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H F Pross

Publications and source records attributed to H F Pross.

At least 37 records · Page 2Linked to original sources
PubMed1982

Impairment of the thymus-dependent humoral immune response by syngeneic or allogeneic pregnancy.

Pregnancy results in a diminished capacity of the gravid mouse to respond to thymus-dependent antigens. The IgM response to thymus dependent and independent antigens is relatively unaltered whereas the IgG response to thymus-dependent antigens is markedly suppressed in both syngeneic and allogeneic pregnancy. The impairment of the humoral immune response is not due to loss of antibody-forming precursor lymphocytes (AFPL) from the spleen since their number remains unaltered. During pregnancy the spleen becomes enlarged and the precursor frequency is diluted somewhat but the AFPLs retain their normal activity in vitro. This implies an alteration in their amplification by accessory cells (T cells or macrophages) is responsible for the impaired IgG responses.

Animals↗
PubMed1981

Induction of malignant lymphoreticular cell line which displays spontaneous killer-cell activity.

The origin and properties of a new malignant "spontaneous killer" cell line are described. The tumor, known as M9-78, was produced by treatment of tissue cultures consisting mostly of dividing DBA/2 mouse macrophages with the chemical carcinogen, 3-methylcholanthrene. Logarithmic phase cultures were treated for 6 days followed by further culture for 1 month in the absence of carcinogen. Subcutaneous injection of normal DBA/2 mice with 2.0 X 10(5) cells led to the formation of palpable tumors at the site of inoculation within 14 days; the tumors grew progressively and were highly metastatic. The malignant cells, though Fc-receptor-positive, did not possess many other properties normally associated with macrophages; morphologically, they bore a strong resemblance to bone-marrow-derived promonocytes. Because promonocytes have been shown previously to possess both antibody-dependent killer (K) cell as well as antibody-independent spontaneous killer-cell function, the M9-78 cells were tested for these biologic activities. The following results were obtained: (1) adherent, but not non-adherent, M9-78 tissue culture cells spontaneously killed a wide variety of (though not all) tumor-cell-line targets in long-term (18-24 h) 51Cr release, whereas no killing was seen in short (4 h) assays; (2) the cells were not capable of killing nucleated targets by antibody-dependent cell-mediated cytotoxicity; (3) a number of clones were obtained and tested for spontaneous killer-cell activity: some were highly active, whereas others were negative, with different patterns of specificity being evident; (4) the clones were unstable; (5) the pattern of target killing, when compared to normal spleen control NK cells, suggested the M9-78 cells were similar to activated macrophages or promonocytes in their target selectivity, although no definitive evidence was obtained which could implicate a promonocyte or monocyte origin for the cells.

Animals↗
PubMed1981

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

On analysis of in vitro assays of human natural killer (NK) cell function the inadequacy of commonly used methods of expressing lytic activity was apparent. A comparison was made of the data obtained using modifications of two equations-the simple exponential fit and the von Krogh equations. Both of these equations were found to satisfy the following essential criteria for use in these assays. First, the majority of the results obtained in the chromium-release assay could be used in data reduction; second, the resultant "dose-response" curve was reduced to linearity; and third, a single numerical expression was obtained which was directly proportional to the cytotoxic activity. Of the two methods the more conventional exponential fit was found to be the simpler to use. The closeness of fit of the experimentally derived data to the ideal curves did not support the possibility that normal lymphocyte preparations contain suppressor cells capable of inhibiting NK activity. Data have also been presented showing that NK-sensitive targets could be categorized with respect to their susceptibility by comparing the slopes of the target cell survival curves obtained using the exponential fit equation. These observations are relevant to the accurate assessment of NK activity in patient populations and to the determination of the effects of disease and its treatment on this activity.

Animals↗
PubMed1981

The use of modified Cunningham chambers for the enumeration of H rosettes, E rosettes, and lymphocyte-tumour cell conjugates.

