) 500 +/- 130 microV (first night) and of 760 +/- 200 microV (second night) were reached at the end of the 20 min post-sleep onset interval. A number of possible technical and biological artifacts were controlled. It is reasonable to assume that the slow negative shift of the DC potential at the transition from wakefulness to sleep reflects increased cortical excitability. Whether the negative potential shift pertains during sleep, or is of transient nature and closely linked to the process of falling asleep, remains to be clarified.

Chemical, bacteriological and biological examination and evaluation of sediments from drinking water reservoirs--results from the first sampling phase

Between September 1992 and April 1993, samples of sediment were taken from a total of 16 drinking water reservoirs from seven water suppliers. Five different types of raw water were examined, samples being taken with varying frequency. The comparison of surface reservoir water and ground water constituted a central aim in this first series of investigations. The composition of the sediment was determined in terms of its chemical, bacteriological and biological characteristics. It was established that the deposits that normally accumulate in the course of an operating period contain, in addition to the familiar mass-determinant inorganic constituents such as iron, manganese and calcium compounds, in some cases considerable quantities of organic substances. Total organic carbon (TOC) contents of up to 11 weight-% were found. Besides an increased concentration of heavy metals, in particular cadmium, nickel and zinc, were measured in some sediments. The bacteriological examination of the sediments, in accordance with the German drinking water regulation (TrinkwV) showed, in part, very high colony counts. However, there was apparently no influence on the effluent water as the reservoir was emptied. The microscopical examination showed independent of the raw water source the sediments being colonized by invertebrates. Up to 9000 organisms per litre of fresh sediment were recorded. The predominant group of animals, in terms of numbers, was the rotifers followed by threadworms. The comparison of water from impounding reservoirs and ground water made evident that the presence of organisms in reservoir sediments is not restricted to the use of surface water.

Acute and long-term effects of adrenocorticotropin and dexamethasone on the auditory brainstem response in multiple sclerosis patients

Auditory brain-stem responses (ABRs) were compared in two groups of multiple sclerosis (MS) patients receiving standard treatment with adrenocorticotropin (ACTH) and with dexamethasone (DEX). ABRs were recorded prior to treatment, on the 1st and 8th day of therapy, and 21 days after the hormonal treatment had been discontinued. ABRs in MS patients were within the normal range of variability. Latencies of ABR components increased with increasing rate of presentation, and with decreasing intensity of the click stimuli. Changes in ABRs displayed a consistent pattern in patients treated with ACTH, but showed less coherence after DEX. In ACTH treated patients' latencies of the late ABR waves V and Vn were prolonged after clicks of high intensity, and reduced following clicks of low intensity resulting in a decreased slope of the latency-intensity function of these ABR waves. This pattern became most prominent in the recordings after the treatment had been discontinued, and could reflect an improved transmission across both afferent excitatory and recurrent inhibitory synapses in the auditory pathways. The findings indicate that--besides a common anti-inflammatory action--therapies with ACTH and DEX differ with regard to their influence on central nervous functioning.

Prevention of runting and cachexia by a chimeric TNF receptor-Fc protein

Tumor necrosis factor alpha (TNF) is an important mediator of septic shock and cachexia. A soluble form of the human type 2 TNF receptor, constructed by joining the Fc region of human IgG1 to the TNF receptor, prevents weight loss in nude mice bearing a TNF-secreting tumor. This soluble receptor was also used to treat TNF transgenic mice which were runting and died before reaching reproductive age. After continuous treatment with soluble TNF receptor, the TNF transgenic mice grew to normal size and reproduced. Thus, soluble TNF may be useful in counteracting the detrimental systemic effects of TNF in a clinical setting.

