A First Unexplained Invasive Encapsulated Bacterial Infection in Young Adults Associated With High Mortality and Readmission Rates.

We find that patients <40 years old with a first invasive encapsulated bacterial infection have a high likelihood of death or readmission within 23 months. It is imperative to highlight them for immunological screening and initiate prophylactic interventions and treatment.

Multiple redundant stress resistance mechanisms are induced in Salmonella enterica serovar Typhimurium in response to alteration of the intracellular environment via TLR4 signalling.

Toll-like receptor 4 (TLR4) senses bacterial LPS and is required for the control of systemic Salmonella enterica serovar Typhimurium infection in mice. The mechanisms of TLR4 activation and its downstream signalling cascades are well described, yet the direct effects on the pathogen of signalling via this receptor remain unknown. To investigate this we used microarray-based transcriptome profiling of intracellular S.

Relevance of biallelic versus monoallelic TNFRSF13B mutations in distinguishing disease-causing from risk-increasing TNFRSF13B variants in antibody deficiency syndromes.

TNFRSF13B encodes transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), a B cell- specific tumor necrosis factor (TNF) receptor superfamily member. Both biallelic and monoallelic TNFRSF13B mutations were identified in patients with common variable immunodeficiency disorders. The genetic complexity and variable clinical presentation of TACI deficiency prompted us to evaluate the genetic, immunologic, and clinical condition in 50 individuals with TNFRSF13B alterations, following screening of 564 unrelated patients with hypogammaglobulinemia.

Fcgamma receptors are crucial for the expression of acquired resistance to virulent Salmonella enterica serovar Typhimurium in vivo but are not required for the induction of humoral or T-cell-mediated immunity.

Antibodies play an important role in immunity to Salmonella enterica. Here we evaluated the requirement for Fcgamma receptors in host resistance to S. enterica using an in vivo model of systemic infection.

Bacterial derived proteoliposome as ideal delivery system and cellular adjuvant.

We explored the potential of a proteoliposome (PL) from the outer membrane of N. meningitidis B, as an immunopotentiator and as a vector for antigen delivery to dendritic cells (DC). DC were incubated with PL resulting in up-regulation of MHC-II, CD40, CD80, and CD86 expression and production of TNFalpha and IL12(p70).

Interactions of proteoliposomes from serogroup B Neisseria meningitidis with bone marrow-derived dendritic cells and macrophages: adjuvant effects and antigen delivery.

Exposure to proteoliposomes from serogroup B Neisseria meningitidis (PL) induced up-regulation of MHC-II, MHC-I, CD40, CD80 and CD86 expression on the surface of murine bone marrow-derived dendritic cells (DC). CD40, CD80 and CD86 were up-regulated on bone marrow-derived macrophages (MPhi) upon stimulation with PL. Both DC and MPhi released TNFalpha, but only DC produced IL12(p70) in response to PL.

Characterization and development of T-Cell immune responses in B-cell-deficient (Igh-6(-/-)) mice with Salmonella enterica serovar Typhimurium infection.

Infection of mice with Salmonella enterica serovar Typhimurium induces strong Th1 T-cell responses that are central to the control of the infection. In the present study, we examined the role of B cells in the development of Th1 T-cell responses to Salmonella by using gene-targeted B-cell-deficient mice (Igh-6(-/-) mice). The development of Th1 T-cell responses in Igh-6(-/-) mice was impaired in the early stage of a primary infection.