Expression Of Various Antigens Research Articles

Immunophenotyping and functional analysis of purified human uterine mast cells

Human mast cells have been purified from uterine tissues, and their surface marker profile and function have been evaluated as part of ongoing studies of mast cell heterogeneity. Using a panel of antibodies, purified uterine mast cells (UMC; 81% +/- 7% purity, n = 10) were analyzed by immunofluorescence and flow cytometry for surface expression of various antigens. Consistent with previous analyses of mast cells from other tissues, UMC expressed HLA class I, IgE, c-kit receptor, CD9, CD33, CD43, CD45, and CD54, while CD11a, CD11b, CD14, CD16, CD23, and CD64 were not detected. Unlike other mast cells, UMC expressed CD11c/CD18 (p150,95) and CD32 (Fc gamma RII). Additional antigens not previously studied on mast cells included the selectin LECAM-1 (Leu-8) and several beta 1 and beta 3 integrins; expression of very late activation antigen-4 (VLA-4) (CD49d/CD29), VLA-5 (CD49e/CD29), and the vitronectin receptor (CD51/CD61) was seen. Functional studies showed that treatment of human umbilical vein endothelial cells with interleukin-1 (5 ng/mL for 4 hours) resulted in a twofold to threefold increase in adhesiveness for UMC. Purification procedures did not alter histamine release responses to anti-IgE or the calcium ionophore A23187, and treatment of UMC with an anti-CD32 monoclonal antibody (IV.3) did not induce histamine release or alter anti-IgE-induced release. These data suggest that UMC may possess unique phenotypic characteristics, and support the concept of mast cell heterogeneity.

Pathology of kidney transplantation

The graft is vulnerable to all of the diseases that may affect the native kidney but exhibits several special patterns of damage. Fine needle aspiration has provided much useful information about the character of cellular infiltrates and the expression of various antigens but core biopsy remains the most useful diagnostic tissue procedure. Rejection (cellular, glomerular and vascular) is the major target for graft biopsies but other patterns may be encountered and special diagnostic problems include recurrent or de novo glomerulonephritis scarring without specific features and the normal or near normal biopsy. Early experience with Cyclosporin A given in high doses delineated specific vascular and tubular lesions but the toxic changes are more subtle in current dosage protocols. Thrombotic complications are more common in patients’ receiving Cyclosporin A and need to be distinguished from the haemotytic uraemic syndrome. Immunofluorescence and electron microscopy are as important in the examination of graft as of natural kidney biopsies and may detect evidence of glomerulonephols - recurrent or de novo - that is not apparent by light microscopy. Assessment of the glomerular cell population in evolving glomerulonephritis and glomerulopathy may provide insights into some of the mechanisms of damage and “proliferation” in native kidney disease.

Cell markers in gastrointestinal stromal tumors

Stromal tumors of the gastrointestinal (GI) tract have generated considerable controversy about their direction and level of differentiation, particularly about whether the tumor cells are smooth muscle or Schwann cells. In an attempt to characterize these tumors, the immunohistochemical staining patterns of desmin, vimentin, actin, and S-100 protein were studied in 41 GI stromal tumors, using the avidin-biotin method, and compared with normal host smooth muscle and nerve and with esophageal and uterine leiomyomas. Twenty gastric and one rectal tumor stained diffusely with vimentin and actin, but not with desmin, and had scattered strongly S-100-positive cells that might either be trapped Schwann cells or tumor cells. Twenty small bowel tumors stained similarly to the gastric tumors with regard to vimentin, actin, and desmin, but most (17/20) had a unique, strongly positive geographic staining pattern with S-100. No differences in staining were noted between benign and malignant tumors in either gastric or small bowel sites, and most histologic patterns in tumors from similar locations stained similarly. These results suggest that GI stromal tumors are not truly "leiomyomas and leiomyosarcomas," but relatively undifferentiated tumors, with the expression of various antigens depending on their location in the gut.

EXPRESSION OF VARIOUS ANTIGENS BY DIFFERENT COMPONENTS OF UTERINE MIXED MÜLLERIAN TUMORS: An Immunohistochemical Study

An immunohistochemical study of keratin, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), vimentin, desmin, myoglobin and S-100 protein in 15 cases of uterine mixed Müllerian tumor was performed in order to analyze the expression of various antigens in different elements of this tumor. In general, the epithelial and mesenchymal components were separated easily by the presence of keratin/EMA or vimentin, respectively. However, in eight cases vimentin was expressed by epithelial cells and in four cases keratin by solid "sarcomatous" element. EMA was also identified in the "sarcomatous" areas of two cases. Specific differentiation was much easier to identify by immunohistochemical staining than by routine histologic examination. Areas with muscle differentiation were positive for desmin; myoglobin was identified in rhabdomyoblasts. S-100 protein was present in chondrosarcomatous and liposarcomatous areas. S-100 protein was also widely distributed in other elements. Quite diverse expression of various antigens revealed by immunohistochemistry reflects the histologic multiplicity of this tumor.

Characterization of T-cell-soluble factors modulating the expression of Ia and H-2 antigens on BALB/c B lymphoma cell lines

The effect of supernatants of concanavalin A-activated spleen cells (CAS) on the expression of various antigens, especially Ia antigens, on BALB/c B lymphoid cells, was examined. This study demonstrates the following: (i) CAS enhanced the expression of Ia antigens on four out of five BALB/c lymphoid cell lines, (ii) CAS selectively modulates the expression of la and H-2D, but not sIgM or viral gp70 expression, on X16C 8.5 tumor cells. The enhanced levels of Ia expression on B lymphoid tumor cells were also detected by using anti-Ia monoclonal antibodies, (iii) The molecular weight of soluble factors) affecting Ia and H-2 was approximately 40,000 estimated by gel nitration on a Sephadex G-200 column. (iv) Type 1 interferon but not interleukin 1, interleukin 2, or T-cell-replacing factor enhanced the expressions of Ia and H-2D antigens, (v) The activity of CAS-modulating Ia and H-2 antigens was eliminated by acidic treatment. It was concluded from this study that at least one of the factor(s) in CAS, modulating the antigenic expression of B-lymphoid cells, was interferon-like in nature. From our findings, a possible immunoregulatory mechanism by interferon was suggested: T cells, after stimulation of mitogens or antigens, secrete interferons which modulate the expression of Ia and H-2 on B cells. Then B cells, whose la and H-2 were modulated selectively by T-soluble factors(s), might interact with T cells much more efficiently.