Frequency distribution of cytokine gene polymorphisms in the healthy North Indian population

Distribution of 22 Single Nucleotide Polymorphisms in 13 Cytokine Genes in Malays, Chinese, and Indians in Peninsular Malaysia

Introduction: Cytokines are cell signaling glycoproteins that are particularly important in immunity and inflammatory responses. Therefore, variations, such as single nucleotide polymorphisms (SNPs), in genes encoding for cytokines may have important consequences for their roles in health. Materials and Methods: A total of 222 unrelated, healthy, and un-admixed Malays (n = 97), Chinese (n = 77), and Indians (n = 48) with a median age of 30 years old (range 21-50) were typed for 22 cytokine gene SNPs: IL-1α -889 T/C, IL-1β (-511 T/C, +3962 T/C), IL-1R pst1 1970 T/C, IL-1RA mspa1 11100 T/C, IL-4Rα +1902 G/A, IL-12 - 1188 C/A, IFN-γ +874 A/T, TGF-β (cdn 10 C/T, cdn 25 G/C), TNF-α (-308 A/G, -238 A/G) IL-2 (+166 G/T, -330 T/G), IL-4 (-1098 T/G, -590 T/C, -33 T/C), IL-6 (-174 C/G, nt565 G/A), and IL-10 (-1082 G/A, -819 C/T, -592 A/C). This involved using well-established polymerase chain reaction procedures with sequence-specific primers and restriction fragment length polymorphism methods. Results: The majority of the screened cytokine gene SNPs are polymorphic in all three ethnicities. Exceptions include TGF-β cdn 25 (G/C), IL-1β +3962 (T/C), and TNF-α -238 (A/G), which were all observed to be monomorphic in Malays, Chinese and Indians. Many of the analyzed cytokine gene SNP genotypes deviated from Hardy-Weinberg equilibrium and the three ethnic study groups were all well-separated from reference Asian, African and European populations in a principal component analysis plot. Conclusion: We successfully typed 22 SNPs in 13 cytokine genes from genetic material collected from unrelated and un-admixed Malay, Chinese and Indian individuals in Peninsular Malaysia. These new cytokine gene population datasets reveal interesting contrasts with other populations.

Clinical relevance of single nucleotide polymorphisms within the 13 cytokine genes in North Indian trauma hemorrhagic shock patients

INTRODUCTION

The susceptibility to adverse outcome from critical injury (occurrence of sepsis, septic shock, organ dysfunction/failure, and mortality) varies dramatically due to different degrees of inflammatory response. We assessed the relationship of the genotype distribution of various cytokine gene polymorphisms (CGP) with regard to the development of sepsis, organ dysfunction or mortality in severely injured patients.

METHOD

Observational, hospital-based cohort study of 114 severely injured North Indian patients from New Delhi admitted to the Emergency Department (ED) of Trauma Centre, AIIMS. Patients were monitored from day first to discharge or death, measuring SOFA score, sepsis and septic shock occurrences up to one month. We have analyzed 13 cytokine genes, including the SNPs of structural and regulatory regions at 22 positions.

RESULTS

Sequence-specific primer based PCR indicated that eight polymorphic loci IL-1α /-889, IL-1β/-511, IL-1R (pstI 1970), TGF-β/ code 10, TNF-α/-308, TNF-α/-238, IL-6/+565 and IL-10/-1082, out of 22 SNPs are significantly associated with sepsis morbidity and outcome. Theses SNPs might be used as risk determinants of the outcome. Patients with IL-10 (-1082A/A) genotypes were found significantly higher in post traumatic sepsis patients and had a significantly higher risk to developed sepsis complication (p < 0.05, OR = 0.86, C.I = 0.08-8.8).In case of TNF-α (-308) position, GA and GG genotype patients have a significantly lower risk of poor outcome (p < 0.05, OR = 0.25, C.I = 0.01-1.3) and (p < 0.05, OR = 0.22, C.I = 0.01-0.5) in comparison to AA genotype. In this study, two polymorphisms (IL-1β (-511) and IL-1R) were significantly associated with the development of MOF and mortality, where as IL-1α (-889) polymorphism associated with susceptibility for sepsis. The distribution of haplotypes of TGF-β and IL-6 were also associated with sepsis susceptibility and outcome.

