In Vitro Function of Chronic Myelocytic Leukemia Granulocytes. Effects of Irradiation and Storage

Granulocyte function was studied in 9 patients with untreated, Ph1-positive chronic myelocytic leukemia (CML). The nitroblue tetrazolium reduction by stimulated granulocytes was impaired in all patients; 4 patients also had diminished phagocytosis and 2 others defective Chemotaxis. In spite of this variety of polymorphonuclear (PMN) functional impairments, there is little evidence of increased susceptibility to infections in CML patients. This suggests that CML-PMN leucocytes (PMNs) may be successfully used for transfusion into neutropenic recipients, as previously reported. To evaluate the effects of irradiation and liquid storage on CML-PMNs, 5 of our patients were subjected to leukapheresis by continuous-flow centrifugation in the Aminco Celltrifuge, and granulocyte functional capacities were also evaluated on the cell-rich plasma immediately after collection and after short-term storage at 4°C with or without irradiation (1500 rads). As evaluated by in vitro studies, granulocytes maintained, even after irradiation, functional activities similar to those found immediately after collection up to 24 h of storage at 4°C and presented a moderate loss of function after 48 h. Chemotaxis appeared to be the most sensitive detector for cellular damage of stored leucocytes, irradiated and non-irradiated, so that it might be used for assessment of leucocyte function before transfusion.

Histological assessment of non-ablative laser stimulation of tissue repair in acellular dermal grafts

AIM

The objective of this study was to compare integration of AlloDerm® acellular dermal grafts in animals subjected to non-ablative laser irradiation and animals not exposed to this therapy.

METHODS

Standardized AlloDerm® fragments measuring 5 mm² were grafted into the subcutaneous tissue overlying the calvaria in 32 Wistar rats. Laser therapy (685 ηm), at a dose of 4 J/cm2 per session, was applied immediately after surgical intervention and every 48 hours thereafter for a total of four applications.

RESULTS

Analysis of histology slides revealed significantly greater edema in the control group. There was no neutrophil infiltration in the laser-irradiated group at any point during the study period, whereas such infiltration was present in control animals at three of the four points of observation. In the laser therapy group, lymphocyte infiltration was observed from day 1, whereas in the control group, it was only apparent from day 3. Vascularization was substantially greater in the control group. In the experimental group, the AlloDerm® graft was completely replaced by fibrous tissue.

CONCLUSION

These findings suggest that add-on non-ablative laser therapy is an effective stimulator of healing and graft integration after placement of AlloDerm® acellular dermal grafts.

Spontaneous effects of low-level laser therapy (650 nm) in acute inflammatory mouse pleurisy induced by carrageenan

OBJECTIVE

Our aim was to investigate the effect of low-level laser therapy (LLLT), 650-nm wavelength, on acute inflammatory pleurisy.

BACKGROUND DATA

There is only scattered evidence of anti-inflammatory effects from LLLT and dosage characteristics, and the effect on pleurisy inflammation has yet to be investigated.

METHODS

A classical experimental model of pleurisy was used in a sample of 40 Balb male mice, randomly divided into five groups. Inflammation was induced by carrageenan (0.5 mg/cavity) administered by intrathoracic injections. Four groups received the inflammatory agent, and one received injections of sterile saline solution. At 1, 2, and 3 h after injections, LLLT irradiation was performed, with the same power (2.5 mW), but different irradiation times. The energy densities at each of the three treatment sessions were 0 J/cm(2) (placebo), 3 J/cm(2), 7.5 J/cm(2), and 15 J/cm(2), respectively.

RESULTS

Total and differential cell analysis at 4 h after induction of pleurisy showed a significant reduction of inflammatory cell migration for all groups treated with active laser. However, at 4 h after injection, the most significant (p < 0.001) reduction of leukocyte cell migration was seen in the 7.5 J/cm(2) group, at 2.7 (95% CI: 2.5-2.9) x 10(6), versus 7.9 (95% CI: 6.7-9.1) x 10(6) in the placebo control group. The greatest reduction of inflammatory cells was registered for neutrophils.

CONCLUSIONS

LLLT administered at 1-3 h after the induction of inflammatory pleurisy significantly reduces the inflammatory cell migration measured. Under these conditions and at 2.5 mW, 7.5 J/cm(2) was more effective than 3 J/cm(2) and 15 J/cm(2).

Solar-simulated ultraviolet radiation induces abnormal maturation and defective chemotaxis of dendritic cells

Exposure to ultraviolet (UV) light induces immunosuppression. Different evidences indicate that this phenomenon is mainly a consequence of the effect of UV light on skin dendritic cells (DC). To investigate the cellular and molecular basis of this type of immunosuppression, we assessed in vitro the effect of solar-simulated UV radiation on the phenotypic and functional characteristics of human monocyte-derived DC and Langerhans-like DC. UV radiation induced a decreased expression of molecules involved in antigen capture as DC-SIGN and the mannose receptor. This effect was accompanied by a diminished endocytic capacity, an enhanced expression of molecules involved in antigen presentation such as major histocompatibility complex-II and CD86, and a significant increase in their capability to stimulate T cells. Furthermore, irradiated DC failed to acquire a full mature phenotype upon treatment with lipopolysaccharide. On the other hand, solar-simulated radiation induced the secretion of tumor necrosis factor-alpha and interleukin (IL)-10 by DC, but no IL-12. Interestingly, solar-simulated UV radiation also caused an altered migratory phenotype, with an increased expression of CXCR4, and a lack of induction of CCR7, thus correlating with a high chemotactic response to stromal cell-derived factor 1(SDF-1) (CXCL12), but not to secondary lymphoid tissue chemokine (SLC) (CCL21). These data indicate that solar-simulated UV radiation induces a defective maturation and an anomalous migratory phenotype of DC.

