Neutrophil Granule Constituents and Their Release in Health and Disease

Periodontitis and bone metabolism in patients with advanced heart failure and after heart transplantation

AIMS

Heart failure (HF) is a multi-organ, pro-inflammatory syndrome that impairs bone metabolism. Pro-inflammatory cytokines and bone catabolism enhance periodontal disease, a local inflammatory, bacteria-induced disease that causes bone loss and periodontal soft tissue destruction.

METHODS AND RESULTS

Medical and dental examinations were performed on patients with HF (n = 39), following heart transplantation (post-HTx, n = 38) and controls (n = 32). Blood, saliva, and gingival crevicular fluid were analysed for bone metabolism and inflammation markers. HF average New York Heart Association classification was III. Average time since HTx was 1414 days. Pro-inflammatory tumour necrosis factor-alpha was higher in HF and HTx as compared with controls (P < 0.05). Both HF and HTx participants had higher levels of bone resorption marker C-terminal telopeptide and parathyroid hormone with subjects in the HF group having the highest serum levels of all groups (P ≤ 0.05). In contrast, 25-hydroxyvitamin D was lowest in HF. HF patients had greater clinical attachment loss, cumulative pockets depth (greater than 3 mm) and probing depth (P < 0.05) as compared with controls. Cumulative pockets depth correlated significantly with measures of the inflammatory burden, β-glucuronidase in saliva (r = 0.4863, P < 0.01), interleukin-1b in saliva (r = 0.5149, P < 0.01), and gingival crevicular fluid (r = 0.6056, P < 0.001) in HF. However, adjustment of periodontal results for measures of oral hygiene (plaque, bleeding on probing), systemic 25-hydroxyvitamin D, and race attenuated significant differences between groups.

CONCLUSIONS

Patients with HF exhibit more severe periodontal disease associated with increased bone turnover markers when compared with control patients. However, local and systemic factors may account for this association and should be evaluated in future studies.

Acute appendicitis: transcript profiling of blood identifies promising biomarkers and potential underlying processes

Background

The diagnosis of acute appendicitis can be surprisingly difficult without computed tomography, which carries significant radiation exposure. Circulating blood cells may carry informative changes in their RNA expression profile that would signal internal infection or inflammation of the appendix.

Methods

Genome-wide expression profiling was applied to whole blood RNA of acute appendicitis patients versus patients with other abdominal disorders, in order to identify biomarkers of appendicitis. From a large cohort of emergency patients, a discovery set of patients with surgically confirmed appendicitis, or abdominal pain from other causes, was identified. RNA from whole blood was profiled by microarrays, and RNA levels were filtered by a combined fold-change (>2) and p value (<0.05). A separate set of patients, including patients with respiratory infections, was used to validate a partial least squares discriminant (PLSD) prediction model.

Results

Transcript profiling identified 37 differentially expressed genes (DEG) in appendicitis versus abdominal pain patients. The DEG list contained 3 major ontologies: infection-related, inflammation-related, and ribosomal processing. Appendicitis patients had lower level of neutrophil defensin mRNA (DEFA1,3), but higher levels of alkaline phosphatase (ALPL) and interleukin-8 receptor-ß (CXCR2/IL8RB), which was confirmed in a larger cohort of 60 patients using droplet digital PCR (ddPCR).

Conclusions

Patients with acute appendicitis have detectable changes in the mRNA expression levels of factors related to neutrophil innate defense systems. The low defensin mRNA levels suggest that appendicitis patient’s immune cells are not directly activated by pathogens, but are primed by diffusible factors in the microenvironment of the infection. The detected biomarkers are consistent with prior evidence that biofilm-forming bacteria in the appendix may be an important factor in appendicitis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-016-0200-y) contains supplementary material, which is available to authorized users.

The novel strategy of glucocorticoid drug development via targeting nongenomic mechanisms

Glucocorticoids (GCs) are widely used in clinical practice as potent anti-inflammatory and immunosuppressive agents. Unfortunately, they can also produce numerous and potentially serious side effects that limit their usage. This problem represents the driving force for the intensive search for novel GCs with a better benefit-risk ratio compared to conventional GCs. GCs are believed to take effects mainly through classical genomic mechanisms, which are also largely responsible for GCs' side effects. However, in addition to these genomic effects, GCs also demonstrate rapid genomic-independent activities. It has become increasingly evident that some of the anti-inflammatory, immunosuppressive, anti-allergic and anti-shock effects of GCs could be mediated through nongenomic mechanisms. Thus, theoretically, trying to use nongenomic mechanisms of GCs more intensively may represent a novel strategy for development of GCs with low side effect profile. The new GCs' drugs will take clinical effects mainly via nongenomic mechanisms and do not execute the classical genomic mechanism to reduce side effects.

Skin fibroblasts from individuals with Chediak-Higashi Syndrome (CHS) exhibit hyposensitive immunogenic response

Background

Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disease characterized by immunodeficiency, oculocutaneous albinism, neurological dysfunction, and early death. Individuals with CHS present with increased susceptibility to infections of the skin, upper-respiratory tract, gastrointestinal tract, and oral tissues. Classical CHS is caused by mutations in the gene encoding lysosomal trafficking regulator (LYST). Although defects in cytotoxic T cell lytic secretory granule secretion and neutrophil phagocytosis are suggested to contribute to the immunodeficiency in CHS, the underlying molecular mechanisms are unknown. We hypothesized that skin fibroblasts from CHS subjects exhibit impaired immune response due to defective trafficking of inflammatory factors.

Methods and results

Primary skin fibroblasts from CHS subjects or healthy controls were assessed for genes encoding inflammatory response factors using PCR array. At baseline, we found CD14, IL1R1 and TLR-1 were down-regulated significantly (≥2 fold change) and the genes encoding TLR-3, IL-1β and IL-6 were up-regulated in CHS cells compared to control cells. When challenged with E. coli lipopolysaccharide (LPS), CHS cells were less responsive than control cells, with only 8 genes significantly up-regulated (3–68 fold change) compared to baseline values, whereas 28 genes in control cells were significantly up-regulated at a much higher magnitude (3–4,629 fold change). In addition, 50% of the genes significantly up-regulated in LPS-treated control cells were significantly lower in LPS-treated CHS cells. IL-6, a fibroblast-derived proinflammatory cytokine essential for fighting infections was significantly lower in culture media of CHS cells with or without LPS. Furthermore, Western blot and immunofluorescent staining revealed that TLR-2 and TLR-4 were diminished on cell membranes of CHS cells and dissociated from Rab11a.

Conclusions

For the first time, results from our study indicate defective trafficking of TLR-2 and TLR-4 contributes to the hyposensitive response of CHS skin fibroblasts to immunogenic challenge, providing a potential therapeutic target for clinical intervention in CHS.

Why do we need nongenomic glucocorticoid mechanisms?

