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Biomedical subjects

D M Murasko

Publications and source records attributed to D M Murasko.

At least 55 records · Page 3Linked to original sources
PubMed1989

Interferon-induced inhibition of Moloney sarcoma virus-transformed cells: requirement for T-cells.

We previously demonstrated that although natural killer (NK) cells participated in interferon (IFN)-induced inhibition of growth of the Moloney sarcoma MSC cell tumor, the need for NK cells could be circumvented by using a small tumor cell challenge or an increased amount of IFN. These studies were performed in normal, euthymic mice. The role of T-cells remained undefined. In the present study, nude mice were used to evaluate the role of T-cells. Investigation of various treatment regimens revealed that IFN could not totally inhibit tumor growth in nude mice. A significant delay in tumor growth was observed when 1 x 10(5) units of IFN were administered at the site of tumor on days 1-4 after tumor challenge. Increasing the dose of IFN or extending therapy to 7 days did not afford any further inhibition of tumor growth. In vivo depletion of NK cells with anti-asialo monoganglioside antibody revealed that the delay in tumor growth was dependent on NK cells when IFN was given on days 1-4. Treatment for days 1-7, however, still inhibited tumor growth in the NK cell-depleted nude mice. In order to further ascertain the role of T-cells in IFN-induced tumor inhibition, T-cell reconstitution studies of nude mice were performed. Nude mice were reconstituted with 1 x 10(7), 2 x 10(7), and 5 x 10(7) T-cells on day -1 to tumor challenge and treated with IFN on days 1-7. The extent of the observed decrease of tumor sizes and tumor incidences among the T-cell-reconstituted groups was dependent on the dose of T-cells being administered in both IFN-treated and untreated animals. These data indicate that T-cells are essential for maintaining the growth-inhibitory effects of IFN. This is in contrast to NK cells whose role in IFN-induced inhibition of MSC tumor growth can be circumvented by increasing the dose of IFN.

Animals↗
PubMed1989

The role of T cell phenotypes in decreased lymphoproliferation of the elderly.

A possible mechanism of the decreased mitogen-induced lymphoproliferation of the elderly is a shift in the relative numbers of T lymphocyte subpopulations. Results from studies examining such changes have been conflicting. In an effort to resolve this conflict, alterations in T cell subsets in the peripheral blood of a large number of relatively healthy, elderly subjects (149; mean age 84.6) were evaluated. Although there were several differences in percentages of subpopulations between elderly and young subjects, no significant differences in the absolute numbers of lymphocytes, monocytes, or T cell subsets between the groups were observed. In addition, there was no correlation between mitogen-induced lymphoproliferation and T cell subsets. Since the decreased mitogen response could reflect a difference in the ability of one T cell subset to proliferate, the phenotype of the T cells after stimulation with PHA was determined. Although the elderly demonstrated a decreased number of all T cell subsets after PHA stimulation compared to young subjects, the most pronounced decrease was in CD8+ cells. Further, young individuals demonstrated a significant increase in the percentage of CD8+ cells (p less than 0.001) after 72 hr of culture with PHA; elderly subjects showed no change in the percentage of T cell subsets. Although both groups had an increase in interleukin 2 receptor (IL2R), transferrin receptor (TfR), and MHC class II Ag (HLA-DR) positive cells after PHA stimulation, the mean percentage of TfR+ cells was significantly greater in the young than in the elderly (p less than 0.05). This decreased expression of TfR+ cells in the elderly was reflected by a decreased percentage of CD8+ cells expressing TfR. In addition, the percentages of CD8+ cells, CD8+ cells expressing TfR, and CD8+ cells expressing IL2R after activation correlated with PHA-induced proliferation. These results suggest that the impaired lymphoproliferative ability of elderly cells is not related to the proportions of T cell subsets present in peripheral blood. Rather, there appears to be some defect in the ability of all T cells, but especially of the T suppressor/cytotoxic cells, of the elderly to respond to PHA manifested by a decreased expression of transferrin receptors.

Adult↗
PubMed1989

Inhibition of lymphocyte recirculation by murine interferon: effects of various interferon preparations and timing of administration.