Influence of fractionated irradiation on neutrophilic granulocyte function

BACKGROUND

A recent study has demonstrated that radiation therapy with single doses of up to 32 Gy has only a minor effect on neutrophilic granulocyte function. In clinical practice, by contrast, fractionated irradiation is applied. Therefore, the aim of the current study was to verify the influence of fractionated radiation therapy on granulocyte function.

MATERIAL AND METHODS

Density gradient-purified granulocytes of voluntary healthy donors were used for all experiments. Granulocytes were kept in RPMI 1640 without fetal calf serum, incubated for 48 h and irradiated. Their function was assessed by measuring luminol-enhanced chemiluminescence after stimulation with phorbol myristate acid (PMA). All tests were performed at least five times.

RESULTS

Relative changes (any reactive oxygen species [ROS] release before stimulation was defined as being equal to 100%) in ROS release increased after stimulation wit PMA (mean +/- SD): 0 Gy: 785 +/-, 462.2%; 2 Gy: 704.3 +/- 388.1%; 6 Gy: 1,360.3 +/- 710.5%; 12 Gy: 1,119.4 +/- 581.1%; 18 Gy: 1,087.3 +/- 622.4; 6 Gy (3 x 2 Gy): 279.4 +/- 201.1%; 12 Gy (6 x 2 Gy): 278.8 +/- 175.3%; 18 Gy (9 x 2 Gy): 84.2 +/- 41.5%. Comparing relative changes in ROS release after PMA stimulation, the differences between 0, 2, 6, 12, 18 Gy, and 6 Gy (3 x 2 Gy), 12 Gy (6 x 2 Gy), 18 Gy (9 x 2 Gy), and between 6 Gy (3 x 2 Gy), 12 Gy (6 x 2 Gy) and 18 Gy (9 x 2 Gy) proved to be significant (all p < 0.005).

CONCLUSION

The study shows, that clinically used fractionated irradiation has an impact on granulocyte function, but contrary to common assumption, it is not to total dose itself but rather the fractionation which influences granulocyte function. This could have a major clinical impact on radiation treatment schemes especially for benign diseases or anti-inflammatory treatment.

Double-decker chemotaxis: no evidence for photonic stimulation of directed locomotion by human blood polymorphonuclear leukocytes

The study was carried out under direct videomicroscopic control to ascertain whether electromagnetic forces (photons) can initiate directed cell motility of human polymorphonuclear neutrophils (PMN). Cell suspensions containing a mixture of randomly motile white blood cells and erythrocytes (red cells) were placed in a double-decked preparation created by a glass slide and two cover slips and sealed by paraffin. Erythrocytes in the upper or lower chamber were destroyed by a single burst from a narrow ruby laser beam. Directed locomotion of PMN toward the erythrocyte debris occurred exclusively in the chamber in which the erythrocytes had been destroyed. Only random PMN locomotion was observed in the adjacent chamber. The results indicate that in this experimental model, electromagnetic forces do not initiate directed locomotion.

Interaction of disease-related antigen-reactive T-cell lines from multiple sclerosis patients with type IV collagen: role of integrin VLA-1 and effects of irradiation

Multiple sclerosis (MS), a chronic demyelinating disease, is thought to be initiated by pathogenic T cells that transmigrate the vascular endothelium and enter the brain through vascular and parenchymal basement membranes (BM). Vaccination with T-cell lines reactive with myelin basic protein (MBP) and myelin oligodendrocytic glycoprotein (MOG) epitopes, expanded with interleukin-2 (IL-2), and attenuated by ionizing radiation is currently being evaluated as a therapeutic modality for this disease. We examined mechanisms potentially involved in pathogenic cell migration into the central nervous system (CNS) and the influence of irradiation on these processes. Seven of 7 autoantigen-responsive T-cell lines from MS patients adhered to collagen IV, the major collagenous constituent of BMs. This adhesion was inhibited almost completely by monoclonal antibody (MAb) to very late antigen (VLA)-1 and partially by anti-VLA-2. T-cell lines from healthy donors adhered more variably to collagen IV. Furthermore, patient derived T cells actively transmigrated through a collagen IV gel toward medium containing TNF-a, in a process that was inhibited by MAbs to VLA-1. Ionizing radiation at the dose used in vaccine preparation, inhibited morphological polarization associated with migratory capability, induced integrin clustering on the cell membrane, and abrogated adhesion to collagen IV. These findings may have important implications for understanding the pathogenesis of MS and how irradiation of potentially pathogenic T cells produces a reagent with possible therapeutic effects in T-cell vaccination (TCV).