Glucocorticoids (GCs) are a class of steroid hormones that have been known to be involved in various physiological processes and to play a pivotal role in preserving basal and stress-related homeostasis. GCs are also widely used clinically as anti-inflammatory, immunosuppressive, anti-shock drugs. It is believed traditionally that GCs exert most of their effects genomically. In addition to the well-known classical genomic mechanisms, GCs also affect various functions via rapid, nongenomic mechanisms. The therapeutic benefits of nongenomic GC actions have been exploited in clinical medicine, especially with high-dose pulsed glucocorticoid administration. However, it is certainly not the case that the inherent nongenomic glucocorticoid mechanisms evolved only for their clinical utility. Here, we review the recent literature on nongenomic actions of GCs related to stress and the physiological significance of these actions, and we propose reasons why nongenomic mechanisms of GC actions are needed.

Genome-wide and gene-centric analyses of circulating myeloperoxidase levels in the charge and care consortia

Increased systemic levels of myeloperoxidase (MPO) are associated with the risk of coronary artery disease (CAD). To identify the genetic factors that are associated with circulating MPO levels, we carried out a genome-wide association study (GWAS) and a gene-centric analysis in subjects of European ancestry and African Americans (AAs). A locus on chromosome 1q31.1 containing the complement factor H (CFH) gene was strongly associated with serum MPO levels in 9305 subjects of European ancestry (lead SNP rs800292; P = 4.89 × 10(-41)) and in 1690 AA subjects (rs505102; P = 1.05 × 10(-8)). Gene-centric analyses in 8335 subjects of European ancestry additionally identified two rare MPO coding sequence variants that were associated with serum MPO levels (rs28730837, P = 5.21 × 10(-12); rs35897051, P = 3.32 × 10(-8)). A GWAS for plasma MPO levels in 9260 European ancestry subjects identified a chromosome 17q22 region near MPO that was significantly associated (lead SNP rs6503905; P = 2.94 × 10(-12)), but the CFH locus did not exhibit evidence of association with plasma MPO levels. Functional analyses revealed that rs800292 was associated with levels of complement proteins in serum. Variants at chromosome 17q22 also had pleiotropic cis effects on gene expression. In a case-control analysis of ∼80 000 subjects from CARDIoGRAM, none of the identified single-nucleotide polymorphisms (SNPs) were associated with CAD. These results suggest that distinct genetic factors regulate serum and plasma MPO levels, which may have relevance for various acute and chronic inflammatory disorders. The clinical implications for CAD and a better understanding of the functional basis for the association of CFH and MPO variants with circulating MPO levels require further study.

Effects of vitamin E on pathological changes induced by diabetes in rat lungs

Twenty-fourmale rats were divided into three groups: Control (C), non-treated diabetic (NTD), and vitamin E-treated diabetic (VETD) groups. After 6 weeks, we evaluated the changes in the alveolar epithelium, alveolar septum thickness, Hcy, and cathepsin G levels in the lung tissue and plasma serine protease inhibitor levels.The results revealed a significant increase in alveolar septum thickness, a high number of type II pneumocytes, high number of glycogen granules, increased vascular elastic membrane thickness, and increased Hcy and cathepsin G levels in the diabetic rats. Plasma level of serine protease inhibitors showed a significant decrease in the NTD animals. The vitamin E-treated rats showed significant amelioration of lung tissue changes, as well as restoration of high cathepsin G, Hcy levels, and serine protease inhibitors when compared to the control rats. These results suggest that diabetes induces lung tissue changes that may be stimulated by Hcy and cathepsin G mediated oxidative stress by, and protective effect could be achieved by using vitamin E.

Neutrophil granules in health and disease

Neutrophil granules store proteins that are critically important for the neutrophil to move from the vascular bed to tissues and to kill microorganisms. This is illustrated in nature when individual proteins are deleted due to inherited mutations of their cognate genes, and such deficiencies result in the conditions leucocyte adhesion deficiency and chronic granulomatous disease. The granules of the neutrophil have traditionally been divided into two or three major types but are instead a continuum where several subtypes can be identified with differences in protein content and propensity for mobilization. This is explained by the 'targeting by timing hypothesis' which states that granules are filled with granule proteins that are synthesized at the time the granule is formed. The heterogeneity of granules arises because the synthesis of granule proteins is individually controlled and major differences exist in the timings of biosynthesis during granulocytopoiesis. This is largely controlled by gene transcription.

Use of liposomes to evaluate the role of membrane interactions on antioxidant activity

In this study the possibility of using liposomes as membrane mimetic systems was evaluated to estimate the antioxidant properties of oxicams and establish a relationship between the interactions of the drugs with the membrane and their consequent antioxidant activity. Different experiments were performed covering the study of the protective effect of oxicams in lipid peroxidation induced by the peroxyl radical (ROO) derived from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and using two fluorescence probes with distinct lipophilic properties. Lipid peroxidation using the hydrophilic probe fluorescein was evaluated in lipid and aqueous media. Lipid systems labelled with the fluorescent probe diphenylhexatriene propionic acid (DPH-PA) were used to assess the effects of the drugs on membrane peroxidation simultaneously by fluorescence intensity decay and changes in membrane fluidity by steady-state anisotropy measurements. The use of different probes and liposomes as membrane mimetic systems allowed to conclude that membrane lipoperoxidation is related not only to the scavenging characteristics of the antioxidants but also to their ability to interact with the lipid bilayers.

Application of intracellular alkaline phosphatase activity measurement in detection of neutrophil adherence in vitro

We have proposed the use of the fluorimetric method with 4-methylumbelliferyl phosphate (4-MUP) specific substrate for the alkaline phosphatase determination in the neutrophil adhesion assay. We provide evidence that the endogenous neutrophil alkaline phosphatase (NAP) activity evaluation is reliable to quantify neutrophil adhesion at a wide range of cell numbers (10(4)-10(6)). The results obtained by fluorimetric NAP activity test correlate to the results of adherence evaluated using the MTT reduction assay. The fluorimetric NAP activity test may be applied for resting as well as activated neutrophils without the risk of the activators interferences into the test. The alkaline phosphatase survey with the use of 4-MUP substrate is recommended herein as a sensitive, repeatable, simple, and reliable method of the neutrophil adherence determination in vitro.

Disorders of neutrophil function: an overview

Primary disorders of neutrophil function result from impairment in neutrophil responses that are critical for host defense. This chapter summarizes inherited disorders of neutrophils that cause defects in neutrophil adhesion, migration, and oxidative killing. These include leukocyte adhesion deficiencies, actin defects, and other disorders of chemotaxis; hyperimmunoglobulin E syndrome; Chédiak-Higashi syndrome; neutrophil specific granule deficiency; chronic granulomatous disease; and myeloperoxidase deficiency. Diagnostic tests and treatment approaches are also summarized for each neutrophil disorder.

