30. 針刺麻酔に関する文献的ならびに基礎的研究(第519回千葉医学会例会 第8回佐藤外科例会)

<p>Cytokine response in lung homogenates, BALF and plasma of WT and <i>Trem-2</i>^<i>-/-</i> mice during experimental melioidosis.</p

Reduced lung inflammation in TLR2 KO mice early after infection with D39 or PLN

<p><b>Copyright information:</b></p><p>Taken from "Toll-like receptor 2 contributes to antibacterial defence against pneumolysin-deficient pneumococci"</p><p></p><p>Cellular Microbiology 2008;10(1):237-246.</p><p>Published online Jan 2008</p><p>PMCID:PMC2253695.</p><p>© 2007 The Authors Journal compilation © 2007 Blackwell Publishing Ltd</p> Representative lung tissue slides from WT mice (A and C) and TLR2 KO mice (B and D) 6 h after infection with 5 × 10 cfu D39 (A and B) or PLN (C and D). HE staining: magnification 4×. Insets show Ly-6G staining

Cell composition in BALF of PBS-, LPS-, PLN- and heat inactivated PLN-treated mice.

<p>Macrophage and neutrophil counts in BALF from WT mice, 6 hours after inoculation of PBS, LPS (2 pg/mouse), heat inactivated PLN (HIPLN 500 ng/mouse) or PLN (500 ng/mouse). Data are plotted in Box&Whiskers graph (median+interquartile range N = 5 per group). * P<0.05 versus PBS.</p

Inflammatory and cytolytic effects of PLN on mouse alveolar macrophage MH-S cells.

<p>MH-S cells were incubated with increasing doses of PLN for 6 hours with/without polymyxin B (10 µg/ml ) and TNF-α, MIP-2 and cell death were determined thereafter. Cell death was measured using MTT assay as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007993#s2" target="_blank">Methods</a> section. Data are mean±SEM (N = 5 per group). * P<0.05, † P<0.01 versus control.</p

Roles of TLR2 and TLR4 in lung inflammatory response to high dose PLN <i>in vivo</i>.

<p>Macrophage and neutrophil counts, total protein, IL-6, IL-1β, TNF-α and KC concentrations in BALF from WT, TLR2 KO and TLR4 KO mice, 6 hours after inoculation of 500 ng/mouse. Data are plotted in Box&Whiskers graph (median+interquartile range N = 8 per group). * P<0.05, † P<0.01, ‡ P<0.001 versus WT mice. Dotted line indicates mean value of PBS-treated mice.</p

Dissemination of <i>S.</i> Typhi during systemic infection.

<p>Typhoid is usually contracted by ingestion of food or water contaminated by fecal or urinary carriers excreting <i>S.</i> Typhi. The incubation period is usually 7 to 14 d. In the small intestine the bacteria adhere to the mucosa and then invade the epithelial cells. The Peyer's patches, which are aggregrated lymphoid nodules of the terminal ileum, play an important role in the transport to the underlying lymphoid tissue. Specialized epithelial cells such as M cells overlying these Peyer's patches are probably the site of internalization of <i>S.</i> Typhi. Once the bacteria have penetrated the mucosal barrier, the invading organism translocates to the intestinal lymphoid follicles and the draining mesenteric lymph nodes, and some pass on to the reticuloendothelial cells of the liver and spleen. During the bacteremic phase, the bacteria are widely disseminated throughout the body. Secondary infection can occur with liver, spleen, bone-marrow, gallbladder, and Peyer's patches as the most preferred sites. The gallbladder is the main reservoir during a chronic infection with <i>S.</i> Typhi and invasion occurs either directly from the blood or by retrograde spread from the bile. Of interest, the ability of <i>Salmonella</i> to form biofilms on gallstones is likely to be a critical factor in establishment of chronic carriage and shedding of <i>S.</i> Typhi <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Crawford1" target="_blank">[88]</a>. The bacteria that are excreted in the bile can then reinvade the intestinal wall by the mechanism previously described or are excreted by feces. Typical clinical symptoms are fever, malaise, and abdominal discomfort. Clinical features such as a tender abdomen, hepatomegaly, splenomegaly, and a relative bradycardia are common. Rose spots, the classical skin lesions associated with typhoid fever, are relatively uncommon and occur in 5%–30% of cases. The most severe manifestations of typhoid leading to sepsis and death are either necrosis of the Peyer's patches resulting in gut perforation and peritonitis or a toxic encephalopathy associated with myocarditis and haemodynamic shock <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Parry1" target="_blank">[8]</a>, <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Everest1" target="_blank">[89]</a>.</p

<i>Salmonella</i> and its first encounter with the host.