Role of CD13/aminopeptidase N in rat lymphocytic alveolitis caused by thoracic irradiation

CD13/aminopeptidase N is a cell surface glycoprotein that is widely distributed in a variety of mammalian cells. It was recently shown to have chemotactic activity for T lymphocytes. This study examined the role of CD13/aminopeptidase N in lymphocytic alveolitis in radiation-induced lung injury caused by a single-dose thoracic irradiation (15 Gy) in rats. Significantly increased aminopeptidase activity was detected in bronchoalveolar lavage fluid obtained from irradiated rats at 4 weeks after irradiation compared to the activity in unirradiated rats. Significantly higher aminopeptidase activity was detected on alveolar macrophages from irradiated rats at 2 and 4 weeks than on those from unirradiated rats. Western blot analysis showed an increased expression of CD13/aminopeptidase N protein in alveolar macrophages from irradiated rats at 4 weeks. Chemotactic activity for normal rat lymphocytes was detected in bronchoalveolar lavage fluid from irradiated rats at 4 weeks, and approximately 60% of the activity was inhibited by pretreatment of bronchoalveolar lavage fluid with bestatin, a specific aminopeptidase inhibitor. This study suggests that CD13/aminopeptidase N may play an important role as a lymphocyte chemoattractant in lymphocyte-mediated alveolitis in experimental radiation-induced lung injury.

Inflammatory-type responses after exposure to ionizing radiation in vivo: a mechanism for radiation-induced bystander effects?

Haemopoietic tissues exposed to ionizing radiation are shown to exhibit increased macrophage activation, defined by ultrastructural characteristics and increased lysosomal and nitric oxide synthase enzyme activities. Macrophage activation post-irradiation was also associated with enhanced respiratory burst activities and an unexpected neutrophil infiltration. Examination of p53-null mice demonstrated that macrophage activation and neutrophil infiltration were not direct effects of irradiation, but were a consequence of the recognition and clearance of radiation-induced apoptotic cells. Increased phagocytic cell activity was maintained after apoptotic bodies had been removed. These findings demonstrate that, contrary to expectation, recognition and clearance of apoptotic cells after exposure to radiation produces both a persistent macrophage activation and an inflammatory-type response. We also demonstrate a complexity of macrophage activation following radiation that is genotype dependent, indicating that the in vivo macrophage responses to radiation damage are genetically modified processes. These short-term responses of macrophages to radiation-induced apoptosis and their genetic modification are likely to be important determinants of the longer-term consequences of radiation exposure. Furthermore, in addition to any effects attributable to immediate radiation-induced damage, our findings provide a mechanism for the production of damage via a 'bystander' effect which may contribute to radiation-induced genomic instability and leukaemogenesis.

In vitro and in vivo expression of endothelial von Willebrand factor and leukocyte accumulation after fractionated irradiation

Previous investigations have demonstrated an increased release of von Willebrand factor (VWF; also known as vWF) in endothelial cells after high single-dose irradiation in vitro. We have also found increased levels of Vwf protein in mouse glomeruli after a high single dose of renal irradiation in vivo. In addition, increased numbers of leukocytes were observed in the renal cortex after irradiation in vivo. The aim of the present study was to investigate and quantify these biological processes after clinically relevant fractionated irradiation and to relate them to changes in renal function. A significantly greater increase in release of VWF was observed in cultured human umbilical vein endothelial cells (HUVECs) after fractionated irradiation (20 x 1.0 Gy) than after a single dose of 20 Gy (147% compared to 115% of control, respectively, P < 0.0005). In contrast with the in vitro observations, glomerular Vwf staining was lower after fractionated irradiation in vivo (20 x 2.0 Gy or 10 x 1.6 Gy +/- re-irradiation) than after a single dose of 16 Gy. The number of leukocytes accumulating in the renal cortex was also lower after fractionated in vivo irradiation than after a single radiation dose. The onset of these events preceded renal functional and histopathological changes by approximately 10 weeks. These data indicate that radiation-induced changes in endothelial VWF expression after in vivo irradiation may be distinct from the in vitro observations. Increased VWF expression may reflect pivotal processes in the pathogenesis of late radiation nephropathy and provide a clue to appropriate timing of pharmacological intervention.

