Evaluation of humoral immune function in patients with bronchiectasis

Bronchiectasis is a chronic debilitating condition characterized by abnormal dilated thick-walled bronchi. To investigate humoral immune function in bronchiectatic patients, this study was performed. Forty patients with established diagnosis of bronchiectasis, who were referred from two tertiary care pulmonology centers in Tehran, were investigated in this study. Immunoglobulin isotypes concentrations and IgG-subclasses were measured by nephelometry and enzyme-linked immunosorbent assay (ELISA) methods, respectively. All patients received unconjugated pneumococcal vaccine, and blood samples were taken before and 21 days after vaccination. Specific antibodies against whole pneumococcal antigens were measured using the ELISA method. Fifteen (37.5%) out of 40 patients were diagnosed to have defects in antibody mediated immunity including 5 (12.5%) patients with immunoglobulin class deficiency (2 with common variable immunodeficiency and 3 with IgA deficiency), 3 (7.5%) with IgG subclass deficiency and 7 (17.5%) patients had Specific antibody deficiency (SAD) against polysaccharide antigen despite normal levels of serum immunoglobulins and IgG subclasses. Our study along with several other studies confirmed that all patients with bronchiectasis should undergo thorough immunological evaluation in order to identify the presence of the underlying immunologic defect. This evaluation should include serum immunoglobulins, IgG subclasses concentrations and also determination of serum antibodies against pneumococcal antigens. Early diagnosis and appropriate treatment will prevent the subsequent complications and improve quality of life of affected individuals.     

Dunkerque City air pollution particulate matter-induced cytotoxicity, oxidative stress and inflammation in human epithelial lung cells (L132) in culture.

Exposure to urban airborne particulate matter (PM) has been associated with adverse health effects. In this work, we focused our attention on the capacity of air pollution PM to induce cytotoxic, oxidative stress, and inflammatory responses in human epithelial lung cells (L132) in culture. PM were collected in Dunkerque, a French seaside city, and their physical and chemical characteristics were carried out. Their size distribution showed that 92.15% of the PM were equal or smaller than 2.5 and their specific surface area was 1 m2/g. Inorganic (i.e. Fe, Al, Ca, Na, K, Mg, Pb, etc.) and organic (i.e. VOC, PAH, etc.) chemicals were found in PM. Physical and chemical properties of Dunkerque City's PM suggested that much of the collected PM derived from wind-borne dust from the industrial complex and the heavy motor vehicle traffic. Their cytotoxicity, as evaluated by survival rate determination, lactate dehydrogenase activity, and mitochondrial dehydrogenase activity showed concentration and time-dependent effects in L132 cells (LC10 = 18.84 microg PM/ml; LC50 = 75.36 microg PM/ml). Moreover, in PM-exposed L132 cells, there were concentration- and time-dependent changes in lipid peroxidation, superoxide dismutase activity, 8-hydroxy-2'-deoxyguanosine formation, and poly(ADP-ribosyl)ation, on the one hand, and in tumor necrosis factor-alpha secretion, inducible nitric oxide synthase activity, and nitric oxide release, on the other hand. Taken together, these findings suggested that oxidative stress and inflammatory responses proceeded cytotoxicity in PM-exposed L132 cells.     

Biologic markers of oxidative stress and nephrotoxicity as studied in biomonitoring of adverse effects of occupational exposure to lead and cadmium

OBJECTIVES: In this work, we studied impregnation levels of workers occupationally exposed to lead (Pb) and cadmium (Cd), usefulness of early urinary markers of nephrotoxicity, and occurrence of oxidative stress as the underlying mechanism involved in Pb- or Cd-induced adverse effects. Thirty-five men were recruited from a nonferrous metal smelter. Pb and Cd in blood (B-Pb, B-Cd) and urine (U-Pb, U-Cd) were measured. Relations between oxidative stress markers (malondialdehyde, superoxide dismutase, glutathione peroxidase, selenium, glutathione reductase, glutathione status, 8-hydroxy-2'-deoxyguanosine) and exposure levels, on the one hand, and early urinary markers (alpha-1-microprotein, beta-2-microglobulin, retinol binding protein, alpha and pi-glutathione S-transferases) and exposure levels, on the other hand, were evaluated. RESULTS: Mean exposure levels were moderate (B-Pb = 395.71 microg Pb/L; U-Pb = 95.19 microg Pb/g creatinine; B-Cd = 5.83 microg Cd/L; U-Cd = 4.67 microg Cd/g creatinine). Changes in malondialdehyde, glutathione status, 8-hydroxy-2'-deoxyguanosine, and alpha-glutathione S-transferases were closely correlated with exposure levels and did not depend on tobacco consumption. We showed that these workers showed moderate Pb and Cd exposure levels. CONCLUSIONS: Taken together, the data suggests the use of alpha-glutathione S-transferases excretion in urine as a hallmark of early changes in the proximal tubular integrity that could later lead to clinical disease if exposure is not reduced.     

