Corticosteroids inhibit the generation of lymphokine-activated killer activity in vitro

Intralesional lymphokine-activated killer cells as adjuvant therapy for primary glioblastoma

Despite recent advances, median survival for patients with resectable glioblastoma multiforme (GBM) is only 12 to 15 months. We previously observed minimal toxicity and a 9.0-month median survival after treatment with intralesional autologous lymphokine-activated killer (LAK) cells in 40 patients with recurrent GBM. In this study, GBM patients were treated with adjuvant intralesional LAK cells. Eligible patients had completed primary therapy for GBM without disease progression. LAK cells were produced by incubating autologous peripheral blood mononuclear cells with interleukin-2 for 3 to 7 days and then placed into the surgically exposed tumor cavity by a neurosurgeon. The 19 men and 14 women had a median age of 57 years. Prior therapy included surgical resection (97%), partial brain irradiation (97%), gamma knife radiosurgery (97%), and temozolomide chemotherapy (70%). Median time from diagnosis to LAK cell therapy was 5.3 months (range: 3.0 to 11.1 mo). LAK cell treatment was well tolerated; average length of hospitalization was 3 days. At the time of this analysis, 27 patients have died; the median survival from the date of original diagnosis is 20.5 months with a 1-year survival rate of 75%. In subset analyses, superior survival was observed for patients who received higher numbers of CD3+/CD16+/CD56+ (T-LAK) cells in the cell products, which was associated with not taking corticosteroids in the month before leukopheresis. Intralesional LAK cell therapy is safe and the survival sufficiently encouraging to warrant further evaluation in a randomized phase 2 trial of intralesional therapies with LAK or carmustine-impregnated wafers.

Psychosocial adaptation and cellular immunity in breast cancer patients in the weeks after surgery: An exploratory study

BACKGROUND

The period just after surgery for breast cancer requires psychosocial adaptation and is associated with elevated distress. Distress states have been associated with decreased cellular immune functioning in this population, which could have negative effects on physical recovery. However, little is known about relations between psychological status [negative and positive mood states and overall quality of life (QOL)] and cellular signaling cytokines that could account for these associations in women undergoing treatment for breast cancer.

METHODS

The present study examined associations between psychological adaptation indicators (mood, QOL) and T-helper cell type 1 (Th1) cytokine production from stimulated peripheral mononuclear cells in women who had recently undergone surgery for early-stage breast cancer but had not yet begun adjuvant therapy. These associations were evaluated while controlling for relevant disease/treatment, sociodemographic, and health behavior covariates.

RESULTS

Lower anxiety related to greater production of the Th1 cytokine interleukin-2 (IL-2), while greater positive mood (affection) related to greater production of the Th1 cytokines IL-12 and interferon-gamma (IFN-gamma). Better QOL related to greater production of the Th1 cytokine, tumor necrosis factor-alpha (TNF-alpha).

CONCLUSION

Individual differences in psychosocial adaptation in women with breast cancer during the period after surgery relate to biological parameters that may be relevant for health and well-being as they move through treatment.

Interferon-gamma-induced calcium influx in T lymphocytes of multiple sclerosis and rheumatoid arthritis patients: a complementary mechanism for T cell activation?

Autoreactive T lymphocytes are considered to play a crucial role in orchestrating a chronic inflammation in the central nervous system (CNS) of multiple sclerosis (MS) patients and in the joints of rheumatoid arthritis (RA) patients. However, it has been suggested that the majority of T cells in the immune infiltrate are nonspecifically recruited into the CNS and into the inflamed joint. In addition, several lines of evidence suggest an important role for interferon-gamma (IFN-gamma) in the pathogenesis of MS and RA. We have studied whether peripheral blood T cells from patients with autoimmune diseases are more susceptible to activation in the presence of IFN-gamma. The results indicate that IFN-gamma mediates a sustained elevated [Ca(2+)](i) in T cells of (active) MS and RA patients as compared to healthy controls and patients with common viral infections. No [Ca(2+)](i) increase was observed in Ca(2+)-free medium, excluding an effect of IFN-gamma on Ca(2+)-release from intracellular stores. Although the IFN-gamma-activated Ca(2+)-influx is insufficient to induce T cell proliferation in vitro, our data indicate a significantly augmented proliferation in response to suboptimal doses of PHA in the presence of IFN-gamma. This study suggests that the IFN-gamma-induced Ca(2+)-influx can act as a complementary mechanism in the activation of blood T lymphocytes from MS and RA patients.