The role of interleukins 1, 6 and 8 as lymphocyte attractants in the photodermatoses polymorphic light eruption and chronic actinic dermatitis

The two photodermatoses, polymorphic light eruption (PLE) and chronic actinic dermatitis (CAD), are characterized by lymphocyte-rich inflammatory infiltrates, the pathogeneses of which are not fully understood. We have therefore studied suction blister fluid (SBF) samples from patients with these conditions before and at two time points after the induction of experimental lesions by means of a solar simulator; this SBF was then tested for the presence of selected cytokines known to induce peripheral blood lymphocyte (PBL) migration in vitro. A specific EL-4 NOB-1 bioassay was used to detect interleukin (IL)-1 activity, which has already been noted in normal skin and this was found in pre-irradiation control samples as well as 1-3 h and 24 h post-irradiation in both patient groups, but at levels not significantly different from those of controls. Use of a B9 cell proliferation assay showed no detectable IL-6-like activity pre-irradiation, but there was substantial activity in samples at both post-irradiation time points in both patient groups. Further, in other experiments, retained SBF samples were tested in an in vitro PBL migration assay in the presence and absence of neutralizing antibodies against IL-1 alpha, IL-1 beta, IL-6 and IL-8; considerable PBL attractant activity was noted in the pre-irradiation SBF from both patient groups; a finding consistent with previous reports of such activity in samples from normal skin, and at least in CAD patients, a proportion of this activity appeared to be due to IL-1, pre-incubation of SBF with neutralizing antibodies against IL-1 alpha and IL-1 beta reducing the effect significantly. Substantial PBL attractant activity was present also in the SBF from 1-3 h and 24 h post-irradiation samples in both patient groups and again, IL-1 neutralizing antibodies reduced this in the 1-3 h and 24 h CAD samples. In addition, neutralizing antibodies against IL-6 and IL-8 reduced the activity in the 24 h PLE samples significantly and although not fully conclusive in the case of IL-1, these data suggest that IL-6, IL-8 and possibly IL-1 may be involved in the induction of PBL infiltrates, and perhaps other events, in both PLE and CAD.

The effects of photodynamic therapy on human neutrophil migration using bacteriochlorin a

Bacteriochlorin a photodynamic therapy (BCA-PDT) caused inhibition of interleukin (IL)-8-activated neutrophil migration, at concentrations that did not induce membrane damage. Random migration and migration induced by other chemoattractants were also inhibited, indicating that the effect of BCA-PDT was not at the level of chemoattractant-receptor interaction but down stream. The BCA-PDT completely blocked superoxide production of phorbol ester-stimulated neutrophils indicating that superoxide production by neutrophils present in the tumor before and during BCA-PDT is not the cause of inactivation of tumor cells. Both type I and type II quenchers prevented inhibition by BCA-PDT but only in electroporated cells. Confocal laser scanning microscopy showed that the fluorescence of BCA was located inside the cell. These results show that the effects of BCA-PDT are intracellular and of a mixed type I/type II character and that the neutrophils present in the tumor during illumination probably do not contribute to tumor eradication by releasing reactive oxygen species.

Ultraviolet B irradiation modulates the immune system of fish (Rutilus rutilus, Cyprinidae). I. Phagocytes

Roach (Rutilus rutilus) were irradiated with a single dose of ultraviolet B (UVB) radiation (0.4 J/cm2) in order to study the effects of UVB on the nonspecific immune defense mechanisms of fish. Neutrophils and macrophages were isolated from the head kidney of fish on days 1-14 postirradiation. Both random and directed migration of neutrophils, studied by migration under agarose assay, were suppressed on day 1 after UVB irradiation. The respiratory burst of phorbol 12-myristate 13-acetate-stimulated neutrophils and macrophages was also suppressed at days 1 and 2 after UVB irradiation. The suppression of migration and respiratory burst were restored or the responses were even enhanced later, but on the other hand spontaneous cytotoxicity of neutrophils toward 51chromium-labeled K562 target cells stayed suppressed throughout the 14 day follow-up. This study indicates that UVB radiation has the potential to suppress the functioning of phagocytes and to compromise the immune system of fish.

[The effects of UVA irradiation on human neutrophil function]

We investigated the in vitro effects of ultraviolet A (UVA) irradiation on human neutrophil function. For measurements of reactive oxygen species (ROS) and serum opsonic activity, chemiluminescence was used. Chemotactic activity was determined by the Boyden technique. In this study, for detection of the effects of UVA irradiation on human neutrophil ROS production, we used luminol-dependent and lucigenin-dependent chemiluminescence, in addition to two kinds of action stimuli, opsonized zymosan and phorbol myristate acetate (PMA). We found that UVA irradiation at low doses of UVA (0.2-0.4J/cm2) did not affect the generation of OC1-, and it was suggested that high doses of UVA (0.6-1.0J/cm2) suppressed OC1- production by inactivating the signalling cascade which induces ROS on the membrane surface of neutrophils. No significant difference was observed in the chemotactic activity. The serum opsonic activity was increased by UVA irradiation. These results suggest that low doses of UVA do not impair neutrophil phagocytic activity, and that higher doses of UVA suppress the ROS generating capacity of neutrophils. However, to compensate for ths suppression, serum opsonic activity was induced, so it seemed that the neutrophil-related immune system could be retained.

