Normalization of defective monocyte chemotaxis during chemotherapy in patients with small cell anaplastic carcinoma of the lung

Summary Monocyte chemotactic responsiveness (MCR) in 14 patients with small cell anaplastic bronchogenic carcinoma was depressed before treatment compared with the MCR in 28 normal controls (P=0.00004). MCR was subsequently monitored during combination chemotherapy and after 6 months the MCR had become normalized compared with pretreatment values (P=0.00006).In addition, chemotactic factor inhibitor (CFI) activity in plasma was measured before treatment and after 6 months. When incubated with plasma before treatment casein had 62% of normal activity and when incubated with plasma after chemotherapy, 81% of normal activity (P=0.0009). CFI activity decreased by greater amounts in patients in complete remission than in patients in partial remission or in non-responders (P=0.01). This study supports the concept that cancer patients have depressed monocyte function. Chemotherapy seems to enhance monocyte chemotaxis in vitro and to decrease CFI activity in plasma.     

Augmentation of monocyte chemotaxis by 1 alpha,25-dihydroxyvitamin D3. Stimulation of defective migration of AIDS patients

Preincubation for 20 h with 1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3) markedly augmented the chemotactic responsiveness of human blood monocytes to the classical chemoattractant, FMLP. A modest enhancement of monocyte spontaneous locomotion in the absence of chemoattractants was also observed. Maximal increase of monocyte migration was observed after pretreatment with 10(-9) M 1,25(OH)2D3 and was detectable at FMLP concentrations ranging from 10(-10) to 10(-7) M. Pretreatment with 1,25(OH)2D3 augmented the number of monocyte high affinity FMLP receptors (1500 +/- 220 and 3800 +/- 300 sites per cell for untreated and 1,25(OH)2D3-pretreated cells, respectively) with no significant changes in Kd values (2 +/- 0.5 nM and 4 +/- 1 nM, for untreated and 1,25(OH)2D3-pretreated monocytes). Enhanced chemotaxis was not restricted to FMLP, because 1,25(OH)2D3-treated monocytes showed enhanced migration also in response to activated C components and chemotactic cytokines. In agreement with previous observations, monocytes from AIDS patients showed defective migration capacity. In vitro exposure to 1,25(OH)2D3 stimulated monocyte migration in all 10 patients examined with considerable quantitative differences among individuals. Regulating the responsiveness of mature monocytes to chemo-attractants, 1,25(OH)2D3, produced systemically or in situ by immunocompetent cells, could play a role in the regulation of the recruitment of monocytes at sites of inflammation, cell-mediated immunity, or bone resorption. The potential of 1,25(OH)2D3 as a restorative agent under conditions of defective phagocyte recruitment deserves further exploration.     

Influenza-induced depression of monocyte chemotaxis: Reversal by levamisole

Depression of monocyte chemotactic responsiveness that occurs in patients with acute influenza may be a factor in causing the high incidence of superinfection seen in this viral disease. Levamisole, a pharmacological agent capable of enhancing monocyte chemotaxis, was effective in counteracting the depression of chemotaxis produced by incubating normal monocytes with influenza in vitro. The drug, moreover, enhanced the subnormal in vitro chemotactic responses of monocytes from patients with serologically proven acute influenza. These studies suggest that levamisole may be useful in enhancing depressed cellular immune function in patients with acute influenza.     

Radiotherapy in the treatment of Hodgkin's disease.

Eighty-seven untreated patients with localised Hodgkin''s disease seen from 1969 to 1975 were treated by megavoltage radiotherapy. All were followed for at least 33 months. Thirty-three patients were staged clinically and 54 underwent more extensive investigation by lapaortomy and splenectomy. The projected five-year disease-free survival figures for patients staged surgically were 100% for the 17 with stage IA disease, 70% for the 19 with stage IIA disease, and 73% for the 15 with stage IIIA disease. These results were consistently better than those obtained in clinically staged patients. Five patients died, one of them without evidence of Hodgkin''s disease. As irradiation seems to produce excellent disease-free survival in most patients who are staged accurately at diagnosis, caution should be exercised in the routine use of adjuvant chemotherapy until the full risks of such treatment are clear. Combined modality therapy may be appropriate for patients with unfavourable features at presentation.     