In this paper, we have described the use of a slide-coverslip Cunningham chamber which is ideal for counting delicate rosettes and lymphocyte-tumour cell conjugates. The ease of construction, facility of use, and economy of cost in comparison with hemocytometers make the use of these chambers the method of choice for rosette counts in general. In contrast to standard double-slide Cunningham chambers, the design of these rosette chambers is such that they can be used with ordinary light microscope objectives (including oil immersion), they can be more easily loaded without trapping air bubbles, and they can be sealed without tilting the slide. As an example of one potential application of these chambers to tumour immunology, data have been presented showing the high proportion of lymphocyte-tumour cell conjugates which can be formed by human peripheral blood cells. The ability of any particular tumour cell to form conjugates did not necessarily reflect the susceptibility of that cell type to natural killer (NK) cell-mediated lysis, nor was there any evidence that E rosette-forming cells preferentially formed conjugate in comparison to non E rosette-forming cells.

Killer Cells, Natural↗
PubMed1980

Human lymphocyte/human erythrocyte rosettes. I. Blood "H" rosettes are high-affinity E-rosetting-forming T lymphocytes occurring in high frequency.

Human lymphocytes will rosette with human red blood cells under certain conditions (H rosettes). The work presented in this paper documents the following: (1) a reproducible short-term assay for the detection of H rosettes in proportions similar to those reported recently in the literature (25-30%); (2) technical improvements on the basic assay system demonstrating that, in fact, 40-65% of human lymphocytes form H rosettes; (3) the fact that, in normal donors, auto and allo H rosettes are formed by identical lymphocyte subpopulations; (4) that H rosettes are formed independently of the ABH, Rh and Thomsen-Freidenreich (TF) red-cell antigens on the indicator red cells; and (5) that H rosette-forming cells consist almost entirely of T lymphocytes having high-affinity receptors for sheep erythrocytes. The large difference in size between sheep and human RBC made it possible to do double rosette assays in which high- and low-affinity E-rosette-forming T cells could be visualized on the same slide. As with T lymphocytes in general, a large proportion of HRFC was found to have Fc-IgM receptors while a smaller proportion has Fc-IgG receptors. Studies done on a small group of leukemic patients supported the T-cell nature of the H rosette-forming cell.

Animals↗
PubMed1978

Spontaneous human lymphocyte-mediated cytotoxicity against tumor target cells. IV. The suppressive effect of normal pregnancy.

The effects of pregnancy and other donor characteristics on spontaneous lymphocyte-mediated cytotoxicity (SLMC) were studied. Sex, age, and stage of the menstrual cycle had no significant effect on the SLMC of the control donors, the SLMC was significantly lower in pregnant donors in the second or third trimester. However, this lowered level of activity was still within the 95 per cent confidience limits of the normal population and parity had no cumulative effect. At delivery, fetal cord blood lymphocytes possessed substantial cytotoxic activity, further evidence that the fetus is immunologically competent at birth. The relevance of these data to the immunologic coexistence of the mother and fetus is discussed.

Adult↗
PubMed1977

Analysis of established human carcinoma cell lines for lymphoreticular-associated membrane receptors.

Thirty-one different long-term established human carcinoma culture cell lines were examined for the presence or absence of receptors for the Fc portion of immunoglobulin G (IgG) ("Fc receptors"), the third component of complement (C3 receptors), sheep erythrocytes and mouse erythrocytes. Included in the catalogue of lines tested were adenocarcinoma of the adrenal cortex, colon, rectum, lung, liver, breast and kidney, and carcinomas of the uterine cervix, bladder and vulva. All lines were found to be consistently Fc receptor-negative, as assayed by rosette formation with sheep erythrocytes coated with subhemagglutinating amounts of anti-sheep erythrocyte antibodies, or bovine erythrocytes heavily coated with non-hemagglutinating anti-bovine erythrocyte antibodies. This is similar to results obtained with murine tumors: carcinomas are consistently Fc receptor-negative, while those lines which are Fc receptor-positive are invariably lymphoreticular in nature. The human carcinoma cell lines were also negative for complement (C3) receptors and spontaneous T and B rosette markers. It is proposed that, in most cases, rosette-forming cells found in primary human carcinomas are, as in the mouse or rat, representative of infiltrating non-malignant lymphoreticular cells.

Adenocarcinoma↗
PubMed1977

Spontaneous human lymphocyte-mediated cytotoxicity against tumor target cells. II. Is the complement receptor necessarily present on the killer cells?