Rat ultraviolet ray B photodermatitis: an experimental model of psoriasis vulgaris

Ultraviolet ray B (UV-B) induced dermatitis in the rat may be a model for human psoriasis vulgaris. Detailed studies of this model are reported. Rat skin responded to UV-B irradiation quite differently from human, guinea-pig, or mouse skin. Rat UV-B dermatitis was characterized by a sharply demarcated brownish-red lesion with scale formation lasting for 10 days. Histologically, microvascular dilatation, intraepidermal accumulation of polymorphonuclear leucocytes with microabscess, mononuclear cell infiltration at the papillary dermis and hyperproliferation of epidermal cells were observed. These features were similar to those of clinical psoriasis vulgaris in man. Leucocyte suppression, induced by systemic ferritin administration to the irradiated rats, resulted in loss of the epidermal hyperproliferation and inhibition of the tissue leucocytosis. This leucocyte suppression remodelled the picture of the rat UV-B dermatitis into that seen in other mammalian species, where microvascular dilatation and degeneration of keratinocytes (so-called sunburn cells) are characteristic. The irradiated epidermis of the rats treated with ferritin possessed an in vitro PMN chemotactic property. Rat UV-B dermatitis seems to be a useful model to investigate aetiopathogenic mechanisms in psoriasis vulgaris. However, the former heals after injury and does not relapse as does psoriasis.

A role for neutrophil elastase in the progression of solar elastosis

Hairless (SKH-1) mice were mated with Beige (C57B/bb) mice to produce a hairless mouse deficient in neutrophil elastase (hhbb). These mice were exposed to 0.09J UVB irradiation for 5 months to see if neutrophil elastase was an important factor in elastin remodeling and development of solar elastoses. Analysis of peritoneal neutrophils confirmed that the hhbb mouse was deficient in elastase, retaining only 10% as much activity as the normal littermates (hhHb). Skin MPO activity was equally elevated in all the mice receiving UVB suggesting an equal influx of inflammatory cells. The absolute breaking strength of the skin in both the hhBb and hhbb mice was not altered by UVB treatment over the 5 month exposure period. Elastin quantitated biochemically as desmosine, or visualized histologically, was increased following UVB exposure in the normal mice. In the elastase deficient mice, however, the elastin fibers appeared to be unaffected by exposure to UVB irradiation at this level. The results suggest that neutrophil elastase is an important mediator in the development of solar elastosis resulting from continued exposure to UVB irradiation.

Influence of inductive chemoradiotherapy on salivary polymorphonuclear leukocyte (SPMN) functions in oral cancer

Salivary polymorphonuclear leukocyte (SPMN) functions were examined in 18 patients with oral squamous cell carcinoma and in 20 healthy individuals. SPMN obtained from patients before therapy exhibited significantly less FMLP-stimulated chemotactic activity (132.4 +/- 17.5 cells/0.26 mm2) than that in SPMN from controls (177.1 +/- 11.6 cells/0.26 mm2), although no difference in phagocytosis was observed. When stimulated with PMA or FMLP, control SPMN generated superoxide (O2-) at levels of 50.3 +/- 10.5 pmol/min/10(4) cells and 88.4 +/- 15.4 pmol, respectively, while SPMN from untreated patients generated significantly reduced O2- in the presence of PMA or FMLP (24.3 +/- 3.5 pmol and 59.5 +/- 9.8 pmol, respectively). Only slightly lower chemiluminescence was observed in SPMN from untreated patients however, compared to controls, values being 68.0 +/- 18.9 vs 81.3 +/- 14.9 peak mV by PMA and 62.4 +/- 13.7 vs 64.4 +/- 12.9 peak mV by FMLP. Compared to Candida killing in control subjects (24.9 +/- 3.1%). SPMN from patients before treatment exhibited significantly reduced activity (18.7 +/- 4.9%). Further suppression of the SPMN functions examined was observed after chemoradio-therapy. Suppressed SPMN function in cancer patients, especially that associated with chemoradiotherapy, may therefore play a part in oral candidiasis.

Possible application of the laser in immunobiology

The human immune system acts a defence mechanism against exogenous or indigenous potentially harmful bodies, such as bacteria and viruses. The major histocompatibility complex (MHC class I and class II antigens) form key elements of legitimate body components, and the organization of MHC molecules allows T-lymphocytes to distinguish between legitimate and foreign bodies. On detection of a foreign component, T-cells activate the necessary pathways for destruction of the foreign body. Occasionally however the system breaks down and the result is a disease of an autoimmune nature. Both visible light and infrared low reactive-level laser therapy (LLLT) has been shown to act on immune system cells in a number of ways, activating the irradiated cells to a higher level of activity. Infrared LLLT has been shown to increase both the phagocytic and chemotactic activity of human leukocytes in vitro, for example. This is an example of photobiological activation. Photobiological cell-specific destruction is also possible using doses of low incident laser energy on cells which have been photosensitized for the specific wavelength of the laser, such as in photodynamic therapy (PDT) for superficial cancers. LLLT has also been shown to act directly and selectively on the autoimmune system, restoring immunocompetence to immunocompetence cells. Although much more research needs to be done, there are enough experimental and clinical data to show that the laser, and LLLT in particular, has a possibly exciting role both in immunobiological therapy for diseases of the immune system, and to activate and boost the normal reaction of the immune system components against harmful foreign bodies.

