Polymorphisms in the promoter of the CD14 gene and their associations with susceptibility to pulmonary tuberculosis

Association analysis between CD14 gene polymorphisms and peri-implantitis susceptibility in a Chinese population

OBJECTIVE

The goal of the study was to examine the genetic correlation of cluster of differentiation 14 (CD14) gene polymorphisms with peri-implantitis (PI) predisposition in a Chinese Han population.

METHODS

In the case-control study, blood samples were collected from PI patients and healthy individuals (n = 120/group), who were admitted to the Affiliated Hospital of Yangzhou University from 2021 to 2023. One-way analysis of variance (ANOVA) was applied to compare differences of continuous variables among different groups. Genotype and allele distributions of CD14 gene rs2569190 and rs2915863 polymorphisms were analyzed between groups via χ2 test.

RESULTS

A high percentage of rs2569190 GG genotype or G allele carriers were identified in PI group compared with control group (p < .01). Rs2569190 GG genotype carriers had high risk to develop PI (odds ratio: 2.545, 95% confidence interval: 1.257-5.156, p = .009). The rs2569190 AA genotype carriers had the lowest values of gingival index, plaque index, calculus index, peri-implant pocket depth, and clinical attachment level, which were the highest in cases with GG genotype.

CONCLUSION

Rs2569190 polymorphism of CD14 gene was significantly associated with PI predisposition in the Chinese Han population, and the GG genotype and G allele were risk factors for the development of PI.

Inborn Errors in the LRR Domain of Nod2 and Their Potential Consequences on the Function of the Receptor

The innate immune system plays a critical role in the early detection of pathogens, primarily by relying on pattern-recognition receptor (PRR) signaling molecules. Nucleotide-binding oligomerization domain 2 (NOD2) is a cytoplasmic receptor that recognizes invading molecules and danger signals inside the cells. Recent studies highlight the importance of NOD2′s function in maintaining the homeostasis of human body microbiota and innate immune responses, including induction of proinflammatory cytokines, regulation of autophagy, modulation of endoplasmic reticulum (ER) stress, etc. In addition, there is extensive cross-talk between NOD2 and the Toll-like receptors that are so important in the induction and tuning of adaptive immunity. Polymorphisms of NOD2′s encoding gene are associated with several pathological conditions, highlighting NOD2′s functional importance. In this study, we summarize NOD2′s role in cellular signaling pathways and take a look at the possible consequences of common NOD2 polymorphisms on the structure and function of this receptor.

The influence of single nucleotide polymorphisms of NOD2 or CD14 on the risk of Mycobacterium tuberculosis diseases: a systematic review

BACKGROUND

Tuberculosis (TB) is still one of the leading causes of death worldwide. Genetic studies have pointed to the relevance of the NOD2 and CD14 polymorphic alleles in association with the risk of diseases caused by Mycobacterium tuberculosis (Mtb) infection.

METHODS

A systematic review was performed on PubMed, EMBASE, Scientific Electronic Library Online (SciELO), and Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) to examine the association between single nucleotide polymorphisms (SNP) and risk of Mtb diseases. Study quality was evaluated using the Newcastle-Ottawa Quality Scale (NOQS), and the linkage disequilibrium was calculated for all SNPs using a webtool (Package LDpop).

RESULTS

Thirteen studies matched the selection criteria. Of those, 9 investigated CD14 SNPs, and 6 reported a significant association between the T allele and TT genotypes of the rs2569190 SNP and increased risk of Mtb diseases. The genotype CC was found to be protective against TB disease. Furthermore, in two studies, the CD14 rs2569191 SNP with the G allele was significantly associated with increased risk of Mtb diseases. Four studies reported data uncovering the relationship between NOD2 SNPs and risk of Mtb diseases, with two reporting significant associations of rs1861759 and rs7194886 and higher risk of Mtb diseases in a Chinese Han population. Paradoxically, minor allele carriers (CG or GG) of rs2066842 and rs2066844 NOD2 SNPs were associated with lower risk of Mtb diseases in African Americans.

CONCLUSIONS

The CD14 rs2569190 and rs2569191 polymorphisms may influence risk of Mtb diseases depending on the allele. Furthermore, there is significant association between NOD2 SNPs rs1861759 and rs7194886 and augmented risk of Mtb diseases, especially in persons of Chinese ethnicity. The referred polymorphisms of CD14 and NOD2 genes likely play an important role in risk of Mtb diseases and pathology and may be affected by ethnicity.

SYSTEMATIC REVIEW REGISTRATION

CRD42020186523.

