No abstract

Iris yellow spot is an economically important disease of onion that reduces bulb size and yield and is difficult to control. The disease is spread by Thrips tabaci (onion thrips) and disease symptoms are exacerbated by hot, dry climatic conditions that also favor rapid thrips multiplication and make control programs less effective. Currently, no onion cultivar is resistant to the disease and/or thrips. Certain onion foliar characteristics have shown nonpreferential feeding activity by thrips and may be the first step in developing Iris yellow spot (IYS)-tolerant onion cultivars. Seventy-five onion PI accessions from the U.S. germplasm collection were evaluated for leaf color, waxiness (bloom), and axil pattern; thrips number per plant; and IYS disease severity under conditions that favored thrips and disease buildup. Plants of PI 289689 were less attractive to thrips and had a lower number of thrips per plant than plants of most other accessions. These plants were rated as having light green to green-colored foliage and a relatively low amount of epicuticular leaf wax. Plants of PIs 239633 and 546192 generally exhibited less severe IYS disease symptoms than those of other accessions. Individual plants, that exhibited less leaf area exhibiting IYS disease symptoms, were selected at bulb maturity from 22 different accessions with PI 546140 producing the largest number of selected bulbs. Physiological plant development, environmental conditions, and tolerance to plant stress may influence the degree of disease symptom expression. Further work that examines the role of plant maturity and host plant tolerance to stress with respect to disease expression is needed.

Pulmonary surfactant protein-D (SP-D) is a multifunctional, pattern recognition molecule involved in resistance to allergen challenge and pulmonary inflammation. In view of therapeutic effects of exogenous SP-D or recombinant fragment of human surfactant protein-D (rhSP-D) (composed of eight Gly-X-Y collagen repeat sequences, homotrimeric neck and lectin domains) in murine models of lung allergy and hypereosinophilic SP-D gene-deficient mice, we investigated the possibility of a direct interaction of purified rhSP-D with human eosinophils derived from allergic patients and healthy donors. rhSP-D showed a sugar- and calcium-dependent binding to human eosinophils, suggesting involvement of its carbohydrate recognition domain. While eosinophils from allergic patients showed a significant increase in apoptosis, oxidative burst and CD69 expression in presence of rhSP-D, eosinophils from healthy donors showed no significant change. However, these eosinophils from healthy donors when primed with IL-5 exhibited increase in apoptosis on incubation with rhSP-D. Apoptosis mediated by rhSP-D in primed eosinophils was not affected by the antioxidant, N-acetyl-L-cysteine. There was a manifold increase in binding of rhSP-D to apoptotic eosinophils than the normal eosinophils and rhSP-D induced a significant increase in uptake of apoptotic eosinophils by J774A.1 macrophage cells. The study suggests that rhSP-D mediated preferential increase of apoptosis of primed eosinophils while not affecting the normal eosinophils and increased phagocytosis of apoptotic eosinophils may be important mechanisms of rhSP-D and plausibly SP-D-mediated resolution of allergic eosinophilic inflammation in vivo.

Allergic bronchopulmonary aspergillosis (ABPA) is an immunologically complex allergic disorder caused by the fungal pathogen Aspergillus fumigatus. Elevated levels of total immunoglobulin E (IgE), specific IgE, and IgG antibodies in sera are important immunodiagnostic criteria for ABPA. International reference standards or standardized immunodiagnostic assays are not available due to a lack of well-defined diagnostic antigens. The present study was carried out to identify and evaluate the immunodiagnostic relevance of synthetic epitopic peptides of Asp f 1, a major allergen, antigen, or cytotoxin of A. fumigatus. Five overlapping peptides were synthesized from the N terminus of Asp f 1, one of the potential immunodominant regions predicted by algorithmic programs. The 11-amino-acid synthetic peptide (P1) significantly inhibited both IgG binding (89.10% ؎ 4.45%) and IgE binding (77.32% ؎ 3.38%) of the standardized diagnostic antigen (SDA) (a well-defined pool of diagnostically relevant allergens and antigens of A. fumigatus). With a panel of sera of ABPA patients, allergic patients with skin test negativity to A. fumigatus, and healthy individuals, P1 showed a higher diagnostic efficiency than SDA (specific IgG, 100%; specific IgE, 98.3%). The diagnostic efficiency of P1 could be attributed to the presence of homologous epitopes in various immunodominant allergens or antigens of A. fumigatus. The ability of P1 to induce histamine release from sensitized mast cells and a Th2 type of cytokine profile in peripheral blood mononuclear cells of ABPA patients suggests its potential for use in intradermal testing. P1 could be further explored for development of a standardized, specific, and sensitive immunodiagnostic test for aspergillosis.

SummaryMUC4 is a transmembrane glycoprotein more highly expressed in cervical dysplasia than benign cervical epithelium. We sought to determine whether MUC4 expression differs between benign and malignant cervical tissue. Fifty-eight patients with benign, dysplastic, or malignant cervical pathology were identified retrospectively, and representative sections were stained with a mouse monoclonal anti-MUC4 antibody. Semiquantitative analysis was performed on benign, dysplastic, and malignant regions by scoring staining intensity (0: negative, 1: weak, 2: moderate, and 3: strong) and distribution (focal <10%, multifocal = 10%-60%, diffuse ≥60%). In samples with benign glycogenated squamous epithelium, only the parabasal cells had MUC4 staining, and 48.5% had an intensity of 2 or 3. All samples with immature squamous metaplasia were positive through the entire epithelial thickness. Cervical intraepithelial neoplasia (CIN) 1 samples had variable staining with an intensity similar to glycogenated squamous epithelium but distribution similar to squamous metaplasia. All CIN 3 (n = 21) and invasive squamous cell carcinomas (n = 17) had increased MUC4 staining intensity (P<0.001 and P<0.001) and increased diffuse staining (P<0.001 and P<0.001) compared with the limited staining in glycogenated squamous epithelium. In contrast, no differences in staining were observed between benign endocervical glands, adenocarcinoma in situ, and invasive adenocarcinoma. These expression patterns suggest that MUC4 is a lineage marker in benign cervical tissue that may have aberrant expression in squamous dysplasia and carcinoma. Further studies may elucidate the role of MUC4 in the development of squamous cell cervical cancer. Recently, it has been noted that MUC4, a membrane-bound mucin, is upregulated in several different malignancies including pancreatic, ovarian, and breast cancer (6-10). Our recent studies have shown that ErbB2 (also known as HER2/neu) signaling is regulated by MUC4 in pancreatic tumor cells (11). In addition, rat Muc4/sialomucin complex serves as a ligand for rat p185/neu, a homolog of ErbB2 (12). Activation of this receptor can lead to an increase in signaling molecules that stimulate cell proliferation and the dissociation of cell-cell adhesions, promoting metastatic potential (13,14). Variable ErbB2 expression in some types of cervical cancer has been examined in attempts to correlate expression with prognosis (15-20). KeywordsPrior studies have provided evidence that MUC4 is upregulated in squamous cervical dysplasia (21). In addition, a study of only glandular lesions of the cervix found MUC4 expression in benign endocervical glands and 38% of adenocarcinoma in situ (AIS) and 75% of adenocarcinoma (AC) (22). No studies have evaluated the expression of MUC4 in squamous cell carcinoma (SCC) of the cervix. Thus, we sought to evaluate MUC4 expression in benign and malignant cervical epithelia. Differential expression could suggest a role for MUC4 in the signaling pathways involved in cervical cancer and lead to fur...