Granulocyte dysplasia and dysfunction, and CD11/CD18 defects in myelodysplastic syndromes

In myelodysplastic syndromes (MDS), dysplastic changes in neutrophils are a common feature reflecting the total degree of bone marrow dysplasia. Furthermore, granulocyte function is abnormal, so that a high risk of life-threatening infections has been documented. In this review we shall focus on the defects of both granulocytes and their CD11b/CD18 glycoprotein complex, which regulate granulocyte adherence, locomotion, diapedesis and migration into inflammatory sites, in patients suffering from primary MDS. The defective surface membrane glycoprotein expression of myelodysplastic phagocytes is not only a useful diagnostic tool, but also a powerful prognostic one, since MDS patients with such defects present both an increased susceptibility to infections and a decreased survival. Moreover, the administration of colony-stimulating factors is known to be able to elicit long-lasting improvement in neutrophil count, CD11b/CD18 expression and function, marrow myeloid maturation, and possibly to decrease bacterial infections in MDS patients.

Iloprost effects on phagocytes in patients suffering from ischaemic diseases: in vivo evidence for down-regulation of alpha M beta 2 integrin

This study has been designed to demonstrate the in vivo effects of iloprost therapy on expression of adhesion molecules on phagocytes. Sixty patients suffering from peripheral arterial occlusive disease (PAOD) and/or from skin ulcers due to secondary progressive systemic sclerosis (PSS) were enrolled in a double-blind controlled parallel study. Thirty patients (group I) underwent iloprost infusion and 30 patients (group II) were treated with aspirin. Clinical assessment and measurement of phagocyte activation in vivo, using quantitative flow cytometry, were performed on entry and after 6 h on the first day of therapy. After 3 months of therapy, complete healing of all cutaneous lesions was observed in 84% of the patients treated with iloprost compared with the control patients (P < 0.001). Neutrophils and monocytes of PAOD and PSS patients showed a significant decrease in the expression of the alpha M beta 2 integrin adhesion receptor after 6 h of iloprost infusion. Neutrophils and monocytes released a lower amount of anion superoxide (O2-) after 6 h of iloprost treatment. These data confirm other clinical observations but demonstrate that in vivo this drug modifies the expression of the alpha M beta 2 integrin of phagocytes that has a key role in leukocyte-endothelium interactions in cases of inflammation and thrombosis.

Expression of neutrophil and monocyte CD11B/CD18 adhesion molecules at different sites of the coronary tree in unstable angina pectoris

To assess the site of leukocyte activation in unstable angina, the expression of neutrophil and monocyte CD11B/CD18 adhesion molecules in 26 patients was measured from blood samples taken from the coronary ostium, the coronary sinus, and the coronary artery just distal to the culprit lesion (postobstructive chamber). CD11B/CD18 adhesion molecules detected by direct immunofluorescence evaluated by flow cytometry were significantly higher in the coronary sinus blood than in both the coronary ostium and the postobstructive chamber blood, suggesting that leukocyte activation takes place at the microcirculatory interface with the injured myocardium, probably as the result of short but repeated episodes of myocardial ischemia.

[Job syndrome (hyper-IgE) and hypo-IgA. A rare association of immunodeficiencies]

Job' syndrome and IgA immunodeficiency are a rare dysfunction of the immune system. In this work, we reported a case of a young woman who had recurrent episodes of bacterial infections in the urinary tract and genital, generalized erythematous eczematous patches and stomatitis of oral mucosa and fever. During the hospitalization, laboratory data showed high immunoglobulin IgE and low IgA levels. The T-lymphocyte presented a reduction of CD8+ cells. Tests of granulocyte function have showed a global deficit in the in vitro and in vivo chemotaxis. The correlation between these two clinic conditions is not completely clarified but it is possible to hypothesize that CD8+ lymphocytes produce an inhibition factor of chemotaxis. Job' syndrome is characterized by a selective reduction of CD8+ cells subpopulation which have an immunoregulatory function on the production of IgE by plasmacells. In the ipoIgA, an intrinsic inability of B-IgA cells to proliferate and to differentiate produce a defect in the IgA production. In these two clinic disorders there is an effective dysfunction of immune system. It is possible to hypothesize that an effective defect of CD8+ cells and an immaturity of B-cells may coexist in our patient. That justifies an abnormal production of Ig and a defect in granulocyte chemotaxis.

