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   imunologie   MeSH
• multigenová rodina MeSH
• přirozená imunita * genetika   MeSH
• toll-like receptor 6 * genetika   MeSH
• toll-like receptory * genetika   metabolismus   MeSH
• vazebná nerovnováha MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• toll-like receptor 6 * MeSH
• toll-like receptory * MeSH

BACKGROUND: To determine differences in the blood innate gene expression signatures of systemic lupus erythematosus (SLE) patients across various organ manifestations and disease activity, with a focus on lupus nephritis (LN) and central nervous system (CNS) involvement. METHODS: Toll-like receptor family (TLR 1-10) mRNA expression was investigated in peripheral blood mononuclear cells from patients with SLE (n = 74) and healthy controls (n = 34). We compared patients with histologically confirmed active LN or neuropsychiatric systemic lupus erythematosus (NPSLE) with patients without these symptoms. The expression of TLR mRNA was determined by RT‒qPCR using a high-throughput SmartChip Real-Time-qPCR system (WaferGen). Multivariate analysis and nonparametric statistics were used for data analysis to assess the associations between TLRs and disease activity and severity. RESULTS: TLR4 (0.044 vs. 0.081, p = 0.012) was upregulated and TLR10 (0.009 vs. 0.006, p = 0.0007) was downregulated in the whole cohort of SLE patients compared to healthy controls. A comparison of the active LN group with participants without kidney involvement revealed increased expression of TLR2 (0.078 vs. 0.03, p = 0.009), and TLR5 (0.035 vs. 0.017, p = 0.03). Moreover, a significant difference was observed in TLR9 expression between inactive LN and the control group (0.014 vs. 0.009, p = 0.01), together with borderline correlation in TLR2 expression (0.04 vs. 0.03, p = 0.06). Receiver operating characteristic (ROC) curve analysis revealed that TLR1 and TLR2 expression were the best potential diagnostic markers for active LN. The NPSLE group showed upregulation of TLR1 (0.088 vs. 0.048, p = 0.01), TLR4 (0.173 vs. 0.066, p = 0.0003) and TLR6 (0.087 vs. 0.036, 0.007). Our correlation analysis supported the close relationships among the expression of individual TLRs in the whole lupus cohort and its subgroups. CONCLUSION: Our study revealed differences in TLR expression between a lupus cohort and healthy controls. Additionally, our analysis provides insight into specific TLR expression in cases with severe organ manifestations, such as LN and NPSLE. The multiple mutual relationships of TLRs demonstrate the activation of innate immunity in SLE and suggest promising targets for future therapies or diagnostics.

• Klíčová slova
• Disease activity, Innate immunity, Lupus nephritis, Systemic lupus erythematosus, Toll-like receptors,
• MeSH
• dospělí MeSH
• exprese genu MeSH
• leukocyty mononukleární metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• nefritida při lupus erythematodes * genetika   krev   diagnóza   MeSH
• systémový lupus erythematodes * genetika   krev   MeSH
• toll-like receptory * genetika   krev   biosyntéza   MeSH
• vaskulitida centrálního nervového systému při lupus erythematodes * genetika   krev   diagnóza   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• toll-like receptory * MeSH

Toll-like receptors (TLRs) represent an important part of the innate immune system. While human and murine TLRs have been intensively studied, little is known about TLRs in non-model species. The order Perissodactyla comprises a variety of free-living and domesticated species exposed to different pathogens in different habitats and is therefore suitable for analyzing the diversity and evolution of immunity-related genes. We analyzed TLR genes in the order Perissodactyla with a focus on the family Equidae. Twelve TLRs were identified by bioinformatic analyses of online genomic resources; their sequences were confirmed in equids by genomic DNA re-sequencing of a panel of nine species. The expression of TLR11 and TLR12 was confirmed in the domestic horse by cDNA sequencing. Phylogenetic reconstruction of the TLR gene family in Perissodactyla identified six sub-families. TLR4 clustered together with TLR5; the TLR1-6-10 subfamily showed a high degree of sequence identity. The average estimated evolutionary divergence of all twelve TLRs studied was 0.3% among the Equidae; the most divergent CDS were those of Equus caballus and Equus hemionus kulan (1.34%) in the TLR3, and Equus africanus somaliensis and Equus quagga antiquorum (2.1%) in the TLR1 protein. In each TLR gene, there were haplotypes shared between equid species, most extensively in TLR3 and TLR9 CDS, and TLR6 amino acid sequence. All twelve TLR genes were under strong negative overall selection. Signatures of diversifying selection in specific codon sites were detected in all TLRs except TLR8. Differences in the selection patterns between virus-sensing and non-viral TLRs were observed.

