The present study was designed to elucidate the role of Toll-like receptor (TLR) 2 and TLR4 in the host response to Cryptococcus neoformans. Both TLR2 knockout (KO) and TLR4KO mice produced interleukin-1beta (IL-1beta), IL-6, IL-12p40 and tumor necrosis factor-alpha (TNF-alpha) in sera and cleared this fungal pathogen from infected lungs at a comparable level to control littermate (LM) mice. Synthesis of these cytokines was not significantly different in the lungs of these KO mice and LM mice, although IL-1beta, IL-6 and IL-12p40 tended to be lower in TLR2KO, but not TLR4KO, mice than in controls. In addition, there was no significant reduction detected in the synthesis of IL-12 and TNF-alpha by bone marrow-derived dendritic cells from TLR2KO and TLR4KO mice upon stimulation with live yeast cells. Finally, HEK293 cells expressing either TLR2/dectin-1 or TLR4/MD2/CD14 did not respond to C. neoformans in the activation of nuclear factor kappa B (NFkappaB) detected by a luciferase assay. Our results suggest that TLR2 and TLR4 do not or only marginally contribute to the host and cellular response to this pathogen.

The role of Toll-like receptors (TLRs) in innate immunity to Legionella pneumophila, a gram-negative facultative intracellular bacterium, was studied by using bone marrow-derived macrophages and dendritic cells from TLR2-deficient (TLR2 ؊/؊ ), TLR4 ؊/؊ , and wild-type (WT) littermate (C57BL/6 ؋ 129Sv) mice. Intracellular growth of L. pneumophila was enhanced within TLR2 ؊/؊ macrophages compared to WT and TLR4؊/؊ macrophages. There was no difference in the bacterial growth within dendritic cells from WT and TLR-deficient mice. Production of interleukin-12p40 (IL-12p40) and IL-10 after infection with L. pneumophila was attenuated in TLR2 ؊/؊ macrophages compared to WT and TLR4 ؊/؊ macrophages. Induction of IL-12p40, IL-10, and tumor necrosis factor alpha secretion from macrophages by the L. pneumophila dotO mutant, which cannot multiply within macrophages, and heat-killed bacteria, was similar to that caused by a viable virulent strain. There was no difference between the WT and its mutants in susceptibility to the cytopathic effect of bacteria. An L. pneumophila sonicated lysate induced IL-12p40 production by macrophages, but that of TLR2 ؊/؊ macrophages was significantly lower than those of WT and TLR4 ؊/؊ macrophages. Treatment of L. pneumophila sonicated lysate with proteinase K and heating did not abolish TLR2-dependent IL-12p40 production. Our results show that TLR2, but not TLR4, is involved in murine innate immunity against L. pneumophila, although other TLRs may also contribute to innate immunity against this organism.Legionella pneumophila is the major etiologic agent of Legionnaires' disease, a potentially fatal type of pneumonia affecting immunocompromised and immunocompetent subjects (28,30). This gram-negative bacterium can multiply within the mononuclear cells in vivo and in vitro (6, 14) and evades phagosome-lysosome fusion within these cells (3). Several L. pneumophila virulence factors that facilitate intracellular growth have been identified in screenings with macrophages or in an in vivo screening system with signature-tagged mutagenesis (12). One important set of virulence factors is the dot/icm system, which is a type IV secretion system and is required for evasion of phagosome-lysosome fusion (5, 37, 38) and for the establishment of phagosomes permissive for the growth of L. pneumophila within them (8). However, the effector molecule(s) of this system remains undetermined. The innate immunity to L. pneumophila has been extensively studied. The A/J mouse strain is permissive for the intracellular growth of L. pneumophila (48), whereas other inbred strains of mice, such as BALB/c (49), 57BL/6, and 129X1 (10), are not. In terms of permissiveness of A/J macrophages, the genetic determinant of this permissiveness has been confirmed to be within the Lgn locus, and specifically the Bircle/Naip5 gene (4, 9, 10, 40, 52, 53). However, the role of this gene in regulation of intracellular growth of the bacterium is still unknown.Toll-like receptors (TLRs) have been identified as receptors of pathogen-as...

Although variously shaped urinary red cells have been reported in glomerulonephritic hematuria, no specific shapes with concrete definition have been proposed. This made morphological differentiation of hematuria vague and caused different results among different observers. To solve these problems and improve the diagnostic rate, we employed a uniquely shaped red cell, which only appeared in glomerulonephritic hematuria, as a probe for diagnosis. We studied 182 hematuria cases from 90 glomerulonephritic patients and 95 hematuria cases from 68 urological disease patients. Fresh urine was collected and observed by differential interference microscopy. The red cell, referred to as G1, has a distinctive doughnut-like shape with blebs and was highly specific for glomerulonephritic hematuria. Occurrence of Gl cells increased at lower pH an higher osmolality of urine. A presence of 5% or more G1 cells could be an indicator of glomerulonephritic hematuria. Specificity and sensitivity of this criterion were 100 and 73%. However, when only acidic concentrated urine (pH ≤ 6.4, osmolality ≥ 400 mosm/kg H₂O) was used, the specificity and sensitivity increased to 100 and 99.2%, respectively. Glomerulonephritic and urological hematuria were correctly diagnosed by counting the urinary red cells with doughnut-like shape in acidic and concentrated urine. This method seems to be superior to others in diagnostic rate, simplicity and clarity.

Background: Legionella pneumophila is a facultative intracellular bacterium, capable of replicating within the phagosomes of macrophages and monocytes, but little is known about its interaction with human lung epithelial cells. We investigated the effect of L. pneumophila on the expression of interleukin-8 (IL-8) in human A549 alveolar and NCI-H292 tracheal epithelial cell lines.

Background: Legionella pneumophila pneumonia often exacerbates acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Apoptosis of alveolar epithelial cells is considered to play an important role in the pathogenesis of ALI and ARDS. In this study, we investigated the precise mechanism by which A549 alveolar epithelial cells induced by L. pneumophila undergo apoptosis. We also studied the effect of methyl prednisolone on apoptosis in these cells.