CONCLUSION

In conclusion, we have found that the alternations in the genotype and allele frequency of IL-1β (-511C/T), TNF-α (-308 G/A), TNF-α (-238 G/A) and IL-10 (-1082 G/A) genes are associated with an higher risk of sepsis development in trauma patients and outcomes.

Distribution of cytokine gene single nucleotide polymorphisms among a multi-ethnic Iranian population

Background:

Cytokine gene single nucleotide polymorphisms (SNPs) are widely used to study susceptibility to complex diseases and as a tool for anthropological studies.

Materials and Methods:

To investigate cytokine SNPs in an Iranian multi-ethnic population, we have investigated 10 interleukin (IL) SNPs (IL-1β (C-511T, T-31C), IL-2 (G-384T), IL-4 (C-590T), IL-6 (G-174C), IL-8 (T-251A), IL-10 (G-1082A, C-819T, C-592A) and tumor necrosis factor-alpha (TNF-α) (G-308A) in 415 Iranian subjects comprising of 6 different ethnicities. Allelic and genotypic frequencies as well as Hardy-Weinberg equilibrium (HWE) were calculated by PyPop software. Population genetic indices including observed heterozygosity (H_o), expected heterozygosity (H_e), fixation index (F_IS), the effective number of alleles (N_e) and polymorphism information content (PIC) were derived using Popgene 32 software. Multidimensional scaling (MDS) was constructed using Reynold's genetic distance obtained from the frequencies of cytokine gene polymorphism.

Results:

Genotypic distributions were consistent with the HWE assumptions, except for 3 loci (IL-4-590, IL-8-251 and IL-10-819) in Fars and 4 loci (IL-4-590, IL-6-174, IL-10-1082 and TNF-α-308) in Turks. Pairwise assessment of allelic frequencies, detected differences at the IL-4-590 locus in Gilakis versus Kurds (P = 0.028) and Lurs (P = 0.022). Mazanis and Gilakis displayed the highest (H_o= 0.50 ± 0.24) and lowest (H_o= 0.34 ± 0.16) mean observed heterozygosity, respectively.

Conclusions:

MDS analysis of our study population, in comparison with others, revealed that Iranian ethnicities except Kurds and Mazanis were tightly located within a single cluster with closest genetic affinity to Europeans.

Polymorphisms in the IFNγ, IL-10, and TGFβ genes may be associated with HIV-1 infection

OBJECTIVE

This study investigated possible associations between the TNFα-308G/A, IFN+874A/T, IL-6-174C/G, IL-10-1082A/G, and TGFβ-509C/T polymorphisms with HIV-1 infection, in addition to correlation of the polymorphisms with clinical markers of AIDS progression, such as levels of CD4+/CD8+ T lymphocytes and plasma viral load.

METHODS

A total of 216 individuals who were infected with HIV-1 and on antiretroviral therapy (ART) and 294 individuals from the uninfected control group were analyzed.

RESULTS

All individuals evaluated were negative for total anti-HBc, anti-HCV, anti-T. pallidum, and anti-HTLV-1/2. The polymorphisms were identified by PCR-RFLP. Individuals presenting the IFN+874A allele as well as the AA genotype were more frequent in the HIV-1 infected group compared to the control group (P < 0.05), in addition to having lower levels of CD4+ T lymphocytes. The CD8+ T lymphocytes count was significantly lower in individuals with the IL-10-1082 GG genotype. The TGFβ-509TT genotype was associated with higher plasma viral load.

CONCLUSIONS

The results suggest that the presence of the IFN+874A allele confers susceptibility to HIV-1 infection and a decrease in the number of CD4+ T lymphocytes. In addition, the genotype associated with high serum levels of TGFβ may be associated with an increase in plasma viral load.

