Human autologous rosettes. IV. Their relation with interleukin 2 activity production and natural killer cells in cancer patients

Peripheral blood lymphocytes (PBL) of solid-tumor-bearing cancer patients produced a lower interleukin 2 (IL-2) activity after lectin stimulation than did those from normal subjects. Moreover natural killer (NK) cell activity and autologous rosette forming (ARF) cell rate are found significantly correlated with IL-2 production in these patients. No direct relation is observed between ARF cell ratio and NK cell activity in a given patient. A central role for IL-2 in cancer patient immune dysfunctions is suggested. Two lines of pathogenetic mechanisms are documented. First, PBL exhibited cellular function defects, namely, autologous receptor expression, IL-2 production, and NK activity. Second, these dysfunctions involved, at least partly, plasma factors. The possibility of specific deficiency, (e.g., thymic factors) is not documented. Conversely it is demonstrated that patient plasma contain immunosuppressive factor(s) that block(s) IL-2 production and ARF cell expression. Involvement of ARF cell receptor in T-cell activation is discussed.     

Phenotypic modulation of chronic lymphocytic leukemia cells by phorbol ester: induction of IgM secretion and changes in the expression of B cell-associated surface antigens

Freshly explanted neoplastic populations from 22 cases of phenotypically well-characterized chronic type B lymphocytic leukemia were studied for their capacity to respond to the phorbol ester TPA in vitro. In all but four cases the secretion of IgM was either induced or increased, often to a high level. In contrast, the export of free immunoglobulin (Ig) light chains, an almost consistent feature of the B lymphocytic leukemias, remained relatively constant after TPA treatment. Parallel changes in leukemic cell surface phenotype were probed with both "conventional" and monoclonal antibodies, revealing some modulation of markers in every case investigated. A diminution in the level of surface Ig (preferentially IgD) and the accumulation of cytoplasmic Ig observed after phorbol ester treatment were accompanied by a corresponding reduction or loss of the B1 antigen and usually of B2 when present. The most consistent change induced by TPA was the appearance of BB-1, a marker of activated B lymphocytes, which was rarely expressed on fresh leukemic cells. Another marker of activated lymphocytes, LB-1, was also often induced or increased in its expression after exposure of the cells to TPA. The magnitude of the TPA response appeared to relate to the stage of maturation arrest of the individual leukemic clones rather than to any clinical parameter explored. The significance of the findings to normal B cell differentiation and their potential clinical utility are discussed.     

Enhancing effects of monocytes on modulation of a lymphocyte membrane antigen

Redistribution, or modulation, of some cell surface antigens occurs in the presence of specific antibody. The phenomenon of antigenic modulation may therefore affect the use of antibodies as therapeutic agents. This study was undertaken to investigate modulation of the 65,000 dalton T65 antigen, present on normal and malignant T cells and some malignant B cells, which is recognized by the monoclonal antibody T101. To induce cell surface antigenic modulation, normal or leukemic lymphoid cells were cultured in the presence of monoclonal antibody T101 for 3-hr periods. Removal of monocytes from mononuclear cell preparations resulted in significantly lower degrees of T65 antigenic modulation. The degree of antigenic modulation could be increased by adding monocytes back to monocyte-depleted lymphocyte suspensions. Furthermore, maximal modulation occurred in the presence of monocytes at T101 concentrations that were 3 logs lower than in the absence of monocytes. The enhancing effect of monocytes was dependent on the Fc portion of the T101 antibody molecule, and presumably was mediated by cross-linking of antigen-antibody complexes on the surface membrane of the modulating cell by Fc receptors present on monocytes. Further experiments performed to examine the characteristics of this enhancement of antigenic modulation by monocytes indicated that autologous as well as allogeneic monocytes were effective, indicating that the enhancing phenomenon was not dependent upon recognition of major histocompatibility antigens. Viable monocytes were required, but pretreatment of monocytes with sodium azide to inhibit energy production, or indomethacin to inhibit prostaglandin synthesis had no effect on this phenomenon. Polymorphonuclear leukocytes did not mediate similar enhancement, although monocytic and myeloid cell lines U937, THP-1, and HL-60 did. Spent culture medium from modulated cultures and preparations containing IL 1 activity did not enhance modulation of the T65 surface antigen on lymphocytes, suggesting that direct contact between lymphocytes and monocytes is required to mediate the effect. The finding that leukemic cells from patients with CLL undergo modulation of the T65 antigen to a much lower degree in vitro than observed in vivo, and that this difference can be overcome by the addition of monocytes, suggests that monocytes or the reticuloendothelial system may augment antigenic modulation in vivo.     