SNP Diversity in CD14 Gene Promoter Suggests Adaptation Footprints in Trypanosome Tolerant N'Dama (Bos taurus) but not in Susceptible White Fulani (Bos indicus) Cattle

Immune response to infections has been shown to be mediated by genetic diversity in pattern recognition receptors, leading to disease tolerance or susceptibility. We elucidated naturally occurring variations within the bovine CD14 gene promoter in trypanosome-tolerant (N'Dama) and susceptible (White Fulani) cattle, with genomic and computational approaches. Blood samples were collected from White Fulani and N'Dama cattle, genomic DNA extracted and the entire promoter region of the CD14 gene amplified by PCR. We sequenced this region and performed in silico computation to identify SNP variants, transcription factor binding sites, as well as micro RNAs in the region. CD14 promoter sequences were compared with the reference bovine genome from the Ensembl database to identify various SNPs. Furthermore, we validated three selected N'Dama specific SNPs using custom Taqman SNP genotyping assay for genetic diversity. In all, we identified a total of 54 and 41 SNPs at the CD14 promoter for N'Dama and White Fulani respectively, including 13 unique SNPs present in N'Dama only. The significantly higher SNP density at the CD14 gene promoter region in N'Dama may be responsible for disease tolerance, possibly an evolutionary adaptation. Our genotype analysis of the three loci selected for validation show that mutant alleles (A/A, C/C, and A/A) were adaptation profiles within disease tolerant N'Dama. A similar observation was made for our haplotype analysis revealing that haplotypes H1 (ACA) and H2 (ACG) were significant combinations within the population. The SNP effect prediction revealed 101 and 89 new transcription factor binding sites in N'Dama and White Fulani, respectively. We conclude that disease tolerant N'Dama possessing higher SNP density at the CD14 gene promoter and the preponderance of mutant alleles potentially confirms the significance of this promoter in immune response, which is lacking in susceptible White Fulani. We, therefore, recommend further in vitro and in vivo study of this observation in infected animals, as the next step for understanding genetic diversity relating to varying disease phenotypes in both breeds.

In silico analyses of CD14 molecule reveal significant evolutionary diversity, potentially associated with speciation and variable immune response in mammals

The cluster differentiation gene (CD14) is a family of monocyte differentiating genes that works in conjunction with lipopolysaccharide binding protein, forming a complex with TLR4 or LY96 to mediate innate immune response to pathogens. In this paper, we used different computational methods to elucidate the evolution of CD14 gene coding region in 14 mammalian species. Our analyses identified leucine-rich repeats as the only significant domain across the CD14 protein of the 14 species, presenting with frequencies ranging from one to four. Importantly, we found signal peptides located at mutational hotspots demonstrating that this gene is conserved across these species. Out of the 10 selected variants analyzed in this study, only six were predicted to possess significant deleterious effect. Our predicted protein interactome showed a significant varying protein-protein interaction with CD14 protein across the species. This may be important for drug target and therapeutic manipulation for the treatment of many diseases. We conclude that these results contribute to our understanding of the CD14 molecular evolution, which underlays varying species response to complex disease traits.

CD14 gene polymorphisms associated with increased risk of bovine tuberculosis in Chinese Holstein cows

Cluster differentiation antigen 14 (CD14) is an important pattern recognition receptor protein in innate immunity. The aim of this study was to identify and assess the association of single-nucleotide polymorphisms (SNPs) in the CD14 gene with susceptibility to bovine tuberculosis (BTB) in Chinese Holstein cows. DNA samples from 517 Chinese Holstein cows (257 tuberculosis positive cases and 259 healthy controls) were collected from dairy farms in China. SNPs in the entire CD14 gene, including exonic regions, intronic regions and close to the 5'- and 3'-terminal untranslated regions, were detected by PCR, followed by direct sequencing. Five SNPs (-5C/T, 613G/A, 1023G/A, 1306G/A and 1326G/T) were found in the CD14 gene region. Significantly increased BTB susceptibility was evident in T allele carriers of -5C/T (P<0.001; odds ratio, OR 2.02; 95% confidence interval, CI 1.57-2.77), G allele carriers of 613G/A (P<0.001; OR 2.17, 95% CI 1.50-3.08) and TG haplotype carriers of both SNPs (P<0.001; OR 3.14, 95% CI 1.24-4.50). These results suggest that -5C/T and 613G/A are risk factors for BTB in Chinese Holstein cattle and might be used as candidate genetic markers in breeding cows with natural resistance to BTB.

The Role of Host Genetics (and Genomics) in Tuberculosis

Familial risk of tuberculosis (TB) has been recognized for centuries. Largely through studies of mono- and dizygotic twin concordance rates, studies of families with Mendelian susceptibility to mycobacterial disease, and candidate gene studies performed in the 20th century, it was recognized that susceptibility to TB disease has a substantial host genetic component. Limitations in candidate gene studies and early linkage studies made the robust identification of specific loci associated with disease challenging, and few loci have been convincingly associated across multiple populations. Genome-wide and transcriptome-wide association studies, based on microarray (commonly known as genechip) technologies, conducted in the past decade have helped shed some light on pathogenesis but only a handful of new pathways have been identified. This apparent paradox, of high heritability but few replicable associations, has spurred a new wave of collaborative global studies. This review aims to comprehensively review the heritability of TB, critically review the host genetic and transcriptomic correlates of disease, and highlight current studies and future prospects in the study of host genomics in TB. An implicit goal of elucidating host genetic correlates of susceptibility to Mycobacterium tuberculosis infection or TB disease is to identify pathophysiological features amenable to translation to new preventive, diagnostic, or therapeutic interventions. The translation of genomic insights into new clinical tools is therefore also discussed.