Single nucleotide polymorphic macrophage cytokine regulation by Mycobacterium tuberculosis and drug treatment

Aim: To investigate the survival of Mycobacterium tuberculosis in primary macrophages with SNPs affecting cytokine secretion under treatment with drugs in solution or microparticles. Materials & methods: Volunteers were typed for TNF (-308G/A), IL-10 (-1082A/G) and IL-4 (-590C/T). Monocyte-derived macrophages (MDMs) were infected in vitro. Cytokine secretion and survival of intracellular bacilli were estimated. Results: IL-10 AG associated with high secretion in uninfected and infected MDMs (p < 0.05) and was reduced more effectively by microparticles than drugs, irrespective of genotype (p < 0.05). Differences were observed between IL-4 secretion by MDMs of CC and TT genotypes (p = 0.1). Bacteria proliferated more in MDMs from volunteers with higher IL-4 levels (p = 0.05). Microparticles showed higher efficacy (p = 0.05) than drugs. Conclusion: IL-4 and IL-10 SNPs affect the ability of macrophages to counter infection with M. tuberculosis. Microparticles elicit favorable macrophage cytokines regardless of SNPs.

Original submitted 5 August 2013; Revision submitted 27 November 2013

Effect of IL-12B, IL-2, TGF-β1, and IL-4 polymorphism and expression on hepatitis B progression

The hepatitis B virus (HBV) infection-induced chronic inflammation is considered to be the major etiological factor for HBV-related disease chronicity. Cytokines act as the key coordinators of the inflammatory responses involved in HBV disease pathogenesis. The present study assessed association among IL-12B(+1188), IL-2(-330), TGF-β1(-509), and IL-4(-590) genotypes; mRNA; and protein levels with HBV-hepatocellular carcinoma (HCC) risk in India. For this, 403 subjects (153 controls, 67 inactive HBV-carriers, 62 chronic-active HBV patients, 62 HBV-cirrhotics, and 59 HBV-HCC ssubjects) were enrolled in the study. The genotyping was carried by polymerase chain reaction (PCR)-restriction fragment length polymorphism (IL-12+1188A/C, IL-2-330T/G, and TGF-β1-509C/T), and allele specific (AS)-polymerase chain reaction (IL-4-590C/T). Enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction methods were used for assessing protein and the mRNA expression, respectively, of the mentioned cytokines. The study revealed that the IL-12B(+1188) CC genotype shared a significant positive association with hepatitis, among controls. While, in the case of IL-2(-330), both the TG and GG genotypes were not significantly associated with HCC risk. The TGF-β1(-509) TT genotype acted as a potential protective factor for cirrhosis and the HCC risk, among carriers. On the contrary, the IL-4(-590) CT genotype was found to be a vital protective factor for the development of hepatitis, among carriers. Besides, IL-12B, TGF-β1, and IL-2 seem to be majorly involved in the development of HCC, while, IL-4 might be responsible for the progression of the HBV disease till cirrhosis development. These initial findings are indicative of the vital role of genotypes and/or levels of IL-12B, IL-2, IL-4, and TGF-β1 in HBV disease chronicity in Indian population.

Opposing effects of pro- and anti-inflammatory cytokine gene polymorphisms on the risk for breast cancer in western Indian women: a pilot study

In an earlier study, the genotypes associated with higher level of transforming growth factor-β1 (TGF-β1) were found to reduce the risk for breast cancer in western Indian women. This observation implied that gene polymorphisms affecting the levels of pro- and anti-inflammatory cytokines may influence the risk for breast cancer in this population. Hence, we performed genotyping for three more functional single-nucleotide polymorphisms (SNPs) responsible for variations in the levels of cytokines associated with inflammation. To that effect, polymorphisms in genes coding for IL-4 (IL-4 C-590T; rs2243250), IFN-γ (IFN-G A + 874T; rs2430561) and MCP-1 (MCP-1 A-2578G; rs1024611) were examined in premenopausal, healthy women (N = 239) and patients with breast cancer (N = 182) from western India. In carriers of the IL-4*590T allele, a reduced risk for the disease (dominant model; OR = 0.61, 95% CI 0.37-0.98) was seen similar to that seen in TGF-B1*10C carriers. An opposite trend was observed with respect to the alleles associated with higher expression of MCP-1 or IFN-γ. In individuals positive for three or more alleles associated with higher levels of either pro- or anti-inflammatory cytokines, an additive effect on the modulation of risk for the disease was evident (for TGF-B1 & IL-4, OR = 0.33, 95% CI 0.12-0.87; for IFN-G & MCP-1, OR = 2.29, 95% CI 0.95-5.51). In the context of contrasting observations in other populations, these results indicate a significant contribution of anti-inflammatory genotypes in the modulation of risk for breast cancer in western Indian women.