Studies on ultrastructure and host range of aChlorella attacking virus

Summary A tail-less polygonal virus with a prominent capsid of about 140–150 nm in diameter and about 14–15 nm in thickness has been isolated from a freshwater pond. It shows a marked host specificity in attacking only an endosymbioticChlorella sp. isolated fromParamecium bursaria (Ciliata). Viral replication starts in the algal cytoplasm and both autospores and old cells are lysed. The ecology of the virus in the freshwater habitat is discussed. Screening tests for further phycoviruses were not successful.     

Spontaneous cell-mediated cytolysis by peripheral blood cells obtained from whole-body chronically irradiated beagle dogs

The level of natural killer (NK) activity of continuously gamma-irradiated (whole body) beagle dogs and their nonirradiated controls was studied. For analytical purposes, irradiated dogs were segregated into groups according to their clinical status: clinically normal, hypocellular, or with acute non-lymphocytic leukemia. Since unirradiated control animals exhibited a wide range of NK responses, the data from each irradiated animal were compared to its own age-matched or litter-matched unirradiated control. Of the eight clinically normal irradiated dogs (median = 146% activity of control) only one animal had a NK activity lower than that of its control. The hypocellular group (n = 5, median = 21.8% of control) and the leukemic group (n = 4, median = 52.5% of control) each contained one responder with higher activity than its control. The difference between the percentage of control of the clinically normal and clinically abnormal dogs was found to be significant (P less than 0.05). There is a negative correlation between the NK results obtained and the total accumulated dose of radiation at the time of sampling (correlation coefficient = -0.739, P less than 0.01), suggesting a radiation effect upon natural killer activity, which is evidence by enhancement at lower doses and depression at higher doses of irradiation.     

Suppressive effect of delta 9-tetrahydrocannabinol in vitro on phagocytosis by murine macrophages

Incubation of normal mouse peritoneal cells consisting of over 90% phagocytizing macrophages with delta 9-tetrahydrocannabinol (THC) resulted in a inhibition of phagocytic function. The THC in a dose-related manner suppressed the percentage of macrophages per culture which ingested yeast and the average number of yeast particles ingested by the phagocytizing macrophages. The vehicle used to suspend the THC in vitro, i.e., DMSO, had no detectable effect on macrophage function. Suppression of phagocytosis with no effects on viability or cell number occurred with doses of 10 micrograms or less THC per milliliter culture medium. Measurable suppression also occurred after 24- to 48-hr treatment of the macrophages with the THC. This compound had little if any detectable effect on phagocytosis when added directly to the cultures shortly before testing for phagocytosis. Further studies concerning the effects of THC on macrophage function appear warranted.     

Two adjacent epitopes on a synthetic dodecapeptide induce lactate dehydrogenase B-specific helper and suppressor T cells

The outcome of an immune response to the enzyme lactate dehydrogenase B (LDH-B) is determined by the interplay between two types of regulatory T lymphocytes, T helper (Th) and T suppressor (Ts) cells. Most mouse strains are capable of generating Th but not Ts cells, and are therefore high responders to LDH-B in terms of both antibody production and antigen-specific T-cell proliferation. However, in strains expressing the b or k allele at the E beta locus of the major histocompatibility complex (Mhc), Ts cells are induced that partly or totally abrogate the proliferative response of Th cells to LDH-B. As a result, these strains are phenotypically medium (E beta b expressors) or low (E beta k expressors) responders. Because the suppression in the LDH-B system is antigen-specific (i.e. it only affects LDH-B-specific Th cells), it is conceivable that the Th and Ts cells use the antigen itself to communicate with each other. To investigate this possibility, we set out to determine which epitopes of the LDH-B molecule are recognized by Th and Ts cells. On the basis of previous studies, a loop structure extending from residue 211 to residue 224 of pig LDH-B appeared to be preferentially recognized by most Th-type (class II Mhc-restricted, proliferating) clones. By using a synthetic peptide, we demonstrate here that both Th and Ts cells are induced by the 211-222 stretch of LDH-B sequence. The use of two further dodecapeptides, each with a single amino-acid substitution in comparison with the pig 211-222 sequence, has revealed that Th and Ts cells have different fine specificities. Thus the loop appears to have two closely linked, if not overlapping, epitopes, one recognized by Th and the other by Ts cells. This finding is consistent with two possible mechanisms of suppression, namely bridging of Th and Ts cells by antigen and subsequent transmission of a suppressive signal, and competition for antigen between Th and Ts cells.     