• Klíčová slova
• Equid, Innate immunity, Odd-toe ungulates, Toll-like receptor, Transpecies haplotype sharing,
• MeSH
• Equidae MeSH
• fylogeneze MeSH
• genomika MeSH
• koně genetika   MeSH
• lidé MeSH
• myši MeSH
• Perissodactyla metabolismus   MeSH
• toll-like receptor 1 * genetika   MeSH
• toll-like receptor 3 * MeSH
• toll-like receptory genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• toll-like receptor 1 * MeSH
• toll-like receptor 3 * MeSH
• toll-like receptory MeSH

Toll-like receptors (TLRs) form a key component of animal innate immunity, being responsible for recognition of conserved microbial structures. As such, TLRs may be subject to diversifying and balancing selection, which maintains allelic variation both within and between populations. However, most research on TLRs in non-model avian species is focused on bottlenecked populations with depleted genetic variation. Here, we assessed variation at the extracellular domains of three TLR genes (TLR1LA, TLR3, TLR4) across eleven species from two passerine families of buntings (Emberizidae) and finches (Fringillidae), all having large breeding population sizes (millions of individuals). We found extraordinary TLR polymorphism in our study taxa, with >100 alleles detected at TLR1LA and TLR4 across species and high haplotype diversity (>0.75) in several species. Despite recent species divergence, no nucleotide allelic variants were shared between species, suggesting rapid TLR evolution. Higher variation at TLR1LA and TLR4 than TLR3 was associated with a stronger signal of diversifying selection, as measured with nucleotide substitutions rates and the number of positively selected sites (PSS). Structural protein modelling of TLRs showed that some PSS detected within TLR1LA and TLR4 were previously recognized as functionally important sites or were located in their proximity, possibly affecting ligand recognition. Furthermore, we identified PSS responsible for major surface electrostatic charge clustering, which may indicate their adaptive importance. Our study provides compelling evidence for the divergent evolution of TLR genes in buntings and finches and indicates that high TLR variation may be adaptively maintained via diversifying selection acting on functional ligand binding sites.

• Klíčová slova
• Allele diversity, Birds, Divergent evolution, Polymorphism, Positive selection, Toll-like receptors,
• MeSH
• ligandy MeSH
• molekulární evoluce MeSH
• Passeriformes * genetika   MeSH
• pěnkavovití * genetika   MeSH
• toll-like receptor 3 genetika   MeSH
• toll-like receptor 4 genetika   MeSH
• toll-like receptory genetika   chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ligandy MeSH
• toll-like receptor 3 MeSH
• toll-like receptor 4 MeSH
• toll-like receptory MeSH

The interactions of evolutionary forces are difficult to analyse in free-living populations. However, when properly understood, they provide valuable insights into evolutionary biology and conservation genetics. This is particularly important for the interplay of genetic drift and natural selection in immune genes that confer resistance to disease. The Galápagos Islands are inhabited by four closely related species of mockingbirds (Mimus spp.). We used 12 different-sized populations of Galápagos mockingbirds and one population of their continental relative northern mockingbird (Mimus polyglottos) to study the effects of genetic drift on the molecular evolution of immune genes, the Toll-like receptors (TLRs: TLR1B, TLR4 and TLR15). We found that neutral genetic diversity was positively correlated with island size, indicating an important effect of genetic drift. However, for TLR1B and TLR4, there was little correlation between functional (e.g., protein) diversity and island size, and protein structural properties were largely conserved, indicating only a limited effect of genetic drift on molecular phenotype. By contrast, TLR15 was less conserved and even its putative functional polymorphism correlated with island size. The patterns observed for the three genes suggest that genetic drift does not necessarily dominate selection even in relatively small populations, but that the final outcome depends on the degree of selection constraint that is specific for each TLR locus.

• Klíčová slova
• conservation genetics, innate immunity, island birds, molecular phenotype, purifying selection,
• MeSH
• genetický drift MeSH
• hustota populace MeSH
• Passeriformes * genetika   MeSH
• populační genetika MeSH
• selekce (genetika) MeSH
• toll-like receptor 4 * genetika   MeSH
• toll-like receptory genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• toll-like receptor 4 * MeSH
• toll-like receptory MeSH

Balancing selection is a classic mechanism for maintaining variability in immune genes involved in host-pathogen interactions. However, it remains unclear how widespread the mechanism is across immune genes other than the major histocompatibility complex (MHC). Although occasional reports suggest that balancing selection (heterozygote advantage, negative frequency-dependent selection, and fluctuating selection) may act on other immune genes, the current understanding of the phenomenon in non-MHC immune genes is far from solid. In this review, we focus on Toll-like receptors (TLRs), innate immune genes directly involved in pathogen recognition and immune response activation, as there is a growing body of research testing the assumptions of balancing selection in these genes. After reviewing infection- and fitness-based evidence, along with evidence based on population allelic frequencies and heterozygosity levels, we conclude that balancing selection maintains variation in TLRs, though it tends to occur under specific conditions in certain evolutionary lineages rather than being universal and ubiquitous. Our review also identifies key gaps in current knowledge and proposes promising areas for future research. Improving our understanding of host-pathogen interactions and balancing selection in innate immune genes are increasingly important, particularly regarding threats from emerging zoonotic diseases.

