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A Eichelmann

Publications and source records attributed to A Eichelmann.

7 recordsLinked to original sources
PubMed1992

Venular endothelium binding molecules CD44 and LECAM-1 in normal and malignant B-cell populations. A comparative study.

Lymphocytes leave the blood via post-capillary venules by binding initially to their specialized endothelium. CD44 is a 80-90 kDa hyaluronate-binding glycoprotein involved in binding to endothelium of high endothelial venules (HEV). LECAM-1 is a 75-85 kDa glycoprotein with lectin activity interacting with human peripheral lymph node vascular addressin (PNAd) on HEV. This immunohistochemical study shows that CD44 and LECAM-1 are essentially coordinately expressed on B-lymphocytes. The mode and level of CD44/LECAM-1 expression dissect the peripheral B-cell development into stages that are closely linked to morphologically defined B-cell compartments. Although statistically correlated in B-cell leukaemias (p < 0.0009) and extranodal B-cell lymphomas (p < 0.003), expression of both molecules was less stringently coordinated in 127 B-cell neoplasms examined. B-cell chronic lymphocytic leukaemia, hairy cell leukaemia and mantle zone lymphoma were CD44/LECAM-1 positive, thus corresponding to their reactive counterparts. Correspondingly, follicular centre cell-derived lymphomas were devoid of both markers. Conversely, CD44 and LEC-AM-1 were infrequently detectable in extranodal malignant B-cell neoplasms, irrespective of their maturational state. Presence versus absence of CD44 and LECAM-1, alone or together, determined neither the leukaemic versus aleukaemic state nor the nodal versus extranodal tumour-forming phenotype of a B-cell tumour.

B-Lymphocytes↗
PubMed1992

[Expression of beta 1 integrins in normal B lymphocytes at different stages of development and in B cell neoplasias].

VLA-1 to -6 are cell surface molecules binding to matrix molecules such as collagen, fibronectin, epiligrin, and laminin. In addition, VLA-4 binds to VCAM-1 and ICAM-2, thus mediating intercellular adhesion prerogative for lymphocyte extravasation or "homing". Using frozen tissue of normal lymphoid organs and of 100 morphologically and immunologically typed B cell neoplasias, monoclonal antibodies to all six VLA-alpha subunits and to the common beta 1-chain were applied to serial sections. VLAs were found differentially expressed in cytologically and microtopographically defined B cell subsets [follicular mantle zone cells (MZ), follicular center cells (FC), extrafollicular cells (EF), and plasma cells (PC)] of normal spleen, lymph node, and thymic medulla (which contains an EF compartment). Thus, these cell types, which correspond to discrete stages of B cell development, can also be defined by their VLA status. Acute B lymphoblastic leukemia (ALL) was VLA-1-, 2-, 3 +/-, 4 +/-, 5 +/-, 6-. The VLA-1-, -2 +/-, -3+, -4+, -5+, -6- phenotype of chronic B lymphocytic leukemia (CLL) resembled that of MZ. Hairy cell leukemia (HCL) differed from CLL in its tendency to lack VLA-2, in its consistent lack of VLA-3, and altogether resembled splenic EF in its VLA profile. Mantle zone lymphoma (MZL) consistently expressed VLA-3 and -4 and frequently VLA-5. Nodal follicular center cell lymphomas (FCCL) were VLA-1- and -2- and very rarely expressed VLA-5 and -6. Thus, FCCL although roughly corresponding to FC, tended to aberrantly express VLA-3 and/or VLA-4. Burkitt's lymphoma resembled FCCL but expressed VLA-4 more frequently and at higher levels.(ABSTRACT TRUNCATED AT 250 WORDS)

B-Lymphocytes↗
PubMed1992

[Expression of APO-1, a cell surface molecule mediating apoptosis, during normal B cell ontogeny and in B cell tumors. Co-expression and coregulation of APO-1 and ICAM-1 (CD54) in germinal central cells].

APO-1 is a 48kDa transmembrane glycoprotein and belongs to the NGF/TNF receptor family of surface molecules. Cross-linking of APO-1 induces apoptotic cell death in sensitive cells. Here we show that APO-1 is an activation molecule on B cells. It could be induced/enhanced on dense and buoyant tonsillar B cells, respectively, through surface immunoglobulin cross-linking in combination with interleukin-2 or by interferon-gamma together with tumor necrosis factor-alpha. These conditions also increased the amount of intercellular adhesion molecule-1 (ICAM-1; CD54) on these cells. Epstein-Barr virus transformants of peripheral B cells co-expressed APO-1 and CD54 at very high levels. Immunohistologically, APO-1 was detectable at low levels in a subpopulation of follicular center B blasts and, at higher levels, in sinusoidal B cells. APO-1 was undetectable in follicular mantle B cells and plasma cells. Neoplastic B cell essentially mimicked their reactive counterpart with regard to APO-1 and CD54 expression.

Antibodies, Monoclonal↗
PubMed1992

Adhesion receptor profile of thymic B-cell lymphoma.