Effect of psoralen + ultraviolet-A on the chemotactic activity of polymorphonuclear neutrophils towards anaphylatoxin C5a des Arg

It was shown that psoralen + UV-A inhibits the chemotactic activity of polymorphonuclear neutrophils towards anaphylatoxin C5a des Arg. This reaction required oxygen and there is a high possibility that the active oxygen species was in a singlet state. Oxygen did not act directly on C5a des Arg, but rather produced oxidized psoralen which inhibited C5a des Arg activity. The effect was dependent on the concentration and types of psoralen and on the UV-A dose. Among the psoralens, the inhibitory effect of 4,5',8-trimethylpsoralen was the strongest, followed by 8-methoxypsoralen and 3-carbethoxypsoralen and finally 4,4',6-trimethylangelicin. Psoralen + UV-A failed to inhibit the chemotactic activity towards chemotactants other than anaphylatoxin C5a such as casein, the cultured filtrate of E. coli, platelet-activating factor, leukotriene B4, 5-hydroxy-6,8,11,14-eicosatetraenoic acid and 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid.

Structural elucidation of the 8-methoxypsoralen oxidized product that inhibits the chemotactic activity of polymorphonuclear neutrophils toward anaphylatoxin C5a

The chemical structure of the 8-methoxypsoralen oxidized product that inhibits the chemotactic activity of anaphylatoxin C5a was determined to be 2,3-dihydro-2,9-dimethoxy-3-hydroxy-7-oxo-7H-furo[3,2-g] [1]benzopyran. Its minimal concentration required to obtain the maximum inhibition of C5a des Arg (1 x 10(-8) M) chemotactic activity is 2.5 x 10(-8) M. Bioactivity of this substance was maintained for 2 weeks, stored in a dark room at room temperature under aerobic conditions. There is a possibility that this substance may be useful in the treatment of immune complex diseases.

[The effect of the laser microirradiation of the cell center on neutrophil motility]

The cell center of human neutrophils spread on polylysine-coated coverslips was irradiated with an argon laser microbeam. After the cells were pretreated with acridine orange, the irradiation of the cell center in a dose of over 0.1 J completely and irreversibly suppressed the motility of neutrophils (both random migration and chemotaxis), even though the cells retained their polarization. The same dose, applied to the cell nucleus and the forward and backward edges of the cytoplasm, resulted in little, if any, effect on cell motility, and did not inhibit their movement toward the target. Electron microscopy of the cells with the irradiated center showed the microtubules to persist for no less than 30 minutes; no visible destruction was caused in the cell center structure. Consequently, the cell center directly controls (not through polymerization of microtubules) the motility of neutrophils.

Perturbation of endothelial functions by ionizing irradiation: effects on prostaglandins, chemoattractants and mitogens

Numerous studies have shown that early radiation injury is characterized by vascular damage and that the initial site of damage appears to be the EC lining of the vessel wall. Chronic irreversible tissue reactions to radiation include thrombotic occlusion of capillaries, enhanced atherosclerosis in larger vessels, inflammatory changes, and late tissue fibrosis. These processes may be mediated by endothelial products released as a result of cellular injury. Using EC cultures, we show that ionizing irradiation affects one of the major vascular defense mechanisms against platelet activation, thrombosis, and atherosclerosis--the capacity to produce PGI2. Dose- and time-related damage to enzymes of the arachidonic acid cascade were demonstrated. Radiation damage is associated with oxidant stress and production of free radicals. The oxygen radical scavenger, vitamin C, was found to protect the capacity of irradiated ECs to produce PGI2. Radiation injury often induces an acute inflammatory response. We found that irradiated ECs release a chemotactic factor for neutrophils, which is a lipid product of the lipoxygenase pathway. Late radiation-induced tissue fibrosis and the capacity of radiation to enhance arteriosclerosis may involve participation of mitogens released from perturbed and damaged ECs. We show that conditioned medium of irradiated ECs contain larger amounts of newly synthesized mitogens capable of stimulating the proliferation of fibroblasts, SMCs, and ECs. Hence, it may be assumed that the mitogenic activity released by irradiated ECs includes both PDGF and FGF-like mitogens.

Complement cleavage products in the phototoxic reaction of porphyria cutanea tarda

We have measured C3, C4, CH50 and complement cleavage products C3a and C5a in in sera and plasma from PCT patients and normal controls 10 min and 1, 4 and 24 h after UVA irradiation. We found elevated C3a concentrations in PCT patients immediately after UVA irradiation and 24 h later. The same was true for CH50, whereas C3, C4 and C5a did not change significantly. No such changes occurred in normal controls. Our data suggest that activation of the complement cleavage product C3a by porphyrin and UV light triggers a series of events that cause tissue damage.

Alteration of lymphocyte functions by 8-methoxypsoralen and longwave ultraviolet radiation. I. Suppressive effects of PUVA on T-lymphocyte migration in vitro

We investigated the influence of 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet radiation (PUVA) on lymphocyte migration in vitro. Nylon wool-purified, mouse splenic T lymphocytes showed locomotive responses to casein, normal mouse serum (NMS), and zymosan-activated mouse serum (ZAS). Migratory responses to casein and NMS, and to ZAS were remarkably suppressed in lymphocytes exposed to 0.5 J/cm2 UVA plus 0.1 micrograms/ml 8-MOP and to 0.8 J/cm2 UVA plus 8-MOP, respectively. The PUVA treatment used in the present study had no effect on random movement and lymphocyte viability. T lymphocytes cultured in the absence of mitogenic agent for 24 h demonstrated a greater increase in their migration activity than noncultured cells, while lymphocytes cultured after 1.0 J/cm2 PUVA pretreatment remained low. These findings suggest that the therapeutic effect of PUVA on inflammatory skin disorders may be due in part to the suppression of lymphocyte migration.