Mycobacterium tuberculosis chaperonin 10 forms stable tetrameric and heptameric structures. Implications for its diverse biological activities

The chaperonin activity of sequence-related chaperonin 10 proteins requires their aggregation into heptameric structures. We describe size-exclusion chromatography and ultracentrifugation studies that reveal that while Escherichia coli chaperonin 10 exists as a heptamer, the Mycobacterium tuberculosis chaperonin 10 is tetrameric in dilute solutions and in whole M. tuberculosis lysate. At high protein concentration and in the presence of saturating amounts of divalent ions, the protein is heptameric. Human chaperonin 10 is predominantly heptameric, although smaller oligomers were detected. These differences in structural assembly between species may explain differences in biological activity such as antigenicity. Using C-terminal and N-terminal fragments, sequence 1-25 was identified as indispensable for aggregation. CD spectroscopy studies revealed that (i) a minimum at 202-204 nm correlates with aggregation and characterizes not only the spectrum of the mycobacterial protein, but also those of E. coli and human chaperonin 10 proteins; (ii) the interactions between subunits are of the hydrophobic type; and (iii) the anti-parallel beta-pleated sheet is the main secondary structure element of subunits in both tetrameric and heptameric proteins.

Clinical and angiographic correlates of leukocyte activation in unstable angina

OBJECTIVES

This study sought to evaluate the relation, if any, between clinical and angiographic findings in patients with unstable angina and monocyte and neutrophil CD11b/CD18 receptor density. The expression of HLA-DR molecules on T lymphocytes, an index of activation of these cells, was also investigated.

BACKGROUND

Although activation of neutrophils and monocytes has recently been shown in unstable angina, no studies have correlated activation indexes with clinical and angiographic features of patients with this clinical condition.

METHODS

Sixty patients underwent diagnostic coronary arteriography and simultaneous blood sampling from the aorta and coronary sinus before injection of contrast medium. Cell surface receptors were detected by direct immunofluorescence evaluated by flow cytometry using monoclonal antibodies tagged with fluorescent markers.

RESULTS

In 38 patients with unstable angina, neutrophils and monocytes showed a significantly higher expression of CD11b/CD18 adhesion receptors in coronary sinus than aortic blood (p < 0.0001 and p < 0.001, respectively). When these patients were analyzed according to clinical characteristics or angiographic findings, no difference in CD11b/CD18 receptor expression in coronary sinus blood was found between the various subgroups, except for patients with at least one episode of chest pain at rest within 48 h of coronary arteriography and a higher neutrophil adhesion molecule density than patients who remained asymptomatic (p = 0.04). Lymphocytes in patients with stable and unstable angina showed a similar percent expression of CD2/CD19 and CD3/HLA-DR antigens, with no difference between aortic and coronary sinus blood.

CONCLUSION

These results in a larger cohort confirm previous data that neutrophil and monocyte CD11b/CD18 adhesion molecules show a higher expression in the coronary sinus blood of patients with unstable angina. Among clinical and angiographic findings in patients with unstable angina, only the occurrence of chest pain within 48 h of coronary angiography was related to significantly higher values of neutrophil fluorescence intensity, suggesting that the degree of neutrophil activation is related to the proximity of rest angina episodes to blood sampling. Finally, our data do not support the concept of systemic or transcardiac lymphocyte activation in unstable angina.

The in Vitro Activity of Two Urinary Polypeptides Respect to G- and GM-CSF and IL3 on the Peripheral CFU of Normal and Leukemic Subjects

