Chemokine-induced secretion of gelatinase B in primary human monocytes

Chemokines help control normal leukocyte trafficking as well as their infiltration into tissues during acute and chronic inflammation. Matrix metalloproteinases (MMPs) help support the extravasation and infiltration of leukocytes through limited proteolysis of basement membranes and matrix material. The effect of the chemokines RANTES/CCL5, MCP-1/CCL and SDF-1 /CXCL12 on secretion of the matrix metalloproteinase B and its endogenous inhibitor TIMP-1 was studied. RANTES/CCL5 and SDF-1/CXCL12 were found to induce MMP-9 secretion in primary human monocytes while TIMP-1 secretion was not affected. RANTES/CCL5 effects were mediated through CCR1 because the CCR1 antagonist BX471 was found to effectively block RANTES/CCL5-induced MMP-9 secretion

Jacalin, another marker for histiocytes in paraffin-embedded tissues

Jacalin is a lectin which reacts with Dgalactose. We have tested jacalin on 75 samples of different formalin- and alcohol-fixed tissues. A consistent cytoplasmic stain of the histiocytes was observed in paraffin-embedded tissues in al1 cases studied of reactive sinus histiocytosis, macrophages in clear centres of follicular hyperplasia, in tuberculosis granulomas and in osteoclast-like giant cells in a breast carcinoma. We failed to find any clear binding of jacalin to the cells of eosinophilic granulomas, giant cell tumors of tendon sheath, pleomorphic malignant fibrous histiocytomas, Hodgkin's disease, melanomas, nevi or signet ring cell carcinomas of the breast and stomach. It seems that jacalin is a good marker for free histiocytesl macrophages, not for fixed histiocytes and tumors related to them. This lectin might play a role in differential diagnosis with histiocyte mimicking processes