Nicolaas A. Bos

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Obesity has recently been linked to the composition of human microbiota and the production of short chain fatty acids (SCFAs). However, these findings rely on experimental studies carried out using rather small and defined groups of volunteers or model animals. Our aim was to evaluate differences within the human intestinal microbiota and fecal SCFA(More)
Antimicrobial peptides are important effectors of innate immunity throughout the plant and animal kingdoms. In the mammalian small intestine, Paneth cell alpha-defensins are antimicrobial peptides that contribute to host defense against enteric pathogens. To determine if alpha-defensins also govern intestinal microbial ecology, we analyzed the intestinal(More)
The commensal microbiota protects the murine host from enteric pathogens. Nevertheless, specific pathogens are able to colonize the intestinal tract and invade, despite the presence of an intact biota. Possibly, effective pathogens disrupt the indigenous microbiota, either directly through pathogen-commensal interaction, indirectly via the host mucosal(More)
Anti-helminth immunity involves CD4+ T cells, yet the precise effector mechanisms responsible for parasite killing or expulsion remain elusive. We now report an essential role for antibodies in mediating immunity against the enteric helminth Heligmosomoides polygyrus (Hp), a natural murine parasite that establishes chronic infection. Polyclonal IgG(More)
Total genomic DNA from samples of intact mouse small intestine, large intestine, caecum and faeces was used as template for PCR amplification of 16S rRNA gene sequences with conserved bacterial primers. Phylogenetic analysis of the amplification products revealed 40 unique 16S rDNA sequences. Of these sequences, 25% (10/40) corresponded to described(More)
Segmented filamentous bacteria (SFB) are autochthonous bacteria inhabiting the intestinal tracts of many species, including humans. We studied the effect of SFB on the mucosal immune system by monoassociating formerly germfree C3H/HeN mice with SFB. At various time points during 190 days of colonization, fragment cultures of small intestine and Peyer's(More)
In Wegener's granulomatosis (WG), a form of autoimmune systemic vasculitis, chronic carriage of Staphylococcus aureus constitutes a risk factor for the development of exacerbations. Circulating T cells in this disease are persistently activated, suggesting the presence of a chronic stimulus. A causal link between chronic carriage of S. aureus and chronic T(More)
Thirty-seven patients with multiple myeloma (stage II and III, 65% increased beta2-microglobulin level) were prospectively treated with a median of 3.7 VAD courses (range 2-8) followed by cyclophosphamide (6 g/m2) in conjunction with G-CSF (5 microg/kg filgrastrim (n = 14), or 3.5 microg/kg lenograstrim (n = 22)), and peripheral stem cell (PSC) isolation.(More)
As a member of the indigenous gut mucosal microbiota, segmented filamentous bacteria (SFB) colonize the guts of a variety of vertebrates and invertebrates. They are potent microbial stimuli of the gut mucosal immune system. In the small intestines of mice and rats, it has been observed that SFB are absent during the suckling period and appear in high(More)
Mucosal IgA is the most abundantly produced Ig upon colonization of the intestinal tract with commensal organisms in the majority of mammals. The repertoire of these IgA molecules is still largely unknown; a large amount of the mucosal IgA cannot be shown to react with the inducing microorganisms. Analysis of the repertoire of used H chain Ig (V(H)) genes(More)