AML M3 and AML M3 variant each have a distinct gene expression signature but also share patterns different from other genetically defined AML subtypes

Acute promyelocytic leukemia (APL) with t(15;17) appears in two phenotypes: AML M3, with abnormal promyelocytes showing heavy granulation and bundles of Auer rods, and AML M3 variant (M3v), with non- or hypogranular cytoplasm and a bilobed nucleus. We investigated the global gene expression profiles of 35 APL patients (19 AML M3, 16 AML M3v) by using high-density DNA-oligonucleotide microarrays. First, an unsupervised approach clearly separated APL samples from other AMLs characterized genetically as t(8;21) (n = 35), inv(16) (n = 35), or t(11q23)/MLL (n = 35) or as having a normal karyotype (n = 50). Second, we found genes with functional relevance for blood coagulation that were differentially expressed between APL and other AMLs. Furthermore, a supervised pairwise comparison between M3 and M3v revealed differential expression of genes that encode for biological functions and pathways such as granulation and maturation of hematologic cells, explaining morphologic and clinical differences. Discrimination between M3 and M3v based on gene signatures showed a median classification accuracy of 90% by use of 10-fold CV and support vector machines. Additional molecular mutations such as FLT3-LM, which were significantly more frequent in M3v than in M3 (P < 0.0001), may partly contribute to the different phenotypes. However, linear regression analysis demonstrated that genes differentially expressed between M3 and M3v did not correlate with FLT3-LM.

The effect of transport stress on neutrophil activation in wild badgers (Meles meles)

Wild badgers (Meles meles) in Wytham woods, Oxfordshire, are routinely trapped, transported to a central field laboratory, studied and released as part of an on-going population study. These procedures have been carefully developed to minimise impact on the badgers' welfare; however they are potentially stressful, and, as part of our on-going welfare refinements, and our exploration to develop methods for quantifying stress in wild mammals, we studied the effects of transport stress on neutrophil activation in wild trapped badgers. Blood samples were obtained from 28 badgers. We compared three transport regimes: transported (n = 9), transported and rested for at least 30 mins (n = 11), and not transported (n = 8). Total and differential white cell counts were carried out and neutrophil activation was measured by the nitroblue tetrazolium test. Our goal was primarily to validate neutrophil activity as an indicator of stress, on the basis that the transport treatment was expected to be more stressful than the non-transport treatment. There were significant increases in % activated circulating neutrophils in response to transport. This study supports the proposition that stress affects circulating neutrophil numbers and the state of their activation, as determined by the nitroblue tetrazolium reduction assay, and therefore adds weight to the idea that neutrophil activation is a potential measure of stress in wild animals.

Beta-glucuronidase activity in saliva: relationship to clinical periodontal parameters

BACKGROUND

Beta-glucuronidase (betaG) in gingival crevicular fluid (GCF), a marker of neutrophil influx into the crevicular environment, has previously been shown to be correlated with periodontal clinical parameters at individual sites (probing depth and clinical attachment level). Furthermore, elevated levels of betaG were found to be a risk factor for periodontal attachment loss. Analysis of betaG in saliva may be a measure of crevicular neutrophil influx for the whole mouth. The purpose of this cross-sectional study was to evaluate the relationship between betaG activity in saliva and periodontal clinical parameters in subjects demonstrating various levels of periodontal disease.

METHODS

The study population consisted of 380 subjects (108 males and 272 females). A sample of unstimulated whole saliva and a venous blood sample were obtained from each subject, and a periodontal examination, which included measurement of probing depth (PD), attachment level (AL), and gingival index (GI) was performed. The unmodified saliva samples were frozen at -20 degrees C and analyzed for betaG activity. The blood samples were analyzed for number of white blood cells, neutrophils, monocytes, lymphocytes, and platelets. Statistical analysis was conducted to determine the association between salivary betaG activity and the whole-mouth clinical periodontal parameters, complete blood count, smoking status, and age.

RESULTS

Highly significant correlations between salivary betaG activity and mean probing depth (MPD), mean gingival index (MGI), and the number of sites with probing depth > or = 5 mm were found. When subjects were divided into tertiles based on their MPD and MGI, elevated salivary betaG activity was detected in subjects in the 2 upper tertiles. Logistic regression modeling was used to determine which of the clinical or laboratory parameters were able to identify patients with at least 4 sites with PD > or = 5 mm. Salivary betaG activity > or = 100 produced an odds ratio (OR) of 3.77. In comparison, current and former smokers had an OR of 3.15 and 2.29, respectively. CONLCUSIONS: The results suggest that a significant association exists between periodontal clinical parameters and salivary betaG activity. Due to the non-invasive and simple nature of saliva collection, this association should be studied to determine its usefulness as a screening test for periodontitis, and a means of monitoring the response to treatment.

Chediak-Higashi Syndrome: a rare disorder of lysosomes and lysosome related organelles

Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder characterized by severe immunologic defects including recurrent bacterial infections, impaired chemotaxis and abnormal natural killer (NK) cell function. Patients with this syndrome exhibit other symptoms such as an associated lymphoproliferative syndrome, bleeding tendencies, partial albinism and peripheral neuropathies. The classic diagnostic feature of CHS is the presence of huge lysosomes and cytoplasmic granules within cells. Similar defects are found in other mammals, the most well studied being the beige mouse and Aleutian mink. A positional cloning approach resulted in the identification of the Beige gene on chromosome 13 in mice and the CHS1/LYST gene on chromosome 1 in humans. The protein encoded by this gene is 3801 amino acids and is highly conserved throughout evolution. The identification of CHS1/Beige has defined a family of genes containing a common BEACH motif. The function of these proteins in vesicular trafficking remains unknown.

Alterations in erythrocyte membrane lipid and fatty acid composition in Chediak-Higashi syndrome

Chediak-Higashi syndrome (CHS) is an autosomal recessive disease characterized by the presence of abnormally large cytoplasmic organelles in all body granule producing cells. The molecular mechanism for this disease is still unknown. Functional disorders in membrane-related processes have been reported. Erythrocyte membranes from four CHS patients and 15 relatives including obligatory heterozygous were studied to examine potential alterations in the lipid and fatty acid profile of erythrocyte membranes associated with this syndrome. Plasma concentrations of cholesterol, triglycerides, phospholipids, and apolipoproteins AI and B100, and the lipid components of very low-, intermediate-, low- and high-density lipoproteins were also determined. CHS erythrocyte membranes were found to be enriched with lipids in relation to protein and to show: (1) an increase in cholesterol and choline-containing phospholipids (sphingomyelin and phosphatidylcholine) that predominate in the outer monolayer, which is higher than the increase in phosphatidylserine and phosphatidylethanolamine, that are chiefly limited to the inner monolayer in normal red blood cells; (2) a relative palmitic acid and saturated fatty acid increase and arachidonic acid and unsaturated fatty acid decrease, this resulting in a lower unsaturation index than controls. Changes in CHS erythrocyte membrane lipids seem to be unrelated to serum lipid disorders as plasma lipid and apolipoprotein concentrations were apparently in the normal range, with the exception of a modest hypertriglyceridemia in patients and relatives and a decreased concentration of HDL cholesterol in patients. These findings indicate that CHS erythrocyte membranes contain an abnormal lipid matrix with which membrane proteins are defectively associated. The anomalous CHS membrane composition can be explained on the postulated effects of the CHS1/Lyst gene.

Analysis of human gingival tissue and gingival crevicular fluid beta-glucuronidase activity in specific periodontal diseases

BACKGROUND

Beta-glucuronidase (betaG) is one of the enzymes involved in the destruction of non-collagenous components of the extracellular matrix. It is also considered an indicator or predictor of periodontal disease activity. The present study was conducted to determine the presence and the levels of betaG activity in gingival tissue and gingival crevicular fluid (GCF) in periodontal disease and health status. The validity of 2 expressions of data, total betaG activity versus betaG concentration, and the correlations between clinical periodontal status and betaG profile was also evaluated.