<p>(a) The intracellular life of <i>Salmonella</i>. Invasion of phagocytic and non-phagocytic cells. <i>Salmonella</i> is a facultative intracellular pathogen that can be found in a variety of phagocytic and non-phagocytic cells, in which it is able to survive and replicate. To establish this intracellular niche, the T3SS1 and -2 play a predominant role; key virulence factors are involved in accessing and utilizing these cells <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Ibarra1" target="_blank">[36]</a>. After ingestion, intestinal colonization follows and <i>Salmonella</i> enters enterocytes and dendritic cells in the intestinal epithelium <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Ibarra1" target="_blank">[36]</a>. Subsequently, <i>Salmonella</i> that reach the submucosa can be internalized by resident macrophages via different mechanisms: by phagocytosis, active invasion using the T3SS1 or T3SS1-independent invasion using fimbriae or other adhesins on the bacterial surface. (1) <i>Salmonella</i>-containing-vacuole. Following internalization <i>Salmonella</i> remains within a modified phagosome known as the <i>Salmonella</i> containing vacuole (SCV) and injects a limited number of effector proteins, such as SipA, SipC, SopB/SigD, SodC-1, SopE2, and SptP into the cytoplasm. These effectors cause rearrangements of the actin cytoskeleton and SCV morphology among other changes. (2) Replication within the SCV. <i>Salmonella</i> survives and replicates within the SCV, where it is able to avoid host antimicrobial effector mechanisms. The T3SS2 is required for systemic virulence in the mouse and survival within macrophages. (3) Transport of <i>Salmonella</i> to distant sites. After penetration of the M cells, the invading microorganisms translocate to the intestinal lymphoid follicles and the draining mesenteric lymph nodes, and some pass on to the reticuloendothelial cells of the liver and spleen. <i>Salmonella</i> organisms are able to survive and multiply within the mononuclear phagocytic cells of the lymphoid follicles, liver, and spleen <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Ibarra1" target="_blank">[36]</a>. (b) Host–pathogen interaction in typhoid and non-typhoid <i>Salmonella</i>. Simplified scheme of the first encounter between <i>Salmonella</i> spp. and the immune system. Specified cells such as neutrophils, macrophages, dendritic, phagocytic, and epithelial cells recognize specific pathogen associated molecular patterns (PAMPs) and danger-associated-molecular patterns (DAMPs), thereby eliciting an immune response. PAMPs such as LPS, Flagella, and bacterial DNA can trigger TRL4, TRL5, and TRL9, respectively. TLR-induced activation of NF-κB is essential for the production of pro-IL-1β, pro-IL-18, which can be negatively regulated by IRAK-M <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Kobayashi1" target="_blank">[90]</a>. The NLRs are situated in the cytosol and can also recognize PAMPs. However, NLRP3 is triggered by a different, yet unknown, mechanism, although DAMPs are thought to play a crucial role. TLR, toll-like receptors; LPS, lipopolysaccharide; NF-κB, regulated nuclear factor kappa-light-chain-enhancer of activated B cells; IRAK-M, IL-1R-assiociated kinase-M; IL, Interleukin; ASC, apoptotic speck protein containing a caspase recruitment domain; NLR, NOD-like receptors (including NLRP3 and NLRC4); MyD88, myeloid differentiation primary response gene <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002933#ppat.1002933-Crawford1" target="_blank">[88]</a>.</p

PLN activates HEK cells via TLR4.

<p>IL-8 production in HEK-293 cells transfected with CD14 and either TLR2 or TLR4 were incubated with medium (control), LPS (100 ng/ml), LTA (5 µg/ml) or PLN (1 µg/ml) for 6 hours. In some experiments polymyxin B (P) was used at 10 µg/ml. Data are mean±SEM (N = 4 per group). * P<0.01 versus control, † P<0.001 versus control, ‡P<0.001 versus LPS.</p

MyD88 KO mice show increased bacterial outgrowth during experimental melioidosis.

<p>WT and MyD88 KO mice were intranasally infected with <i>B. pseudomallei</i> (5×10² CFU). Bacterial loads were measured 24 h and 72 h after inoculation in lungs (A), liver (B) and blood (C). Data are mean±SEM (n = 6–7 per group at each time point). ** <i>P</i><0.01.</p

Effect of MyD88 deficiency on total and differential lung cell counts.

<p>Total leukocyte counts (×10⁵/ml) and differential cell counts in lungs of wild-type (WT) and MyD88 knock-out mice 24 hours after intranasal infection with 5×10² CFU of <i>B. pseudomallei</i>. Data are mean±SEM (n = 6–7/group); ** <i>P</i><0.01 versus WT.</p