Intracellular pH control in Dictyostelium discoideum: a 31P-NMR analysis

Phosphorus metabolites and intracellular pH have been examined in the slime mold Dictyostelium discoideum by non-destructive 31P-NMR measurements. In a spectrum from a suspension of aerobic amoebae, the major peaks are inorganic phosphate, nucleotide di- and triphosphates. In the corresponding perchloric acid extract, resonances originating from purine and pyrimidine nucleotides are resolved. Adenine nucleotides are the most abundant components, but the other nucleotides are present in significant amounts. In a spectrum from intact spores in a dormant state, only inorganic phosphate and polyphosphates are detected and nucleotides are no longer present in large amounts. Of particular importance is the ability to observe separately in aerobic amoebae the resonance of inorganic phosphate localized in two different cell compartments: the cytosol and the mitochondria. The cytosolic pH and mitochondrial pH have been measured as 6.7 and 7.7, respectively, on the basis of intracellular inorganic phosphate chemical shifts. They are essentially unaffected over a large range of external pH and they are not modified transiently or permanently during the initiation of the developmental program of the organism. A weak acid, such as propionate, which modifies the progression of differentiation by favoring prestalk cells, perturbs intracellular pH gradients by selectively decreasing mitochondrial pH without any effect on cytosolic pH.     

Immune reactivity in cattle with ocular squamous cell carcinoma after intralesional BCG immunotherapy

Summary Lymphocyte stimulation with Con A and specific immune reactivity to BCG (antibody formation to BCG and DTH reaction to PPD) were determined in BCG-treated, surgically treated and untreated cows with ocular squamous cell carcinoma. In tumor-bearing cows the Con A-induced proliferation of lymphocytes was reduced when compared to healthy controls. This suppression consisted of a reduced blastogenic response to Con A of lymphocytes from tumor-bearing cows, and the presence of a factor in the sera of these animals, as these sera suppressed the blastogenic response of lymphocytes from healthy cows. BCG had only a minor influence on the suppressive activity. Antibodies to BCG were demonstrated in 50% of the BCG-treated animals. The formation of antibodies was not influenced by intradermal injection of PPD of Mycobacterium bovis. Absorption of a BCG antibody containing serum with BOSCC tumor extracts did not reveal the existence of cross reacting antigens between BCG and BOSCC. Pretherapeutic and posttherapeutic Con A reactivity could not be correlated with clinical response. Of the 30 BCG treated cows 29 developed a positive DTH reaction to PPD. Correlation between clinical response and immune reactivity was seen only with regard to the DTH reaction to PPD: this reaction remained positive for a longer period after treatment in animals with a favorable clinical outcome than in nonresponding animals.Animals were maintained under the guidelines laid down by the Faculty of Veterinary Medicine, State University, Utrecht, The NetherlandsGrant recipient of the Koningin Wilhelmina Fonds (Netherlands Cancer Foundation) Abbreviations used: BCG, Bacillus Calmette-Guerin; BOSCC, bovine ocular squamous cell carcinoma PBL peripheral blood leukocytes; PPD, purified protein derivative of Mycobacteria; DTH, delayed type hypersensitivity Con A, concanavalin A; PHA, phytohemagglutinin; PWM, pokeweed mitogen     

Lysis of autologous tumor cells by blood lymphocytes tested at the time of surgery

Summary Lymphocyte-mediated lysis of autologous tumor cells (autologous lymphocyte cytotoxocity ALC) was tested at the time of surgery in 108 patients (46 squamous cell carcinomas of the lung, 25 adenocarcinomas of the lung, 19 soft tissue sarcomas and 18 osteosarcomas). The clinical course of these patients in relation to the test results has been published previously. The group was evaluated again after an extended observation time, now with a mean of 80.2 months (range 36–108). The test was rarely positive in patients with metastasis (2 out of 28 experiments).There was a correlation between the ALC results and the postsurgical clinical course for patients without detectable metastasis in that (1) a negative test was invariably a bad prognostic sign, i.e., all 32 patients with negative ALC died within 3 years (mean survival time 16.1 months). (2) The remission and survival times were longer for the ALC positive patients (p<0.001). (3) All 37 individuals who are alive at present without recurrence belong to the reactive group.The ALC results correlated with the clinical course in 88% of patients. The correlation was highest for the groups of soft tissue sarcoma and adenocarcinoma of the lung. There was no correlation between killing of K562 cells and ALC, or between lymphoproliferative response to PHA and ALC reactivity.