IFN-γ (+874) and not TNF-α (-308) is associated with HBV-HCC risk in India

Tumor necrosis factor (TNF)-α and interferon (IFN)-γ, the pro-inflammatory Th1 cytokines are the indispensable coordinators of the inflammatory responses involved in hepatitis B virus (HBV) pathogenesis. This study attempted to evaluate any possible association among TNF-α (-308G>A) and IFN-γ (+874T/A) genotypes, the spontaneous blood and mRNA levels and expression of their major signal transducers, namely STAT1 and NF-кB with hepatitis B virus-induced hepatocellular carcinoma (HCC) susceptibility in India. For this, 398 subjects (146 controls, 68 inactive-HBV-carriers, 64 chronic-active HBV patients, 61 HBV-cirrhotics, and 59 HBV-HCC subjects) were enrolled. Polymerase chain reaction-restriction fragment length polymorphism, allele-specific PCR, enzyme-linked immunosorbent assay, reverse transcriptase-PCR, and Western blot analysis were done for assessing polymorphism, blood levels, mRNA expression, and protein expression of signal transducers, respectively, of TNF-α and IFN-γ. The study revealed no significant association of TNF-α (-308) GA genotype, while a significant negative association of IFN-γ (+874) TA and AA genotypes, in HBV-HCC risk. Moreover, blood levels of TNF-α were significantly elevated as disease progresses to HCC, while IFN-γ levels were raised in HCC patients only. Besides, IFN-γ mRNA levels were significantly elevated in cirrhotics, with no change observed in TNF-α transcript levels. Moreover, NF-кB expression also consistently increased during HCC progression. These observations suggest a vital negative association of IFN-γ (+874) with HBV-HCC risk, with no significant association evident in TNF-α (-308). However, the TNF-α and IFN-γ levels markedly increased in HCC development.

Interleukin-12 gene polymorphism and cervical cancer risk

AIM

: To investigate the effect of interleukin-12 p40 gene (IL-12β) 3'-untranslated region polymorphism on the risk of cervical cancer.

METHODS

DNA was isolated from peripheral blood of 200 patients with cervical cancer and 200 healthy controls. Polymerase chain reaction restriction fragment length polymorphism was used for the detection of IL-12β (1188A/C) gene polymorphism.

RESULTS

It was observed that genotypes AC [odds ratio (OR) = 1.80, 95% confidence interval (CI) = 1.17-2.78] and AC + CC (OR = 1.71, 95% CI = 1.11-2.63, P = 0.01) increase the risk of cervical cancer. The strength of the risk in passive smokers with AC and AC + CC genotypes was increased to more than 2.8 times in comparison with a nonsmoker with AA genotype (OR = 2.94, 95% CI = 1.56-5.55, P < 0.001; OR = 2.83, 95% CI = 1.52-5.31, P < 0.001, respectively).

CONCLUSION

This is the first study to provide an evidence for the association of IL-12β (1188A/C) gene polymorphism with the risk of cervical cancer.

