Impact of genetic variations in C-C chemokine receptors and ligands on infectious diseases

The effect of TRIM5 variants on the susceptibility to HIV-1 infection and disease progression in the Polish population

BACKGROUD

Tripartite motif containing 5α protein is a factor contributing to intracellular defense mechanisms against human immunodeficiency virus-1 (HIV-1) infection. The studies of TRIM5 variants effects on the risk of HIV-1 infection and the clinical course of disease provided inconclusive results in different ethnic groups. The aim of this study was to investigate the influence of TRIM5 variants on susceptibility to HIV-1 infection and clinical parameters among Polish HIV-1-infected patients.

MATERIALS & METHODS

In our study, we investigated 301 HIV-1-infected patients and 186 age-matched seronegative controls. Seven variants of the TRIM5 gene (rs7127617, rs3824949, rs3740996, rs11601507, rs10838525, rs11038628, and rs28381981) were genotyped using both sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques.

RESULTS AND CONCLUSIONS

The frequencies of rs7127617 TT genotype and T allele occurrence were lower in HIV-1-infected subjects compared to controls (0.14 vs. 0.26 for T/T genotype and 0.45 vs. 0.54 for T allele), suggesting their possible protective effect (p = 0.005 and p = 0.007, respectively). Heterozygosity and presence of the T allele at rs3740996 were enriched in controls compared to HIV-1-infected group (0.19 vs. 0.12 for C/T genotype and 0.11 vs. 0.07 for T allele; p = 0.03 and p = 0.02, respectively). Moreover, rs3824949 CC genotype carriers had a lower viral load than patients bearing rs3824949 GG/CG genotypes (4.0 vs. 4.6 log copies/mL; p = 0.049); however, none of the variants affected CD4+ cell count. In conclusion, our data confirm the role of TRIM5 variants in the HIV-1 transmission and the clinical course of HIV-1 infection. The presence of rs7127617 TT genotype and T allele seems to protect against HIV-1 transmission in examined population.

The impact of pulmonary tuberculosis on immunological and metabolic features of diabetic patients

Impaired immune responses have been observed in patients with type-2 diabetes mellitus (T2DM), which increases susceptibility to tuberculosis infection. However, the effect of the tuberculosis infection on the immunological and metabolic features of T2DM is largely unknown. To investigate this question, age- and sex-matched patients with pulmonary tuberculosis (PTB), T2DM, or T2DM combined with PTB were recruited from the Infectious Disease Hospital of Heilongjiang Province between January and September 2020. Healthy subjects were used as controls. Cytokines and chemokines in fasting serum samples were determined using the Quantibody Inflammation Array. Compared with T2DM alone, patients with T2DM combined with PTB have higher fasting blood glucose levels and monocyte counts in circulation. Among the four groups, circulating IL-10 levels peaked in patients with T2DM and PTB (p<0.05). Univariate linear analysis showed that serum IL-10 levels were positively associated with myeloid cells but negatively correlated with lymphocyte counts in these patients (p<0.05). Serum IL-6 levels were 1.6-fold higher in patients with T2DM plus PTB than in those with T2DM alone. In conclusion, PTB infection in patients with T2DM had distinct inflammatory profiles and sustained hyperglycaemia compared with PTB or T2DM alone. IL-10 levels and elevated monocyte counts could be hallmarks of patients with T2DM infected with PTB.

Transcriptome Profile During Rabies Virus Infection: Identification of Human CXCL16 as a Potential New Viral Target

Rabies virus (RABV), the causative agent for rabies disease is still presenting a major public health concern causing approximately 60,000 deaths annually. This neurotropic virus (genus Lyssavirus, family Rhabdoviridae) induces an acute and almost always fatal form of encephalomyelitis in humans. Despite the lethal consequences associated with clinical symptoms of rabies, RABV limits neuro-inflammation without causing major histopathological lesions in humans. Nevertheless, information about the mechanisms of infection and cellular response in the central nervous system (CNS) remain scarce. Here, we investigated the expression of inflammatory genes involved in immune response to RABV (dog-adapted strain Tha) in mice, the most common animal model used to study rabies. To better elucidate the pathophysiological mechanisms during natural RABV infection, we compared the inflammatory transcriptome profile observed at the late stage of infection in the mouse brain (cortex and brain stem/cerebellum) with the ortholog gene expression in post-mortem brain biopsies of rabid patients. Our data indicate that the inflammatory response associated with rabies is more pronounced in the murine brain compared to the human brain. In contrast to murine transcription profiles, we identified CXC motif chemokine ligand 16 (CXCL16) as the only significant differentially expressed gene in post-mortem brains of rabid patients. This result was confirmed in vitro, in which Tha suppressed interferon alpha (IFN-α)-induced CXCL16 expression in human CNS cell lines but induced CXCL16 expression in IFN-α-stimulated murine astrocytes. We hypothesize that RABV-induced modulation of the CXCL16 pathway in the brain possibly affects neurotransmission, natural killer (NK) and T cell recruitment and activation. Overall, we show species-specific differences in the inflammatory response of the brain, highlighted the importance of understanding the potential limitations of extrapolating data from animal models to humans.