The effects of highly purified and/or recombinant interferon (IFN)-alpha/beta, IFN-alpha, IFN-beta, IFN-gamma, and the IFN-inducer, poly(I):poly(C), on the circulation of peripheral blood leukocytes (PBL) and thoracic duct lymphocytes (TDL) of (BALB/cJ x C57Bl/6J)F1 mice were examined. Although all IFN classes could depress significantly the number of circulating PBL and TDL when given at sufficient doses, IFN-alpha appeared to be the most potent. Phenotypic analysis of lymphocytes in the blood and lymph during the decrease induced by IFN suggests that IFN-alpha/beta and IFN-alpha preferentially decrease the Lyt-2+, or suppressor/cytotoxic, subset. Timing of IFN administration was found to be an important factor. Repeated administration of IFN-alpha/beta once a day for 3 days produced continuous suppression of the number of circulating PBL. Administration of either IFN-alpha/beta or IFN-gamma in the evening resulted in a longer and more extensive inhibition of PBL circulation than when IFN was administered in the morning. Our results suggest that the leukopenia observed in many patients undergoing IFN therapy may, in part, be attributed to decreased lymphocyte recirculation, and that the timing of IFN administration may be important in maximizing its therapeutic index.

Animals↗
PubMed1988

Effect of the mixed bacterial vaccine on the immune response of patients with non-small cell lung cancer and refractory malignancies.

Since 1984, 13 patients were entered into our study and 12 patients have completed one or more cycles of treatment with mixed bacterial vaccine (MBV), a natural biologic response modifier derived from Streptococcus pyogenes and Serratia marcescens. Eight patients with refractory malignancy were treated with MBV only (0.1 ml intravenously [IV]) twice weekly for 3-16 weeks (colorectal cancer, pancreatic cancer, chronic lymphatic leukemia, hepatoma [two patients], sarcoma [three patients]). Four patients with advanced non-small cell lung cancer were treated with MBV in combination with low-dose cyclophosphamide, day 1; cisplatin, day 15; and MBV, 0.1 ml IV, days 5, 7, and 9. Two patients in this study received cyclophosphamide and cisplatin alone. The cycle was repeated every 28 days. Plasma interferon levels, interleukin-2 production by peripheral lymphocytes, and lymphocyte subpopulations were monitored. Interferon levels and interleukin-2 production showed increased or sustained values in general. In some patients, B-cells and helper T-cell populations increased, whereas T-suppressor cell numbers declined. With one exception, side effects were mild and consisted of fever greater than 37.8 degrees C (nine of 13), chills (11 of 13), increased respiratory rate (nine of 13), minor changes in blood pressure (seven of 13), and nausea (three of 13). One patient with non-small cell lung cancer had a partial response. Two patients with non-small cell lung cancer and one patient with refractory malignancy had stable disease and performance status at the end of 8 weeks of treatment; one patient with refractory malignancy was stable at the end of 4 weeks of treatment. In this pilot study, cancer patients treated with MBV showed objective evidence of immune stimulation with acceptable toxicity.

Adult↗
PubMed1988

Inhibition of macrophage-induced antigen-specific T-cell proliferation by interferon-gamma.

The effects of IFN-gamma on macrophage (M phi)-mediated antigen-specific T-cell proliferation was investigated. A well-defined assay system using purified resident populations of antigen-pulsed peritoneal M phi and immune T cells was used to measure M phi-induced antigen-specific T-cell proliferation. Antibody affinity purified or recombinant IFN-gamma inhibited M phi-induced T-cell proliferation when KLH-pulsed M phi from mice given IFN-gamma prior to KLH were cultured with KLH immune T cells from normal mice. Monoclonal rat anti-IFN-gamma antibody neutralized the inhibitory effect of IFN-gamma. This inhibition of T-cell proliferation occurred despite the fact that these M phi appeared to be activated by IFN-gamma treatment as measured by increased tumoricidal activity. The mechanism for the inhibition was unrelated to class II (Ia) expression, IL-1 secretion, and prostaglandin secretion. These results demonstrate the complex and sensitive role IFN-gamma has in regulating the immune response.

Animals↗
PubMed1988

Tumor necrosis factor induces expression of MHC class I antigens on mouse astrocytes.