METHODS

betaG activities in gingival tissues and GCF samples from 57 individuals, divided into 3 equal groups of adult periodontitis (AP), early-onset periodontitis (EOP), and periodontally healthy subjects were spectrophotometrically examined.

RESULTS

Both patient groups had higher betaG levels in both gingiva and GCF than controls. Significant differences were observed among all groups when total GCF betaG activities were examined (P <0.05). However, the difference between AP and controls was not significant when concentration values were compared (P >0.05). The highest GCF betaG activity, with both expressions, was detected in EOP group. No absolute correlations between clinical parameters and betaG activity were observed, except for random correlations in the patient groups with mean total betaG activities. Also GCF/gingiva betaG levels and the 2 expressions did not show absolute correlations.

CONCLUSIONS

The findings of the present study confirm the relationship between betaG activity and periodontal diseases. The differences in data concerning GCF total betaG activity and betaG concentration may suggest that they are not matching measures. Data presentation seems to be an important factor in GCF/enzyme profile studies.

CXC-chemokines stimulate invasion and chemotaxis in prostate carcinoma cells through the CXCR2 receptor

BACKGROUND

Metastasis of prostate carcinoma requires invasion through the basement membrane, a thin extracellular matrix that underlies the epithelial cells, which must be breached by tumor cells invading into surrounding tissue. The CXC-chemokines, which have been shown to promote the migration of neutrophils and carcinoma cells, are candidates to influence prostate carcinoma-cell invasion.

METHODS

CXC-chemokines were examined for the ability to stimulate prostate cell line PC3 invasion in vitro through a reconstituted basement membrane and long-term migration and short-term adhesion to laminin, a major component of the basement membrane.

RESULTS

PC3 cells responded to IL-8 and GROalpha with a 1. 6-2-fold increase in invasion through reconstituted basement membrane. A corresponding 2-3-fold increase in chemotaxis toward IL-8 and GROa was seen on laminin. Anti-CXCR2 antibody inhibited IL-8-stimulated migration. Expression levels of the beta(1) integrins were not changed by IL-8, and alpha(6beta1) integrin was used for both stimulated and baseline migration. In addition to the increases in migration and invasion, 2-6-fold transient increases in adhesion on laminin were seen with both IL-8 and GROalpha.

CONCLUSIONS

These results suggest that the CXC-chemokines stimulate migration and invasion in part by altering the activation state of the beta(1) integrins. The CXC-chemokines act on prostate carcinoma cells through the CXCR2 receptor to promote behavior important for metastasis, and as such may be important in prostate carcinoma progression and metastasis.

Chédiak-Higashi syndrome: presentation of seven cases

CONTEXT

Chédiak-Higashi Syndrome (CHS) is a rare autosomal recessive disease characterized by recurrent infections, giant cytoplasmic granules, and oculocutaneous albinism.

OBJECTIVE

To describe clinical and laboratory findings from CHS patients.

DESIGN

Case report.

SETTING

The patients were admitted into the Allergy and Immunology Unit of the Instituto da Criança, a tertiary public care institution.

CASES REPORT

Seven patients had oculocutaneous albinism, recurrent infections and giant cytoplasmic granules in the leukocytes. One patient had low IgG levels and three showed impaired bactericidal activity of neutrophils. Six patients died of infectious complications during the accelerated phase. Therapy included ascorbic acid and antibiotics. Chemotherapy was used for the accelerated phase in two patients. Bone marrow transplantation (BMT) was proposed for one patient.

DISCUSSION

The authors emphasize the need for early diagnosis and therapy of CHS. BMT should be indicated before the accelerated phase of the disease has developed.

The influence of polymorphonuclear leukocytes on altered pulmonary epithelial permeability during ozone exposure

Ozone (O3), a pulmonary irritant, and a major toxic component of photochemical smog, is capable of inducing pulmonary inflammation characterized by recruitment of polymorphonuclear leukocytes (PMNs) into the lung. The recruited PMNs, in turn, can release toxic mediators and produce lung injury. The mechanism of ozone-induced changes in lung permeability remains unknown. It is our hypothesis that PMNs migrating into the lung play a significant role in the pathophysiology following O3 exposure and that increasing the number of PMNs coming into the lung will exaggerate the changes in lung permeability. To test this hypothesis, we induced an influx of PMNs into the lungs of Sprague-Dawley rats by intratracheal instillation of 1% rabbit serum and then exposed the animals to either 0.8 ppm O3 or filtered air for 3 h. Control animals were intratracheally instilled with phosphate-buffered saline (PBS) and simultaneously exposed to O3 or filtered air in the same manner as the serum-treated animals. The animals were sacrificed and the lungs lavaged 10-12 h after exposure. The bronchoalveolar lavage fluid (BALF) was analyzed for albumin and protein, as indicators of permeability. In addition, BALF from the various groups was tested for its ability to alter epithelial resistance of pulmonary type II cells in culture. O3 exposure resulted in a significant increase in albumin and protein levels in the BALF as compared to air-exposed controls. The instillation of serum resulted in a significant increase in airway PMNs, but no significant elevations in albumin levels in both the O3 and air-exposed groups, as compared to PBS instillation. In vitro studies did not reveal a differential BALF effect on epithelial resistance. The data demonstrate that an excessive neutrophilia in the lung is not matched by a comparable amplification of epithelial injury. It is therefore suggested that a simple elevation in PMN number in the air spaces, as that induced by serum instillation, does not necessarily augment the lung pathophysiology, but that a more complex interaction with O3 may be required for cellular activation and release of toxic products.

Elevated circulating E-selectin, intercellular adhesion molecule 1, and von Willebrand factor in patients with severe infection

To investigate interactions between the endothelium and leukocytes in patients with sepsis, we measured soluble adhesion molecules (sE-selectin and sICAM-1), von Willebrand factor antigen (vWf:Ag), myeloperoxidase (MPO), and lactoferrin (Lacto-f) as plasma markers of endothelial and neutrophil activation. We tested whether the five proteins were predictors of clinical severity, which was evaluated by simplified acute physiological score (SAPS), number of organ failures (MOF), acute lung injury (ALI), and subsequent final outcome. Levels of the five plasma markers were higher in patients with severe infection (n = 25) than in patients without sepsis (n = 7) and healthy volunteers (n = 9). In the study population, levels of sE-selectin, sICAM-1, and vWf:Ag were higher for nonsurvivors as well as for patients with septic shock or with bacteremia, and they were correlated with SAPS and MOF. Survival outcome was predicted with high sensitivity and specificity by initial plasma levels of sICAM-1 and vWf:Ag. The initial sICAM-1 level appeared to be an independent prognostic variable, based on a logistic regression analysis. Unlike sE-selectin, sICAM-1 remained at high levels indefinitely in nonsurvivors. We conclude that, unlike neutrophil activation markers, levels of endothelium-derived soluble adhesion molecules and vWf:Ag in severe sepsis syndrome are correlated with the severity of illness and may be considered as predictors of survival outcome.

