Corticosteroids and the immune response

Effect of Perfluorooctanesulfonic acid (PFOS) on immune cell development and function in mice

Perfluoroctanesulfonate (PFOS) belongs to a larger family of compounds known as Per- and polyfluoroalkyl substances (PFAS). The strength of the carbon-fluorine bond makes PFOS extremely resistant to environmental degradation. Due to its persistent nature, research has been directed to elucidating possible health effects of PFOS on humans and laboratory animals. Here we have explored the effects of PFOS exposure on immune development and function in mice. We exposed adult mice to 3 and 1.5 μg/kg/day of PFOS for 2 and 4 weeks, respectively, and examined the effects of PFOS exposure on populations of T cells, B cells, and granulocytes. These doses of PFOS resulted in serum levels of approximately 100 ng/mL with no weight loss during exposure. We find that PFOS does not affect T-cell development during this time. However, while PFOS exposure reduced immune cell populations in some organs, it also led to an increase in the numbers of cells in others, suggesting possible relocalization of cells. We also examined the effect of PFOS on the response to influenza virus infection. We find that exposure to PFOS at 1.5 μg/kg/day of PFOS for 4 weeks does not affect weight loss or survival, nor is viral clearance affected. Analysis of antibody and T cell specific antiviral responses indicate that at this concentration, PFOS does not suppress the immune cell development or antigen specific immune response.

Elevated levels of preoperative circulating CD44⁺ lymphocytes and neutrophils predict poor survival for non-small cell lung cancer patients

BACKGROUND

Certain circulating cells have been shown to predict the clinical outcome of several cancers. The objective of this study was to identify clinical, hematological and immunological predictors of prognosis in non-small cell lung cancer (NSCLC) patients.

METHODS

A retrospective study on a prevalent cohort of 225 NSCLC patients hospitalized at the Zhejiang Province Cancer Hospital (ZPCH) was conducted from August 1, 2006 to April 15, 2008. Circulating lymphocytes were measured by flow cytometry. WBC count and classification in peripheral blood were measured with a Coulter counter. We calculated the proportion of patients surviving after first hospital admission and hazard ratios (HR) using the Cox proportional hazards model.

RESULTS

Elevated levels of preoperative circulating CD44(+) lymphocytes, WBCs and neutrophils indicated low cumulative survival. Clinical stage (HR: 2.292; 95% confidence interval (CI): 1.34-3.91, P=0.002), neutrophils (HR: 1.877; 95% CI: 1.34-2.62, P<0.001) and CD44(+) lymphocytes (HR: 1.018; 95% CI: 1.00-1.03, P=0.002) are independent predictors of survival in NSCLC patients, respectively. Elevated levels of CD44(+) lymphocytes and neutrophils correlated with distant metastasis and prognosis in NSCLC patients with stage III/IV, respectively.

CONCLUSIONS

CD44(+) lymphocytes along with neutrophils could serve as an independent prognostic marker for NSCLC patients.

Osmotic effects of ethanol on lymphocytes

The alterations in the immune system caused by ethanol appear to be a complex combination of direct and indirect effects. The role of ethanol as an osmolyte has previously been studied in this laboratory with rat splenocytes. In the present study the osmotic effects of ethanol were investigated in lymphocytes from human normal subjects and alcohol abusers. Mitogen-stimulated lymphocytes were cultured in vitro with ethanol in hyperosmotic isotonic or iso-osmotic hypotonic conditions. The former conditions mimic the physiological situation where ethanol increases osmolality in an electrolyte-balanced environment. Under these conditions, lymphocyte proliferation was unaffected. Ethanol addition in iso-osmotic hypotonic conditions, where there is electrolyte imbalance, was associated with inhibition of T-lymphocyte proliferation. Hyperosmotic hypertonic solutions in the absence of ethanol also resulted in inhibition of T-lymphocyte proliferation. Electron microscopy and measurement of cell viability and metabolic activity (lactate and ATP levels) indicated that the decreased proliferation associated with NaCl-induced hyperosmotic hypertonic conditions was at least partially attributable to cell death together with, and possibly caused by, detrimental effects on mitochondria. Conversely, decreased T-lymphocyte proliferation in iso-osmotic hypotonic high ethanol solutions, appeared not to be due to changes in cell viability, nor alterations to energy metabolism. It is proposed that ion fluxes involved in the maintenance of cell volume, in particular K ⁺ movement, may be important in facilitating normal lymphocyte proliferation in the presence of ethanol in pathological conditions associated with electrolyte imbalance.

Effects of histamine application and water-immersion stress on gizzard erosion and fattening of broiler chicks

Three groups of Hybro broiler chickens, of which one group were controls, a second treated intragastrically with histamine, and a third stressed by immersion in water, were used in the experiment. Serum activities of aspartate and alanine aminotransferase and creatine kinase were evaluated. Gizzard erosion length, body weight during fattening, slaughter-house or final body weight, food consumption and antibody titre after vaccination for Newcastle disease were also measured. Stress induced severe gizzard erosion and decreased body weight, especially in male birds, whilst both stressed and histamine-treated groups of chicks had decreased antibody titres that were especially pronounced in the stressed animals. Food consumption and aspartate aminotransferase and creatine kinase activities were increased in the stressed chicks.