Effect of tuftsin and oligotuftsins on chemotaxis and chemotactic selection in Tetrahymena pyriformis

The chemotactic properties of tuftsin (H-TKPR-OH), tuftsin derivatives (H-KPR-OH, H-TKPKG-NH(2), Ac-TKPKG-NH(2)) and TKPKG-based oligotuftsins (T20, T30, T40) were investigated in Tetrahymena pyriformis GL. In contrast to its effects on Mammalia, tuftsin elicited chemorepellent or neutral responses; truncation of the N-terminal part (KPR) led to similar results, though with more neutral effects. The significance of the C-terminal part of the molecule was revealed by the chemoattractant properties of TKPKG, which are nevertheless abolished by acylation. Among the oligotuftsins, T20 and T40 were chemoattractants at higher concentrations (10(-9)-10(-6) M), while T30 had a wide-ranging chemorepellent effect, indicating that chemotaxis is elicited in Tetrahymena only by ligands with optimal physicochemical characters (mass, conformation, etc.). The chemotactic selection data indicated that tuftsin-induced chemotaxis results from fairly short-term signalling in Tetrahymena.     

Polarization of membrane glycoproteins during monocyte chemotaxis

Distribution of membrane glycoproteins was studied in chemotactic monocytes using ferritin-conjugated lectins. The cells became polarized forming a pseudopodia at a leading head. Membrane glycoproteins were redistributed at the head. This phenomenon was not observed in chemokinetic or non-chemotactic cells suggesting that membrane glycoproteins may have a role in recognition of the chemoattractant.     

Pyrogen release in vitro by lymphoid tissues from patients with Hodgkin's disease

The mechanism of fever in patients with Hodgkin''s disease was investigated by examining endogenous pyrogen production by blood, spleen, and lymph node cells incubated in vitro. Blood leucocytes from febrile or afebrile patients with Hodgkin''s disease did not produce pyrogen spontaneously. Spleen cells, however, frequently released pyrogen during initial incubations, unlike spleen cells from patients with non-malignant diseases. Pyrogen production occurred from spleens without observed pathologic infiltrates of Hodgkin''s disease. Lymph nodes involved with Hodgkin''s disease produced pyrogen more frequently than did nodes involved with other diseases. Pyrogen production by tissue cells was prolonged, required protein synthesis, and in some cases was due to mononuclear cells; it did not correlate with fever in the patient. These studies demonstrate spontaneous production of endogenous pyrogen in vitro by lymphoid tissue cells from patients with Hodgkin''s disease.     

An angiogenic extract from skeletal muscle stimulates monocyte and endothelial cell chemotaxis in vitro.

The purpose of this study was to determine whether the extraction of skeletal muscle with a combination of ethanol and hydrochloric acid yields a product capable of stimulating angiogenesis. The resulting extract stimulated inflammation in the rabbit corneal assay, which was followed by capillary formation. In order to determine whether the observed angiogenesis was stimulated by a factor(s) acting directly on the endothelial cells versus a factor(s) recruiting macrophages that in turn release factors acting on endothelial cells, the muscle extract was tested for endothelial cell and monocyte chemotaxis activity in vitro. The muscle extract stimulated significant endothelial cell chemotaxis at concentrations between 94 and 750 micrograms of protein/ml and significant monocyte chemotaxis at concentrations between 8 and 75 micrograms of protein/ml. Polyacrylamide gel electrophoresis suggests that basic fibroblast growth factor and transforming growth factor-beta may be present in this acid/ethanol extract of skeletal muscle.     

Salmonella typhimurium mutants generally defective in chemotaxis.

The mutations of eight chemotaxis-deficient strains of Salmonella typhimurium, including five new mutants in strain LT2, were mapped by P22 transduction in relation to various fla mot deletions in S. abortus-equi. Seven recessive che mutations mapped between motB and flaC: three, all nontumbling, the che region I, adjacent to motB, and four, including one ever-tumbling, in che region II, adjacent to flaC. Mutant che-107, never-tumbling and dominant to wild type, mapped at flaAII, other mutations of which cause either absence of flagella or lack of locomotor function. We surmise that gene flaAII specifies a protein that polymerizes to form an essential component of the basal apparatus (so that absence of gene product prevents formation of flagela); that a component built up from certain mutationally altered proteins cannot transmit (or generate) active rotation of the hook and flagellum, and so causes the Mot (paralysis) phenyotype; and that a component built up from protein with the che-107 alteration permits only counterclockwise rotation, so that the tumble, normally produced by transient clockwise rotation, cannot be effected.     

