Tumor necrosis factor alpha -308 gene locus promoter polymorphism: an analysis of association with health and disease

Susceptibility and Resistance to Canine Leishmaniose is Associated to Polymorphisms of the Canine TNF-α Gene

The prevalence of canine leishmaniosis (CanL) infection in an enzootic area is considerably higher than the overall prevalence of the disease, suggesting a role of host genetics related to the outcome of the disease. It is accepted that one determining factor for the outcome of CanL is the type of the triggered immune response, which seems to be genetically determined. TNF-α is a cytokine which plays a crucial role during the immune response against Leishmania parasites. In the present study a case-control study with 20 resistant and 20 susceptible dogs was performed. The distribution of breeds was equal in both groups. By Sanger method the nucleotide sequence upstream the Open Reading Frame of the canine TNF-α gene was determined and four polymorphisms were identified (−40 C/A, −1134 T/G, −1150 T/C κα −1243 C/G). Statistical analysis showed that the polymorphism TNF-α −40 C/A is correlated with susceptibility to CanL, while the polymorphism TNF-α −1243 C/G is correlated with resistance to CanL. Further statistical analysis, regarding the possible correlation of gender as well as clinical manifestations of the disease with the above-mentioned polymorphisms of the TNF-α gene, showed no significant findings. Further analysis of the above polymorphisms, as well as identification of more polymorphisms in candidate genes, is required to provide a better understanding of the complex underlying immune response in CanL.

Influence of tumour necrosis factor-α polymorphism-308 and atopy on irritant contact dermatitis in healthcare workers

BACKGROUND

Chronic irritant hand dermatitis is an issue for healthcare workers and may negatively impact infection control.

OBJECTIVES

We examined the effects of a G to A transition at position -308 on the tumour necrosis factor-α (TNF-α) gene on chronically damaged skin of healthcare workers during exposure and recovery from repetitive hand hygiene, after intensive treatment, and on the irritant response in normal skin.

PATIENTS/MATERIALS/METHODS

In 68 healthcare workers with irritant hand dermatitis, we genotyped TNF-α-308 and measured the epidermal response via quantitative digital imaging, erythema, dryness, and barrier integrity.

RESULTS

Excess hand erythema decreased with hand hygiene exposure and increased during time off for AA/GA genotypes, but had opposite effects for GG. AA/GA had smaller reductions in dryness with lotion treatment and larger reductions in excess erythema than GG. The atopic diathesis and heightened neurosensory irritation resulting from water and lactic acid significantly influenced the responses. Repeated exposure to water and sodium lauryl sulfate (0.05, 0.1%) produced higher erythema in normal skin for AA/GA than for GG.

CONCLUSIONS

This study provides evidence that the TNF-α polymorphism at -308 and an atopic history impact the severity of irritation and recovery from exposure and response to treatment for common hand skin products in both chronic irritant hand dermatitis and normal skin.

Carriage of a tumor necrosis factor polymorphism amplifies the cytotoxic T-lymphocyte antigen 4 attributed risk of primary biliary cirrhosis: evidence for a gene-gene interaction

Common genetic variants significantly influence complex diseases such as primary biliary cirrhosis (PBC). We recently reported an association between PBC and a single nucleotide polymorphism (rs231725) of the immunoreceptor gene cytotoxic T-lymphocyte antigen 4 (CTLA4). We hypothesized that PBC risk attributed to this polymorphism might be increased by propensity to an overly robust inflammatory response. Thus, we examined its potential interaction with the commonly studied -308AG promoter polymorphism (rs1800629) of the tumor necrosis factor (TNF) gene for which the variant TNF2A allele causes increased TNF production. The polymorphisms were genotyped in 866 PBC patients and 761 controls from independent US and Canadian registries; the effects of individual single nucleotide polymorphisms (SNPs) and their interaction on PBC risk was assessed by logistic regression. The reported association of PBC with the CTLA4 "A/A" genotype was replicated in the Canadian cohort and significant for PBC risk in the combined data (odds ratio [OR], 1.68; P = 0.0005). TNF2A allele frequency was elevated in PBC patients, but only reached borderline significance using the combined data (OR, 1.21; P = 0.042). Analysis showed that TNF2A carriage was significantly increased in CTLA4 "A/A" PBC patients compared with CTLA4 "A/A" controls (39.7% versus 16.5%, P = 0.0004); no apparent increase of TNF2A carriage was noted in CTLA4 "A/G" or "G/G" individuals. Finally, interaction under a logistic model was highly significant, as TNF2A carriage in combination with the CTLA4 "A/A" genotype was present in 6.5% of PBC patients, compared with 1.7% of controls (OR, 3.98; P < 0.0001).