Conformationally constrained peptide analogues of pTyr-Glu-Glu-Ile as inhibitors of the Src SH2 domain binding

A series of conformationally constrained peptides were designed and synthesized as the Src SH2 domain ligands based on a tetrapeptide sequence pTyr-Glu-Glu-Ile (pYEEI). In general, the constrained peptides such as compounds 6, 7, and 11 (IC(50) = 1.1-1.5 microM) showed higher binding affinities to the Src SH2 domain relative to the corresponding linear peptides 8a, 9a, and 13a, respectively (IC(50) > 100 microM), and pYEEI (IC(50) = 6.5 microM), as evaluated by a fluorescence polarization assay. Molecular modeling studies revealed that in constrained peptides, the isoleucine side chain penetrates very deeply into the hydrophobic binding pocket (P + 3 site) of the Src SH2 domain. These constrained peptides can serve as novel templates for the design of small and nonpeptidic inhibitors of the Src SH2 domain.     

Two distinct pathways of immuno-modulation improve potency of p53 immunization in rejecting established tumors

The p53 gene product is overexpressed by almost 50% of cancers, making it an ideal target for cancer immunotherapy. We previously demonstrated rejection of established p53-overexpressing tumors without stimulating autoimmunity by immunization with modified vaccinia Ankara-expressing murine p53 (MVAp53). Tumor rejection was enhanced through antibody-mediated CTL-associated antigen 4 (CTLA-4) blockade. We examined the role of synthetic oligodeoxynucleotides (ODN) containing unmethylated cytosine-phosphate-guanine (CpG) motifs (CpG ODN) in enhancing MVAp53-mediated tumor rejection. CpG ODN with MVAp53 resulted in tumor rejection in BALB/c mice bearing poorly immunogenic 11A-1 murine mammary carcinomas or Meth A sarcomas and C57Bl/6 mice bearing MC-38 colon carcinomas. The effect was similar to that seen in tumor-bearing mice treated with MVAp53 along with CTLA-4 blockade. Monoclonal antibody depletion experiments demonstrated that the adjuvant effects of CpG ODN and CTLA-4 blockades were CD8 dependent. CpG ODN were partially natural killer cell dependent and ineffective in Toll-like Receptor 9(-/-) and interleukin 6(-/-) mice, whereas CTLA-4 blockade was partially CD4 dependent and functional in Toll-like Receptor 9(-/-) and interleukin 6(-/-) mice. In addition, when administered with MVAp53, both adjuvants enhanced p53-specific cytotoxicity and demonstrated an additive effect when combined. The combination of CpG ODN and CTLA-4 blockade worked synergistically to reject palpable 11A-1 and MC-38 tumors. These experiments demonstrate the potential for augmenting MVAp53-mediated antitumor immunity using CpG ODN and CTLA-4 blockade. This cell-free immunotherapy approach is a candidate for evaluation in cancer patients.     

Influence of iron (56Fe2O3 or 54Fe2O3) in the upregulation of cytochrome P4501A1 by benzo[a]pyrene in the respiratory tract of Sprague-Dawley rats

Any influence of iron in polycyclic aromatic hydrocarbon (PAH)/iron oxide mixtures on the capacity of PAHs to induce metabolizing enzymes will be one of the ways that iron oxides can affect PAH carcinogenicity. Because cytochromes P450 (CYPs) are haemoproteins, it will be of interest to investigate the possible involvement of Fe(2)O(3) in benzo[a]pyrene (BaP)/Fe(2)O(3) mixtures on the induction of CYP1A1 enzymes in the lung. Male Sprague-Dawley rats were instilled intratracheally with haematite ((56)Fe(2)O(3) or (54)Fe(2)O(3), 3 mg), BaP (3 mg) or BaP (3 mg) coated onto haematite ((56)Fe(2)O(3) or (54)Fe(2)O(3)) particles (3 mg). Firstly, mRNA expressions of cyp1a1 were studied. Secondly, protein concentrations and catalytic activities (7-ethoxyresorufin O-deethylase: EROD) of CYP1A1 were determined. Thirdly, (54)Fe from BaP/(54)Fe(2)O(3) mixtures in microsomal proteins was studied using time-of- flight laser microprobe mass spectrometry (ToF-LMMS). Statistically significant increases in mRNA expressions, protein concentrations and catalytic activities of CYP1A1 were observed in animals exposed to BaP, to BaP coated onto (56)Fe(2)O(3) particles or to BaP coated onto (54)Fe(2)O(3) particles versus controls. Both of the BaP/Fe(2)O(3) mixtures induced higher CYP1A1 protein levels and EROD activities than BaP alone. Iron oxide particles per se did not affect mRNA levels of cyp1a1 but only enhanced BaP-mediated increases of CYP1A1 protein levels and activity. The ToF-LMMS spectrum pro fi les showed that the (54)Fe/(56)Fe ratio in the microsomes of BaP coated onto (54)Fe(2)O(3) particle-instilled animals was 1.3 instead of the theoretical ratio (i.e. 0.063) observed in BaP coated onto (56)Fe(2)O(3) particle-instilled animals. Taken together, these novel data support the hypothesis that the Fe(2)O(3)-induced increases of the metabolic activation of BaP might rely on the property of Fe(2)O(3) particles to enhance the BaP-induced translation rate of the cyp1a1 gene into functional haemoproteins.