Chagas disease: Immunology of the disease at a glance

Chagas disease is an important neglected disease that affects 6-7 million people worldwide. The disease has two phases: acute and chronic, in which there are different clinical symptoms. Controlling the infection depends on innate and acquired immune responses, which are activated during the initial infection and are critical for host survival. Furthermore, the immune system plays an important role in the therapeutic success. Here we summarize the importance of the immune system cytokines in the pathology outcome, as well as in the treatment.

Quantile-specific heritability of monocyte chemoattractant protein-1, and relevance to rs1024611-disease interactions

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) concentrations are 34% to 47% heritable. Larger -2518 G/A (rs1024611) genotypes differences are reported for: 1) MCP-1 production in stimulated vs. basal cells; and 2) MCP-1 concentrations in diseased (sepsis, brain abscess, hepatitis B virus, Alzheimer's disease, Behcet's disease, and systemic lupus erythematosus) vs. healthy patients. Those results suggest that the -2518 G/A effect size may depend on whether the phenotype is high or low relative to its distribution (quantile-dependent expressivity).

METHOD

To test whether quantile-dependent expressivity applies more broadly to genetic influences on MCP-1 concentrations, quantile-specific offspring-parent (β_OP) and full-sib regression slopes (β_FS) were estimated by applying quantile regression to the age- and sex-adjusted serum MCP-1 concentrations of Framingham Heart Study families. Quantile-specific heritabilities were calculated as h² = 2β_OP/(1 + r_spouse) and h²={(1 + 8r_spouseβ_FS)^0.5-1}/(2r_spouse)).

RESULTS

Heritability (h² ± SE) of MCP-1 concentrations increased from 0.15 ± 0.05 at the 10th percentile of the MCP-1 distribution, 0.23 ± 0.04 at the 25th, 0.32 ± 0.05 at the 50th, 0.43 ± 0.07 at the 75th, and 0.44 ± 0.07 at the 90th percentile, or an 0.0041 ± 0.0009 increase for each one-percent increment in the MCP-1 distribution (P_{linear trend} = 2.4 × 10^-5) when estimated from β_OP, and (P_{linear trend} = 7.7 × 10^-9) when estimated from β_FS. Compared to the 10th percentile, β_OP-estimated h² was 3-fold greater at the 90th percentile (P_difference = 0.0003), and 6.9-fold greater when estimated from β_FS (P_difference = 3.3 × 10^-6). Re-analysis of in vivo comparison of MCP-1 concentrations in controls vs. patients with MCP-1-elevating conditions, and in vitro studies of MCP-1 production in basal vs. stimulated cells, show rs1024611 genotypes differences that were consistent with quantile-dependent expressivity.

CONCLUSION

The heritability of circulating MCP-1 concentrations is quantile-dependent.

Deficiency in CCR2 increases susceptibility of mice to infection with an intracellular pathogen, Francisella tularensis LVS, but does not impair development of protective immunity

CCR2 is the major chemokine receptor that regulates appropriate trafficking of inflammatory monocytes, but the role of this chemokine receptor and its ligands during primary and secondary infection with intracellular infections remains incompletely understood. Here we used murine infection with the Live Vaccine Strain (LVS) of Francisella tularensis to evaluate the role of CCR2 during primary and secondary parenteral responses to this prototype intracellular bacterium. We find that mice deficient in CCR2 are highly compromised in their ability to survive intradermal infection with LVS, indicating the importance of this receptor during primary parenteral responses. Interestingly, this defect could not be readily attributed to the activities of the known murine CCR2 ligands MCP-1/CCL2, MCP-3/CCL7, or MCP-5/CCL12. Nonetheless, CCR2 knockout mice vaccinated by infection with low doses of LVS generated optimal T cell responses that controlled the intramacrophage replication of Francisella, and LVS-immune CCR2 knockout mice survived maximal lethal Francisella challenge. Thus, fully protective adaptive immune memory responses to this intracellular bacterium can be readily generated in the absence of CCR2.