We isolated two polypeptides on HPLC from the acetonic precipitate of the urine of normal subjects and of patients with untreated AML, APL and AMML. Before separation the quantity of the total urinary factor from leukemic patients was 50±10 mg/24h and from normal subjects was 10±5 mg. We tested the total polypeptidic extract and the two main fractions obtained on liquid cultures of the peripheral CFU of normal and leukemic subjects (AML, APL, CML and CMmL). Colony growth, cell morphology changes and the main cellular markers were examined at the beginning and at the 5th and 10th days of incubation in RPMI 1640 medium. Testing conditions were basal and as determined by the addition of the polypeptidic fractions, both alone and in association with trans-retinoic acid (t-RA) or thioproline (T). Simultaneously and under the same experimental conditions, we tested the activity of G- and GM-CSF and IL3. The results obtained prove the colony stimulating activity of the two fractions and of crude extract; they also prove the ability of such agents to modify the behavior in vitro of peripheral CFU. The urinary extracts are also able to stimulate a moderate differentiation of the elements and an increase both in fibroblasts and in adhesion molecules. We conclude that the dosage of growth factors in urine may be usefull as important marker in several hemopoietic pathological conditions or as a possible source of growth factors.

Sequence and structural homologies between M. tuberculosis chaperonin 10 and the MHC class I/II peptide binding cleft

The peptide corresponding to the C-terminal half of M.tuberculosis hsp10 was synthesised based on the prediction that it might represent an independent structural region of the protein. This hypothesis was confirmed by aggregation and CD studies using this peptide and longer sequences of the protein. The peptide shares about 40-50% sequence homology with alpha 2 and beta 1 chains of MHC class I and II antigens. This and the CD results which indicated that the peptide at acidic pHs folds into an anti-parallel beta-sheet were used to generate a 3D model which has the same "W" fold contained in the MHC peptide binding groove. These data suggest that the hypothesis of molecular mimicry proposed to be one of the mechanisms which triggers autoimmune diseases may be extended to hsp10 proteins. Furthermore the suggested evolutionary relationship between hsp's and MHC antigens may find support from these data.

Expression in Escherichia coli, purification and functional activity of recombinant human chaperonin 10

We have recently reported the cloning of a cDNA coding for a stress inducible human chaperonin 10. The protein was shown to possess 100% identity with the bovine homologue and a single amino acid replacement (glycine to serine at position 52) compared to rat chaperonin 10. Here we report the heterologous expression of human chaperonin 10 in Escherichia coli, its purification and its functional characterization. The recombinant protein was purified to homogeneity as judged by different analytical techniques, and mass spectrometry analysis showed a MW of 10,801 Da in agreement with the predicted sequence. This molecular weight accounts for a protein which is not modified post-translationally. In fact, natural rat chaperonin 10 has been shown to be acetylated at the N-terminus, a feature suggested to be important for targeting and functional activity. Here we show that recombinant human chaperonin 10 is fully active in assisting the chaperonin 60 GroEL in the refolding of denatured yeast enolase, thereby showing that, at least in the present system, post-translational acetylation is not necessary for its activity.

[Pancreatic encephalopathy. Description of an unusual case]

The authors describe a case of pancreatic encephalopathy. This uncommon condition, rarely described in the literature, occurs with neuropsychiatric signs 3-4 days after the onset of acute pancreatitis. Diagnosis is due to clinical and biochemical findings and to post mortem examinations revealing also amylase in CSF.

Cochaperonins are histone-binding proteins

Cochaperonins (cpn10) assist chaperonins (cpn60) in mediating folding of polypeptide substrates in an ATP-dependent reaction. Moreover, they have been shown to be secretory products of living cells and to perform discrete biological activities without the need to interact with cpn60. Here, we have investigated the possible existence of cellular cpn10 binding sites that could mediate such activities. For this purpose, we performed binding studies with iodinated cpn10 on whole cells and on electrophoretically separated eukaryotic cell lysates. The former studies yielded negative results, whereas in the latter binding to several proteins was detected. These proteins were identified as being histones. Binding was observed to all core histones (H2A, H2B, H3 and H4) and, although weaker, to the linker histone H1 as well. These results show that cpn10 are histone-binding proteins.

[Echinococcosis with crural localization. A case report]

The authors report a case of echinococcosis with an atypical localisation. It involved hydatid cysts with a single, extramuscular and extravasal primary right crural localisation. After examining the international literature the authors affirm that this localisation has not been described previously in other reports. They conclude that surgery is vital for the remission of the disease, as is the use of an atraumatic and accurate technique in order to avoid possible sequelae linked to the iatrogenic diffusion of echinococcosis.

