Type 2 diabetes (T2D) is characterized by a chronic
low-grade inflammatory state. SNP in Toll-li... more Type 2 diabetes (T2D) is characterized by a chronic
low-grade inflammatory state. SNP in Toll-like receptor
(TLR) genes has been associated with impaired inflammatory
response. We genotyped the TLR4⁄ D299G,
TLR4 ⁄ T399I and TLR2 ⁄R753Q polymorphisms. Low
frequency was found with no association with T2D,
nevertheless the TLR2 SNP was associated with lower
levels in HDL-cholesterol values.
Colonization of the gastric mucosa by Helicobacter pylori can lead to peptic ulcer and gastric ad... more Colonization of the gastric mucosa by Helicobacter pylori can lead to peptic ulcer and gastric adenocarcinoma. TLRs are signaling receptors involved in the recognition of microorganisms, and polymorphisms in their genes may influence the innate and adaptive immune response to H. pylori, affecting the clinical outcomes of the infection. We assessed the association between single nucleotide polymorphisms in TLR9 and TLR5 and gastroduodenal diseases. All patients were genotyped by allelic discrimination in regions 1174C > T and 1775A > G of TLR5 and -1237T > C and 2848G > A of TLR9. The 2848A allele of TLR9 was more frequent in duodenal ulcer and showed an association of risk with this pathology. Polymorphisms in TLR5 were not found to be associated with disease. Patients with polymorphisms in TLR9 and TLR5 expressed significantly lower levels of IL-1β and TNF-α, whereas polymorphisms in TLR5 also decreased the expression of IL-6 and IL-10. Our findings suggest that…
Entamoeba histolytica is a human pathogen that may invade the intestinal mucosa, causing amoebic ... more Entamoeba histolytica is a human pathogen that may invade the intestinal mucosa, causing amoebic colitis or hepatic abscesses when the trophozoites travel through the portal circulation to the liver. Lipopeptidophosphoglycan (LPPG) is a molecular pattern of E. histolytica recognized by the human immune system. Here we report that LPPG is exposed on the cell surface of E. histolytica trophozoites, and is recognized by the host through toll-like receptor (TLR) 2 and TLR4. Correspondingly, human embryonic kidney (HEK)-293 cells were rendered LPPG responsive through overexpression of TLR2 or TLR4/MD2. Moreover, co-expression of CD14 enhanced LPPG signal transmission through TLR2 and TLR4. The interaction of LPPG with TLR2 and TLR4 resulted in activation of NF-kappaB and release of interleukin (IL)-10, IL-12p40, tumour necrosis factor (TNF)-alpha, and IL-8 from human monocytes. Consistent with these findings, responsiveness of mouse macrophages lacking TLR2 expression (TLR2-/-) or functional TLR4 (TLR4d/d) to E. histolytica LPPG challenge was impaired while double deficient macrophages were unresponsive. In contrast to wild-type control and TLR2-/- animals succumbing to lethal shock syndrome, TLR4d/d mice were resistant to systemic LPPG challenge-induced pathology.
Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. Leishmania pro... more Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. Leishmania promastigotes primarily infect macrophages in the host, where they transform into amastigotes and multiply. Lipophosphoglycan (LPG), the most abundant surface molecule of the parasite, is a virulence determinant that regulates the host immune response. Promastigotes are able to modulate this effect through LPG, creating a favourable environment for parasite survival, although the mechanisms underlying this modulation remain unknown. We analysed the participation of TLR2 and TLR4 in the production of cytokines and explored the possible phosphorylation of ERK and/or p38 MAP kinase signalling cascades in human macrophages stimulated with Leishmania mexicana LPG. The results show that LPG induced the production of TNF-α, IL-1β, IL-12p40, IL-12p70 and IL-10 and led to phosphorylation of ERK and p38 MAP kinase. Specific inhibitors of ERK or p38 MAP kinases and mAbs against TLR2 and TLR4 reduced c...
Innate and adaptive immune responses in humans have evolved as protective mechanisms against infe... more Innate and adaptive immune responses in humans have evolved as protective mechanisms against infectious microorganisms. Toll-like receptors (TLRs) have an important role in the recognition of invading microorganisms. TLRs are the first receptors to detect potential pathogens and to initiate the immune response, and they form the crucial link between the innate and adaptive immune responses. TLRs also have an important role in the pathophysiology of infectious and inflammatory diseases. Increasing data suggest that the ability of certain individuals to respond properly to TLR ligands may be impaired by single-nucleotide polymorphisms (SNPs) within TLR genes, resulting in an altered susceptibility to infectious or inflammatory disease that might contribute to the pathogenesis of complex diseases such as cancer. The associations between diseases and SNPs are in the early stage of discovery. Important clinical insights are emerging, and these polymorphisms provide new understanding of common diseases. This review summarizes and discusses the studies that shed light on the relevance of these polymorphisms in human infectious and inflammatory diseases and cancer.
Type 2 diabetes (T2D) is characterized by a chronic
low-grade inflammatory state. SNP in Toll-li... more Type 2 diabetes (T2D) is characterized by a chronic
low-grade inflammatory state. SNP in Toll-like receptor
(TLR) genes has been associated with impaired inflammatory
response. We genotyped the TLR4⁄ D299G,
TLR4 ⁄ T399I and TLR2 ⁄R753Q polymorphisms. Low
frequency was found with no association with T2D,
nevertheless the TLR2 SNP was associated with lower
levels in HDL-cholesterol values.
