Inmunoterapia activa en pacientes con neoplasias de célula B

Tesis doctoral inédita leída el 27 de Enero de 1999 en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicin

Inmunoterapia activa en pacientes con neoplasias de celula B

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

Length of the antibody heavy chain complementarity determining region 3 as a specificity-determining factor

lThe antigen binding site of an antibody is made up of residues residing in six hypervariable loops of the heavy and light chains. In most cases several or all of these loops are required for the establishment of the antigen-binding surface. Five of these loops display a limited diversity in length and sequence while the third complementarity determining region (CDR) of the heavy chain is highly different between antibodies not only with respect to sequence but also with respect to length. Its extensive diversity is a key component in the establishment of binding sites allowing for the recognition of essentially any antigen by Immoral immunity. The relative importance of its sequence vs its length diversity in this context is however, not very well established. To investigate this matter further we have used an approach employing combinatorial antibody libraries and antigen-specific selection in the search for CDRH3 length and sequence diversity compatible with a given antigen specificity, the major antigenic determinant on the tumour-associated antigen mucin-1. In this way we have now defined heavy chain CDR3 length as a critical parameter in the creation of an antigen-specific binding site. We also propose that this may reflect a dependence of a particular structure of this hypervariable loop, the major carrier of diversity in the binding site, for establishment of a given specificity. Copyright (C) 2004 John Wiley Sons, Ltd

Chain shuffling to modify properties of recombinant immunoglobulins.

Combinatorial libraries and selection of variants from such libraries have proven to be a successful approach for identifying molecules with novel or improved properties. The importance of antibody (Ab) molecules in basic and applied research, as well as the extensive knowledge of how they interact with their antigen (Ag) targets, have made them favorite targets for modification by this approach. The binding site of Abs can be described as a set of modules that together make up the Ag-binding site. These modules may be defined either as the heavy-chain (HC) and light-chain (LC) variable domains (VH and VL respectively) or as the six individual complementarity-determining regions (CDRs) or hypervariable loops, which act together to form this structure. The variable CDRs reside in a relatively fixed framework region (FR) that makes up the basic structure and fold of the protein

Clonal repertoire diversification of a neutralizing cytomegalovirus glycoprotein B-specific antibody results in variants with diverse anti-viral properties.

Cytomegalovirus induces a chronic infection that in normal individuals is controlled by the immune system. In the case of humoral immunity, epitopes, in particular antigenic domain-1, in glycoprotein B have proven to be important for the induction of virus-neutralizing activity. Such antibodies can exert potent virus-neutralizing activity but can also block neutralizing antibodies from binding. Furthermore, these antibodies differ in their fine recognition of antigenic domain-1 as determined by epitope mapping. By using combinatorial library and phage display technologies we have now isolated a large array of clonally related antibody fragments to understand the origin of this diversity. This procedure allowed us to demonstrate that much of the diversity in functional activity (virus neutralization) and epitope recognition can arise from a single parental molecule through somatic mutation processes. We have thus demonstrated that the clonal diversification of a single antigen-specific clone can account for much of the diversity in antibody anti-viral activity. These findings have implications on the development of a gB-based subunit vaccine, as an effective vaccine preparation need not only to recruit appropriate clones into the immune response but also to evolve them properly so as to maintain an appropriate biological function

Evaluation of major mite allergens from European standardized commercial extracts for in vivo diagnosis: addressing the need for precision medicine

Abstract Background Skin prick testing is the first-line interventional method to diagnose IgE mediated allergic diseases. Methodological differences in manufacturing processes and extract standardization may lead to variations in the reagent quality and potency. The current study evaluates sixteen commercially available Dermatophagoides pteronyssinus and Blomia tropicalis extracts for allergy diagnosis from different European manufacturers regarding allergen composition and content and whether these differences could influence their biological activity. Methods Mite-allergic subjects (n = 21) were skin-tested with the extracts and studied for immunoglobulin E reactivity. Nine extracts from D. pteronyssinus and seven from B. tropicalis were analysed for total protein content by Bradford and ELISA double sandwich was used to quantify specific antibodies for D. pteronyssinus and B. tropicalis major allergens from nine different manufacturers. Results Mite extracts showed a 10–60 fold variation regarding the total protein content. The contents of the major allergens of D. pteronyssinus and B. tropicalis differed considerably (30–53 fold change) among the extracts. Blo t 5 was quantitatively present in < 50% of the of the B. tropicalis reagents and could not be clearly detected by immunoblotting in the majority of the B. tropicalis commercial extracts. Conclusions Certain natural D. pteronyssinus and B. tropicalis extracts lack important allergens showing a considerable variability in composition and content. A closer collaboration among clinicians, allergen manufacturing companies and regulatory agencies to improve the quality and consistency of D. pteronyssinus and B. tropicalis extracts is warranted to achieve a more precise diagnosis and treatment of house dust mite allergy