Granulocyte defects and opioid receptors in chronic exposure to heroin or methadone in humans

In order to elucidate better the immunological effect of opioid abuse in the absence of HIV infection as a confounding factor, granulocyte function was investigated in three groups of HIV-negative subjects, including 20 active parenteral heroin abusers (H), 20 long-term methadone-maintained former opiate abusers (M) and 20 healthy controls (C). Chemotaxis to N-formyl methionyl-leucyl-phenylalanine (fMLP), casein and activated plasma were markedly and similarly reduced (approx. 50%) in both H and M groups, as was true for superoxide production after fMLP and PMA stimulation, 47% decrease of C values. Polymorphonuclear (PMN) of H and M subjects also exhibited a very marked and similar reduction in the expression of CD11b/CD18 integrin receptors after fMLP treatment, with values that were less than 10% of those in controls, as observed by flow cytometry. In parallel, PMN of H and M individuals presented an approximately four-fold increase in opioid receptors numbers compared to controls, a significant inverse correlation existing between the increase in opiate receptors and defective chemotaxis. The possible mechanism underlying the observed changes in PMN of H and M individuals is discussed.

[The role of the granulocytes in ischemic cardiopathy]

Recent studies suggest that granulocytes (PMNs) play a role in the pathogenesis of acute and chronic myocardial ischemia and extension of myocardial injury. Granulocytes can release a variety of mediators tissue injury and synergize with these different mediators, cytokines and other cells resulting in amplification of neutrophil stimulation and rising to additional products with enhanced endothelial injury. Free radicals released by PMNs during ischemia or reperfusion produce deleterious effects on cell membranes, endothelial cells and myocardium. Experience in humans shows the modification of PMNs function in angina and during myocardial ischemia: upon reperfusion PMNs accumulate and produce an inflammatory response leading to endothelial injury. Rabbit derived antiserum dependent-reduction of circulating PMNs in the dog or using monoclonal antibody anti-CD11b/CD18 of PMNs resulted in smaller myocardial infarction. Another aspect of PMNs function is related to leukotriene C4 release; the vasoconstrictor effect of this leukotriene on coronary arteries is synergistic with that induced by platelet-released thromboxane A2, and the decrease in coronary flow produced by the combination of both substances is greater than the sum of changes caused by the two eicosanoids separately administered. The potential role of leukocytes, oxygen radicals, leukotrienes and granulocyte enzymes in the pathophysiology of myocardial injury due to regional ischemia and reperfusion is an area of intense investigation. This overview will not attempt to be exhaustive. Experimental and clinical studies to elucidate these events should not only provide insight into acute and chronic pathologic tissue damage, but may also lead to the identification of important new targets of pharmacologic intervention.

[Correlations between membrane integrins and granulocyte defects in myelodysplastic syndromes]

The aim of the present study was to evaluate some functions of neutrophil granulocytes (PMNs), such as aggregation, superoxide production, chemotaxis and adhesion molecules involved in these processes, in 22 patients suffering from Myelodysplastic Syndrome (MDS), to clarify if granulocytes alterations described in this syndrome is really correlated with the expression of surface membrane integrins. Several patients suffering from MDS present granulocytopenia and/or absolute monocytoses; neutrophil granulocytes can have typical nuclear and cytoplasmatic alterations. These granulocytic anomalies are valuable in about 90% of patients suffering from MDS. The granulocytes showed a significant deficit in chemotaxis stimulated by serum activated with E. Coli, casein and formyl-methionyl-leucylphenylalanine (fMLP) (p < 0.01) and in superoxide production stimulated by phorbol-myristate-acetate (PMA). We also studied the role of membrane integrin CD11/CD18 using specific monoclonal antibodies (MoAb). The cytofluorimetric analysis demonstrated a significant inhibition in expression of CD11b/CD18 receptors in patients suffering from MDS (p < 0.001), while the expression of CD11a/CD18 and CD11c/CD18 receptors was normal. In conclusion we found specific alterations in PMNs functions in MDS and a correlation of these anomalies with membrane integrins of PMNs is therefore possible.