Tumors with reduced expression of a cytotoxic T lymphocyte recognized antigen lack immunogenicity but retain sensitivity to lysis by cytotoxic T lymphocytes

A murine solid tumor was transfected to express various levels of an allogeneic major histocompatibility complex class I gene (K216), in order to test the effect of the level of antigen expression on immunogenicity and sensitivity to lysis by cytotoxic T lymphocytes (CTL). The growth rates of clones of tumor cells expressing different levels of the transfected gene were similar in vitro and in nude mice. Although all tumor cells, including cells freshly isolated from growing tumors, were equally sensitive to lysis by specific CTL, only tumor cells expressing the highest level of the K216 antigen stimulated CTL and were rejected by normal mice. In contrast, tumor cells expressing lower levels of antigen failed to immunize for CTL and grew progressively in normal mice, despite retaining expression of the transfected gene and remaining fully sensitive to CTL-mediated lysis; thus, the threshold of antigen needed to stimulate CTL responses was considerably higher than that needed to lyse tumor cells. Reduction of K216 antigen expression from 100-fold to 40-fold above background, impaired significantly the ability of the tumor cells to induce a K216-specific immune response, while tumor cells expressing K216 at levels 2-fold above background were as susceptible to CTL-mediated lysis as tumor cells expressing 50-fold more antigen. The important implication of these findings is that some tumors occurring in nature may not be immunogenic but nevertheless express antigens which are potential targets for immune therapy.

Cytomegaloviral acalculous cholecystitis in acquired immunodeficiency syndrome patients

Abdominal pain and fever in patients with the acquired immunodeficiency syndrome (AIDS) may indicate cytomegaloviral (CMV) acalculous cholecystitis. We reviewed clinical, laboratory, and outcome data from 12 patients with CMV cholecystitis. Ten of 12 patients were homosexual males. Six patients had markedly low CD4: CD8 lymphocyte count ratios. Total leukocyte counts were normal or decreased, serum liver function tests normal or cholestatic, and only one patient had hyperbilirubinemia. Sonographic transmural gallbladder edema is typically more severe than expected for the presenting illness. Five of six patients investigated with HIDA scintigraphy had a nonvisualizing gallbladder. Open cholecystectomy had a 9.1 per cent operative morbidity and a 0 per cent mortality. Cholecystectomy is a safe and curative intervention, regardless of the immunocompromised condition of the host. Intraoperative cholangiography will identify papillary stenosis or sclerotic bile ducts as a potential cause of recurrent symptoms following surgery. A search for other sites of tissue invasion by CMV should follow cholecystectomy.

A tumor escape variant that has lost one major histocompatibility complex class I restriction element induces specific CD8+ T cells to an antigen that no longer serves as a target

After loss of expression of a major histocompatibility complex class I Kk allele, the escape variant of an immunogenic tumor grows progressively in normal mice. This progressor variant is resistant to killing by cytotoxic T lymphocytes (CTLs) directed against the A and B antigens presented by Kk. Although the variant retains the expression of the Dk allele and is sensitive to CTLs directed against the C antigen presented by Dk, the variant failed to induce CTLs to this antigen in vivo. Instead, the variant induced CD8+ T cells directed to the A antigen. This was shown at the molecular level by T cell receptor beta chain sequence analysis of the responding cells. Further evidence for the presence of A antigen in the variant came from the finding that spleen cells of mice injected intraperitoneally with the variant tumor cells were primed for an anti-A CD8+ CTL response in vivo. Thus, in contrast to other variants that lost a target antigen and induced a CTL response to remaining target antigens, the Kk loss variant continued to induce an immune response to a tumor antigen that is no longer presented on the tumor cell surface. Even though the variant escapes in a single step because an effective CTL response to secondary antigens is prevented, these secondary antigens remain as potential targets of immunotherapy on the variant's cell surface.

Genetically engineered vaccines. Comparison of active versus passive immunotherapy against solid tumors

Late tumor bearers (LTB), that is, mice that had tumors 3 weeks or longer, can have a selective immune dysfunction and fail to respond to target antigens expressed by the cancer cells. Such mice, however, do respond to nonmalignant cells engineered to express the rejection antigen, and they can be vaccinated with such cells to reject growing tumors. In this study, we compared the efficacy of passive immunization with that of active immunization using the engineered vaccine. An allogeneic MHC class I molecule was used as model tumor antigen. We found that active immunotherapy was only effective for small tumors in early stages of growth. In a later stage of tumor growth, active immunotherapy did not cure any mice, whereas passive immunotherapy was successful in all animals. Reasons for the failure of these LTB to respond to active vaccination with the engineered vaccine may be related to the decreased primary or secondary response we observed in these mice after active immunization. It is suggested that normal antigen-presenting cells expressing the tumor rejection antigen can elicit, in the presence of IL-2, antigen-specific T-cell responses by LTB, and that such T cells may be curative when used in adoptive therapy. We also suggest that the stage of tumor growth and the immune status of LTB more closely simulate the conditions observed in cancer patients.

