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Biomedical subjects

J J Hooks

Publications and source records attributed to J J Hooks.

At least 73 records · Page 4Linked to original sources
PubMed1985

Interleukin 2 enhances the natural killer cell activity of acquired immunodeficiency syndrome patients through a gamma-interferon-independent mechanism.

Patients with the acquired immunodeficiency syndrome (AIDS) exhibit a variety of disorders of cellular immunity, including a deficient ability to generate cytotoxic T cells and depressed levels of natural killer (NK) cell activity. Interleukin 2 (IL 2) in vitro can markedly augment these depressed immune functions. Because IL 2 can induce the release of interferon-gamma (IFN-gamma) from normal peripheral blood lymphocytes (PBL), and because IFN-gamma may play a role in the regulation of NK cell activity, this study was performed to determine if the IL 2 enhancement of the NK cell activity of patients with AIDS was an IFN-gamma-dependent effect. PBL from eight healthy heterosexual donors and from nine patients with AIDS were studied for their ability to release IFN-gamma in response to IL 2 at a concentration of 100 U/ml. After 60 hr of culture, the PBL of all eight healthy donors produced IFN-gamma with a mean titer of 113 U/ml (range 40 to 320 U/ml). In contrast, the PBL from only two of nine patients with AIDS released measurable amounts of IFN-gamma (40 U/ml each) in response to IL 2 with a mean titer of 13.5 U/ml for all nine. Although the PBL from patients with AIDS were deficient in their capacity to produce IFN-gamma in response to 100 U/ml of IL 2, significant enhancement of NK cell activity could be obtained after only 1 hr of PBL treatment with 10 U/ml of IL 2, with an optimal NK enhancing effect occurring at doses of 50 to 100 U/ml of IL 2. The use of an anti-IFN-gamma monoclonal antibody resulted in complete neutralization of the IFN released from the normal PBL cultured with IL 2, but failed to inhibit the IL 2 enhancement of NK cell activity. Exogenous IFN-gamma exhibited different kinetics of enhancement of NK cell activity when compared to IL 2, requiring substantially more than 1 hr of pretreatment of PBL. These results indicate that the PBL from patients with AIDS usually do not release IFN-gamma when cultured with IL 2, and that IL 2 enhancement of the depressed NK cell activity of these patients may be an IFN-gamma-independent event. These results may have important implications for the therapy of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Interferon determinations in evaluating the immune response.

IFNs are natural regulatory proteins with a variety of activities. The presence of IFN in the sera and the ability of lymphoid cells to produce IFN in vitro can be useful in the analysis of certain immunologically-mediated disorders. Moreover, analysis of the IFN system may be a very sensitive way to monitor chemically induced changes in immunity.

Humans↗
PubMed1983

The binding of insulin to mouse leucocytes during viral infections.

The effect of viral infections on insulin binding in vivo was evaluated by measuring the binding of 125I-insulin to several different tissues. We found that splenic leucocytes from mice infected with either the diabetogenic (D) or non-diabetogenic (B) variants of encephalomyocarditis virus, herpes simplex virus, or lactic dehydrogenase virus showed up to a 130% increase in insulin binding. As much as a 300% increase in the binding of 125I-insulin to splenic leucocytes was observed in mice given bacterial lipopolysaccharide. In neither virus-infected nor lipopolysaccharide-treated mice was there any substantial change in insulin receptors on thymocytes, liver membranes, or peripheral erythrocytes. Thus, the increased binding of insulin appears to be limited to leucocytes and does not appear to represent a generalized metabolic alteration. These experiments suggest that during infection, the binding of insulin to leucocytes, which is widely used to measure insulin receptors, may not always accurately reflect the insulin receptor status of other tissues.

Animals↗
PubMed1983

Retinitis pigmentosa associated with a defect in the production of interferon-gamma.

Peripheral lymphocytes from patients with retinitis pigmentosa have a deficiency in their ability to produce the lymphokine, interferon-gamma. In 12 patients we found that peripheral leukocytes produced subnormal levels of interferon-gamma. These findings suggested that altered immune reactivity is one of the abnormalities associated with retinitis pigmentosa.

Humans↗
PubMed1983

Interleukin 2-mediated immune interferon (IFN-gamma) production by human T cells and T cell subsets.