• Klíčová slova
• TLR, Toll-like receptors, balancing selection, host–pathogen interactions, innate immune genes, polymorphism,
• MeSH
• frekvence genu MeSH
• hlavní histokompatibilní komplex MeSH
• polymorfismus genetický * MeSH
• přirozená imunita genetika   MeSH
• selekce (genetika) MeSH
• toll-like receptory * genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• toll-like receptory * MeSH

Penguins (Sphenisciformes) are an iconic order of flightless, diving seabirds distributed across a large latitudinal range in the Southern Hemisphere. The extensive area over which penguins are endemic is likely to have fostered variation in pathogen pressure, which in turn will have imposed differential selective pressures on the penguin immune system. At the front line of pathogen detection and response, the Toll-like receptors (TLRs) provide insight into host evolution in the face of microbial challenge. TLRs respond to conserved pathogen-associated molecular patterns and are frequently found to be under positive selection, despite retaining specificity for defined agonist classes. We undertook a comparative immunogenetics analysis of TLRs for all penguin species and found evidence of adaptive evolution that was largely restricted to the cell surface-expressed TLRs, with evidence of positive selection at, or near, key agonist-binding sites in TLR1B, TLR4, and TLR5. Intriguingly, TLR15, which is activated by fungal products, appeared to have been pseudogenized multiple times in the Eudyptes spp., but a full-length form was present as a rare haplotype at the population level. However, in vitro analysis revealed that even the full-length form of Eudyptes TLR15 was nonfunctional, indicating an ancestral cryptic pseudogenization prior to its eventual disruption multiple times in the Eudyptes lineage. This unusual pseudogenization event could provide an insight into immune adaptation to fungal pathogens such as Aspergillus, which is responsible for significant mortality in wild and captive bird populations.

• Klíčová slova
• Toll-like receptors, avian immunology, host–pathogen interaction, immunogenetics, pseudogenization, wildlife disease,
• MeSH
• molekulární evoluce MeSH
• selekce (genetika) MeSH
• Spheniscidae * genetika   MeSH
• toll-like receptory genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• toll-like receptory MeSH

A number of human autoinflammatory diseases manifest with severe inflammatory bone destruction. Mouse models of these diseases represent valuable tools that help us to understand molecular mechanisms triggering this bone autoinflammation. The Pstpip2cmo mouse strain is among the best characterized of these; it harbors a mutation resulting in the loss of adaptor protein PSTPIP2 and development of autoinflammatory osteomyelitis. In Pstpip2cmo mice, overproduction of interleukin-1β (IL-1β) and reactive oxygen species by neutrophil granulocytes leads to spontaneous inflammation of the bones and surrounding soft tissues. However, the upstream signaling events leading to this overproduction are poorly characterized. Here, we show that Pstpip2cmo mice deficient in major regulator of Src-family kinases (SFKs) receptor-type protein tyrosine phosphatase CD45 display delayed onset and lower severity of the disease, while the development of autoinflammation is not affected by deficiencies in Toll-like receptor signaling. Our data also show deregulation of pro-IL-1β production by Pstpip2cmo neutrophils that are attenuated by CD45 deficiency. These data suggest a role for SFKs in autoinflammation. Together with previously published work on the involvement of protein tyrosine kinase spleen tyrosine kinase, they point to the role of receptors containing immunoreceptor tyrosine-based activation motifs, which after phosphorylation by SFKs recruit spleen tyrosine kinase for further signal propagation. We propose that this class of receptors triggers the events resulting in increased pro-IL-1β synthesis and disease initiation and/or progression.