Effects of in vitro treatment with fluticasone propionate on natural killer and lymphokine-induced killer activity in asthmatic and healthy individuals

BACKGROUND

Topical corticosteroids are beneficial in the treatment of allergic respiratory disorders; they exert effects on a number of cells involved in allergic inflammatory reactions. On the other hand, major histocompatibility complex (MHC)-unrestricted cytotoxicity (i.e., natural killer [NK] cell activity) may play a role in the inflammatory allergic reaction. The objective was to gain insight into the mechanisms of the therapeutic effects of fluticasone propionate (FP), an inhaled corticosteroid used in asthma and rhinitis therapy. Therefore, we evaluated the NK and lymphokine-activated killer (LAK) activity of effector cells in vitro treated or not with FP.

METHODS

Evaluations were made on peripheral blood mononuclear cells (PBMNCs), obtained from healthy volunteers (n = 10) and from asthmatic atopic subjects (n = 10) with allergy to Parietaria.

RESULTS

Asthmatic patients had significantly increased NK activity (P= 0.0008), and interleukin (IL)-2- (P=0.0005) and interferon (IFN)-alpha-induced LAK activities (P=0.0005). In both groups, FP 10(-7) M significantly reduced NK activity (P<0.0001), IL-2-induced LAK activity (P<0.0001), and IFN-alpha-induced LAK activity (P<0.0001). Similar results were obtained with FP 10(-8) M.

CONCLUSIONS

Since MHC-unrestricted cytotoxicity has been implicated in the development of allergen-induced eosinophilic airway inflammation, inhibition of NK and LAK activity by FP may contribute to the steroid therapeutic effect in asthma.

Evidence that cisplatin induces serotonin release from human peripheral blood mononuclear cells and that methylprednisolone inhibits this effect

Corticosteroids counteract cisplatin (CDDP)-induced acute emesis but the mechanism involved is still unknown. Therefore, the aim of this study was to verify whether CDDP can induce serotonin (5HT) release from peripheral blood mononuclear cells (PBMC) and determine whether methylprednisolone (MP) can inhibit such release. Blood from 10 healthy volunteers was used. Our study showed that CDDP did induce 5HT release from PBMC dose-dependently (10 +/- 1 nM for controls, 18 +/- 4 nM for CDDP 0.01 microgram and 30 +/- 4 nM for CDDP 0.1 microgram, P < 0.001) and that the addition of MP to cultures of PBMC in the presence of CDDP induced a significant decrease of 5HT concentrations. Our results highlight a new mechanism through which CDDP could induce emesis and suggest a further mechanism by which corticosteroids mediate their anti-emetic effect.

Interleukin-2 as a neuroregulatory cytokine

Interleukin-2 (IL-2), the cytokine also known as T-cell growth factor, has multiple immunoregulatory functions and biological properties not only related to T-cells. In the past decade, substantial evidence accumulated to suggest that IL-2 is also a modulator of neural and neuroendocrine functions. First, extremely potent effects of IL-2 on neural cells were discovered, including activities related to cell growth and survival, transmitter and hormone release and the modulation of bioelectric activities. IL-2 may be involved in the regulation of sleep and arousal, memory function, locomotion and the modulation of the neuroendocrine axis. Second, the concept that IL-2 could act as a neuroregulatory cytokine has been supported by reports on the presence in rodent and human brain tissues of IL-2-like bioactivity, IL-2-like immunoreactivity, IL-2-like mRNA, IL-2 binding sites, IL-2 receptor (IL-2R alpha) and beta chain mRNA and IL-2R immunoreactivity. IL-2 and/or IL-2R molecules mainly localize to the frontal cortex, septum, striatum, hippocampal formation, hypothalamus, locus coeruleus, cerebellum, the pituitary and fiber tracts, such as the corpus callosum, where they are likely expressed by both neuronal and glial cells. Although the molecular biology of the brain IL-2/IL-2R system (including its relation to IL-15/IL-15R alpha) is not yet fully established by cloning and complete sequencing of all respective components, similarities (and to some extent differences) to peripheral counterparts are now apparent. The ability of IL-2 to readily penetrate the blood-brain barrier further suggests that this cytokine could regulate interactions between peripheral tissues and the central nervous system. Taken together, these data suggest that IL-2 of either immune and CNS origin can have access to functional IL-2R molecules on neurons and glia under normal conditions. Additionally, dysregulation of the IL-2/IL-2 receptor system could lead or contribute to functional and pathological alterations in the brain as in the immune system. Understanding the neurobiology of the IL-2/IL-2 receptor system should also help to explain neurologic, neuropsychiatric and neuroendocrine side effects occurring during IL-2 treatment of peripheral and brain tumors. Immunopharmacological manipulation either aiming at the activation or suppression of IL-2 signaling should consider functional interference with constitutive and inducible IL-2 receptors on brain cells in order to fulfil the high expectations associated with the use of this cytokine as a promising agent in immunotherapies, especially of brain tumors.