Primary thymic B-cell lymphoma is clinically characterized by aleukemic, highly aggressive local growth, infrequent distant metastasis, and infrequent secondary lymph node involvement. VLA-1 to VLA-6 are cell surface molecules binding to matrix molecules such as collagen, fibronectin, epiligrin, and laminin. VLA-4 additionally binds to VCAM-1 and ICAM-2, thus mediating intercellular adhesion. Other molecules involved in cell/cell adhesion are LFA-1 (CD11a/CD18), Mac-1(CD11b/CD18) and their ligand ICAM-1 (CD54), p150,95 (CD11c/CD18), LFA-3 (CD58), CD44, and LECAM-1. Twenty-three tumors, together with normal lymphoid tissue, were immunohistochemically examined to investigate the expression pattern of these molecules in thymic B-cell lymphomas and in their putative normal counterparts, namely thymic medullary B cells. Thymic B-cell lymphomas consistently lacked VLA-1,-2,-3,-5,-6, and CD11b, expressed ICAM-1 in 21 of 23 cases but were heterogenous for VLA-4, LFA-1, CD11c, LFA-3, CD44, and LECAM-1. Presence of LFA-1 correlated with LFA-3 expression (P = 0.029). The receptor profile of thymic B-cell lymphoma was reminiscent of the expressional status of normal thymic medullary B cells in some aspects but deviated in others: Assuming that, in terms of differentiation, thymic B-cell lymphoma is related to the asteroid variant of thymic medullary B cells, a propensity to down-regulate/lose VLA-4, CD11a, CD44, and LECAM-1 would have to be supposed in conjunction with a tendency to overexpress ICAM-1 and LFA-3. Sclerosis as an inconsistent phenomenon in thymic B-cell lymphoma was absent in 8 of 23 tumors. Presence of sclerosis correlated with LECAM-1 expression of the tumor cells (P = 0.038). Recent studies suggest that a locally growing/aleukemic phenotype of a B-cell neoplasia might be determined by the phenotype VLAs-, LFA-1+, ICAM-1+, CD44-, and LECAM-1-. Our data corroborate this view.

Antibodies, Monoclonal↗
PubMed1992

Adhesion molecules VLA-1 to VLA-6 define discrete stages of peripheral B lymphocyte development and characterize different types of B cell neoplasia.

VLA-1 to VLA-6 are cell-surface molecules binding to matrix molecules such as collagen, fibronectin, epiligrin, and laminin. In addition, VLA-4 binds to VCAM-1 and ICAM-2, thus mediating intercellular adhesion prerogative for lymphocyte extravasation or 'homing'. Using frozen tissue of normal lymphoid organs and of 100 morphologically and immunologically typed B cell neoplasias, monoclonal antibodies to all six VAL-alpha and to the common beta-chain were applied to serial sections. VLAs were found differentially expressed in cytologically and microtopographically defined B-cell subsets [follicular mantle zone cells (MZ), follicular center cells (FC), extrafollicular cells (EF), and plasma cells (PC)] of normal spleen, lymph node, and thymic medulla (which contains an EF compartment). Thus, these cell types, which correspond to discrete stages of B cell development, can also be defined by their VLA status. Acute B lymphoblastic leukemia (ALL) was VLA-1-, 2-, 3 +/-, 4 +/-, 5 +/-, 6-. The VLA-1-, -2 +/-, 3+, -4+, -5+, -6-phenotype of chronic B lymphocytic leukemia (CLL) resembled that of MZ. Hairy cell leukemia (HCL) differed from CLL in its tendency to lack VLA-2, in its consistent lack of VLA-3, and altogether resembled splenic EF in its VLA profile. Mantle zone lymphoma (MZL) consistently expressed VLA-3 and -4 and frequently VLA-5. Nodal follicular center cell lymphomas (FCCL) were VLA-1- and -2- and very rarely expressed VLA-5 and -6. Thus, FCCL although roughly corresponding to FC, tended to aberrantly express VLA-3 and/or VLA-4. Burkitt's lymphoma resembled FCCL but expressed VLA-4 more frequently and at higher levels. Mediastinal clear cell lymphoma of B-cell type differed from FCCL in its regular lack of VLA-3, -5, and -6 and in frequently lacking VLA-4. Medullary plasmacytoma was VLA-1-, -2-, -3 +/-, -4 +/-, -5-, -6+, thus being the only B cell neoplasia which was consistently VLA-6+. With respect to the well-known clinical characteristics of the B cell malignancies examined, the leukemic phenotype might crucially depend on the presence of VLA-5.

B-Lymphocytes↗
PubMed1991

Expression of beta 1-integrins, H-CAM (CD44) and LECAM-1 in primary gastro-intestinal B-cell lymphomas as compared to the adhesion receptor profile of the gut-associated lymphoid system, tonsil and peripheral lymph node.

beta 1-Integrins (VLA-1 to -6) are cell-surface molecules binding to matrix molecules such as collagen, fibronectin and laminin. VLA-4 is the human homologue to the murine Peyer's patch homing receptor mediating cell/cell adhesion required for lymphocyte extravasation or "homing". Other structures which have a homing-receptor function through recognition of venular endothelium are H-CAM (CD44) and LECAM-1 (LAM-1, human MEL-14 equivalent). In order to elucidate whether these adhesion receptors are expressed in primary gastro-intestinal malignant B-cell lymphomas (GI BmL) which, in this case, might contribute to the initial confinement to this extranodal site, 31 extensively characterized tumors were examined together with reactive lymphoid tissues from small and large intestine, tonsil and lymph node using monoclonal antibodies (MAbs) against these receptors. All types of adhesion receptors were differentially expressed in the cytologically and microtopographically defined B-cell subsets [follicular center cells (FC), mantle-zone cells (MZ), extrafollicular cells (EF) and plasma cells (PC)] of the normal B-cell system. With the exception of differences in LECAM-1 levels among EF and PC of intestinal vs. nodal vs. tonsillar sites, receptor profiles were almost identical in different lymphoid organs. The expression pattern of these molecules in GI BmL was markedly heterogeneous, mimicking to some extent the receptor equipment of their reactive cellular counterpart. Thus, we failed to find a unifying adhesion receptor profile indicative of a tissue-specific homing of reactive and neoplastic B-cells.

Antibodies, Monoclonal↗