Adhesion molecule profiles of B-cell non-Hodgkin's lymphomas in the leukemic phase

We evaluated the expression of 10 adhesion molecules on peripheral blood tumor cells of 17 patients with chronic lymphocytic leukemia, 17 with mantle-cell lymphoma, and 13 with nodal or splenic marginal B-cell lymphoma, all in the leukemic phase and before the beginning of any therapy. The diagnosis of B-cell non-Hodgkin's lymphomas was based on cytological, histological, immunophenotypic, and molecular biology methods. The mean fluorescence intensity of the adhesion molecules in tumor cells was measured by flow cytometry of CD19-positive cells and differed amongst the types of lymphomas. Comparison of chronic lymphocytic leukemia and mantle-cell lymphoma showed that the former presented a higher expression of CD11c and CD49c, and a lower expression of CD11b and CD49d adhesion molecules. Comparison of chronic lymphocytic leukemia and marginal B-cell lymphoma showed that the former presented a higher expression of CD49c and a lower expression of CD11a, CD11b, CD18, CD49d, CD29, and CD54. Finally, comparison of mantle-cell lymphoma and marginal B-cell lymphoma showed that marginal B-cell lymphoma had a higher expression of CD11a, CD11c, CD18, CD29, and CD54. Thus, the CD49c/CD49d pair consistently demonstrated a distinct pattern of expression in chronic lymphocytic leukemia compared with mantle-cell lymphoma and marginal B-cell lymphoma, which could be helpful for the differential diagnosis. Moreover, the distinct profiles of adhesion molecules in these diseases may be responsible for their different capacities to invade the blood stream.

CD137 induces adhesion and cytokine production in human monocytic THP-1 cells

CD137, which is expressed on activated T cells, plays a critical role in inflammatory responses. However, the exact role that CD137 plays in monocytes is not fully known. Here we studied the expression and function of CD137 in human monocytic THP-1 cells, which we found constitutively expresses CD137 at the mRNA and protein level. Cross-linking of CD137 increased the secretion of IL-8 and TNF-alpha, promoted the expression of CD54 and CD11b, and increased adhesion to extracellular matrix (ECM) proteins. In particular CD137-induced adhesion of THP-1 cells was inhibited by an inhibitor of mitogen-activated protein kinase kinase (MEK), but not by a p38 kinase inhibitor. Taken together, these results show that the adhesion and cytokine production of THP-1 cells induced by CD137 occur via activation of MEK, which results in the activation of ERK-1/2 signaling pathways. Therefore, this study suggests that CD137 induces an activating and migrating signal during inflammatory processes.

Expression of CD99 in Pleomorphic Carcinomas of the Lung

Pleomorphic carcinoma of the lung (PCL) is characterized by a mixture of sarcomatoid and carcinoma components, and a poor prognosis. However, no immunophenotype of tumor markers has been characterized in PCL. To charaterize the immunophenotype for CD99 in PCL, we performed an immunohistochemical evaluation of PCLs for thyroid transcription factor-1 (TTF-1), cytokeratin (CK) 7 and 20, and for CD99. CD99 was found to be expressed in both carcinomatous (47%) and sarcomatous components such as spindle cells (92%) and giant cells (57%). In the case of spindle cells, CK7 was expressed in 6 cases (46%) and TTF-1 in 2 cases (15%), whereas for giant cells CK7 was expressed in 8 cases (57%) and TTF-1 in one case (7%). However, CK20 was not expressed in either the carcinomatous or sarcomatous components in any case. Thus, CD99 was found to be widely expressed in both sarcomatous and carcinoma component in PCL. A clinicopathological analysis showed no direct correlation between the expression of CD99 and the clinical indices (stage, survival rate, invasion) of PCL.

Moléculas de cooperación y regulación durante la migración celular en la respuesta inflamatoria / Molecules for cooperation and regulation during cell migration in the inflammatory response

En la superficie de todas las células existen estructuras sacarídicas, dentro de sus múltiples funciones fisiológicas se ha logrado identificar que funcionan como comunicadores intercelulares. En el caso de los leucocitos estas estructuras le permiten, por mecanismos de adherencia, identificar a los sitios de inflamación, este proceso se efectúa gracias a la interacción específica de diversas familias de glicoproteínas de superficie celular entre las que se considera a las denominadas "selectinas", las integrinas y las moléculas pertenecientes a la superfamilia de las inmunoglobulinas. En este Trabajo, se revisan las características moleculares de estas proteínas adhesivas y, los diversos procesos inflamatorios en los que están involucradas

The cutaneous lesion in American leishmaniasis: leukocyte subsets, cellular interaction and cytokine production

Interactions between immunocompetent cells require the participation of T cell antigen receptor (TCR) and the integrin lymphocyte function-associated molecule-1 (LFA-1, CD11a/CD18). These interactions are mediated by interlinking cytokines, which are important in determining the type of immune response. In the present study, we have shown that in American cutaneous leishmaniasis (ACL) lesions, most infiltrating T cells expressed the alpha beta TCR including those selectively migrating to the epidermis. In contrast, gamma delta T cells were abundant in localized (LCL) and scarce in muco-cutaneous (MCL) and diffuse (DCL) cutaneous leishmaniasis, suggesting a role in effective granulomas. There were differences in the expression of LFA-1 alpha and beta subunits, with most cells expressing LFA-1 beta. The ratio LFA-1 beta/LFA-1 alpha was higher in LCL (11.8:1) than in MCL (3.3:1) and DCL (2.4:1). Similar results were observed in Leishmania mexicana-infected C57BL/6 mice. DCL lesions showed a higher proportion of LFA-1 alpha+ cells than MCL and LCL lesions. A reverse-transcriptase polymerase chain reaction (RT-PCR) analysis of the cytokine profiles showed that most T cells present in the MCL and DCL lesions secrete a mixture of Type 1 and Type 2 cytokine patterns, but in DCL granulomas predominate the Type 2 cytokines. In LCL the cytokine patterns show a preponderance of INF gamma over IL-4, and low levels of IL-5 and IL-10, suggesting a Type 1 cytokine profile