Activation of complement by 405-nm light in serum from porphyria cutanea tarda

Sera from three patients with porphyria cutanea tarda (PCT) were examined for evidence of complement activation. The irradiation of sera in vitro with 405-nm light resulted in a dose-dependent diminution of total hemolytic complement activity and the hemolytic titers of C1, C4, C2, C3, and C5. Furthermore, such irradiated sera showed immunoelectrophoretical C3 conversion, chemotactic activity for rat polymorphonuclear leukocytes inhibited by incubation with anti-C5 antisera but not anti-C3 antisera, and C5a generation as measured by radioimmunoassay. Factor-B conversion did not occur in such irradiated sera. Using Sephadex G-75 chromatography, the irradiated sera showed a multiphasic elution profile of chemotactic activity similar to that of zymosan-activated serum. The generation of C5a even occurred in factor-B-depleted serum. These studies indicate that the irradiation of PCT serum with 405-nm light induces the activation of the complement system via the classical pathway, resulting in the development of a chemotactic factor.

Activation of the complement system in patients with porphyrias after irradiation in vivo

Irradiation of the forearms of two patients with erythropoietic protoporphyria and one patient with porphyria cutanea tarda resulted in an in vivo activation of the complement system, as assessed by diminution of the hemolytic titers of the third component of complement by 23-57%, and of the fifth component of complement (C5) by 19-47%. Such treatment also generated chemotactic activity for human polymorphonuclear cells; the chemotactic activity was stable at 56 degrees C and antigenically related to human C5. On Sephadex G-75 chromatography the chemotactic activity eluted with an apparent molecular weight of 15,000. These in vivo results extend our previous in vitro observation of photoactivation of complement in sera from patients with erythropoietic protoporphyria and porphyria cutanea tarda, and suggest that the complement system may participate in the pathogenesis of cutaneous phototoxicity in these patients.

T gamma cell levels in mammary and cervical uterine cancer patients before and after local irradiation treatment

Total T and T gamma cell populations were studied in patients suffering from mammary of cervical uterine cancer. The results show that for both groups of patients there were no changes in the total T cell counts when compared with controls: but T gamma subpopulation values were greatly increased in the cancer patient groups, irrespective of in the mammary cancer group, whether the tumor mass was present at the moment of evaluation or surgically removed. The percentage of T mu cells returned to normal level after local irradiation treatment in all cases studied. We speculate about the possible changes in lymphocyte migration as a consequence of irradiation which may affect cells in the blood stream.

In vivo and in vitro effects of dexamethasone on leukocyte migration in the rat adjuvant arthritis model

When polymorphonuclear leukocytes (PMNs) and mononuclear cells were isolated from the blood of dexamethasone-treated normal rats, in vitro mononuclear cell migration was inhibited and PMN migration was stimulated in comparison to controls. Inflammogen-induced PMNs showed inhibited cell migration due to dexamethasone treatment. Gamma camera imaging was then used to detect cells in vivo after labeling with indium-111. When the dexamethasone-treated blood cells were injected into adjuvant arthritis diseased rats, mononuclear cells showed depressed migration into the inflamed paws, while PMNs showed stimulated migration into the inflamed paws in comparison to controls. When the recipient adjuvant arthritic animals were treated with dexamethasone, both normal mononuclear cell and normal PMN migration to the inflamed paws were inhibited.

Effect of antiarrhythmic drugs on In-111-labeled leukocytes: chemotaxis and adherence to nylon wool

The influence of lidocaine (L) and procainamide (P) on the chemotactic ability and adherence to nylon wool of In-111-labeled human polymorphonuclear leukocytes (PMNs) was investigated. At the normal therapeutic levels of L (0.022 mM whole blood) or P (0.03 mM whole blood) no change in PMN function was observed. However, at and above five times the aforementioned blood levels of L, significant reduction in the chemotactic ability of PMNs was noted (p less than 0.005). The adverse effects of In-111 radiation appeared insignificant at all L or P concentrations during the 3-hr observation period. The labeled PMNs were resistant to the toxic effects of a higher concentration of P than that of L, and the reduction in PMN chemotaxis and adherence to nylon wool was not apparent until the P concentration reached 1.5 mM.