Colonization of the gastric mucosa by Helicobacter pylori can lead to peptic ulcer and gastric ad... more Colonization of the gastric mucosa by Helicobacter pylori can lead to peptic ulcer and gastric adenocarcinoma. TLRs are signaling receptors involved in the recognition of microorganisms, and polymorphisms in their genes may influence the innate and adaptive immune response to H. pylori, affecting the clinical outcomes of the infection. We assessed the association between single nucleotide polymorphisms in TLR9 and TLR5 and gastroduodenal diseases. All patients were genotyped by allelic discrimination in regions 1174C > T and 1775A > G of TLR5 and -1237T > C and 2848G > A of TLR9. The 2848A allele of TLR9 was more frequent in duodenal ulcer and showed an association of risk with this pathology. Polymorphisms in TLR5 were not found to be associated with disease. Patients with polymorphisms in TLR9 and TLR5 expressed significantly lower levels of IL-1β and TNF-α, whereas polymorphisms in TLR5 also decreased the expression of IL-6 and IL-10. Our findings suggest that…
Entamoeba histolytica is a human pathogen that may invade the intestinal mucosa, causing amoebic ... more Entamoeba histolytica is a human pathogen that may invade the intestinal mucosa, causing amoebic colitis or hepatic abscesses when the trophozoites travel through the portal circulation to the liver. Lipopeptidophosphoglycan (LPPG) is a molecular pattern of E. histolytica recognized by the human immune system. Here we report that LPPG is exposed on the cell surface of E. histolytica trophozoites, and is recognized by the host through toll-like receptor (TLR) 2 and TLR4. Correspondingly, human embryonic kidney (HEK)-293 cells were rendered LPPG responsive through overexpression of TLR2 or TLR4/MD2. Moreover, co-expression of CD14 enhanced LPPG signal transmission through TLR2 and TLR4. The interaction of LPPG with TLR2 and TLR4 resulted in activation of NF-kappaB and release of interleukin (IL)-10, IL-12p40, tumour necrosis factor (TNF)-alpha, and IL-8 from human monocytes. Consistent with these findings, responsiveness of mouse macrophages lacking TLR2 expression (TLR2-/-) or functional TLR4 (TLR4d/d) to E. histolytica LPPG challenge was impaired while double deficient macrophages were unresponsive. In contrast to wild-type control and TLR2-/- animals succumbing to lethal shock syndrome, TLR4d/d mice were resistant to systemic LPPG challenge-induced pathology.
Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. Leishmania pro... more Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. Leishmania promastigotes primarily infect macrophages in the host, where they transform into amastigotes and multiply. Lipophosphoglycan (LPG), the most abundant surface molecule of the parasite, is a virulence determinant that regulates the host immune response. Promastigotes are able to modulate this effect through LPG, creating a favourable environment for parasite survival, although the mechanisms underlying this modulation remain unknown. We analysed the participation of TLR2 and TLR4 in the production of cytokines and explored the possible phosphorylation of ERK and/or p38 MAP kinase signalling cascades in human macrophages stimulated with Leishmania mexicana LPG. The results show that LPG induced the production of TNF-α, IL-1β, IL-12p40, IL-12p70 and IL-10 and led to phosphorylation of ERK and p38 MAP kinase. Specific inhibitors of ERK or p38 MAP kinases and mAbs against TLR2 and TLR4 reduced c...
Innate and adaptive immune responses in humans have evolved as protective mechanisms against infe... more Innate and adaptive immune responses in humans have evolved as protective mechanisms against infectious microorganisms. Toll-like receptors (TLRs) have an important role in the recognition of invading microorganisms. TLRs are the first receptors to detect potential pathogens and to initiate the immune response, and they form the crucial link between the innate and adaptive immune responses. TLRs also have an important role in the pathophysiology of infectious and inflammatory diseases. Increasing data suggest that the ability of certain individuals to respond properly to TLR ligands may be impaired by single-nucleotide polymorphisms (SNPs) within TLR genes, resulting in an altered susceptibility to infectious or inflammatory disease that might contribute to the pathogenesis of complex diseases such as cancer. The associations between diseases and SNPs are in the early stage of discovery. Important clinical insights are emerging, and these polymorphisms provide new understanding of common diseases. This review summarizes and discusses the studies that shed light on the relevance of these polymorphisms in human infectious and inflammatory diseases and cancer.
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Papers by C Maldonado-Bernal
low-grade inflammatory state. SNP in Toll-like receptor
(TLR) genes has been associated with impaired inflammatory
response. We genotyped the TLR4⁄ D299G,
TLR4 ⁄ T399I and TLR2 ⁄R753Q polymorphisms. Low
frequency was found with no association with T2D,
nevertheless the TLR2 SNP was associated with lower
levels in HDL-cholesterol values.
low-grade inflammatory state. SNP in Toll-like receptor
(TLR) genes has been associated with impaired inflammatory
response. We genotyped the TLR4⁄ D299G,
TLR4 ⁄ T399I and TLR2 ⁄R753Q polymorphisms. Low
frequency was found with no association with T2D,
nevertheless the TLR2 SNP was associated with lower
levels in HDL-cholesterol values.