CONCLUSION

TNF2A amplifies the CTLA4 rs231725 "A/A" genotype risk for PBC. Although the mechanisms remain unclear, the premise that deficiency in T-cell regulation resulting in an increased risk of PBC is amplified by overexpression of an important proinflammatory cytokine provides a basis for future functional studies.

TNFR 2 M196R polymorphism and acne vulgaris in Han Chinese: a case-control study

In this case-control study, the relationship between M196R (676 T-->G) variant in exon 6 of tumor necrosis factor receptor type 2 (TNFR2) gene and genetic susceptibility of acne vulgaris in Han Chinese was investigated. A total of 93 acne vulgaris patients and 90 healthy subjects from Han Chinese ethnic group were enrolled in this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was adopted to analyze the single nucleotide polymorphisms (SNPs) of TNFR2 M196R gene, and to examine the association between acne vulgaris and the polymorphisms in TNFR2 M196R gene. The relationship between different genotypes and the susceptibility of acne vulgaris was analyzed. The results showed that there was significant difference in the frequency of the genotype M/R+R/R in the TNFR2 M196R genetic polymorphisms between acne vulgaris patients and healthy controls (chi2=4.343; P=0.037; OR=1.899; 95% CI: 1.036-3.445); and there was significant difference in the allele (R) frequency between acne vulgaris patients and healthy controls (chi2=5.588; P=0.018; OR=1.838; 95% CI: 1.105-3.057). It was concluded that the high frequency of 196R allele in the functional M196R polymorphism of TNFR2 is a risk factor for acne vulgaris in Han Chinese.

Congenital toxoplasmosis: candidate host immune genes relevant for vertical transmission and pathogenesis

Toxoplasma gondii infects a variety of vertebrate hosts, including humans. Transplacental passage of the parasite leads to congenital toxoplasmosis. A primary infection during the first weeks of gestation causes vertical transmission at low rate, although it causes major damage to the embryo. Transmission frequency increases to near 80% by the end of pregnancy, but the proportion of ill newborns is low. For transmission and pathogenesis, the parasite genetics is certainly important. Several host innate and adaptative immune response genes are induced during infection in adults, which control the rapidly replicating tachyzoite. The T helper 1 (Th1) response is protective, although it has to be modulated to avoid inflammatory damage. Paradoxical observations on this response pattern in congenital toxoplasmosis have been reported, as it may be protective or deleterious, inducing sterile abortion or favoring parasite transplacental passage. Regarding pregnancy, an early Th1 microenvironment is important for control of infectious diseases and successful implantation, although it has to be regulated to support trophoblast survival. Polymorphism of genes involved in these parallel phenomena, such as Toll-like receptors (TLRs), adhesins, cytokines, chemokines or their receptors, immunoglobulins or Fc receptors (FcRs), might be important in susceptibility for T. gondii vertical transmission, abortion or fetal pathology. In this study some examples are presented and discussed.