Human interleukin 2 (IL 2, or T cell growth factor), which was free of lectin and interferon activity (IFN), induced human peripheral T lymphocytes to produce immune IFN (IFN-gamma). In contrast, non-T cells and macrophages did not produce IFN-gamma in response to IL 2. IL 2 acted directly on unstimulated T cells to induce IFN-gamma production, and also acted in synergy with a suboptimal dose (2 micrograms/ml) of concanavalin A (Con A) to enhance IFN-gamma production. The IFN-gamma-inducing activity of partially purified IL 2 was absorbed along with the IL 2 activity by murine IL 2-dependent CT-6 cell line cells. This further supports the view that IFN-gamma-inducing activity is identical to IL 2. When T cells were separated further into helper/inducer T4+ and suppressor/cytotoxic T8+ subsets by negative selection with monoclonal antibody and complement, both T4+ and T8+-enriched cells produced significant levels of IFN-gamma in response to IL 2. Complete removal of macrophages from purified T lymphocyte populations by treatment of OKM1 plus complement consistently reduced IFN-gamma production in response to IL 2 to a limited degree; readdition of macrophages restored IFN-gamma production by both T cell subsets. This observation that IL 2 contributes to the production of IFN-gamma by human lymphocytes suggests that a cascade of lymphocyte-cell interactions participates in human immune responses.

Absorption↗
PubMed1982

Multiple interferons in the circulation of patients with systemic lupus erythematosus and vasculitis.

Recently, we found interferon in the sera of patients with systemic lupus erythematosus, rheumatoid arthritis, scleroderma, and Sjögren's syndrome. In this study, we surveyed a variety of other immunologically mediated diseases. We did not find interferon in the sera of patients with Wegener's granulomatosis, sarcoidosis, infectious mononucleosis, minimal change nephritis, kidney transplants, myasthenia gravis, or uveitis, but we did find this protein in the sera of patients with active systemic and cutaneous vasculitis. Attempts to characterize the interferon in the sera of patients with systemic lupus erythematosus and vasculitis revealed that antibody to alpha (leukocyte) interferon, but not to beta (fibroblast) interferon, partially or completely neutralized the antiviral activity. The failure of antibody to alpha interferon to completely neutralize the antiviral activity in certain specimens and the lability of the antiviral activity in some specimens to pH 2.0 treatment both suggest that more than one type of interferon was present.

Humans↗
PubMed1982

Gamma (immune) interferon production by leukocytes from a patient with a TG cell proliferative disease.

We report a patient with a disease characterized by proliferation of T cells with Fc receptors for IgG (TG). However, unlike lymphoid cells from normal individuals or from patients with other lymphoid malignancies, the patient's lymphocytes spontaneously produced gamma interferon (IFN-gamma) in vitro. The peripheral lymphocytes consisted of 95% TG cells, which exhibited the morphological characteristics of T-cell chronic lymphocytic leukemia (CLL) and were normal on cytochemical and chromosome analysis. The majority of TG cells were OKT3+, OKT8+, and OKT4-, 3A1-. These cells failed to express suppressor cell activity and displayed depressed levels of natural killer activity, but mediated antibody-dependent cell-mediated cytotoxicity. The spontaneous production of IFN-gamma by human peripheral lymphoid cells as demonstrated in this study may serve as a probe for studying the relationship between IFN-gamma and the proliferation of human T-cell subsets.

Cells, Cultured↗
PubMed1982

Modulation of polyclonal B cell differentiation by human leucocyte alpha interferon.

Although interferon (IFN) profoundly affects immune responses in animals, less is known about its immunoregulatory activity in man. Therefore, peripheral blood mononuclear cells (PBM) from 20 healthy volunteers were incubated with pokeweed mitogen (PWM) in the presence and absence of human leucocyte alpha interferon (IFN alpha). In 18/20 experiments, IFN alpha added at initiation of culture markedly suppressed PWM-induced generation of immunoglobulin secreting cells (IgSC). IFN alpha suppressed proliferative responses in all experiments but the degree of suppression was not correlated with concomitant suppression of IgSC responses. Suppressive activity was resistant to pH 2 treatment but sensitive to treatment with trypsin. Delayed addition of IFN alpha was associated with decreased suppression. Suppression was not due to non-specific cytotoxicity since we observed (1) comparable viabilities in cultures with or without IFN alpha and (2) negligible effect when IFN alpha was added for the final 24 hr of culture. The data confirm previously described effects of IFN on mitogen stimulated PBM and, more importantly, provide convincing evidence that IFN alpha regulates human B cell functions.

B-Lymphocytes↗
PubMed1981

Enhancement of basophil chemotaxis in vitro by virus-induced interferon.