Dental indicators of stress and reduced age at death in prehistoric Native Americans

Considerable evidence supports the hypothesis that developmental enamel defects represent stress-induced growth disruptions. In this investigation, the relationship between different kinds of enamel defects and age at death is examined in the prehistoric Libben population from Ottawa County, Ohio. The sample consisted of the permanent dentitions of 143 individuals. Defects were classified based on the criteria of the Developmental Defects of Enamel (DDE) Index. The multifactorial age at death determinations of Lovejoy and coworkers (1977) were used in this analysis. Results reveal a significantly lower mean age at death for individuals with enamel defects vs. individuals with normal teeth. This pattern was clearly present for all defect types examined. No significant differences by sex were detected. The age-at-death distribution for individuals with normal teeth approximated the normal curve. The modal value was reached in the 35-40 year age class. The age-at-death distribution for individuals with enamel defects showed two peaks. The mode occurred in the 15-20 year age class, and the second, lower peak occurred in the 30-35 year age class. The early mortality of individuals with enamel defects may be related to biological damage to the immune system during prenatal or postnatal development.

Effects of midazolam on T-cell immunosuppressive response to surgical stress in mice

Mice submitted to surgical stress induced by laparotomy and treated with chronic midazolam (1 mg/kg) showed a reduction in stress-induced suppression of thymus and spleen cellularity and in peripheral lymphocyte population. The blastogenic response of spleen lymphoid cells was also assessed and midazolam was found to partially attenuate the suppressive effect of surgery.

Effects of alprazolam on the development of MTV-induced mammary tumors in female mice under stress

Female C3H/He mice carrying the mammary tumor virus (MTV) were monitored for mammary tumor incidence and latent periods while subjected to a daily intraperitoneal (i.p.) injection of placebo or alprazolam (1 mg/kg per day). Although all of the mice were potential candidates for MTV-induced breast cancer, those injected with alprazolam were partially protected against adverse effects of stress induced by the daily administration of placebo.

Effects of amphetamine on the development of MTV-induced mammary tumors in female mice

Female C3H/He mice carrying the mammary tumor virus (MTV) were monitored for mammary tumor incidence and latent periods while submitted to a daily subcutaneous injection with amphetamine (0,4 mg/kg/day). Results show that amphetamine caused an increase in incidence and a decrease in latency of tumors compared with placebo. There was also appreciated a correlation with the lethality of mice.

Glucocorticoids regulate the synthesis of glial fibrillary acidic protein in intact and adrenalectomized rats but do not affect its expression following brain injury

Short (5 days)- to long-term (4 months) corticosterone (CORT) administration by injection, pellet implantation, or in the drinking water decreased glial fibrillary acidic protein (GFAP) by 20-40% in hippocampus and cortex of intact rats. In contrast to CORT, adrenalectomy (ADX) caused elevations (50-125%) in hippocampus and cortex GFAP within 12 days of surgery that persisted for at least 4 months. CORT replacement of ADX rats decreased GFAP amount in hippocampus and cortex. The effects of long-term CORT and ADX on GFAP in hippocampus and cortex were also seen in striatum, midbrain, and cerebellum, findings suggestive of brain-wide adrenal steroid regulation of this astrocyte protein. The changes in GFAP amount due to CORT and ADX were paralleled by changes in GFAP mRNA, indicating a possible transcriptional or at least genomic effect of adrenal steroids. Glucocorticoid regulation of GFAP was relatively specific; it could not be generalized to other astrocyte proteins or other major structural proteins of neurons. The negative regulation of GFAP and GFAP mRNA by adrenal steroids suggested that increases in GFAP that result from brain injury may be attenuated by glucocorticoids. However, chronic CORT treatment of intact rats did not reverse or reduce the large increases in GFAP caused by trauma- or toxicant-induced brain damage. Thus, glucocorticoids and injury appear to regulate the expression of GFAP through different mechanisms. In contrast to the lack of effects of CORT on brain damage-induced increases in GFAP, CORT treatment begun in 2-week ADX rats, after an increase in GFAP had time to occur, did reverse the ADX-induced increase in GFAP. These results suggest that the increase in GFAP resulting from ADX is not mediated through an injury-linked mechanism.

Effects of alprazolam on T-cell immunosuppressive response to surgical stress in mice

Mice submitted to surgical stress induced by laparotomy and treated with chronic alprazolam (1 mg/kg) showed a reduction in stress-induced suppression of thymus and spleen cellularity, as well as in peripheral T lymphocyte population. The blastic response of spleen lymphoid cells was also assessed and found to partially supress the inhibitory effect of surgery.

Effects of amphetamine on T-cell immune response in mice

Mice chronically injected with amphetamine (0.4 mg/kg/day) showed a reduction in thymus and spleen cellularity, and in peripheral T lymphocyte population. The blastogenic response of spleen lymphoid cells was assessed and amphetamine was found to inhibit T-cell proliferation. Amphetamine also reduced the capacity of mice to the development and passive transfer of immunity to Listeria monocytogenes.