Effect of human breast milk on innate immune response: Up-regulation of bacterial pattern recognition receptors and innate cytokines in THP-1 monocytic cells

Human breast milk (HBM) contains many bioactive components that protect infants from various microorganisms. Pattern recognition receptors on phagocytic cells recognize microbial pathogens and promote the innate immune system. This study aimed to evaluate the effect of HBM on the expression of pattern recognition receptors and innate cytokines in the monocytic cell line THP-1 and the phagocytic activity of RAW264.7 macrophages. Expression levels of specific mRNAs in THP-1 cells were quantitated using reverse transcription-polymerase chain reaction. Phagocytic activity was measured by fluorescence microscopy to detect the uptake of fluorescent dye-labeled carboxylate-modified polystyrene latex beads in RAW264.7 macrophages. HBM stimulated the phagocytic activity of RAW264.7 macrophages. HBM increased mRNA expression of pattern recognition receptors, including the cluster of differentiation 14 and toll-like receptor 2 and 4, and various innate cytokines, including tumor necrosis factor α, interleukin-1β, C-X-C motif chemokine 8, and C-C motif chemokine ligand 2, in THP-1 monocytic cells. Furthermore, milk oligosaccharides in HBM, such as lacto- N-fucopentaose I, enhanced the expression of pattern recognition receptors and various innate cytokines. HBM is able to modulate the innate immune response by upregulating the expression of pattern recognition receptors and various innate cytokines in monocytes/macrophages.

Chemokine receptor gene polymorphisms and COVID-19: Could knowledge gained from HIV/AIDS be important?

Emerging results indicate that an uncontrolled host immune response, leading to a life-threatening condition called cytokine release syndrome (also termed "cytokine storm"), is the major driver of pathology in severe COVID-19. In this pandemic, considerable effort is being focused on identifying host genomic factors that increase susceptibility or resistance to the complications of COVID-19 and translating these findings to improved patient care. In this regard, the chemokine receptor-ligand nexus has been reported as potentially important in severe COVID-19 disease pathogenesis and its treatment. Valuable genomic insights into the chemokine receptor-ligand nexus have been gained from HIV infection and disease progression studies. Applying that knowledge, together with newly discovered potential host genomic factors associated with COVID-19, may lead to a more comprehensive understanding of the pathogenesis and treatment outcomes in COVID-19 patients.

Association between Monocyte Chemoattractant Protein-1 -2518 (A/G) Single Nucleotide Polymorphism and Chronic Periodontitis in End-stage Renal Disease Patients - A Case-control Study

Monocyte chemoattractant protein 1 (MCP-1) plays an important role in the development of periodontitis. The purpose of this investigation was to evaluate association of the  MCP-1 gene polymorphism with chronic periodontitis in patients with end-stage renal disease (ESRD). One hundred fifty ESRD patients with chronic periodontitis (CP), 100 without CP and 190 healthy controls were included in this study. Genomic DNA from all participants was genotyped for the -2518 (A/G) polymorphism by a polymerase chain reaction - restriction fragment length polymorphism (PCR--RFLP) assay. Significant differences were observed in the genotype and allele frequencies between patients with ESRD and CP and controls.  The G allele frequency was significantly higher in patients than in control subjects, with odds ratio 1.77 (95 % CI 1.2-2.5), p = 0.0014. For the GG genotype the OR was 3.63 (95 % CI 1.5-8.76), p = 0.041.  No significant differences in the polymorphism distribution were observed between ESRD patients  without CP and control subjects. Comparison of the MCP-1 gene polymorphism distribution in ESRD patients with various primary diseases leading to ESRD did not show any significant differences. The mean MCP-1 serum levels were compared between subgroups. They were significantly higher in ESRD patients with CP (582 ± 112 pg/ml) than in patients without CP (309 ± 103 pg/ml) and controls (265 ± 85 pg/ml). Our results suggest that the MCP-1-2518 A/G  polymorphism might be a novel risk factor for developing chronic periodontitis in patients with ESRD.