Effect of in vitro X-irradiation on lymphocyte and granulocyte function

Granulocyte transfusions have been complicated by graft-versus-host disease (GVHD) in the recipients. This risk can be eliminated by irradiation of the cell product. The effect of in vitro irradiation on elements of lymphocyte and granulocyte function was therefore studied in order to determine the dose of irradiation which blocked lymphocyte function without affecting the function of granulocytes. Lymphocyte blast transformation after stimulation with mitogens was reduced by 90% after irradiation with 1500 rad and by 97% after 5 000 rad. The response to microbial agents and allogeneic cells was far more radio-sensitive, being completely abolished after irradiation with 1 000 and 500 rad, respectively. Mobility was the function of polymorphonuclear leucocytes (PMN) most affected by irradiation, being slightly but significantly reduced after irradiation with 10 000-20 000 rad. The bactericidal activity was reduced only after irradiation with 40 000 rad or more, while the hexose monophosphate shunt activity and the myeloperoxidase activity were largely unaffected by irradiation with doses of up to 120 000 rad. Hence the results indicate that the irradiation of leucocytes intended for transfusion with a dose of 2 000 rad is likely to prevent GVHD without causing any apparent damage to the PMN.

Effect of leukaemia therapy on neutrophil chemotaxis

The in vivo effect of various cytotoxic drugs and cranial irradiation on neutrophil chemotaxis was tested in 62 children with acute lymphoblastic leukaemia and in 10 patients with other malignant disease. Cranial radiotherapy had a transient adverse effect on neutrophil chemotaxis after completion of the course which was most marked in children. Methotrexate (MTX) and 6-mercaptopurine (6-MP) alone and in combination had a variable effect of chemotaxis, which was most marked nine days after the end of the course. The effect of 6-MP was clearly dose-related, but continuous therapy (75 mg/m2 day) had the greatest inhibitory effect of all the regimens tested. The in vitro effect was studied in 48 leukaemics and in 85 controls (adults and children); all the patients with leukaemia had been off treatment for at least six months. No difference was found between the effects of drugs tested on control or leukaemic cells. The greatest inhibitory effect was found in vinblastine, adriamycin, 6-MP, and vincristine, all of which were closely dose-dependent, MTX, prednisolone, and asparaginase had no effect on chemotaxis when tested in this way.

Complement-derived chemotactic activity is generated in human serum containing uroporphyrin after irradiation with 405 nm light

Patients with porphyrias have varying degrees of photosensitivity, associated with elevated levels of porphyrins in plasma, erythrocyte, urine and/or feces. To investigate the role of complement in the pathogenesis of cutaneous lesions, varying amounts of uroporphyrin were added to normal human serum (0.1-10 microgram/ml), and the mixtures were then exposed to 405 nm irradiation. Such treatments result in the diminution of total hemolytic complement activity and hemolytic titers of C1, C4, C2, C3, and C5; furthermore, cleavage products of C3 and C5 were detected. Chemotactic activity for human polymorphonuclear leukocytes was generated that was inhibitable by incubation with anti-C5, but not with anti-C3 antisera. No chemotactic activity was generated in Mg++-EGTA treated serum nor in C4-deficient guinea pig serum. These data indicate that irradiation with 405 nm light of normal human serum containing uroporphyrin results in activation of the complement system via the classical pathway, and the generation of complement (C5)-derived chemotactic activity for human polymorphonuclear leukocytes.

Production of chemotactic activity in mixed leukocyte cultures: maximum effect caused by H-2I region disparity

Primary mixed mouse leukocyte culture supernatants contain an activity chemotactic for mouse peritoneal exudate cells and it can be detected within 72 h after initiation of the culture. Disparity for H-21 region leads to maximum production of chemotactic activity whereas H-2K or H-2D region differences result in the production of significantly less activity. The rate of production of chemotactic activity follows closely the rate of incorporation of 3H-thymidine, and both attain the peak on day 4 after initiation of the culture. But whereas proliferation is sensitive to gamma-irradiation, chemotactic activity production is not. It is our hypothesis that proliferating cells are primarily responsible for the production of chemotactic activity. The possible relevance of chemotactic activity production to graft rejection is discussed.

Effect of 8-methoxypsoralen plus UVA on psoriasis leukotactic factor

The effect of psoralen phototherapy on the chemotactic activity of psoriasis leukotactic factor (PLF) was studied. The chemotactic activity of PLF extracted from psoriasis scales was evaluated using modified Boyden chambers. Treatment of (1) psoriasis lesions, (2) psoriasis scale and (3) extracted PLF with 8-methoxypsoralen plus UVA irradiation reduced the chemotactic activity of PLF. These results may help define the mechanism of psoralen phototherapy in psoriasis.

Leukocyte chemotaxis after in vitro treatment with 8-methoxypsoralen and UVA

Isolated human polymorphonuclear leukocytes were submitted to long wave ultraviolet light (UVA) with and without preincubation of the cells with 8-methoxypsoralen (8-MOP). Leukocyte chemotaxis was determined in modified Boyden chambers using caseine as the attractant. Combined treatment (8-MOP + UVA) significantly inhibited the chemotactic activity with 8-MOP concentrations above 0.1 mug/ml and 2 J/cm(2). However, with high dosage of UVA (5 J/cm(2)) with and without 8-MOP still 25-30% cells migrated through the filters. Also, cell viability as determined by trypan blue exclusion was only moderately affected by combined treatment. The results indicate that these nonreplicating cells are comperatively insensitive to UVA and 8-MOP.