It is well established that viral infections may precipitate or worsen attacks of bronchial asthma. Furthermore, in symptomatic atopic subjects, the local accumulation of basophils and the production of a basophil chemotactic factor have been reported. We have investigated the effect of cell-free supernates from viral stimulated cultures of human mononuclear cells on the in vitro migration of human basophils. Our results show the presence of a factor in these culture supernates that enhances the migration of basophils toward two separate chemoattractants, a peptide from C5 and a lymphokine. The enhancing activity, while affecting basophil migration, did not change the response of monocytes. The enhancing activity resembled viral-induced interferon when (a) pH 2 stability, (b) heat resistance, (c) trypsin sensitivity, and (d) species-specificity were compared. Finally, the enhancing activity for basophil chemotaxis and the interferon titer were highly correlated in preparations with a 10(4)-fold difference in interferon specific activity. Our studies show that viral-induced interferon can augment the in vitro chemotactic response of basophils. Because mediators present in basophils may be involved in the pathogenesis of immediate hypersensitivity, the modulation of basophil movement by interferon suggests a possible mechanism for the association between viral infections and atopic disorders.

Animals↗
PubMed1980

The role of interferon in immediate hypersensitivity and autoimmune diseases.

We have presented evidence showing that interferon can enhance the IgE-mediated release of histamine. We have also shown that immune interferon is present in the circulation of patients with certain autoimmune diseases. Furthermore, there is a positive correlation between active systemic lupus erythematosus and interferon levels. Systemic lupus erythematosus is characterized by immune hyperactivity. The continuous presence of type II, immune interferon in the circulation of these patients may, on one hand, contribute to the immunological aberrations, while on the other hand, protect against viral infections. At the present time we are looking for interferon in the circulation of patients with other autoimmune disorders.

Autoimmune Diseases↗
PubMed1980

Virus-induced decrease of insulin receptors in cultured human cells.

Viral infections may produce abnormalities in carbohydrate metabolism in normal subjects and profound changes in glucose homeostasis in insulin-dependent diabetics. Using an in vitro radio-receptor assay with 125I-labeled insulin and human-amnion (WISH) cells, the effect of viral infections on insulin receptors was examined. Both herpes simplex virus and vesicular stomatitis virus produced a 50% decrease in insulin binding. There was no evidence that this decrease was due to degradation of insulin. On quantitative analysis, this decrease in binding was found to be the result of a decrease in receptor concentration with no change in receptor affinity. The decrease in receptors occurred between 4 and 12 h, at the time viral antigens were being inserted into the plasma membrane of infected cells. Because the t 1/2 of insulin receptors in uninfected cells was between 14 and 24 h, the decrease in insulin receptors cannot be explained solely by virus-induced shut-off of macromolecular synthesis. Moreover, viruses such as encephalomyocarditis that do not insert new antigens into the plasma membrane, did not cause changes in the number of insulin receptors. The most likely explanation is that virus-induced changes in the plasma membrane altered or displaced insulin receptors. It is concluded that the insulin receptor assay is a sensitive and quantitative method for studying the effect of viral infections on cell membranes. These data also suggest that abnormalities in glucose metabolism associated with some viral infections may be due, in part, to changes in the concentration of insulin receptors.

Amnion↗
PubMed1980

Enhancement of IgE-mediated histamine release from human basophils by immune-specific lymphokines.

Human leucocytes (basophils) release histamine when exposed to ragweed antigen E or anti-IgE. The present study shows that when leucocytes from BCG-positive donors are first incubated with PPD and then challenged with anti-IgE, histamine release is enhanced. In contrast, when leucocytes from BCG-negative donors are incubated with PPD and then challenged with anti-IgE there is no enhancement of histamine release. The enhancement of histamine release was detected within 24 hr after addition of PPD, but was maximal at 48 to 72 hr. Supernatant fluids collected from these leucocyte cultures revealed the presence of a soluble mediator(s) which, when incubated with leucocytes from BCG-negative donors, enhanced the release of histamine. Examination of the supernatant fluids from BCG-positive leucocyte cultures stimulated with PPD showed a correlation between histamine-release enhancing activity and interferon. Treatment of the culture fluids at pH 2.0 abolished the anti-viral activity, indicating that the interferon was of the type II or 'immune' class. The same treatment only partly abolished the histamine-release enhancing activity. It is concluded that immune-specific stimulation of leucocytes results in the release of soluble mediators that are capable of enhancing IgE-mediated histamine release.

Adult↗
PubMed1979

Immune interferon in the circulation of patients with autoimmune disease.

The observation that type II, or immune, interferon could be produced by peripheral-blood leukocytes in vitro on an immune-specific basis suggested that it also might be produced in vivo in various autoimmune disorders. We found immune interferon in the serums of patients with systemic lupus erythematosus, rheumatoid arthritis, scleroderma and Sjögren's syndrome. Among 28 patients with systemic lupus erythematosus, 71 per cent of those with active and 21 per cent of those with inactive disease showed interferon in their serums. Serial serum samples showed a good correlation between interferon titers and disease activity. Moreover, interferon titers correlated positively with antibodies to DNA and negatively with serum levels of the third component of complement. It is possible that the production of interferon may contribute to immunologic aberrations in auto-immune diseases and also protect the already compromised host from viral infections.

Adult↗