Toll-like receptors (TLRs) play important roles in innate immunity and developmental processes. Due to their nature as molecular pattern recognition receptors, their genetic diversity may reflect the effects of various pathogen pressures. Here, the extent of variability in the TLR1-6-10 gene cluster in three geographically and historically distinct breeds of horses was analysed. A genetically diverse group of representatives of 14 other horse breeds provided additional information on the variability of this gene cluster in the domestic horse. Altogether, 25 SNPs were identified in the TLR6-1-10 gene cluster across the 4 equine breed groups studied, of which 7 were synonymous and 18 non-synonymous. Twenty-eight inferred SNPs and 22 in silico translated amino acid haplotypes were identified. A predominant major haplotype present in all breed groups along with several group-specific haplotypes were identified. Strong linkage disequilibrium was detected for several SNPs, as well as effects of pervasive, site-specific selection. The existence of a major haplotype suggests it may confer a selective advantage across breeds. Less frequent breed-specific haplotypes may represent variability required or beneficial for responses to local pathogen pressures. Purifying site-specific selection was detected in the TIR domain and its vicinity in TLR6, whereas AA sites under diversifying selection were located in LRR domains and/or their surroundings in TLR1. Population structure models based on immune-related TLR6-1-10 markers did not distinguish between breed groups, whereas in models based on neutral microsatellite markers, breed groups clustered separately. This supports the assumption that the diversity of the TLR6-1-10 cluster is of adaptive value. The TLR6-1-10 alleles and haplotypes identified represent potential candidate markers for disease association studies.

• Klíčová slova
• equine, haplotype, innate immunity, toll‐like receptor,
• MeSH
• genetická variace * MeSH
• haplotypy * MeSH
• jednonukleotidový polymorfismus * MeSH
• koně genetika   MeSH
• multigenová rodina MeSH
• přirozená imunita * genetika   MeSH
• toll-like receptor 6 genetika   MeSH
• toll-like receptory genetika   MeSH
• vazebná nerovnováha MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• toll-like receptor 6 MeSH
• toll-like receptory MeSH

Uptake of bacteria by phagocytes is a crucial step in innate immune defence. Members of the disintegrin and metalloproteinase (ADAM) family critically control the immune response by limited proteolysis of surface expressed mediator molecules. Here, we investigated the significance of ADAM17 and its regulatory adapter molecule iRhom2 for bacterial uptake by phagocytes. Inhibition of metalloproteinase activity led to increased phagocytosis of pHrodo labelled Gram-negative and -positive bacteria (E. coli and S. aureus, respectively) by human and murine monocytic cell lines or primary phagocytes. Bone marrow-derived macrophages showed enhanced uptake of heat-inactivated and living E. coli when they lacked either ADAM17 or iRhom2 but not upon ADAM10-deficiency. In monocytic THP-1 cells, corresponding short hairpin RNA (shRNA)-mediated knockdown confirmed that ADAM17, but not ADAM10, promoted phagocytosis of E. coli. The augmented bacterial uptake occurred in a cell autonomous manner and was accompanied by increased release of the chemokine CXCL8, less TNFα release and only minimal changes in the surface expression of the receptors TNFR1, TLR6 and CD36. Inhibition experiments indicated that the enhanced bacterial phagocytosis after ADAM17 knockdown was partially dependent on TNFα-activity but not on CXCL8. This novel role of ADAM17 in bacterial uptake needs to be considered in the development of ADAM17 inhibitors as therapeutics.

• Klíčová slova
• ADAM17, bacterial phagocytosis, chemokines, iRhom2, infection, inflammation, metalloproteinase, phagocytes, shedding,
• MeSH
• antigeny CD36 genetika   metabolismus   MeSH
• Escherichia coli patogenita   MeSH
• fagocytóza MeSH
• fagocyty metabolismus   mikrobiologie   MeSH
• interleukin-8 metabolismus   MeSH
• intracelulární signální peptidy a proteiny genetika   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• myši MeSH
• protein ADAM17 genetika   metabolismus   MeSH
• RAW 264.7 buňky MeSH
• receptory TNF - typ I genetika   metabolismus   MeSH
• Staphylococcus aureus patogenita   MeSH
• THP-1 buňky MeSH
• toll-like receptor 6 genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ADAM17 protein, human MeSH Prohlížeč
• antigeny CD36 MeSH
• CD36 protein, human MeSH Prohlížeč
• interleukin-8 MeSH
• intracelulární signální peptidy a proteiny MeSH
• protein ADAM17 MeSH
• receptory TNF - typ I MeSH
• RHBDF2 protein, human MeSH Prohlížeč
• TLR6 protein, human MeSH Prohlížeč
• toll-like receptor 6 MeSH

The bovine genes TLR1, TLR2 and TLR6, which encode Toll-like receptors, key components of the innate immune system, were screened for polymorphisms in Czech Red Pied (Czech Simmental) cattle, and the different variants present in the population were tested for association with reproductive and fitness traits. Diversity was investigated in a group of 164 bulls using hybrid resequencing of pooled amplicons with PacBio technology and of pooled genomic DNA using HiSeq X-Ten technology. The validated single nucleotide polymorphisms (SNPs) were genotyped in individual animals using the primer extension technique. The association of genotypic classes of 16 polymorphisms with six phenotypic traits were estimated with one-way analysis of variance (ANOVA) and with restricted maximum likelihood (REML) algorithm. The evaluated traits included the incidence of cystic ovaries, index of early reproductive disorders, paternal and maternal indicators of calving ease, production longevity and calf vitality index. The estimated breeding values were used for combined trait quantification. Early traits, namely, cystic ovaries and early reproductive disorders, were not associated with any of the tested polymorphisms according to the general ANOVA test. By contrast, five variants of all three genes were associated with calving ease, both paternal and maternal. The production longevity correlated with two variants of TLR1 and the calf vitality index correlated with the 1044 T > C (rs68268249) polymorphism in TLR2. The false discovery rate (FDR) according to Benjamini-Hochberg was favourable for the calving ease trait (0.221) and maternal calving ease (0.214), which allows to consider the observed associations real, regardless of the error arising from the multiple comparisons. These results were supported by REML only partially, probably in view of the additivity assumption. Two mechanisms of action on calving are conceivable, either via infection resistance or via the involvement of TLR2 in signalling in the myometrium. The known formation of heterodimers by the TLR1, -2 and -6 products might be responsible for the shared pattern of action in these genes. The association of the calf vitality index with TLR2 variation might reflect the increased role of infections in calves compared to adult animals.

• Klíčová slova
• Cattle, Diversity, Effect prediction, Health traits, Toll-like receptors,
• MeSH
• chov MeSH
• dlouhověkost genetika   MeSH
• fenotyp MeSH
• genotyp MeSH
• jednonukleotidový polymorfismus * MeSH
• rozmnožování genetika   MeSH
• skot genetika   MeSH
• toll-like receptor 1 genetika   MeSH
• toll-like receptor 2 genetika   MeSH
• toll-like receptor 6 genetika   MeSH
• toll-like receptory genetika   MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• skot genetika   MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• toll-like receptor 1 MeSH
• toll-like receptor 2 MeSH
• toll-like receptor 6 MeSH
• toll-like receptory MeSH