Interleukin-1 polymorphism and expression in hepatitis B virus-mediated disease outcome in India

The present study evaluated any possible association among Interleukin-1-beta (IL-1B)-511 and IL-1 receptor antagonist (IL-1RN) variable number tandem-repeat (VNTR) genotypes, haplotypes, and IL-1B expression with risk for hepatitis B virus-related hepatocellular carcinoma (HBV-HCC) development in India. For this, 406 subjects (153 controls, 67 inactive HBV-carriers, 65 patients with chronic-active HBV, 62 HBV-cirrhotics, and 59 subjects with HBV-HCC) were enrolled in the study. Polymerase chain reaction (PCR)-restriction fragment length polymorphism, reverse transcriptase-PCR, and enzyme-linked immunosorbent assay methods were used for assessing polymorphism, mRNA, and protein levels, respectively, of IL-1. The study revealed no significant association of IL-1B(-511) CT and TT genotypes, while a significant positive association of the IL-1RN (VNTR) 1/2 genotype with HCC development, among controls and carriers. Besides, 2/2 genotypes acted as a potential risk factor for hepatitis and subsequent cirrhosis development, among the same groups. Furthermore, the IL-1 haplotypes 2 and 3 were found to be significant protective factors for hepatitis and subsequent HCC development, among controls. However, haplotype 4 shared a significant negative association with hepatitis only. Moreover, proinflammatory IL-1B levels significantly and steadily elevated with the disease progression to HCC, as compared to controls. These preliminary findings indicate a key role of IL-1 in the HBV-mediated disease chronicity, in the Indian population.

Cytokine gene polymorphisms: methods of detection and biological significance

In recent years, several functional polymorphisms, particularly, SNPs have been identified in cytokines and their receptor genes that regulate levels of cytokine expression. These have been implicated as immune prognostic markers in diseases, including differential response to therapy and as biomarkers of graft outcome following organ and stem cell transplantation. Population distribution of cytokine gene polymorphisms (CGPs) reveals significant variations in allele frequencies in different ethnic groups and this might explain, to some extent, the observed differences in SNP associations with various diseases and immune-pathologies. A number of molecular methods are available for defining CGPs. These include PCR-SSP, AFLP, Taqman probe assays as well as sequencing based typing. Of these, the PCR-based sequence-specific primer based test is the most widely accepted technique. This chapter describes steps involved in this procedure along with sources for procuring essential reagents. An important aspect of CGP analyses is the correct interpretation of results particularly determination of their multilocus haplotypes.

Genetic correlates influencing immunopathogenesis of HIV infection

Variability to HIV infection, its progression as well as responsiveness to antiretroviral therapy (ART) is observed among individuals including viraemia controllers or exposed uninfected, rapid versus slow progressors and ART responders compared to non responders. This differential responsiveness/vulnerability to HIV-1 is governed by multiple host genetic factors that include HLA, cytokines, chemokines, their receptors and others. This review highlights the influence of these genetic factors on HIV/AIDS outcome; however, in India, the information in this area is very limited and most of these genetic studies have been conducted in Caucasian and South African populations. Considering, the population specific differences in the frequencies of protective or susceptibility favouring alleles and their influence on the disease outcome, it is of utmost importance to strengthen ongoing efforts towards defining largely unknown genetic propensity in Indian population, particularly by recruitment of large cohorts of well categorized exposed uninfected individuals, rapid, long term non progressors and elite viraemic controllers. Multi-parametric analysis of these potentially interactive immunogenetic variables in these cohorts may help to define potential targets for diagnostics and therapy in a population specific manner.

Tumor necrosis factor-associated susceptibility to type 1 diabetes is caused by linkage disequilibrium with HLA-DR3 haplotypes

Tumor necrosis factor-α (TNF-α) is an important proinflammatory cytokine involved in the pathogenesis of autoimmune type 1 diabetes (T1D). The TNF gene locus is located in the major histocompatibility complex (MHC) class III region and its genetic polymorphisms have been reported to be associated with T1D. However, it is not clear whether these associations are primary or caused by their linkage disequilibrium with other predisposing genes within the MHC. We have tested 2 TNF-α single nucleotide polymorphisms at positions -308G/A and -238G/A in the 5' untranslated region and a (GT)n microsatellite TNFa in the North Indian healthy population and T1D patients with known HLA-A-B-DR-DQ haplotypes. The allele frequencies of TNFa5, -308A, and -238G were determined to be significantly increased among patients compared with controls. Although the observed positive association of -238G was caused by its presence on all 3 DR3(+) groups, namely, B8-DR3-DQ2, B50-DR3-DQ2, and B58-DR3-DQ2 haplotypes associated with T1D in this population, the increase of the -308A allele was caused by its association with the latter 2 haplotypes. On the other hand, TNF -308G occurred on B8-DR3 haplotypes along with -238G and TNFa5 alleles, particularly in T1D patients with late disease onset (at >20 years of age). These results indicate that TNF associations with T1D are caused by their linkage disequilibrium with specific HLA-DR3-DQ2 haplotypes in the Indian population. Because polymorphisms in the promoter region regulate TNF expression levels (e.g., -308A), they retain crucial immunological significance in the development of T1D and its management.

