Distinct early cellular kinetics in participants protected against colonization upon Bordetella pertussis challenge.

BACKGROUNDTo date, only limited data are available on the mechanisms of protection against colonization with Bordetella pertussis in humans.METHODSIn this study, the cellular responses to B. pertussis challenge were monitored longitudinally using high-dimensional EuroFlow-based flow cytometry, allowing quantitative detection of more than 250 different immune cell subsets in the blood of 15 healthy donors.

Defective formation of IgA memory B cells, Th1 and Th17 cells in symptomatic patients with selective IgA deficiency.

Objective: Selective IgA deficiency (sIgAD) is the most common primary immunodeficiency in Western countries. Patients can suffer from recurrent infections and autoimmune diseases because of a largely unknown aetiology. To increase insights into the pathophysiology of the disease, we studied memory B and T cells and cytokine concentrations in peripheral blood.

Human IgG2- and IgG4-expressing memory B cells display enhanced molecular and phenotypic signs of maturity and accumulate with age.

The mechanisms involved in sequential immunoglobulin G (IgG) class switching are still largely unknown. Sequential IG class switching is linked to higher levels of somatic hypermutation (SHM) in vivo, but it remains unclear if these are generated temporally during an immune response or upon activation in a secondary response. We here aimed to uncouple these processes and to distinguish memory B cells from primary and secondary immune responses.

Expression profile of novel cell surface molecules on different subsets of human peripheral blood antigen-presenting cells.

Although major steps have been recently made in understanding the role of the distinct subsets of dendritic cells (DC)/antigen-presenting cells (APC), further studies are required to unravel their precise role, including in-depth immunophenotypic characterisation of these cells. Here, we used eight-colour flow cytometry to investigate the reactivity of a panel of 72 monoclonal antibodies (including those clustered in seven new Cluster of Differentiation, CD) on different subsets of APC in peripheral blood (PB) samples from five healthy adults. These experiments were performed in the context of the Tenth International Workshop on Human Leukocyte Differentiation Antigens (HLDA10).

Immunoglobulin/T-cell receptor clonality diagnostics.

Clonality testing in lymphoid malignancies has become technically relatively easy to perform in routine laboratories using standardized multiplex polymerase chain reaction protocols for Ig/T-cell receptor (TCR) gene analysis. Expertise with clonality diagnostics and knowledge about the biology of Ig/TCR recombination are essential for correct interpretation of the Ig/TCR clonality data. Several immunobiologic and technical pitfalls that should be taken into account to avoid misinterpretation of data are addressed in this review.