The effect of tumor necrosis factor (TNF) on expression of major histocompatibility complex (MHC) antigens was examined in mouse glial cells in vitro. TNF induced MHC class I, but not class II, antigen expression on the surface of astrocytes but not on oligodendrocytes. Glial cells do not normally express detectable amounts of MHC antigens. Thus TNF may play a role in the immunopathogenesis of neurologic diseases that involve MHC class I-restricted reactions.

Animals↗
PubMed1988

Interferon-induced inhibition of lymphocyte circulation: lack of effect on humoral immune responses to T-dependent or T-independent antigens.

We have previously demonstrated that interferon (IFN) transiently inhibits the number of recirculating thoracic duct lymphocytes (TDL), while other researchers have demonstrated similar decreases in lymphocytes in peripheral blood. In the present study we examined whether or not this decreased lymphocyte recirculation contributes to IFN's suppressive effects on antibody formation. Immunizing at varying times during the period of maximal decrease in lymphocyte recirculation, there are no significant differences in the number of plaque-forming cells (PFC) or antibody titers generated to either a T-dependent antigen, sheep erythrocytes (SRBC) or a T-independent antigen, Type III pneumococcal polysaccharide (SSS-III). These results suggest that: (i) the suppressive effects of IFN on antibody responses are not related to changes in lymphocyte recirculation and (ii) lymphocyte circulation is not required during the early phases of the humoral immune response to antigens.

Agglutination Tests↗
PubMed1987

Interferon-gamma, interferon-alpha/beta, and tumor necrosis factor differentially affect major histocompatibility complex class I expression in murine leukemia virus-induced tumor cell lines.

Tumor cell lines induced by Gross murine leukemia virus were examined for cell-surface major histocompatibility complex class I expression. Three of five cell lines constitutively express H-2K and H-2D class I protein. Culturing these cells with interferon (IFN)-gamma, IFN-alpha/beta, or tumor necrosis factor increases both K and D expression in these cell lines. Two of five tumor cell lines express no class I proteins by fluorescence-activated cell sorter analysis, specific immunoprecipitation, and specific hybridization in Northern analysis. Treatment with IFN-gamma induces D, but not K protein expression in one of these cell lines. IFN-alpha/beta and tumor necrosis factor induce neither D nor K expression in this cell line. Thus, these two cytokines appear to have different mechanisms of action than IFN-gamma for altering class I expression. The other class I-negative tumor cell line does not express either K or D proteins under any conditions tested. All five cell lines express beta 2-microglobulin; this expression is increased by IFN-gamma treatment even in cell lines which do not express class I heavy chain. The results of this study demonstrate that 1) different tumor cell lines demonstrate variations in class I gene regulation, and 2) differences in regulation between class I genes may occur within a single cell line.

AKR murine leukemia virus↗
PubMed1987

Expression of MHC class I genes in mouse hepatitis virus (MHV-A59) infection and in multiple sclerosis.

Our studies revealed that virus induced demyelination as well as human inflammatory demyelination involves upregulation of class I MHC genes and surface expression of antigens encoded by these genes. Induction involves the action of an intermediate soluble factor/s which is at present unknown. These findings suggest that MHC class I restricted, cytotoxic T lymphocyte (CTL) reactions, against self or foreign antigens may play a role in these conditions. These findings may help to elucidate the mechanism of coronavirus-induced demyelination as well as the pathogenesis of multiple sclerosis.

Animals↗
PubMed1987

Decline in mitogen induced proliferation of lymphocytes with increasing age.