Association of the TNF-{alpha}-C-857T polymorphism with resistance to the cholesterol-lowering effect of HMG-CoA reductase inhibitors in type 2 diabetic subjects

OBJECTIVE An association of the C-857T polymorphism of the tumor necrosis factor-alpha (TNF-alpha) gene promoter region with LDL cholesterol levels has been reported. This study was designed to evaluate the relationship between the TNF-alpha-C-857T polymorphism and LDL cholesterol levels according to statin treatment in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS DNA was obtained from 322 Japanese subjects (160 male and 162 female) with type 2 diabetes, and TNF-alpha-C-857T polymorphisms were determined by direct sequencing. Serum LDL cholesterol was measured by a direct method. RESULTS Although serum LDL cholesterol levels were significantly higher in the T carriers (C/T + T/T) than in the non-T carriers (C/C) (3.14 +/- 0.86 vs. 2.89 +/- 0.75 mmol/l, P < 0.05), there was no difference in LDL cholesterol levels between the non-T carriers and the T carriers in statin-untreated subjects (2.87 +/- 0.73 vs. 2.89 +/- 0.76 mmol/l, NS), whereas in statin-treated subjects, LDL cholesterol levels were significantly higher in the T carriers than in the non-T carriers (3.43 +/- 0.89 vs. 2.90 +/- 0.78 mmol/l, P = 0.0007). There were no differences in HDL cholesterol and triglyceride levels between the non-T carriers and the T carriers in both statin-treated and -untreated subjects. The percent decrease in LDL cholesterol levels after administration of statins was significantly smaller in the T carriers compared with the non-T carriers (27.6 vs. 36.4%, P = 0.031). CONCLUSIONS The mutant allele of the C-857T promoter polymorphism of the TNF-alpha gene may predispose to resistance to the LDL cholesterol-lowering effect of statins and could be one of the markers used to predict the efficacy of statins.

Genetic polymorphisms of matrix metalloproteinases and their inhibitors in potentially malignant and malignant lesions of the head and neck

Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases that are capable of cleaving all extra cellular matrix (ECM) substrates. Degradation of matrix is a key event in progression, invasion and metastasis of potentially malignant and malignant lesions of the head and neck. It might have an important polymorphic association at the promoter regions of several MMPs such as MMP-1 (-1607 1G/2G), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T) and TIMP-2 (-418 G/C or C/C). Tissue inhibitors of metalloproteinases (TIMPs) are naturally occurring inhibitors of MMPs, which inhibit the activity of MMPs and control the breakdown of ECM. Currently, many MMP inhibitors (MMPIs) are under development for treating different malignancies. Useful markers associated with molecular aggressiveness might have a role in prognostication of malignancies and to better recognize patient groups that need more antagonistic treatment options. Furthermore, the introduction of novel prognostic markers may also promote exclusively new treatment possibilities, and there is an obvious need to identify markers that could be used as selection criteria for novel therapies. The objective of this review is to discuss the molecular functions and polymorphic association of MMPs and TIMPs and the possible therapeutic aspects of these proteinases in potentially malignant and malignant head and neck lesions. So far, no promising drug target therapy has been developed for MMPs in the lesions of this region. In conclusion, further research is required for the development of their potential diagnostic and therapeutic possibilities.

Tumor necrosis factor alpha (TNF-alpha) polymorphisms in Chinese patients with Graves' disease

OBJECTIVES

Tumor necrosis factor alpha (TNF-alpha) may play a central role in the development of Graves' disease (GD). The aim of this study was to investigate the association of TNF-alpha polymorphisms with GD in Chinese population.

DESIGN AND METHODS

Genomic DNA was extracted from peripheral blood lymphocyte of 436 GD patients and 316 control subjects. TNF-alpha polymorphisms at positions -308 (G-308A, rs1800629), -238 (G-238A, rs361525), and +419 (G+419A, rs3093661) were genotyped.

RESULTS

The distribution of TNF-alpha -238 and +419 allelic frequencies between GD and control individuals was significantly different. Both the G alleles of TNF-alpha -238 (OR 2.385, 95%CI 1.359-4.184) and +419 (OR 2.293, 95%CI 1.303-4.035) SNPs conferred higher risk of GD as compared with A alleles. No significant difference of -308 allelic frequency was observed. Further haplotype analysis revealed that the haplotype GGG was associated with an increased risk of GD (OR 1.554, 95%CI 1.125-2.146), whereas the haplotype GAA was found to be protective (OR 0.419, 95%CI 0.239-0.736).

CONCLUSIONS

This study demonstrated the association of TNF-alpha gene with GD in Chinese patients.