IL1 gene polymorphisms in enthesitis related arthritis category of juvenile idiopathic arthritis (ERA-JIA)

Cytokine gene loci are one of the potential susceptibility factors in immuno-inflammatory diseases. Interleukin1 (IL-1) is a major monocyte derived proinflammatory cytokine that mediates tissue damage and cartilage loss in chronic arthritis. IL-1 locus has been linked to various autoimmune diseases, but data on juvenile idiopathic arthritis (JIA) is limited. Ninety-four patients with enthesitis related arthritis (ERA) category of JIA (ILAR criteria) were included in the study. One hundred eighty-five healthy blood donors were used as controls. IL-1Ra VNTR polymorphism was done by PCR using specific primers, and allele assignment was done on product size obtained on 2% agarose gel. IL-1α-889 and IL-β-511 polymorphism was done using PCR-RFLP method. Among 94 patients, 87 were males, and the mean age at onset of disease was 11.8 + 1.8 years; 17 had history of uveitis, and 13 had positive family history. Forty-two had enthesitis, and 51 had inflammatory back pain; all had arthritis. Seventy-six were HLA B27 positive. All three loci genotypes were in the Hardy-Weinberg equilibrium in controls. There was no difference in genotype frequency among patients and controls for IL-1Ra, IL-1α-889 and IL-β-511. IL1*RN2 homozygosity was more common in patients, whereas carriage rate for IL1*RN1 was less frequent in patients. Haplotype frequencies were also similar in both groups. IL-1 gene cluster is not a susceptibility locus for ERA.

Transforming growth factor β signaling pathway associated gene polymorphisms may explain lower breast cancer risk in western Indian women

Transforming growth factor β1 (TGFB1) T29C and TGF β receptor type 1 (TGFBR1) 6A/9A polymorphisms have been implicated in the modulation of risk for breast cancer in Caucasian women. We analyzed these polymorphisms and combinations of their genotypes, in pre menopausal breast cancer patients (N = 182) and healthy women (N = 236) from western India as well as in breast cancer patients and healthy women from the Parsi community (N = 48 & 171, respectively). Western Indian women were characterized by a higher frequency of TGFB1*C allele of the TGF β T29C polymorphism (0.48 vs 0.44) and a significantly lower frequency of TGFBR1*6A allele of the TGFBR1 6A/9A polymorphism (0.02 vs 0.068, p<0.01) as compared to healthy Parsi women. A strong protective effect of TGFB1*29C allele was seen in younger western Indian women (<40 yrs; OR = 0.45, 95% CI 0.25-0.81). Compared to healthy women, the strikingly higher frequencies of low or intermediate TGF β signalers in patients suggested a strong influence of the combination of these genotypes on the risk for breast cancer in Parsi women (for intermediate signalers, OR = 4.47 95%CI 1.01-19.69). The frequency of low signalers in Parsi healthy women, while comparable to that reported in Europeans and Americans, was three times higher than that in healthy women from western India (10.6% vs 3.3%, p<0.01). These observations, in conjunction with the low incidence rate of breast cancer in Indian women compared to White women, raise a possibility that the higher frequency of TGFB1*29C allele and lower frequency of TGFBR1*6A allele may represent important genetic determinants that together contribute to a lower risk of breast cancer in western Indian women.