Potentiation of the in vitro cytotoxicity of chlorambucil by monoclonal antibodies

It had previously been shown by using polyclonal antibodies that chlorambucil (CBL) and antibody did not have to be covalently bound to selectively inhibit tumor cell growth. This paper has reexamined this phenomena by using monoclonal antibodies (MoAb) and has sought to determine how antibody may serve to focus and to increase the cytotoxic effect of non-covalently bound CBL. In vitro, it was shown that MoAb per se had no effect, the MoAb had to be reactive with and to bind to tumor target cells for CBL to have an enhanced cytotoxicity. Furthermore, not all MoAb were effective; IgM and IgG2a subclasses enhanced CBL cytotoxicity, but IgG3 did not. At the cell surface, studies clearly showed that endocytosis of CBL and MoAb did not occur, as metabolic inhibitors, and lowered temperatures, which both inhibit endocytosis, had no effect on their cytotoxicity. In addition, NH4Cl an inhibitor of lysosomal enzymes did not reduce the cytotoxicity of CBL and MoAb. Thus CBL that is non-covalently bound to MoAb enters the cell independently of the MoAb. We conclude therefore that cell-bound MoAb is able to concentrate CBL on the surface of tumor cells by an unknown mechanism thereby enabling CBL to selectively alkylate their cell membranes and subsequently inhibit additional tumor cell growth.     

Homocysteine stimulates the expression of monocyte chemoattractant protein-1 in endothelial cells leading to enhanced monocyte chemotaxis

The effect of intraperitoneal administration of tocopherol (100 mg/kg wt/24 h) on ascorbate (0.4 mM) induced lipid peroxidation of mitochondria and microsomes isolated from rat liver and testis was studied. Special attention was paid to the changes produced on the highly polyunsaturated fatty acids C20:4 n6 and C22:6 n3 in liver and C20:4 n6 and C22:5 n6 in testis. The lipid peroxidation of liver mitochondria or microsomes produced a significant decrease of C20:4 n6 and C22:6 n3 in the control group, whereas changes in the fatty acid composition of the tocopherol treated group were not observed. The light emission was significantly higher in the control than in the tocopherol treated group. The lipid peroxidation of testis microsomes isolated from the tocopherol group produced a significant decrease of C20:4 n6 , C22:5 n6 and C22:6 n3, these changes were not observed in testis mitochondria. The light emission of both groups was similar. The treatment with tocopherol at the dose and times indicated showed a protector effect on the polyunsaturated fatty acids of liver mitochondria, microsomes and testis mitochondria, whereas those fatty acids situated in testis microsomes were not protected during non enzymatic ascorbateFe²⁺ lipid peroxidation. The protector effect observed by tocopherol treatment in the fatty acid composition of rat testis mitochondria but not in microsomes could be explained if we consider that the sum of C20:4 n6 + C22:5 n6 in testis microsomes is 2-fold than that present in mitochondria.     

Mutants defective in bacterial chemotaxis show modified protein phosphorylation

To examine the correlation between CheA phosphorylation and bacterial chemotaxis, cheA mutations leading to defects in chemotaxis were mapped and characterized. Mutant CheA proteins were tested in vitro for phosphorylation and were grouped into four classes: nonphosphorylated, partially phosphorylated, phosphorylated but not dephosphorylated by CheB and CheY, and phosphorylated and dephosphorylated. Nearly all the mutants were found to be defective in an aspect of phosphorylation. Furthermore, the mutant phenotypes were found to cluster in different regions of the cheA gene. We suggest that the CheA protein has three functional domains: one for interaction with CheB and CheY, a second for regulating phosphorylation and controlling the stability of the protein, and a third for receiving input signals regulating CheA activity.     

Metabolic products of soluble epoxide hydrolase are essential for monocyte chemotaxis to MCP-1 in vitro and in vivo

Monocyte chemoattractant protein-1 (MCP-1)-induced monocyte chemotaxis is a major event in inflammatory disease. Our prior studies have demonstrated that MCP-1-dependent chemotaxis requires release of arachidonic acid (AA) by activated cytosolic phospholipase A₂ (cPLA₂). Here we investigated the involvement of AA metabolites in chemotaxis. Neither cyclooxygenase nor lipoxygenase pathways were required, whereas pharmacologic inhibitors of both the cytochrome-P450 (CYP) and the soluble epoxide hydrolase (sEH) pathways blocked monocyte chemotaxis to MCP-1. To verify specificity, we demonstrated that the CYP and sEH products epoxyeiscosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs), respectively, restored chemotaxis in the presence of the inhibitors, indicating that sEH-derived products are essential for MCP-1-driven chemotaxis. Importantly, DHETs also rescued chemotaxis in cPLA₂-deficient monocytes and monocytes with blocked Erk1/2 activity, because Erk controls cPLA₂ activation. The in vitro findings regarding the involvement of CYP/sEH pathways were further validated in vivo using two complementary approaches measuring MCP-1-dependent chemotaxis in mice. These observations reveal the importance of sEH in MCP-1-regulated monocyte chemotaxis and may explain the observed therapeutic value of sEH inhibitors in treatment of inflammatory diseases, cardiovascular diseases, pain, and even carcinogenesis. Their effectiveness, often attributed to increasing EET levels, is probably influenced by the impairment of DHET formation and inhibition of chemotaxis.