Increased expression of neutrophil and monocyte adhesion molecules in unstable coronary artery disease

BACKGROUND

A rapid increase in leukocyte adhesion to endothelial cells is one of the first events in the acute inflammatory response and in the pathogenesis of vascular diseases. A subgroup of cell surface glycoproteins (the CD11/CD18 complex) play a major role in the leukocyte adhesion process; in particular, the CD11b/CD18 receptor can be upregulated severalfold in response to chemotactic factors. The purpose of this study was to assess whether upmodulation of granulocyte and monocyte CD11b/CD18 receptors takes place during the passage of blood through the coronary tree of patients with clinical manifestations of ischemic heart disease.

METHODS AND RESULTS

Thirty-nine patients who underwent diagnostic coronary arteriography were studied. Group 1 (15 patients) had a clinical diagnosis of unstable angina, group 2 (14 patients) had stable exertional angina, and group 3 (10 patients) had atypical chest pain. Simultaneous sampling from the coronary sinus and aorta was obtained before coronary arteriography. Cell surface receptors were detected by direct immunofluorescence evaluated by flow cytofluorimetry using monoclonal antibodies tagged with fluorescent markers. Leukocytes were stained in unseparated blood to avoid in vitro manipulation that could activate phagocytes. Group 1 and 2 patients had significant coronary artery disease (> 50% coronary narrowing in at least one major coronary vessel), whereas group 3 patients had normal coronary arteries. In group 1, granulocytes and monocytes showed a significantly higher expression of the CD11b/CD18 adhesion receptor in the coronary sinus than in the aorta (both P < .01), whereas no difference in CD11b/CD18 expression was seen in groups 2 and 3.

CONCLUSIONS

Patients with unstable angina have an increased expression of granulocyte and monocyte CD11b/CD18 adhesion receptors, indicating that an inflammatory reaction takes place within their coronary tree. Activation of these leukocytes may induce coronary vasoconstriction, favor thrombotic processes, and further activate platelets, thus having potential implications on the pathogenesis of unstable coronary artery disease.

The role of integrins in granulocyte dysfunction in myelodysplastic syndrome

The aim of the present study was to evaluate the function of granulocytes in 20 patients affected by myelodysplastic syndrome (MDS) and correlate this with the expression of surface membrane integrins. The granulocytes showed a deficit in chemotaxis (34 +/- 12 vs 84 +/- 10, p < 0.01) in superoxide release (12 +/- 7 vs 30 +/- 10, p < 0.01) and in aggregation 12 +/- 6 vs 36 +/- 9, p < 0.01 using fMLP as stimulus. We also demonstrated with cytofluorimetric and alkaline phosphatase immunoenzymatic analysis (APAAP), decreased expression of CD11b/CD18 receptor detected by OKM1 (p < 0.001) and CD18 detected by MoAb IOT-18 (p < 0.001). PMNs CD11b/CD18 up-regulation and APAAP image analysis studies showed a lower level of expression of CD11b/CD18 in granulocytes from MDS patients compared to controls (p < 0.001). We concluded that granulocyte dysfunction in MDS may be correlated with modification of leukocyte integrins.

The CD11/CD18 granulocyte adhesion molecules in myelodysplastic syndromes

We have evaluated the function of granulocytes in 14 patients suffering from myelodysplastic syndrome (MDS). We also evaluated the functional and immunochemical activities of five monoclonal antibodies (MoAbs) reactive with the CD11/CD18 leucocyte adhesion molecules of granulocytes. Granulocytes showed a decrease in chemotaxis (P < 0.001) and in aggregation (P < 0.01) using various agents as a stimulus. Cytofluorimetric and immunoenzymatic assays with alkaline phosphatase (APAAP) analysis showed decreased expression of the CD11b/CD18 receptor detected by OKM1 (P < 0.001). Despite LFA-1 and-CD11a/CD18 was expressed in normal amounts. The studies of upregulation of granulocytes CD11b/CD18 and image analysis of immunochemical preparation (APAAP) demonstrated decreased expression of CD11b/CD18 in granulocytes from MDS compared to controls (P < 0.001). We conclude that granulocyte dysfunction in MDS may be correlated with decreased expression of surface CD11b/CD18 leucocyte adhesion molecules or their structural modification.