Antiretroviral therapy in sporadic adult amyotrophic lateral sclerosis

Clinical and experimental findings in idiopathic amyothrophic lateral sclerosis (ALS) would be compatible with a retroviral involvement. In 35 adult patients with non-familial ALS we observed elevated circulating immune complexes, a decrease in IgG3 isotype and enzyme-linked sorbent assay (ELISA) serum antibodies against human spuma retrovirus (HSRV), confirmed by specific human foamy virus immunoblots. All 35 were negative for IgM or relevant IgG anti-ganglioside antibodies. We treated 12 HIV-negative, immune-complex-positive ALS patients with 500 mg d-1 zidovudine p.o. over 2-10 months and found reductions of serum creatine kinase and circulating immune complexes from two days to two weeks after the beginning of medication.

CD4-positive and B lymphocytes in transplantation immunity. I. Promotion of tumor allograft rejection through elimination of CD4-positive lymphocytes

The elimination of CD4+ cells by anti-CD4 antibody caused regression of a malignant solid tumor allograft that does not lose a cytotoxic T lymphocyte-defined target antigen during tumor progression and requires specific CD8+ CTL for tumor rejection. Treatment with anti-CD4 antibody was effective when started 1-2 weeks after tumor challenge and was at least as effective as treating with anti-CD3 antibody or specific immunization with the antigen expressed on malignant or nonmalignant cells. None of these treatments caused rejection of tumors that were larger than 1 cm3 or had been growing for 3 weeks or longer in the host. Mice bearing large and long-established tumors treated with anti-CD4 antibody rejected a new tumor challenge but failed to reject the long-established tumor. Similarly, mice with established tumors mounted effective CTL responses to reject skin grafts but failed to reject tumors which expressed the same antigen. Treatment with anti-CD4 antibody eliminated primary T lymphocyte dependent antibody responses but failed to suppress ongoing antibody responses to continuous antigenic stimulation. Possibly, the effectiveness of early treatment and the failure of later treatment with anti-CD4 antibody results indirectly from the effect treatment has on B lymphocytes.

CD4+ and B lymphocytes in transplantation immunity. II. Augmented rejection of tumor allografts by mice lacking B cells

To test the importance of B lymphocytes in immunity to major histocompatibility complex class I alloantigens, B cell-deficient mice were generated by reconstituting severe combined immunodeficiency mice, which lack functional B and T lymphocytes, with T cells or with both T and B cells. The reconstituted mice were challenged with a cancer that expresses an MHC class I alloantigen at a low level and is susceptible to killing by CD8+ cytotoxic T lymphocytes. Tumors grew more slowly in and were rejected more frequently by the mice lacking B cells. Understanding the mechanism by which B cells suppress tumor allograft rejection may lead to new approaches for suppressing immune attack on transplanted tissues.

Footprinting of individual tumors and their variants by constitutive cytokine expression patterns

We have examined the cytokine mRNA expression profile of six different human cell lines derived from Ewing sarcomas using polymerase chain reaction and found each to constitutively express a characteristic pattern. Furthermore, each cell line differed in the levels of secreted cytokines. We also analyzed the expression of several cytokines in murine UV-induced sarcomas and their heritably stable progressive variants. Each murine tumor also constitutively expressed a large number of cytokines, and in some cases, the more malignant variants differed from their parental tumors. These results demonstrate that tumors of the same type, and even in the same lineage, can have distinct cytokine expression and/or secretion profiles. Some cytokines may stimulate tumor growth while others may have antitumor effects. Cytokine therapy may be tailored depending upon the cytokine profile of the individual malignancy.