The failure of current immunotherapy for malignant glioma. Tumor-derived TGF-beta, T-cell apoptosis, and the immune privilege of the brain

Human malignant gliomas are rather resistant to all current therapeutic approaches including surgery, radiotherapy and chemotherapy as well as antibody-guided or cellular immunotherapy. The immunotherapy of malignant glioma has attracted interest because of the immunosuppressed state of malignant glioma patients which resides mainly in the T-cell compartment. This T-cell suppression has been attributed to the release by the glioma cells of immunosuppressive factors like transforming growth factor-beta (TGF-beta) and prostaglandins. TGF-beta has multiple effects in the immune system, most of which are inhibitory. TGF-beta appears to control downstream elements of various cellular activation cascades and regulates the expression of genes that are essential for cell cycle progression and mitosis. Since TGF-beta-mediated growth arrest of T-cell lines results in their apoptosis in vitro, glioma-derived TGF-beta may prevent immune-mediated glioma cell elimination by inducing apoptosis of tumor-infiltrating lymphocytes in vivo. T-cell apoptosis in the brain may be augmented by the absence of professional antigen-presenting cells and of appropriate costimulating signals. Numerous in vitro studies predict that tumor-derived TGF-beta will incapacitate in vitro-expanded and locally administered lymphokine-activated killer cells (LAK-cells) or tumor-infiltrating lymphocytes. Thus, TGF-beta may be partly responsible for the failure of current adoptive cellular immunotherapy of malignant glioma. Recent experimental in vivo studies on non-glial tumors have corroborated that neutralization of tumor-derived TGF-beta activity may facilitate immune-mediated tumor rejection. Current efforts to improve the efficacy of immunotherapy for malignant glioma include various strategies to enhance the immunogenicity of glioma cells and the cytotoxic activity of immune effector cells, e.g., by cytokine gene transfer. Future strategies of cellular immunotherapy for malignant glioma will have to focus on rendering glioma cell-targeting immune cells resistent to local inactivation and apoptosis which may be induced by TGF-beta and other immunosuppressive molecules at the site of neoplastic growth. Cytotoxic effectors targeting Fas/APO-1, the receptor protein for perforin-independent cytotoxic T-cell killing, might be promising, since Fas/APO-1 is expressed by glioma cells but not by untransformed brain cells, and since Fas/APO-1-mediated killing in vitro is not inhibited by TGF-beta.

Dexamethasone suppresses T cell-mediated immunity and enhances disease susceptibility to Eimeria mivati infection

The effect of dexamethasone (DEX) on Eimeria mivati infection in chickens was examined. Chickens given an extended DEX treatment produced significantly higher numbers of total oocysts following primary and secondary infections with E. mivati. Chickens treated with DEX intramuscularly or orally showed lower body weight gain in E. mivati infected or uninfected chickens as compared with the untreated group. Chickens given DEX intramuscularly showed a lower number of splenic lymphocytes. Flow cytometric analysis of lymphocyte composition revealed that the percentages of splenic lymphocytes bearing CD8 (cytotoxic-suppressor T cells), gamma delta T cell receptor (TCR 1), class II major histocompatibility or surface IgM antigens in DEX-treated chickens were lower than in controls, whereas the percentages of T lymphocytes expressing CD3, CD4 (helper T cells) or alpha beta TCR antigens were significantly higher. Furthermore, concanavalin A-induced lymphoproliferation, interleukin-2 (IL-2) and gamma-interferon (gamma-IFN) production by spleen lymphocytes were generally depressed in DEX-treated chickens. IL-2 production of E. mivati-infected chickens given oral DEX was significantly lower compared with the uninfected-DEX-treated group. Uninfected chickens treated with DEX intramuscularly showed a significantly lower gamma-IFN production compared with other uninfected groups. In contrast, serum IgG levels were enhanced in DEX-treated, E. mivati-infected chickens compared with untreated, infected chickens. These results suggest that enhanced disease susceptibility to coccidiosis in DEX-treated chickens may reflect a drug-mediated immunosuppression of cell-mediated immunity.

