Differential expression of jackfruit-lectin-specific glycoconjugates in metastatic adenocarcinoma and reactive mesothelial cells-a diagnostic aid in effusion cytology

Mannan-binding lectin promotes keratinocyte to produce CXCL1 and enhances neutrophil infiltration at the early stages of psoriasis

Psoriasis is a chronic, relapsing inflammatory skin disorder. Numerous experimental evidence and therapeutic evidence have shown that the innate immune response is critical for the pathogenesis and development of psoriasis. Mannan-binding lectin (MBL), a prototypic pattern recognition molecule of the innate immune system, plays an essential role in the host defense against certain infections and also appears to be a major regulator of inflammation. In this study, we investigated the function of MBL on the course of experimental murine imiquimod (IMQ)-induced psoriasis. Our data showed that MBL-deficient (MBL^-/- ) mice exhibited attenuated skin damage characterized by greatly decreased erythema compared with wild-type control mice during the early stages of IMQ-induced psoriasis-like skin inflammation. The reduced skin inflammation in MBL^-/- mice was associated with the decreased infiltration of neutrophils. Furthermore, we have determined that MBL deficiency limited the chemokine CXCL1 production from skin keratinocytes upon IMQ stimulation, which might be responsible for the impaired skin recruitment of neutrophils. Additionally, we have provided the data that MBL protein promotes the IMQ-induced expression of CXCL1 and activation of MAPK/NF-κB signalling pathway in human keratinocyte HaCaT cells in vitro. In summary, our study revealed an unexpected role of MBL on keratinocyte function in skin, thus offering a new insight into the pathogenic mechanisms of psoriasis.

Significance of a galactose specific plant lectin for the differential diagnosis of adenocarcinoma cells in effusion

Background:

Distinguishing adenocarcinoma cells from reactively proliferated mesothelial cells and macrophages is one of the greatest challenges in the cytodiagnosis of effusions. Aberrant glycosylation of cell surface glycoconjugates is emblematic to malignancy, and lectins being an important class of probes to demonstrate these aberrations, lectin cytochemistry is of great interest to differentiate adenocarcinoma cells from reactive mesothelial cells.

Aim:

The present study analyzed the potential of a plant lectin to distinguish malignant cells from reactive mesothelial cells and macrophages.

Materials and Methods:

Snake gourd lectin (SGL) was isolated, purified and conjugated to horse radish peroxidase (HRP) and incubated with the cells of benign (46) as well as malignant (39) effusions using the standard immunocytochemical method with diaminobenzidine as the chromogen. The lectin-bound areas were quantitatively assessed as mild, moderate and intense binding.

Statistical Analysis:

The mean score for benign and malignant effusions were statistically analyzed. Student's ‘t’-test was performed to assess the significance.

Results:

The lectin HRP complex bind to the cytoplasm of benign and malignant cells as well as macrophages. A significantly higher score for intense binding (P = 0.001) was found to differentiate malignant cells from reactive mesothelial cells. Macrophages showed intense irregular binding.

Conclusions:

SGL binding assay can play a role in the differential diagnosis of metastatic adenocarcinoma in effusions.

Jacalin: a jackfruit (Artocarpus heterophyllus) seed-derived lectin of versatile applications in immunobiological research

Jacalin, the major protein from the jackfruit (Artocarpus heterophyllus) seeds, is a tetrameric two-chain lectin (molecular mass 65 kDa) combining a heavy alpha chain of 133 amino acid residues with a light beta chain of 20-21 amino acid residues. It is highly specific for the alpha-O-glycoside of the disaccharide Thomsen-Friedenreich antigen (Gal beta1-3GalNAc), even in its sialylated form. This property has made jacalin suitable for studying various O-linked glycoproteins, particularly human IgA1. Jacalin's uniqueness in being strongly mitogenic for human CD4+ T lymphocytes has made it a useful tool for the evaluation of the immune status of patients infected with human immunodeficiency virus (HIV)-1. The abundance of source material for the production of jacalin, its ease of purification, yield and stability have made it an attractive cost-effective lectin. It has found applications in diverse areas such as the isolation of human plasma glycoproteins (IgA1, C1-inhibitor, hemopexin, alpha2-HSG), the investigation of IgA-nephropathy, the analysis of O-linked glycoproteins and the detection of tumours.