Abnormal clonogenic potential of T cells from multiple myeloma patients

Peripheral blood lymphocytes (PBLs) from multiple myeloma patients are defective in both proportion and absolute numbers of OKT4+ cells and have a normal proportion but reduced absolute number of OKT8+ cells. To assess the functional capabilities of the T cells in myeloma patients, we cloned the T cells in PBLs using limiting dilution conditions in which 100% of OKT4+ and OKT8+ T cells in normal PBLs are able to form a clone. In contrast, the OKT8+ cells from PBLs of five of seven multiple myeloma patients were severely compromised in their clonogenic potential; only 7% to 25% of OKT8+ T cells appeared to give rise to a clone. Clonogenic potential of the OKT4+ cells in patients was more nearly normal. Analysis of two multiple myeloma patients with abnormally low numbers of T cells in PBLs revealed the existence of abnormalities in the progenitors of T cell clones. In both patients, two to three times as many T cell clones were observed as would have been expected based on the number of PBLs cultured at limiting dilution, indicating that OKT4-8- cells in PBLs are capable of giving rise to OKT4+ and, at lower frequency, to OKT8+ clonal progeny in vitro. We conclude that purely quantitative assessment of T cell subsets should be interpreted with caution, since proportionately normal numbers of OKT8+ cells in patient PBLs are seriously compromised in their ability to give rise to clonal progeny in vitro, and since there appears to be a OKT4-8- population of T cells in PBLs that are committed to become OKT4+ or OKT8+ T cells, but are unable to do so in vivo.     

Route of nutrition influences intercellular adhesion molecule-1 expression and neutrophil accumulation in intestine.

HYPOTHESIS: The levels of intestinal interleukin 10 and interleukin 4, inhibitors of intercellular adhesion molecule-1 (ICAM-1) expression, decline with total parenteral nutrition (TPN). These cytokine changes induced by lack of enteral nutrition may increase ICAM-1 expression, resulting in polymorphonuclear neutrophil accumulation in intestine. DESIGN: Prospective randomized experimental trials. SETTING: Laboratory. MATERIALS: Male mice. INTERVENTIONS: Sixty-three mice were randomized to chow, intravenous TPN, or intragastric TPN. MAIN OUTCOME MEASURES: Experiment 1: After diet manipulation, iodine 125-labeled anti-ICAM-1 antibody and iodine 131-labeled nonbinding antibody were injected to quantify ICAM-1 expression on endothelial cells in the lung, liver, kidney, and small intestine. Measurement of myeloperoxidase was used to quantify polymorphonuclear neutrophil accumulation in the organs. Experiment 2: Intestine was harvested for both ICAM-1 and myeloperoxidase levels after chow refeeding of mice in the intravenous TPN group. RESULTS: In experiment 1, uninjured mice fed intravenous TPN showed significantly increased intestinal ICAM-1 expression and polymorphonuclear neutrophil accumulation with no significant changes in the lung, liver, or kidney. No changes occurred in mice fed chow or intragastric TPN. In experiment 2, reinstitution of enteral feeding returned intestinal ICAM-1 and myeloperoxidase levels to normal. CONCLUSION: Gut changes associated with lack of enteral feeding induce endothelial changes and an immunologic response, which may influence subsequent responses to injury.     

Antihypertensive response to prolonged tempol in the spontaneously hypertensive rat

INTRODUCTION: Tempol is a permeant nitroxide superoxide dismutase (SOD) mimetic that lowers mean arterial pressure (MAP) in spontaneously hypertensive rats (SHRs). We investigated the hypothesis that the antihypertensive response entails a negative salt balance, blunting of plasma renin activity (PRA), endothelin-1 (ET-1), or catecholamines or correction of oxidative stress as indexed by 8-isoprostane prostaglandin F(2alpha) (PGF(2alpha)) (8-Iso). METHODS: Groups (N= 6 to 8) of SHRs were infused for 2 weeks with vehicle or tempol (200 nmol/kg/min) or given tempol (2 mmol/L) in drinking water. RESULTS: Tempol infusion reduced the MAP of anesthetized SHRs (150 +/- 5 vs. 126 +/- 6 mm Hg) (P < 0.005). Oral tempol did not change the heart rate but reduced the MAP of conscious SHRs (-23 +/- 6 mm Hg) (P < 0.01) but not Wistar-Kyoto (WKY) rats. Tempol infusion increased the PRA (2.2 +/- 0.2 vs. 5.0 +/- 0.9 ng/mL/hour) (P < 0.005), did not change excretion of nitric oxide (NO) [NO(2)+ NO(3) (NOx)], ET-1, or catecholamines but reduced excretion of 8-Iso (13.2 +/- 1.4 vs. 9.6 +/- 0.9 ng/24 hours; P < 0.01). Cumulative Na(+) balance and gain in body weight were unaltered by tempol infusion. Tempol prevented a rise in MAP with high salt intake. CONCLUSION: Tempol corrects hypertension without a compensatory sympathoadrenal activation or salt retention. The response is independent of nitric oxide, endothelin, or catecholamines and occurs despite increased PRA. It is accompanied by a reduction in oxidative stress and is maintained during increased salt intake.