Translational repression of Ccl5 and Cxcl10 by 4E-BP1 and 4E-BP2 restrains the ability of mouse macrophages to induce migration of activated T cells

Signaling through the mechanistic target of rapamycin complex 1 (mTORC1) is a major regulatory node of pro-inflammatory mediator production by macrophages (MΦs). However, it is still unclear whether such regulation relies on selective translational control by two of the main mTORC1 effectors, the eIF4E-binding proteins 1 and 2 (4E-BP1/2). By comparing translational efficiencies of immune-related transcripts of MΦs from WT and 4E-BP1/2 double-KO (DKO) mice, we found that translation of mRNAs encoding the pro-inflammatory chemokines CCL5 and CXCL10 is controlled by 4E-BP1/2. Macrophages deficient in 4E-BP1/2 produced higher levels of CCL5 and CXCL10 upon LPS stimulation, which enhanced chemoattraction of activated T cells. Consistent with this, treatment of WT cells with mTORC1 inhibitors promoted the activation of 4E-BP1/2 and reduced CCL5 and CXCL10 secretion. In contrast, the phosphorylation status of eIF4E did not affect the synthesis of these chemokines since MΦs derived from mice harboring a non-phosphorylatable form of the protein produced similar levels of CCL5 and CXCL10 to WT counterparts. These data provide evidence that the mTORC1-4E-BP1/2 axis contributes to regulate the production of chemoattractants by MΦs by limiting translation efficiency of Ccl5 and Cxcl10 mRNAs, and suggest that 4E-BP1/2 act as immunological safeguards by fine-tuning inflammatory responses in MΦs.

Association of Diverse Genotypes and Phenotypes of Immune Cells and Immunoglobulins With the Course of HIV-1 Infection

Disease progression among HIV-1-infected individuals varies widely, but the mechanisms underlying this variability remains unknown. Distinct disease outcomes are the consequences of many factors working in concert, including innate and adaptive immune responses, cell-mediated and humoral immunity, and both genetic and phenotypic factors. Current data suggest that these multifaceted aspects in infected individuals should be considered as a whole, rather than as separate unique elements, and that analyses must be performed in greater detail in order to meet the requirements of personalized medicine and guide optimal vaccine design. However, the wide adoption of antiretroviral therapy (ART) influences the implementation of systematic analyses of the HIV-1-infected population. Consequently, fewer data will be available for acquisition in the future, preventing the comprehensive investigations required to elucidate the underpinnings of variability in disease outcome. This review seeks to recapitulate the distinct genotypic and phenotypic features of the immune system, focusing in particular on comparing the surface proteins of immune cells among individuals with different HIV infection outcomes.

Evaluation of IL-17A, IL-17F, IL-23R, VDR, CCL2, CCL5, CCR2, and CCR5 gene polymorphisms and expression in Chinese individuals with syphilis

Syphilis is a sexually transmitted disease caused by the infection of Treponema pallidum subspecies pallidum. T-helper type 17-related genes, vitamin D receptor (VDR) gene, and chemokine/chemokine receptor genes are crucial in microbial infection. A total of 16 single-nucleotide polymorphisms (SNPs) in eight genes (interleukin [IL]-17A, IL-17F, IL-23R, VDR, C-C motif chemokine ligand [CCL] 2, CCL5, C-C chemokine receptor [CCR] 2, and CCR5) were analyzed in 188 patients with syphilis and 216 healthy controls. The results showed a strong correlation of IL-17A rs2275913 (AA vs AG + GG: odds ratio [OR], 1.78; 95% confidence interval [CI], 1.09 to 2.92; P = 0.020; A vs G: OR, 1.33; 95% CI, 1.01 to 1.76; P = 0.043) and rs3819024 (GG vs AA + GA: OR, 1.76; 95% CI, 1.06 to 2.91; P = 0.028; G vs A: OR, 1.36; 95% CI, 1.03 to 1.80; P = 0.030) with syphilis. In haplotype analysis, IL-17A rs2275913A/rs3819024G showed a risk effect (OR, 1.38; 95% CI, 1.04 to 1.82; P = 0.026), whereas IL-17A rs2275913G/rs3819024A showed a protective effect (OR, 0.76; 95% CI, 0.57 to 0.998; P = 0.048). The expression levels of IL-17A messenger RNA (mRNA) in peripheral blood mononuclear cells and IL-17A secretion in plasma were further examined. No significant differences were found between patients with syphilis and healthy controls. The study also explored whether IL-17A rs2275913 and rs3819024 were associated with the expression of IL-17A mRNA and IL-17A secretion in patients with syphilis. Similar negative results were found. In conclusion, the polymorphisms of IL-17A rs2275913 and rs3819024 and the haplotype containing these two SNPs influenced the susceptibility to syphilis in a Han Chinese population.

