Laminin-332 (Laminin-5) is the major motility ligand for B cell chronic lymphocytic leukemia

Cell adhesion and motility are central aspects in the pathophysiology of B cell chronic lymphocytic leukemia (B-CLL), but the role of specific extracellular matrix proteins is still to be completely unveiled. Purified peripheral blood neoplastic cells of B-CLL patients migrated poorly on laminins-111,-411,-511, but showed pronounced motility on laminin (LM)-332 in a high percentage of cases. B-CLL cell motility on LM-332 was mediated by the α3β1 integrin and was preferentially observed in cells carrying a mutated IgVH gene profile. Within normal lymph nodes, LM-332 was circumscribed around blood vessels and to areas corresponding to marginal zones, where it was deposited in a pattern reminiscent of reticular fibers. Conversely, in B-CLL involved lymph nodes, a positive LM-332 reticular mesh was diffusely evident, throughout the disrupted nodal architecture. In the present study we identified LM-332 as a crucial motility-promoting factor for B-CLL lymphocytes and as a potential constituent favoring the dissemination of B-CLL lymphocytes through vascular basement membranes and possibly lymph node compartments. © 2007 International Society of Matrix Biology

A Peptide-Based Plasmodium falciparum Circumsporozoite Assay To Test for Serum Antibody Responses to Pre-Erythrocyte Malaria Vaccines ▿

Various pre-erythrocyte malaria vaccines are currently in clinical development, and among these is the adenovirus serotype 35-based circumsporozoite (CS) vaccine produced on PER.C6 cells. Although the immunological correlate of protection against malaria remains to be established, the CS antibody titer is a good marker for evaluation of candidate vaccines. Here we describe the validation of an anti-Plasmodium falciparum circumsporozoite antibody enzyme-linked immunosorbent assay (ELISA) based on the binding of antibodies to a peptide antigen mimicking the CS repeat region. The interassay variability was determined to be below a coefficient of variation (CV) of 15%, and sensitivity was sufficient to detect low antibody titers in subjects from endemic regions. Antibody titers were in agreement with total antibody responses to the whole CS protein. Due to its simplicity and high performance, the ELISA is an easy and rapid method for assessment of pre-erythrocyte malaria vaccines based on CS