We previously reported that mitogen-induced proliferative responses of lymphocytes in the elderly were significantly lower than in young individuals. To determine when this decline occurs, we evaluated the responses of 26-30 subjects of each decile from the third to the tenth decile to the T cell mitogens, phytohaemagglutinin (PHA) and concanavalin A (ConA), and the T dependent B cell mitogen, pokeweed mitogen (PWM). There was a significant decrease in the responses of the 70-, 80- and 90-year-olds to PHA and ConA (less than 40% of the 20-year-olds; P less than 0.01). The 80- and 90-year-olds also showed a decreased response to PWM (approximately 50%; P less than 0.01). The 60-year-olds showed a decreased response to all three mitogens but only the PHA and ConA responses were significantly decreased (P less than 0.01). The 50-year-olds showed a decreased response to ConA, while the 40-year-olds showed decreased responses to both PHA and ConA; both significant at P less than 0.01. The decreased response of the 40-year-olds, however, was only seen in the females. This may be due to the hormonal changes associated with menopause. The general trend of the data suggests that there is a gradual decrease in mitogen-induced proliferative responses with increasing age, large differences become apparent at the age of 60, with a further decrease in the 70s, and most importantly, they remain fairly constant thereafter. Of interest is that only three of the 111 subjects less than 60 years old failed to mount a proliferative response and in each case this was to only one mitogen, while 42 of 118 subjects greater than 60 years old did not respond to at least one mitogen. Ten of these older subjects (2/28 of the 60-year-olds) did not respond to any of the three mitogens (P less than 0.01). This lack of response may be important since we have found a significant association between the lack of response to all three mitogens and increased mortality.

Adult↗
PubMed1986

Immunologic response in an elderly population with a mean age of 85.

Previous studies of changes in immune responses in the elderly have been limited in both number and age of elderly subjects and have produced conflicting results. Using 260 subjects, mean age 84.6, the present study conclusively demonstrates that T cell response is decreased in the elderly. Decreases in response to phytohemagglutinin and concanavalin A were demonstrated in groups aged 70 to 79, 80 to 84, and 85 to 89, although a group 90 to 106 years old showed a decreased response only to phytohemagglutinin. None of the groups had a decreased response to pokeweed mitogen. No response to all three mitogens was observed in 13 percent of the group aged 70 to 89, but in none of the group aged 90 to 106 or in the young groups. No differences in natural killer cell cytotoxicity were observed among the elderly groups. In contrast to previous studies, these results suggest that: the decreased immune response of the elderly is not directly related to age, over age 70; and there may be a selection process in which subjects who live to the age of 90 are those in whom the least decrease in immune response is demonstrated.

Adult↗
PubMed1986

Effect of antibody to interferon on genital herpesvirus infection in mice.

The effect of anti-mouse interferon (IFN) antibody on the course of genital herpes infection was studied in C57B1/6J mice. As we have previously described, intravaginal inoculation of C57 mice with herpes simplex virus type 2 (HSV-2) results in the development of genital lesions, subsequent encephalitis and death, with the mortality rate dependent on virus dose. In the present study, we found that intravaginal application of 1 x 10(5) units of anti-mouse (alpha/beta) IFN antibody did not significantly affect the course of infection. However, intraperitoneal or intravenous injection (the latter to a lesser extent) of anti-IFN antibody resulted in increased morbidity and mortality. In addition, intraperitoneal injection of anti-IFN antibody decreased the level of detectable endogenous IFN in peripheral blood and at the site of infection. The clear effect of anti-IFN antibody during early stages of infection points to the possible significance of early endogenous IFN production in ameliorating HSV-2 genital infection.

Animals↗
PubMed1986

Cytotoxic and morphologic profile of endogenous and pyrimidinone-activated murine NK cells.

We investigated the effect of therapeutically relevant pyrimidinone molecules on murine natural killer (NK) cell cytotoxicity. Our studies demonstrated that pyrimidinones augmented or induced substantial levels of NK cell anti-YAC-1-directed cytotoxic potential in the spleen, bone marrow, peripheral blood, peritoneal exudate, lungs, and liver of adult and infant mice. The NK cell stimulating effect of pyrimidinones was not restricted to a single mouse strain, but was displayed by six different inbred strains of mice. Percoll density gradient separation studies demonstrated that activated effector cells were of low density, displayed morphology of large granular lymphocytes (LGL), and expressed asialo GM-1 cell surface antigen. The analysis of the mechanism of NK cell potentiation showed that the increase in the cytotoxic activity was manifested on several levels, including an increased kinetics of lysis and an increase in the number of LGL and in their tumor-binding and killing capacity. Furthermore, the pyrimidinone-mediated NK cell-augmenting effect was abolished by anti-interferon serum, indicating the role of interferon in NK cell potentiation. In the light of possible role of NK cells in cancer defense, pyrimidinones may have therapeutic value in defense against primary and metastatic tumors.

Adjuvants, Immunologic↗
PubMed1986

Ultrastructure of antibody dependent cellular cytotoxicity in HSV 1 infected and uninfected Chang liver cells.