Epithelial cell damage is induced by neutrophil-derived, not pseudomonas-derived, proteases in cystic fibrosis sputum

Airway histopathological changes in cystic fibrosis (CF) include damage to the epithelial tissue and accumulation of polymorphonuclear leukocytes (PMN). Airways of CF patients are usually colonized with bacteria such as mucoid Pseudomonas aeruginosa (PA). Bacteria and PMN can both release proteolytic enzymes capable of causing tissue damage. This study aims to clarify and compare the roles of these agents in epithelium damage. Epithelial cell (EC) damage and detachment induced by sputum samples from CF or non-CF patients, with and without lung infection, were assessed on amnionic EC in an in vitro model of airway epithelium. Protease activity was determined using inhibitor profiles, and compared to the proteolytic activity of isolated neutrophils and bacteria. Sputa from CF patients and infected non-CF patients induced high levels of detachment. PA also induced high levels of EC detachment but Staphylococcus aureus and Haemophilus influenzae, two other bacteria commonly isolated from CF sputa, induced no detachment. Antiprotease inhibition profiles were similar for PMN and sputa-induced EC detachment, but different for PA-induced detachment. These results suggest that PMN proteolytic enzymes, probably elastase and cathepsin G, are more likely to be the inducers of tissue damage in the airways of CF patients than PA proteolytic enzymes.

Deficiency of neutrophilic granule membrane glycoproteins in the myelodysplastic syndromes: a common deficiency in 216 patients studied by the Cancer and Leukemia Group B

Previous studies on neutrophils in patients with the myelodysplastic syndromes (MDS) have indicated deficiencies in the contents of primary and secondary granules. However, the granule membrane remains virtually unstudied despite its essential role in the dynamic function of the cytoplasmic granules. In this study, we examined the membrane glycoproteins of primary and secondary granules of peripheral blood and/or bone marrow neutrophils using the monoclonal antibody H36/71 to CD15 glycoproteins. In addition, myeloperoxidase activity and antigen, elastase and lactoferrin were also studied using cytochemical and immunocytochemical stains. A total of 216 patients were included. Deficiencies of granule membrane glycoproteins were the most common, detected in 49%, followed by myeloperoxidase activity (17%), elastase (16%), myeloperoxidase antigen (9%), and lactoferrin (8%). Multiple deficiencies always included granule membrane deficiency. We conclude that granule membrane defects are common in MDS, may provide a common mechanism for multiple granule deficiencies, and may prove to be an additional abnormality associated with granulocyte dysfunction.

Azotemia, TNF alpha, and LPS prime the human neutrophil oxidative burst by distinct mechanisms

The oxidative burst of neutrophils from azotemic patients (AzoPMNs) is primed for an enhanced response compared to neutrophils from normal subjects (NorPMNs). The mechanism for this priming is unknown, although TNF alpha does not further prime AzoPMNs. The present study examines the hypothesis that azotemia and TNF alpha prime neutrophils by the same mechanism. Formyl peptide receptor expression and degranulation were not primed in AzoPMNs, but were primed by both LPS and TNF alpha. LPS was also able to prime the AzoPMN oxidative burst. Guanine nucleotide exchange by multiple guanine nucleotide binding proteins, including heterotrimeric G-proteins and low molecular weight GTP-binding proteins (LMWGs), was increased in AzoPMNs, as demonstrated by GTP gamma S binding and azidoanilide GTP photoaffinity labeling. The plasma membrane density of G-protein alpha i2, alpha i3, and alpha s subunits and the density in the cytosol of the LMWG, Rap1A, was present in significantly greater amounts on plasma membranes from AzoPMNs. FMet-Leu-Phe-stimulated phospholipase D activity, but not basal activity, was significantly greater in AzoPMNs. Finally, incubation of NorPMNs in plasma from azotemic patients resulted in a significant increase in basal GTP gamma S binding. These results demonstrate that priming of AzoPMNs is restricted to oxidative burst activity and that it occurs by a mechanism distinct from that utilized by TNF alpha and LPS. While the exact mechanism remains unknown, it appears to involve a plasma factor and changes in LMWG expression or activity.

Granulocytes from chronic myeloid leukemia (CML) patients show differential response to different chemoattractants

Binding of chemoattractant to polymorphonuclear leukocytes (PMNL) triggers a series of events like polymerization of actin and tubulin, orientation of cells, chemotaxis, increase in fluid pinocytosis and phagocytosis, and stimulation of microbicidal pathways which includes lysosomal degranulation and generation of reactive oxygen species. Earlier studies from our laboratory have shown that stimulation of chemotaxis, fluid pinocytosis, and actin polymerization of CML PMNL in response to a synthetic chemotactic peptide formyl-methionyl-leucyl-phenylalanine (fMLP) is significantly lower than that in normal PMNL. It is not known whether this lower response of CML PMNL to fMLP is a global phenomenon involving different chemoattractant receptors or is restricted to the fMLP pathway. We have evaluated chemoattractant induced degranulation process in normal and CML PMNL to fMLP, platelet activating factor (PAF), leukotriene B4 (LTB4), and an analogue of fMLP viz formyl-methionine-1 aminocyclooctane 1 carboxylic acid-phenylalanine-O-methionine (FACC8) using release of lysozyme as a parameter. We find that after stimulation with fMLP and FACC8, the mean percent release of lysozyme was significantly lower in CML PMNL as compared to that in normal cells (P < 0.001). There was no significant difference between the two after stimulation with PAF and LTB4. The results indicate that the fMLP pathway is suppressed in CML granulocytes whereas PAF and LTB4 pathways appear unaltered in these cells. We therefore also studied the kinetics of peptide-receptor interaction with a labelled hexapeptide fNLPNTL which binds to the fMLP receptor. Our results show that the number of fMLP receptors/cell is significantly lower in CML PMNL (P < 0.05) than in normal PMNL, while their affinity constants and dissociation constants were comparable.

Neutrophil proteinases and matrix degradation. The cell biology of pericellular proteolysis

Neutrophil proteinases have the capacity to degrade almost every component of the extracellular matrix. In marked contrast to the wealth of available data about the structure and activity of these proteinases when they are free in solution, there has been relatively little information about the mechanisms by which neutrophils use and control their proteolytic enzymes in an extracellular milieu that is replete with proteinase inhibitors. However, recent data have provided insights into several mechanisms that permit these enzymes to evade inhibition: (1) compartmentalization; (2) localized inactivation of proteinase inhibitors; (3) tight binding of enzymes to substrates; and (4) binding of proteinases to the neutrophil's cell surface.