The effect of various lymphocyte depletion techniques on SLMC effector cell activity against the cell line K562 could be attributed to the effects that these procedures had on the proportions of Fc/C3 receptor-bearing cells in the preparations. depletion of cytotoxic activity by removal of Fc receptor-bearing cells could be augmented by the presence of complement on the 7S-EA indicator cells used for rosette depletion. Two methods of assessing the presence of surface receptors on cytotoxic cells are presented: (1) linear regression analysis of spontaneous cytotoxicity plotted as a function of the proportions of receptor-bearing cells remaining after various depletion techniques; and (2) the use of a mathmatical formula to estimate the proportion of cytotoxic cells with any particular receptor, based on the effects of receptor-bearing cell depletion. Linear regression analysis of cytotoxicity vs the proportions of SRBC, Fc or C3 receptor-bearing cells demonstrated that all cytotoxic cells had the Fc receptor, but that cytotoxicity could still occur in the absence of cells with the C3 receptor. This indicated that the C3 receptor is not necessary for the demonstration of SLMC activity. The mathematical formula to predict cytotoxicity after depletion of C3 receptor-bearing lymphocytes showed, however, that a significant proportion of the Fc receptor-positive killer cells were also C3 receptor-positive. No direct evidence was found to support a role for T cells in SLMC, although E rosette depletion resulted in lower than expected cytotoxicity in view of the number of Fc receptor-bearing cells remaining in the preparation.

Antibodies, Neoplasm↗
PubMed1977

Lymphocyte populations in peripheral blood during normal human pregnancy.

The effects of normal pregnancy on peripheral blood lymphocytes were investigated. The frequencies of thymus-derived and bone-marrow-derived lymphocytes in maternal peripheral blood does not vary significantly throughout pregnancy. This observation implies qualitative rather than quantitative alterations in lymphocyte functions to explain the reduced cell-mediated immune responses seen during pregnancy.

B-Lymphocytes↗
PubMed1977

Effects of pregnancy on the maternal lymphoid system in mice.

The effects of pregnancy on the lymphocyte populations in the mouse have been studied. Though cell numbers decreased in the thymus and increased in the lymph nodes draining the parauterine area, no significant changes were seen in the proportions of thymus derived (theta allo-antigen positive) and bone marrow derived (Fc receptor positive) lymphocytes. The humoral response to sheep erythrocytes was suppressed during both syngeneic and allogeneic pregnancies following a decline coincidental with that of thymic mitotic activity. Though the observed immunosuppression could be explained by a selective lymphocyte depletion, it appears more likely to be a nonspecific effect of the steroid milieu of pregnancy.

Animals↗
PubMed1976

Spontaneous human lymphocyte-mediated cytotoxicity againts tumour target cells. I. The effect of malignant disease.

Spontaneous human lymphocyte-mediated cytotoxicity (SLMC) against tumour-cell targets was examined in a series of patients with localized or malignant disease, both treated and untreated, and patients with untreated chronic lymphocytic leukemia (CLL). The level of SLMC was assessed by means of two previously established assay systems; the xenogeneic assay involving the mouse mastocytoma line P815, and the allogeneic assay in which the human chronic myelogenous leukemia-derived line, K562, was used. The assay systems involve the use of Ficoll-Isopaque-separated, iron-plus-magnetism-purified lymphocytes in an overnight 51chromium release assay, and reflect the cytotoxic ability of human non-T, complement receptor-, Fc receptor-positive lymphocytes. In the present paper, lymphocytes from all normal donors tested showed significant activity in the SLMC assay, with some variation from day to day. This variation was markedly reduced when different normal donors were tested on the same day and under identical experimental conditions. In contrast, lymphocytes from many patients with malignant disease had decreased SLM activity, and this decrease was highly significant in patients with treated or untreated metastatic disease, or untreated CLL. This was also the case when the data were expressed relative to the number of cytotoxic cells in the normal control population, or in comparison to the relative SLMC activity of lymphocytes from patients with other conditions. Markedly decreased SLMC was observed in some patients in spite of normal T and B lymphocyte proportions, or the presence of the ability to mount a vigorous delayed hypersensitivity reaction to PPD. A comparison of the xenogeneic and allogeneic assays showed that the same information with respect to whether SLMC was normal or abnormal was obtained with both assays in the majority of cases. The significance of the data is discussed with respect to the possible role of SLMC in vivo and the relevance of SLMC to the assessment of specific cell-mediated cytotoxicity in malignant disease.