The two-edged sword of large-dose steroids for spinal cord trauma

OBJECTIVE

In 1990, large-dose steroid administration was advocated in spine-injured patients to lessen neurologic deficits. The authors undertook both prospective and retrospective studies to evaluate the response of such profound pharmacologic intervention.

SUMMARY BACKGROUND DATA

Of all sources of nonfatal injury, spinal cord trauma remains the most devastating in both cost and impact on the quality of the patient's life. One study found that routine large-dose steroid administration after injury lessened the extent of neurologic injury. After uncommonly prompt and broad lay press publicity, this practice was widely accepted. Biased by knowledge of the known immunosuppressive effects of steroids, the authors suspected that pneumonia was both more frequent and severe in steroid-treated patients.

METHODS

Thirty-two patients with cervical or upper thoracic spinal injuries (C3-6, 20 patients; C6-7, 6 patients; and T1-6, 6 patients) were studied at an urban level I trauma center from January 1987 to February 1993. Complete spinal cord injury was present in 22 of 32 patients; 14 patients received steroids postinjury. There was no difference in mean age, cord level, age-adjusted injury severity score, or the percent of injury severity score caused by the spinal injury.

RESULTS

The length of hospital stay was longer in steroid-treated patients (S) than in nonsteroid (NS) patients, that is, 44.4 days versus 27.7 days, respectively (p = 0.065). Seventy-nine per cent of S patients had pneumonia compared with 50% of NS patients (p = 0.614). There was no statistical difference in the episodes of pneumonia per patient between the two groups (p > 0.05). Prospectively, the authors evaluated sequentially several parameters known to be important in human immune responses to bacterial challenges in nine S and five NS patients. In S patients, both the per cent and density of monocyte class II antigen expression and T-helper/suppressor cell ratios were lower than in NS patients. However, S patients did have an initially higher, earlier boost in some host defense parameters that rapidly declined, and their subsequent response was both blunted and delayed. These differences became even clearer when stratified according to cord level and incomplete versus complete cord status. Not surprisingly, infected patients, whether S or NS, had lower levels of monocyte antigen expression, CR3, and helper/suppressor ratios.

CONCLUSIONS

These data do not permit a judgment to be made whether neurologic status was improved by S administration. It is known that vital immune responses were adversely affected, that pneumonia was somewhat more prevalent, and that hospitalization was prolonged and costs therefore increased by an average of $51,504 per admission. Further clinical studies will be needed to determine to what extent these observations offset the putative benefits of large-dose steroids in the treatment of spinal trauma.

Corticosteroids inhibit the delivery of short-term activational pulses of phorbol ester and calcium ionophore to human peripheral T cells

Although there is evidence that corticosteroids inhibit receptor-ligand-induced phospholipid hydrolysis, the immunosuppressive effects of these agents downstream of protein kinase C (PK-C) activation and cytosolic Ca2+ mobilization is unclear. Previous studies indicated that T cell proliferative activation could be achieved with simultaneous short-term (e.g., 15-120 min) exposure to agents activating PK-C and elevating cytosolic Ca2+. In the studies reported here, similar procedures were utilized for determining whether corticosteroids alter T cell activation signals downstream of second messenger events. Dexamethasone interfered with T cell activation induced by short-term exposure to phorbol 12,13-dibutyrate (PDBu) and the calcium ionophore, ionomycin. The inhibitory effect was evident with as little as 15 min of exposure to dexamethasone and T cell activating agents, making mechanisms involving de novo protein synthesis unlikely. Dexamethasone's effects in this system were blocked by the steroid receptor antagonist RU-486, indicating that the inhibition was mediated through the glucocorticoid receptor. The inclusion of recombinant interleukin-2 (IL-2) only partially overcame the dexamethasone inhibitory effect. Long-term (i.e., 48 hr) direct stimulation of PK-C with either PDBu or the non-tumor-promoting PK-C activator, bryostatin 1, also substantially overcame dexamethasone's effects, resulting in a recovery of IL-2 production and significant restoration of the T-cell proliferative response. These observations suggest that treatment with a PK-C-activating agent such as bryostatin 1 could reduce glucocorticosteroid-induced immunosuppression.