Carbohydrate-binding proteins (plant/human lectins and autoantibodies from human serum) as mediators of release of lysozyme, elastase, and myeloperoxidase from human neutrophils

Analysis of cell surface glycosylation not only provides information about cell properties such as their state of differentiation or histogenetic lineage. The carbohydrate chains also provide potentially functional binding sites to endogenous carbohydrate-binding proteins. This interaction can elicit consequent signalling processes. Because of the importance of neutrophils in the host defence system, we monitored the effect of the binding of such sugar receptors to their cell surface on the release of the enzymatic activities of lysozyme, elastase, and myeloperoxidase. Besides the mannose-binding lectin concanavalin A and the immunomodulatory alpha/beta-galactoside-binding lectin from Viscum album L., three preparations of human sugar receptors - beta-galactoside-binding lectin (M(r) 14 kDa) and two affinity-purified polyclonal IgG fractions from serum with the capacity to recognize alpha- or beta-galactosides, respectively - were used. Two animal lectins from chicken liver and intestine that bind beta-galactosides, as well as the lectin-like human serum amyloid P component, were included in order to assess the importance of slight differences in ligand recognition. Cytochalasin B-enhanced enzyme release was invariably seen with the two plant lectins and the chicken liver beta-galactoside-binding lectin, but the related intestinal lectin did not increase enzyme release. The mammalian homologue of these avian lectins triggered lysozyme secretion, and the lactoside-binding IgG fraction enhanced the amount of extracellular elastase activity slightly but significantly. Thus, the actual lectin, not the nominal specificity of sugar receptors, is crucial for elucidation of responses. Due to the highly stimulatory activity of the two plant lectins, neutrophils from patients with non-cancerous diseases and from patients with lung cancer were monitored for the extent of lectin-mediated enzyme release. Only the concanavalin A-mediated reactivity of the neutrophils was associated with the type of disease.

Disorders of neutrophil function

Major bacterial infections are most commonly associated with agranulocytosis or an abnormality of immunoglobulins or complement. Occasionally, repeated infections cannot be attributed to these relatively common causes. In such cases, a quantitative abnormality in neutrophil function should be sought. Complete evaluation of neutrophil function, including: chemotaxis, adhesion, aggregation, phagocytosis, granule content and degranulation, respiratory burst activity and bacterial killing is expensive and requires the services of a specialized laboratory. However, preliminary screening of a patient with a predisposition towards infection can be carried out using simple and inexpensive methods. These include examination of blood films, chemotaxis assay, NBT test and peroxidase staining. For final diagnosis and determination of genetic transmission and treatment, specific tests are indicated. Investigation of neutrophil functions may be useful for the diagnosis of congenital and acquired neutrophil disorders. These assays may also be useful in research, diagnosis and follow up of non-infectious diseases with active inflammatory component.

The Effect of C-Reactive Protein (CRP) on Respiratory Burst of Human Peripheral Blood Phagocytes

The effect of C-reactive protein (CRP) on the oxidative response of human peripheral blood monocytes and granulocytes was investigated. The respiratory burst of phagocytes induced by phorbol-myristate-13-acetate (PMA), phytohaemagglutinin (PHA) or opsonized zymosan (OZ) was measured in luminol-enhanced chemiluminescence.

The effect of CRP on PMA-induced monocyte chemiluminescence (CL) depended both on CRP concentration and incubation time. A short incubation of cells with CRP (15–30 min.) enhanced the oxidative burst. Preincubation of cells for 1h (or longer) with low doses of CRP (about 2 μg/ml) increased, while with higher (>10 μg/ml) inhibited PMA-stimulated chemiluminescence. CRP reduced also PHA or OZ-induced monocyte respiratory response. CRP diminished PMA, PHA, and OZ-induced granulocyte chemiluminescence, except the response to PHA in the presence of low doses CRP (about 5 μg/ml).

The action of CRP on phagocytes probably involves activation of some intracellular mechanisms. During immune response, CRP could protect tissues against damage by excess of free oxygen and its biological active derivatives.

Role of neutrophils in mediating human epithelial cell detachment from native basement membrane

Epithelial cell detachment from underlying basement membrane is a feature of diseases of many organs. In the lungs it is seen in disorders as diverse as bronchiectasis, allograft rejection, and asthma. The potential for different leukocytes to induce this change is not clear. In asthma both eosinophils and neutrophils are found in affected tissues, but the capacity of each of these types of cells to induce detachment of native epithelial cells from basement membrane requires clarification. Although eosinophils damage rather than detach human epithelial cells, the effects of neutrophils on epithelial cells naturally attached to basement membrane have not previously been described. Using the human amnion in vitro model, we tested the hypothesis that neutrophils have the capacity to detach intact human epithelial cells from basement membrane. The data indicate that increasing concentrations of neutrophils are able to detach epithelial cells from their underlying basement membrane. Detachment was increased when the neutrophils were activated in situ with tetradecanoyl phorbol acetate and after longer incubation periods. Platelet activating factor and opsonized zymosan showed similar boosting effects, whereas activated complement and formyl-methyl-leucyl-phenylalanine did not. Physical contact of the neutrophils with the epithelial cells was required to induce detachment. Detachment could be inhibited by glutathione and by soybean trypsin inhibitor, an inhibition pattern similar to cathepsin G and trypsin, but not collagenase, in this system. We conclude that neutrophils are capable of detaching human epithelial cells from basement membrane, which in part involves the release of chymotrypsin-like serine proteases, probably in conjunction with oxidants, and that this detachment can be inhibited.

Further characterization of the gelatinase-containing particles of human neutrophils

In addition to azurophil and specific granules, a third storage compartment is known to exist in the neutrophils. This compartment which consists of morphologically heterogeneous particles is characterized by a high specific activity in gelatinase. A gelatinase enriched fraction was prepared by subcellular fractionation of neutrophil homogenates using rate zonal centrifugation. This fraction was enriched in diamine oxidase. Among the proteins released from the neutrophils upon stimulation by formyl peptides, those belonging to the gelatinase enriched fraction were determined after removal of the proteins from specific and azurophil granules by selective immunoadsorption. Gelatinase was recovered together with tetranectin, beta 2-microglobulin and diamine oxidase in the same fraction. Differences in the kinetics of release of gelatinase and diamine oxidase versus vitamin B-12-binding protein suggest that the proteins belong to distinct subcellular structures.

Comparison of human polymorphonuclear neutrophil elastase, polymorphonuclear neutrophil cathepsin-G, and alpha 2-macroglobulin levels in healthy and inflamed dental pulps

Polymorphonuclear neutrophils (PMNs) are found in dental pulp secondary to carious exposures, periodontal disease, or trauma. Lysosomal degranulation of these cells liberates cellular proteases, including elastase (PMN-E) and cathepsin-G (PMN-CG), which produce connective tissue degradation. However, nonspecific pulpal tissue destruction can be modified by a naturally occurring serum protease inhibitor alpha 2-macroglobulin (A2-M). This study relates the concentrations of human PMN-E, PMN-CG, and A2-M in healthy and inflamed pulpal samples. Evaluation of 21 specimens yielded statistically significant differences between healthy and moderate to severely inflamed pulps for all groups (p < 0.05). No significant correlation was detected among human PMN-E, PMN-CG, and A2-M in the healthy tissues (P > 0.05). However, in the moderate to severely inflamed pulps, there was a significant correlation between PMN-CG and A2-M (p < 0.05).

Effect of antibiotic treatment on inflammatory markers and lung function in cystic fibrosis patients with Pseudomonas cepacia

BACKGROUND

The acquisition of Pseudomonas cepacia in patients with cystic fibrosis is associated with increasing deterioration in lung function and more frequent hospital admissions. Pseudomonas cepacia is usually resistant to several antibiotics in vitro, but the response of patients colonised with the organism has not been extensively studied in vivo.