Adult↗
PubMed1976

Fc receptor-bearing cells as a reliable marker for quantitation of host lymphoreticular infiltration of progressively growing solid tumors.

Disaggregated cell suspensions made from transplanted solid tumors, either chemically-induced fibrosarcomas, or spontaneous mammary carcinomas, can contain very high numbers of Fc receptor-bearing cells which are of host origin. Because most types of lymphoreticular cells have Fc receptors, and because T cells--most of which are Fc receptor-negative--appear to infiltrate such tumors only to a very limited degree, the possibility that Fc receptor cells could serve as a reliable and simple marker for host lymphoreticular cell infiltration of solid tumors was tested. This was accomplished by comparing the ratios of Fc rosetting cells to serologically detectable host cells in H2d or H2k haplotype tumor cell suspensions grown in (H2d X H2k)f1 hybrid mice, where host cells could be distinguished from tumor cells by treatment with the appropriate anti-H2 serum. Ratios of 0.8 to 1.08 were obtained for four different tumors including the SaD/2 fibrosarcoma, a CBA spontaneous fibrosarcoma, and the T1699 and CaD/2 mammary carcinomas. Analysis of the results showed that enumeration of Fc rosettes was a reliable host cell maker for at least three of the four tumors tested. The mean non-malignant host cell content of the various tumors, as assessed by anti-H2 cytotoxicity tests, ranged from 23% to 41%.

Animals↗
PubMed1976

An assessment of intratumor phagocytic and surface marker-bearing cells in a series of autochthonous and early passaged chemically induced murine sarcomas.

Single cell suspensions from five different 3-methylcholanthrene-induced tumors in CBA mice were examined in the autochthonous host and sequentially for 5-11 passages. They were also examined for Fc receptor-bearing, phagocytic, theta antigen-positive, and surface immunoglobulin-bearing cells. The preparations contained a high proportion of phagocytic and marker-bearing cells both in the original host and during early passage. This proportion was consistent for any particular tumor and passage. Between different tumors, however, the proportions were sufficiently different to allow the tumor to be identified on this basis; this suggested that various chemically induced tumors may be unique in their tumor-host relationship as measured by the type of cells which infiltrate them. With on-going early passage of the tumors, the proportion of marker-bearing cells decreased to a constant level in most instances, mainly because of a reduction in the percentage of phagocytic cells. The tumor with the least macrophages (MBQA, less than 5%) consistently appeared more rapidly and killed the host more rapidly than did the tumor with the most macrophages (MBQD, 15-30%), but was not significantly different in its growth rate. The theta antigen- and Fc receptor-positive cells within these tumors were derived from the animal receiving the tumor inoculum, and thus represented host cell infiltration of the tumor. The results were discussed with reference to fundamental concepts of the immunology of chemically induced tumors and the importance of host cell infiltration within these tumors.

Animals↗
PubMed1975

Antibody-dependent cell-mediated cytotoxic activity in syngeneic moouse ascites tumors.

Eight different syngeneic murine ascites tumor preparations were tested for their ability to lyse antibody-coated chicken erythrocytes in an assay for antibody-dependent cell-mediated cytotoxicity (ADCC). All of the tumor preparations demonstrated significant ADCC effector activity, even at effector-cell:target-cell ratios of less than 1:1. In contrast, none of eight in vitro murine tumor-cell lines showed any consistent ability to function as ADCC effector cells. Several cell fractionation experiments were performed to ascertain the nature of the effector cells in the ascites tumors. Adherent cells were removed from tumor preparations by passage of cells over columns of Degalan plastic beads and 19S Fc-receptor-bearing cells were removed by sedimentation of EA rosette-forming cells. Although each of these procedures depleted only a minority of the total cells, all the ADCC activity was simultaneously removed in each case. Depletion of phagocytic cells by treatment of tumor preparations with carbonyl iron and magnetism only slightly diminished the ADCC activity. These results indicate that the ADCC activity associated with ascites tumors is due to effector cells most probably of host origin, but possibly representing an atypical sub-population of tumor cells. The characteristics of the effector cell closely parallel those defined for the major non-phagocytic ADCC effector cell in normal mouse spleen and peritoneal exudate.

Animals↗