The binding and ultrastructural features of antibody dependent cellular cytotoxicity (ADCC) mediated by human peripheral blood lymphocytes were studied in herpes simplex virus type I (HSV-1) infected Chang liver (CL) cells plus human anti-HSV-1 serum, and in uninfected CL cells plus guinea pig anti-CL antiserum. Non-cytolytic controls included target cells treated with normal serum in place of sensitized targets and heat shocked lymphocytes instead of normal lymphocytes. By transmission electron microscopy, target cell membranes were either broadly indented by effector cells or locally invaginated by means of effector cell filopodia. In neither case did the indentation appear to break the plasma membrane of the target. Control preparations showed only non-indented areas of simple membrane contact. By scanning electron microscopy, the effector lymphocytes in both the active ADCC and normal serum control preparations had a sparse distribution of short microvilli over their surfaces. The majority of heat shock control lymphocytes appeared normal, but 12-20% demonstrated surface patches devoid of microvilli. The hypothesis that ADCC may involve a three-step process is discussed.

Animals↗
PubMed1986

Ultrastructural study of biochemically modulated ADCC in HSV-1 infected and uninfected Chang liver cells.

The effect of cytochalasin B, ouabain and 25-OH cholesterol on specific lysis due to antibody dependent cellular cytotoxicity (ADCC) in allogeneic and xenogeneic systems was studied using Herpes simplex I infected Chang liver cells. Cytochalasin B reduced both cytotoxicity and lymphocyte/target (LT) binding in the allogeneic system whereas cytotoxicity but not LT binding was reduced in the xenogeneic system. Ouabain inhibited ADCC in both systems as well as LT binding in the allogeneic system; however, binding in the xenogeneic system was not significantly reduced. The 25-OH cholesterol produced a marked decrease in ADCC in both systems but had no significant effect on LT binding in either system. The biochemical and ultrastructural data suggest that the modulators act at different stages in the ADCC response and that there may be more than one mechanism of ADCC to handle different types of target antigens.

Animals↗
PubMed1986

Role of natural killer cells in the mechanism of the antitumor effect of interferon on Moloney sarcoma virus-transformed cells.

The growth of tumors induced by inoculation of cells transformed by Moloney sarcoma virus can be inhibited by in situ administration of interferon (IFN) beginning one day after tumor challenge and continuing for 2 or 3 additional days. Inhibition of tumor growth by IFN was associated with a marked augmentation of natural killer (NK) cell activity, both in the spleen and at the site of tumor challenge, by day 5 after tumor challenge. However, using optimal conditions for IFN treatment, depletion of NK cells by in vivo treatment with anti-asialo GM1 prior to tumor challenge had no significant effect on inhibition of tumor growth by IFN. When the tumor load was greater or when IFN treatment was shorter, treatment with anti-asialo-GM1 partially abrogated the inhibition of tumor growth by IFN. In vitro assays gave no evidence of IFN enhancement of specific T-cell or activated macrophage antitumor effect. These results suggest that under optimal treatment conditions, the mechanism of the antitumor effect of IFN was independent of augmentation of NK activity, but under suboptimal conditions NK cells play a role in the mechanism of the antitumor effect of IFN.

Animals↗
PubMed1985

Induction of natural killer cell activity of thoracic duct lymphocytes by polyinosinic-polycytidylic acid (poly(I:C)) or interferon.

Natural killer (NK) cell activity of thoracic duct lymphocytes (TDL) was examined in normal mice and in mice treated with polyinosinic-polycytidylic acid (poly(I:C) and interferon (IFN). TDL from mice treated with phosphate-buffered saline (PBS) expressed little or no NK cell activity against YAC-1 target cells at effector-to-target ratios of up to 200:1, even after in vitro treatment with murine L-cell IFN. In contrast, TDL from poly(I:C)- or IFN-treated mice expressed significant NK activity, which correlated with the significantly higher NK activity of splenocytes from these mice compared to the NK activity of splenocytes from PBS-treated mice. These data indicate that although TDL from normal mice express no detectable NK cell activity, NK cell activity can be induced in TDL by in vivo treatment with poly(I:C) or IFN.

Animals↗