METHODS

A three month prospective study was performed to investigate the response of 14 Ps cepacia positive patients and 10 Ps cepacia negative patients to a two week course of intravenous antibiotics. All those who were Ps cepacia negative and six of the 14 Ps cepacia positive patients had Ps aeruginosa in their sputum which was sensitive to the prescribed therapy. The inflammatory markers C-reactive protein, white blood cell count, serum lactoferrin, neutrophil elastase/alpha 1-antitrypsin complex, and tumour necrosis factor alpha were measured at the start and end of each antibiotic course.

RESULTS

The median (range) % improvement in baseline FEV1 and FVC following treatment in the group as a whole was 15.2% (-23.5% to 156.3%) and 23.9% (-36.8% to 232.7%) respectively. There was no statistical difference in improvement in lung function, body weight, or inflammatory markers between individuals who were Ps cepacia positive and those who were Ps cepacia negative.

CONCLUSIONS

Patients who are Ps cepacia positive appear to respond as well to intravenous antibiotics as those who are Ps cepacia negative, despite having lower lung function and a bacterium in their sputum which is resistant in vitro to the antibiotics used.

Chediak-Higashi lymphoblastoid cell lines: granule characteristics and expression of lysosome-associated membrane proteins

Chediak-Higashi syndrome (CHS) is characterized morphologically by the presence of giant lysosomal granules resulting from the dysregulated fusion of primary lysosomes. Lysosome-associated membrane proteins comprise a family of highly glycosylated proteins which are postulated to facilitate many aspects of normal lysosomal function. In this study, Epstein-Barr virus-transformed lymphoblastoid cell lines derived from a patient with CHS were analyzed for the presence of giant granules and the expression of the lysosome-associated membrane proteins lamp1 and lamp2. Giant myeloperoxidase positive granules typical of CHS, which had a complex structure when examined by electron microscopy, could be demonstrated in the lymphoblastoid cell lines. In situ immunofluorescence with antibodies directed against lamp1 and lamp2 demonstrated abundant expression of each of these proteins in the giant CHS granules. Lack of expression of lysosomal cathepsin G in these granules was also noted. These observations suggest that the lymphoblastoid cell lines provide a convenient model for the study of Chediak-Higashi granules and the lysosome-associated membrane proteins and provide additional evidence that CHS is a "lysosomal" disease. Further study will be necessary to delineate whether the function of these membrane proteins is altered in Chediak-Higashi syndrome.

Eosinophils and major basic protein damage but do not detach human amniotic epithelial cells

Damage and detachment of epithelial cells is thought to contribute to the pathologenesis of asthma. Both eosinophils and neutrophils are found in asthmatic airways and several studies have suggested that eosinophils may be responsible for the epithelial cell detachment of asthma. To compare the capacity of purified human eosinophils and neutrophils to mediate epithelial cell detachment, we utilized a human amniotic epithelial cell-basement membrane model that we have recently described. Activated eosinophils induced little detachment at 4 h (less than 10% detachment), which contrasted with that seen with equivalent numbers of identically handled neutrophils (29 +/- 6% detachment, p less than .05). In contrast, eosinophils did induce damage to epithelial cells to an extent similar to neutrophils when assessed using a 51Cr release assay (17 +/- 6% and 18 +/- 9% release of 51Cr, respectively). When purified preparations of the major eosinophil-derived protein major basic protein (MBP) were studied, similar effects on epithelial cells were observed, i.e., damage (77 +/- 13% release of 51Cr) without detachment (less than 5% cell detachment). These data suggest that neutrophils are more effective in inducing detachment of human epithelial cells, whereas both eosinophils and neutrophils damage human epithelial cells.

Chediak-Higashi syndrome in a black child

Chediak-Higashi syndrome (CHS) is an uncommon genetic disorder with a constellation of clinical, pathologic, and immunologic manifestations. It is rarely reported in blacks. Pathognomonic intracellular inclusions in white blood cells are well recognized; however, characteristic abnormal melanin aggregation into giant melanosomes also occurs, as can be readily seen by histologic evaluation of hair. We present a case of CHS in a black child.

Host mediators in gingival crevicular fluid: implications for the pathogenesis of periodontal disease

During the past few years, a considerable number of studies have examined different aspects of the host response in gingival crevicular fluid (GCF), including the relationship of specific markers to the active phases of periodontal disease. Various indicators of the acute inflammatory response (the lysosomal enzymes beta-glucuronidase and collagenase, the cytoplasmic enzyme aspartate aminotransferase, and the arachidonic acid metabolite PGE2) have been shown to be associated with clinical attachment loss in chronic adult periodontitis in man and experimental periodontitis in animal models. In contrast, the relationship of indicators of the humoral immune response in GCF to active periodontal disease is equivocal. Furthermore, a number of indicators of the cellular immune response have been identified recently in GCF (i.e., Interleukin-1 alpha, IL-1 beta, tumor necrosis factor-alpha), but their relationship to active phases of periodontal disease have not been studied. The polymorphonuclear leukocyte (PMN) is the cellular hallmark of acute inflammation. Evidence from the GCF studies suggests that hyperreactivity of these cells plays a critical role in the active phases of some forms of periodontal disease. Metabolic activation of PMN can be associated with a number of potentially destructive reactions. The major effector mechanism for tissue destruction that can be specifically identified with the PMN is the synergistic effect of the release of PMN proteases and the generation of reactive oxygen metabolites by these cells. Priming of the PMN, where the PMN response is enhanced by agents that do not initiate the response, may be an important mechanism for PMN activation in the crevicular environment; for example, cytokines such as IL-1 beta and TNF-alpha, and lipopolysaccharides released from subgingival Gram-negative bacteria, can serve this function. The hypothesis proposed here argues that in addition to the severe forms of periodontal disease that have been associated with qualitative or quantitative PMN defects, tissue destruction in the periodontum can be observed with hyperreactivity of these cells. These differing conclusions do not create a dilemma, but may represent opposite ends of a balance that is no longer in equilibrium.

Human polymorphonuclear granule components: relative levels detected by a modified enzyme-linked immunosorbent assay in normal and inflamed dental pulps

Lysosomal granules of polymorphonuclear leukocytes (PMN's) contain proteolytic enzymes and other components important in the regulation of inflammation and the elimination of bacteria or debris associated with pulp disease. However, PMN lysosomal degranulation is nonspecific and can result in destruction of healthy connective tissue adjacent to the areas of damaged or infected tissue. For this study a modified enzyme-linked immunosorbent assay was used to detect the human PMN lysosomal granule products: elastase, cathepsin G, and lactoferrin. Evaluation of 55 pulp samples yielded a statistically significant difference (p less than 0.05) among the levels of elastase and lactoferrin in normal and moderate to severely inflamed pulps. Although cathepsin G levels were increased, there was no statistical significance (p greater than 0.05) among groups. The results indicate that a modified enzyme-linked immunosorbent assay technique can be used to measure PMN lysosomal granule components in dental pulp tissues. Additionally, elastase and lactoferrin levels appear to be valid diagnostic markers of advanced dental pulp disease.

