| Research Abstract |
We have investigated different beta1 integrins on EC for their role in modifing the structure on/in matrigel, a gel reconstituted from EHS sarcoma. The inhibition of matrigel-induced capillary formation by antibodies against subunits of beta1 integrins was examined quantitatively by using computer digital analyzer. Antibodies to CD_w49b, CD29 caused a marked inhibition (up to 70% inhibition) in a dose dependent manner, whereas antibodies to CD_w49b, CD_w49f were less inhibitory (30% inhibition). We next examined the appearances of EC cultured in the matrigel. EC suspended in matrigel for 24hr formed extended cell processes and each cell onnected together end to end resulting capillary network. Furthermore after 48hr culture in matrigel, some of EC (20% of total) showed the capillary-unit of a lumen encircled by EC which may mimic the basic putative unit in the formation of capillaries, although those pretreated with antibodies to CD_w49b, CD29 failed to form significant processes and a
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hollow lumen. These phenomenon may illustrate the importance of EC-basement membrane matrix interaction occuring during differentiation of EC in angiogenesis.
Methods for the isolation and purification ofmast cells from human skin by using enzymatic digestion permitted us to analyze the biochemical and morphological characteristics of these cells and to make more intensive comparison with mast cells from other anatomical sites. In this study, we used immunohistochemical methods to determine whether isolated adult human skin mast cells (SMC) express surface antigens, such as adhesion molecules of the integrin, a variety of leukocyte antigens, and newly identified high affinity IgE receptor. By enzymatic digestion of the adult skin and centrifugation on discontinuous percoll density gradient, approximately 1x10^6 mast cells were recovered from one gram (wet weight) of the tissue. 50%-75% of the cells in cytocentrifugation speciemens were mast cells, assessed with alcian blue staining. Using APAAP immunohistochemical staining, we examined the expression of cell surface antigens. Consistent with previous reports examining surface markers on human lung or uterine mast cells, SMC were stained HLA class I,IgE,CD29, CD43, CD45, CD49d, CD49e, CD61, and CD68, however CD11b, CD23, and CD49b were not stained. In contrast to previous reports on other mast cells, SMC expressed CD11a and CD49f weakly, but CD11c, CD18, CD54, and c-kit were not detected. Additional surface molecules present on SMC included high affinity IgE receptor whichi was detected by two different monoclonal antibodies. we reported that SMC possess unique phenotypic characteristics probably responsible for the immunological reaction in skin. Less
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