Genetic determinants of HIV-1 infection and progression to AIDS: immune response genes

Genomic studies involving well-defined multicenter cohorts of HIV-1/AIDS covering multiple populations have led to a greater understanding of the role of host determinants in viral acquisition, disease progression, transmission, and response to anti-retroviral therapy. Similarly, recent knowledge on the virus genetic diversity has helped in elucidating mechanisms leading to the evolution of viral escape mutants and the role played by host immune determinants, in particular the major histocompatibility complex (MHC) associated genes. At least two alleles, HLA-B*27 and B*57, have been identified as 'protective' against HIV-1 while B*35 and B*53 act as susceptibility favoring factors. How human leukocyte antigen (HLA)-mediated selection drives the evolution of HIV-1 and which circulating variants are more likely to evade immune surveillance of the population are now beginning to become clear. Importantly, the rare HLA alleles in a population bear a selective advantage to the host because these can induce immune responses against pre-adapted viruses. It is conceivable that previously established protective HLA associations are shifting with the evolving cytotoxic T lymphocyte (CTL) epitopes and may not remain protective in future. At the same time, this process is unraveling novel sub-dominant epitopes of the virus which could now be incorporated as the dominant target CTL epitopes. An insight into the population-specific correlates of protection is hence necessary for designing future anti-HIV therapeutic and/or prophylactic vaccine formulation(s).

Functional gene polymorphisms in canadian aboriginal populations with high rates of tuberculosis

The present study determined whether a pattern of functional single-nucleotide polymorphisms (SNPs) was present that could predispose a Dené cohort to a suboptimal response to Mycobacterium tuberculosis. Compared with a Caucasian cohort, the Dené and Cree were found to maintain a significantly higher frequency of SNPs associated with low expression of vitamin D receptor (VDR), interferon (IFN)-gamma (+874), and tumor necrosis factor-alpha (-308) and high production of monocyte chemoattractant protein (MCP)-1 (-2518) and interleukin (IL)-6 (-174). Given the roles played by IFN-gamma and VDR in facilitating macrophage containment of M. tuberculosis and the opposing role of MCP-1 and IL-6, the observed allelic variation by ethnicity may in part contribute to the high rates of tuberculosis among the Dené.

Genetic association of IL-10 gene promoter polymorphism and HIV-1 infection in North Indians

INTRODUCTION

Cytokines play a significant role in host immune defense. IL-10 is an anti-inflammatory, immunomodulatory cytokine that can both stimulate and suppress the immune response and inhibits HIV-1 replication in vivo. Interindividual variations in IL-10 production were genetically contributed to polymorphisms within IL-10 promoter region.

AIMS

The aim of this study was to investigate the association of IL-10 gene promoter -1082 G/A, -819 C/T, and 592 C/A polymorphism on HIV-1 transmission /progression in North Indian individuals.

PATIENTS AND METHODS

A total of 180 HIV-1 seropositive (HSP) stratified on the basis of disease severity (stage I, II, and III), 50 HIV-1 exposed seronegative (HES) and 305 HIV-1 seronegative (HSN) individuals were genotyped for IL-10 gene promoter by polymerase chain reaction-restriction fragment length polymorphism. A suggestive evidence of association was obtained for IL-10 592 C/A promoter polymorphism at the level of allele and genotype distribution. The frequency of IL-10 592 A allele and genotype was significantly increased in HSP compared to HSN (p = 0.013; OR = 1.412 and p = 0.034; OR = 1.685 respectively). Further comparison in between different clinical stages of HIV-1 infected patients of IL-10 592 A allele and genotype revealed a significant increase in its frequency in the stage III compared with those together in stage I (p = 0.004, OR = 2.181 and p = 0.002, OR = 4.156, respectively). This study reports for the first time that IL-10 gene promoter 592 C/A polymorphism may be a risk factor for HIV-1 transmission/progression in HIV-1 infected North Indian individuals.

Distribution of CCR2 polymorphism in HIV-1-infected and healthy subjects in North India

Substitution of V64I in CCR2 relates to delayed progression to AIDS and protects against HIV-1 infection. We examined the distribution of V64I in HIV-infected and healthy North Indian subjects. No significant difference in the allele or genotype distribution of CCR2 V64I polymorphism was observed, indicating that there is no association between CCR2 V64I polymorphism and susceptibility to HIV infection in North Indian population.