In vitro analysis of the proliferative potential of T cells from patients with brain tumor: glioma-associated immunosuppression unrelated to intrinsic cellular defect

Patients harboring a malignant brain tumor have been described as being highly immunosuppressed, as evidenced by reduced numbers of T cells and the decreased ability of their lymphocytes to produce interleukin-2 (IL-2). In order to determine whether an intrinsic abnormality exists in the T lymphocytes of glioma patients and to evaluate what role corticosteroids may play in glioma-associated immunosuppression, in vitro T cell proliferative function in the presence of recombinant IL-2 (rIL-2) was examined in age-matched groups of normal control subjects, steroid-free patients with glial tumors, steroid-dependent patients with glial tumors, and steroid-dependent patients with nonglial cerebral tumors. The results demonstrated that, when enriched T cell populations of all brain-tumor patients were stimulated with rIL-2 and phytohemagglutinin (PHA), there were no statistically significant differences between any groups. In contrast, when T cell populations were stimulated with mitogenic combinations of phorbol ester, calcium ionophore, and rIL-2, those from steroid-dependent patients with glial tumors had a significantly lower response than those from normal control subjects, suggesting that a population of T cells capable of responding to phorbol ester/ionomycin and not PHA stimulation is inhibited by corticosteroid therapy in glioma patients. In addition, T cells of four brain-tumor patient/age-matched control subject pairs were stimulated with either phorbol ester/ionomycin or PHA for 24 hours; three of the four patients expressed low-affinity IL-2 receptor levels as high or higher than their respective control subjects, suggesting that IL-2 receptor expression in these patients may be quantitatively normal once the T cell number is corrected. Taken together, these results show that the decreased PHA responsiveness that has been previously reported in lymphocytes of glioma patients is not due to a cellular abnormality within the potentially responsive cells, but rather reflects the reduced proportion of T cells within their peripheral blood which, as a consequence, reduces the level of IL-2 production attained upon activation.

T-cell growth factors and the treatment of patients with cancer

T-cell maturation has traditionally been felt to occur primarily within the thymus but it is now clear that dynamic processes in the periphery govern many functions such as T-cell activation, proliferation, tolerization, and migration into peripheral tissues. Four T-cell growth factors have now been identified. These include: interleukin-2 (IL-2), IL-4, IL-7, and a potent cofactor recently described, IL-10. These factors are believed to work synergistically in the fine regulation of the lymphoid pool. Both IL-2 and IL-4 have entered clinical trials with significant responses in the IL-2-based regimens of up to 40 to 50% in certain tumors. IL-7 and IL-10 are in preclinical studies. Although IL-2, IL-4, and IL-7 have been shown to induce lymphokine-activated killer cell activity from sensitive precursors, such studies have yet to be performed with IL-10.

Immunotherapy for malignant glioma using human recombinant interleukin-2 and activated autologous lymphocytes. A review of pre-clinical and clinical investigations

Over the past few years, we and a number of other groups have conducted laboratory experiments and clinical trials of human recombinant interleukin-2 (rIL-2) alone or in combination with autologous 'activated' lymphocytes expressing in vitro tumoricidal activity in order to define toxicity and indicate its potential efficacy in patients with high-grade glioma. Because high rIL-2 concentrations can be attained with considerably less toxicity than with a systemic approach, all of the clinical trials, to date, have chosen a direct route; injecting lymphokine and cells into tumor tissue, the cystic cavity remaining after tumor excision, and/or neural parenchyma surrounding the site of tumor excision. While the rIL-2 therapies, as they have been applied in animal glioma models and patients, are safe, cerebral edema around the site of treatment has been a consistent finding. We have also seen, however, that steroid medications used by patients to control their cerebral edema may depress the anti-tumor activity of rIL-2 by depressing the capacity of lymphocytes to develop normal LAK activity. Although none of the immunotherapies involving rIL-2 have produced cures, the fact that sustained clinical responses have been reported, suggests that such therapies may slow a recurrence of tumor at the site of treatment. Efforts to improve outcome from rIL-2--based immunotherapies for malignant glioma are continuing with manipulation of rIL-2 dosing and scheduling and also with combinations of rIL-2 and other recombinant cytokines.