• Klíčová slova
• CD45, PSTPIP2, PTPRC, autoinflammation, chronic recurrent multifocal osteomyelitis,
• MeSH
• adaptorové proteiny signální transdukční genetika   imunologie   MeSH
• antigeny CD45 genetika   imunologie   MeSH
• cytoskeletální proteiny genetika   imunologie   MeSH
• diabetes mellitus 1. typu genetika   imunologie   patologie   MeSH
• interleukin-1beta genetika   imunologie   MeSH
• myši knockoutované MeSH
• myši MeSH
• neutrofily imunologie   patologie   MeSH
• osteomyelitida genetika   imunologie   patologie   MeSH
• signální transdukce genetika   imunologie   MeSH
• stupeň závažnosti nemoci MeSH
• toll-like receptory genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• antigeny CD45 MeSH
• cytoskeletální proteiny MeSH
• IL1B protein, mouse MeSH Prohlížeč
• interleukin-1beta MeSH
• Pstpip2 protein, mouse MeSH Prohlížeč
• Ptprc protein, mouse MeSH Prohlížeč
• toll-like receptory MeSH

Various stressors including temperature, environmental chemicals, and toxins can have profound impacts on immunity to pathogens. Increased eutrophication near rivers and lakes coupled with climate change are predicted to lead to increased algal blooms. Currently, the effects of cyanobacterial toxins on disease resistance in mammals is a largely unexplored area of research. Recent studies have suggested that freshwater cyanotoxins can elicit immunomodulation through interaction with specific components of innate immunity, thus potentially altering disease susceptibility parameters for fish, wildlife, and human health owing to the conserved nature of the vertebrate immune system. In this study, we investigated the effects of three microcystin congeners (LR, LA, and RR), nodularin-R, and cylindrospermopsin for their ability to directly interact with nine different human Toll-like receptors (TLRs)-key pathogen recognition receptors for innate immunity. Toxin concentrations were verified by LC/MS/MS prior to use. Using an established HEK293-hTLR NF-κB reporter assay, we concluded that none of the tested toxins (29-90 nM final concentration) directly interacted with human TLRs in either an agonistic or antagonistic manner. These results suggest that earlier reports of cyanotoxin-induced NF-κB responses likely occur through different surface receptors to mediate inflammation.

• Klíčová slova
• Cyanotoxin, Inflammation, NF-κB, Toll-like receptor,
• MeSH
• alkaloidy MeSH
• cyklické peptidy MeSH
• HEK293 buňky MeSH
• lidé MeSH
• mikrocystiny * toxicita   MeSH
• tandemová hmotnostní spektrometrie * MeSH
• toll-like receptory genetika   MeSH
• toxiny kmene Cyanobacteria MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alkaloidy MeSH
• cyklické peptidy MeSH
• cylindrospermopsin MeSH Prohlížeč
• mikrocystiny * MeSH
• nodularin MeSH Prohlížeč
• toll-like receptory MeSH
• toxiny kmene Cyanobacteria MeSH

OBJECTIVES: A growing body of evidence highlights the persistent activation of the innate immune system and type I interferon (IFN) signature in the pathogenesis of rheumatoid arthritis (RA) and its association with disease activity. Since the recent study revealed heterogeneity in the IFN signature in RA, we investigated for the first time the heterogeneity in innate signature in RA. METHODS: The innate gene expression signature (10 TLRs, 7 IL1/IL1R family members, and CXCL8/IL8) was assessed in peripheral blood mononuclear cells from RA patients (n=67), both with active (DAS28≥3.2, n=32) and inactive disease (DAS28<3.2, n=35), and in healthy control subjects (n=55). RESULTS: Of the 13 deregulated innate genes (TLR2, TLR3, TLR4, TLR5, TLR8, TLR10, IL1B, IL1RN, IL18, IL18R1, IL1RAP, and SIGIRR/IL1R8) associated with RA, TLR10 and IL1RAP are being reported for the first time. Multivariate analysis based on utilising patient similarity networks revealed the existence of four patient's subsets (clusters) based on different TLR8 and IL1RN expression profiles, two in active and two in inactive RA. Moreover, neural network analysis identified two main gene sets describing active RA within an activity-related innate signature (TLR1, TLR2, TLR3, TLR7, TLR8, CXCL8/IL8, IL1RN, IL18R1). When comparing active and inactive RA, upregulated TLR2, TLR4, TLR6, and TLR8 and downregulated TLR10 (P<0.04) expression was associated with the disease activity. CONCLUSIONS: Our study on the comprehensive innate gene profiling together with multivariate analysis revealed a certain heterogeneity in innate signature within RA patients. Whether the heterogeneity of RA elucidated from diversity in innate signatures may impact the disease course and treatment response deserves future investigations.

• MeSH
• interferon typ I * imunologie   MeSH
• leukocyty mononukleární MeSH
• lidé MeSH
• multivariační analýza MeSH
• revmatoidní artritida * genetika   imunologie   metabolismus   MeSH
• toll-like receptory * genetika   imunologie   metabolismus   MeSH
• transkriptom MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• interferon typ I * MeSH
• toll-like receptory * MeSH