Genetic Polymorphism at CCL5 Is Associated With Protection in Chagas' Heart Disease: Antagonistic Participation of CCR1+ and CCR5+ Cells in Chronic Chagasic Cardiomyopathy

Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD), a disease caused by Trypanosoma cruzi infection. A hallmark of chronic chagasic cardiomyopathy (CCC) is a fibrogenic inflammation mainly composed of CD8⁺ and CD4⁺ T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs) in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines CCL2 (rs1024611) and CCL5 (rs2107538, rs2280788) and the CCL5/RANTES receptors CCR1 (rs3181077, rs1491961, rs3136672) and CCR5 (rs1799987) with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A, n = 110) or cardiopathic (mild, B1, n = 163; severe, C, n = 133). Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity, CCL5 -403 (rs2107538) CT heterozygotes (OR = 0.5, P-value = 0.04) and T carriers (OR = 0.5, P-value = 0.01) were associated with protection against CCC. To gain insight into the participation of the CCL5-CCR5/CCR1 axis in CCC, mice were infected with the Colombian T. cruzi strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1⁺ CD8⁺ T cells and CD14⁺ macrophages were decreased, while frequencies of CCR5⁺ cells were increased. Importantly, CCR1⁺CD14⁺ macrophages were mainly IL-10⁺, while CCR5⁺ cells were mostly TNF⁺. CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met-RANTES therapy) in infected Ccr5^-/- mice supported a protective role for CCR1 in CCC. Furthermore, parasite antigen stimulation of CD patient blood cells increased the frequency of CCR1⁺CD8⁺ T cells and CCL5 production. Collectively, our data support that a genetic variant of CCL5 and CCR1⁺ cells confer protection against Chagas heart disease, identifying the CCL5-CCR1 axis as a target for immunostimulation.

γ-Oryzanol-Rich Black Rice Bran Extract Enhances the Innate Immune Response

The innate immune response is an important host primary defense system against pathogens. γ-Oryzanol is one of the nutritionally important phytoceutical components in rice bran oil. The goal of this study was to investigate the effect of γ-oryzanol-rich extract from black rice bran (γORE) on the activation of the innate immune system. In this study, we show that γORE increased the expression of CD14 and Toll-like receptor 4 and enhanced the phagocytic activity of RAW264.7 macrophages. Furthermore, γORE and its active ingredient γ-oryzanol promoted the secretion of innate cytokines, interleukin-8, and CCL2, which facilitate phagocytosis by RAW264.7 cells. These findings suggest that γ-oryzanol in the γORE enhances innate immune responses.

The possible role of CCR5Δ32 mutation in Crimean-Congo hemorrhagic fever infection

Crimean-Congo hemorrhagic fever infection (CCHF) is a viral zoonosis. The pathogenesis of this disease has not been established so far, however, cytokines account for its progression and outcome. The aim of the present study is to investigate the association between chemokine receptor 5 (CCR5) gene Δ32 mutation and pathogenity, severity, and mortality of CCHF. This case-control study included 133 CCHF patients diagnosed by detection of CCHV RNA positivity and 97 healthy control subjects. CCR5 gene Δ32 mutation analyzed by polymerase chain reaction (PCR) method. The results were compared by using SPSS 16.0 and WINPEPI software's. The genotype distribution and allele frequency of the CCR5Δ32 were statistically different between the patients and the control group (P = 0.017; OR: 4.98 95% CI = 1.65-14.99 and P = 0.019; OR:4.76 95%CI = 1.30-17.50, respectively). CCR5/CCR5 (W/W) genotype and W allele of CCR5 gene were more common in patient group than in controls. There was no significant difference in severe and mild cases with regard to genotype distribution and allele distribution of CCR5Δ32 mutation (P >0.05). These results suggest that the CCR5 gene and its product might play a role in the pathogenesis of CCHF disease. Future studies will help us to uncover the exact role of CCR5 in the pathogenesis and prognosis of CCHF and to treat the disease.