Gene Association with Leprosy: A Review of Published Data

Leprosy is a chronic infectious disease caused by an obligate intracellular bacterium known as Mycobacterium leprae. Exposure to the bacillus is necessary, but this alone does not mean an individual will develop clinical symptoms of the disease. In recent years, several genes have been associated with leprosy and the innate immune response pathways converge on the main hypothesis that genes are involved in the susceptibility for the disease in two distinct steps: for leprosy per se and in the development of the different clinical forms. These genes participate in the sensing, main metabolic pathway of immune response activation and, subsequently, on the evolution of the disease into its clinical forms. The aim of this review is to highlight the role of innate immune response in the context of leprosy, stressing their participation in the signaling and targeting processes in response to bacillus infection and on the evolution to the clinical forms of the disease.

Relationship between CD14-159C/T gene polymorphism and acute brucellosis risk

Objective

To investigate the association between the cluster of differentiation 14 (CD14)-159C/T (rs2569190) gene polymorphism and susceptibility to acute brucellosis in an Iranian population.

Methods

The study included 153 Iranian patients with active brucellosis and 128 healthy individuals as the control group. Genotyping of the CD14 variant was performed using an amplification refractory mutation system-polymerase chain reaction method.

Results

The prevalence of CD14-159 TT and CT genotypes were associated with increased risk of brucellosis [odds ratio (OR) = 1.993, 95% confidence interval (95% CI) = 1.07–3.71, P = 0.03 for CT; OR = 3.869, 95% CI = 1.91–7.84, P = 0.01 for TT genotype. Additionally, the minor allele (T) was significantly more frequently present in brucellosis patients than in controls (61% vs. 45%, respectively), and was a risk factor for brucellosis (OR = 3.058, 95% CI = 1.507–6.315, P = 0.01).

Conclusions

The findings provided suggestive evidence of association of the CD14-159C/T gene polymorphism with susceptibility to acute brucellosis in the Iranian population.

CD14 -159C/T polymorphism contributes to the susceptibility to tuberculosis: evidence from pooled 1,700 cases and 1,816 controls

CD14 is a receptor for lipopolysaccharide and plays an important role in innate immune against infections induced by microorganisms. A functional polymorphism in promoter region of CD14 gene, -159C/T, was extensively investigated with tuberculosis (TB) risk, but the association results were inconclusive. We performed a meta-analysis to synthesize association results of CD14 -159C/T polymorphism with TB risk from 8 studies including 1,700 TB cases and 1,816 controls. Based on the heterogeneity between studies evaluated by χ2-based Q test, a fixed- or random-effect model was applied to estimate the pooled odds ratio (OR) and 95% confidence interval (CI). Potential publication bias was evaluated with the funnel plot as well as the linear regression asymmetry test proposed by Egger et al. We found that the -159T allele was significantly associated with an increased risk of TB (OR 1.27, 95% CI 1.01-1.61) as compared with -159C allele. Individuals with -159TT genotype showed a significantly increased risk of TB than those with -159CT/CC genotype (OR 1.52, 95% CI 1.11-2.08). These associations were not attributed to potential publication bias (P>0.05 for Egger's test). The results from this meta-analysis indicate that CD14 -159C/T polymorphism is associated with TB predisposition and may serve as a candidate of susceptibility biomarker for TB.

The -159C/T polymorphism in the CD14 gene and tuberculosis risk: a meta-analysis

BACKGROUND

The -159C/T polymorphism in the CD14 gene has been implicated in susceptibility to tuberculosis, but the results were inconclusive. The present meta-analysis aimed to perform a comprehensive assessment of the literature on the possible association between the -159C/T polymorphism and tuberculosis risk.

METHODS

We searched in Pubmed and Embase for studies evaluating the association between the -159C/T gene polymorphism and tuberculosis risk. Data were extracted and statistical analysis was performed using Revman 5.1 and STATA 12.0 software.

RESULTS

A total of seven case-control studies involving 3253 subjects (1,574 tuberculosis cases and 1,679 controls) were included. Combined analysis revealed an obvious association between this polymorphism and tuberculosis risk (odds ratio=1.66 and 95% confidence interval: 1.23-2.25, P<0.05 for TT vs. TC+ CC). Sub-group analysis by ethnicity suggested that the risk of tuberculosis associated with the -159C/T polymorphism was significantly elevated among Asians (odds ratio=1.87 and 95% confidence interval: 1.58-2.21, P<0.05 for TT vs. TC+ CC).

CONCLUSION

This meta-analysis suggests that the -159C/T polymorphism in the CD14 gene contributes to tuberculosis susceptibility. To further investigate gene-gene and gene-environment interactions between this polymorphism and tuberculosis risk, more studies are needed.