Inhibition of neutrophil chemotaxis by elastase-generated IgG fragments

IgG1 is cleaved in vitro by granulocyte elastase into Fc and Fab fragments. The elastase-specific Fc fragment has been previously detected in vivo. Biological activity of the fragments has been described in modulating neutrophil oxidative metabolism and enzyme release. To investigate further effects granulocyte chemotaxis (CT) was tested. The CT was assayed in Boyden chambers and the chemotactic index (CI) was calculated which represents the mean distance travelled by the activated cells. Stimulation of leucocyte CT by casein, activated serum and FMLP gives maximal values of delta CI = 46.7, 26.4 and 7.2 microns, respectively. Native IgG1 and the elastase-produced IgG fragments do not stimulate leucocyte CT. FMLP-stimulated CT is specifically inhibited by the elastase-produced Fc fragments. Addition of 7 nmol Fc to stimulus concentrations of 16 to 125 nM FMLP results in total inhibition of chemotaxis demonstrated by CI values which are lower than those for unstimulated cells. The inhibition of CT is concentration dependent in the range of 2 to 7 nmol Fc/10(6) PMN. Number and affinity of FMLP receptors are not influenced by Fc fragments, so Fc binds neither to FMLP nor the FMLP receptor. CT stimulated by casein shows a large portion of chemokinesis. Only at suboptimal casein concentrations do Fc and IgG have an inhibitory effect on CT (0.63 mg casein/ml, 10 nmol peptide/10(6) PMN). C5a-stimulated CT is not influenced by IgG or IgG fragments which indicates that the samples are not cytotoxic. So the FMLP and casein-stimulated CT is specifically inhibited by the elastase-produced Fc fragments in a low concentration range.

Ammonium decreases human polymorphonuclear leukocyte cytoskeletal actin

Ammonium, a weak base produced as a metabolic by-product of urea metabolism by bacterial pathogens, inhibits a variety of motile polymorphonuclear leukocyte (PMN) functions. It was initially assumed that the mechanism of leukocyte inhibition was due to cytoplasmic alkalinization. However, while it is clear that ammonium can effect cytoplasmic alkalinization, current data indicate that alterations in chemotaxis, degranulation, and receptor recycling occur independently of cytoplasmic alkalinization. Since these are motility-related events, we examined the possibility that alterations in cytoskeletal actin may account for the effects of ammonium on PMN function. The results indicate that ammonium can inhibit degranulation, decrease cytoskeletal actin, and increase actin depolymerization rates. These findings are supported by five lines of evidence. First, formylmethionyl-leucyl-phenylalanine (fMLP)-induced elastase release was inhibited by 85% +/- 3% in the presence of ammonium, and ammonium by itself did not stimulate elastase release. Second, ammonium treatment of resting PMNs caused a rapid 38% +/- 6% decrease in cytoskeletal actin. Third, ammonium treatment accelerated the fMLP-induced depolymerization phase of the cytoskeletal actin transient by 150% +/- 12%. Fourth, in resting PMNs treated with cytochalasin B or D, ammonium induced a 21% +/- 4% and a 25% +/- 5% decrease in cytoskeletal actin, respectively. Conversely, ammonium did not affect the ability of the cytochalasins to inhibit an fMLP-induced cytoskeletal actin transient. Fifth, pertussis toxin treatment of neutrophils did not affect the ammonium-stimulated decrease in cytoskeletal actin. These results suggest that ammonium can inhibit neutrophil function by altering cytoskeletal actin and therefore provide new information regarding potential pathogenic mechanisms for bacterial pathogens.

Decreased specific anti-elastase activity in the uninvolved skin of patients with psoriasis

Inhibitory activities against elastase, chymotrypsin and trypsin were studied in the fluid from experimentally developed suction blisters in the uninvolved skin of patients with psoriasis. These activities determined by spectrophotometry of specific synthetic low molecular weight substrates were compared with respective antiproteinase activities in sera of 32 patients with psoriatic lesions, ten patients in remission, and ten healthy volunteers. A marked reduction (29.2%) in the specific elastase inhibitory activity of blister fluid was found in patients with psoriasis when compared with normal subjects (p less than 0.05), since neither chymotrypsin nor trypsin inhibitory activities were altered. This reduction was despite about a 30% increase in the elastase inhibitory activity in the sera of these patients, which was related presumably to their increased activity of alpha 1-proteinase inhibitor, the main serum antiserine proteinase inhibitor. A decreased blister fluid:serum elastase inhibition ratio was shown in a large majority of patients with psoriasis, even in symptomless patients. The deficiency in specific elastase inhibitory activity of suction blister fluid was predominantly associated with early onset of psoriasis, guttate lesions and inactive lesions, skin involvement less than 20% of body surface, duration of relapse shorter than 2 months, and frequent relapses. These data indicate that the uninvolved skin of patients with psoriasis contains low concentrations of specific elastase tissue inhibitor, which deficiency might result in an excessive in vivo hydrolytic activity of neutrophil elastase released from migrating cells in the psoriatic skin.

Ultrastructure of neutrophilic granulopoiesis in the bone marrow of patients with chronic myeloid leukemia (CML). A morphometric study with special emphasis on azurophil (primary) and specific (secondary) granules

In seven patients with chronic myeloid leukemia (CML) and ultrastructural and morphometric study was performed on neutrophilic granulopoiesis in bone marrow trephine biopsies. Bone marrow specimens from five patients without hematological abnormalities served as controls. In stable phases of CML, abnormalities of the maturing granulocytic lineage were most conspicuously expressed by an infrequently occurring nuclear disfiguration (blebs and disturbed bridging of segments). Morphometric evaluation included the numbers of azurphil (primary) and specific (secondary) granules, the cisternal length of the endoplasmic reticulum and the area of the mitochondrial profiles. These variables could be determined in early and late myeloblasts, promyelocytes, metamyelocytes, band cells and mature polymorphonuclear granulocytes. Statistical analysis with regard to control specimens demonstrated no significant differences in the total amount of neutrophil granules or of the other cell organelles.

Stimulation of neutrophil elastase and myeloperoxidase release by IgG fragments

Human leucocyte elastase (HLE) cleaves IgG into Fab and Fc fragments. The Fc fragment bears an elastase-specific antigen and has previously been reported to be found in synovial fluid during rheumatoid arthritis. In addition, biological activity of elastase-specific Fc fragments has been described in modulating granulocyte oxidative metabolism. To investigate further regulatory effects of the elastase-induced IgG cleavage products, we tested the elastase and myeloperoxidase release of granulocytes. IgG fragments induce no enzyme release of unstimulated neutrophils. But elastase and myeloperoxidase release of cytochalasin b/FMLP-treated neutrophils is stimulated in a dose-dependent manner by the Fab fragments. The extent of stimulation depends on stimulus concentration and is at its maximum for low (e.g. 2.5 x 10(-8) M) FMLP concentration. Ten nanomoles Fab/4 x 10(6) PMN augment elastase release to 206% and myeloperoxidase release to 155% after pre-stimulation with 2.5 x 10(-8) M FMLP. Fc fragments stimulate elastase release to 162% but no MPO release. Untreated IgG1 and analog Fab and Fc fragments produced by papain cleavage react similarly. Elastase-generated IgG fragments may therefore up-regulate their concentration by simulating elastase release. The concomitantly stimulated release of myeloperoxidase may influence bactericidal activity and termination of oxidative burst.