CCR5基因敲除小鼠有哪些方麵異常？

CCR5基因敲除小鼠有報道對部分炎症免疫反應下降，對機體有保護作用。然而，也有負麵作用的報道：
1)

J Gastroenterol Hepatol. 2017 Jun;32(6):1258-1264. doi: 10.1111/jgh.13657.

C-C chemokine receptor type 5 deficiency exacerbates alcoholic fatty liver disease through pro-inflammatory cytokines and chemokines-induced hepatic inflammation.

Park JH¹, Lee DH¹, Park MS², Jung YS³, Hong JT¹.

Abstract

BACKGROUND AND AIM:Chemokines and chemokine receptors implicated with alcoholic liver disease. Studies have shown that inflammation and oxidative stress induce fat molecules aggregation in liver. We evaluated the relationship between alcoholic fatty liver disease and C-C chemokine receptor 5 (CCR5) and impact of inflammation and oxidative stress in fat molecule deposition.

METHODS:Lieber-DeCarli diet containing ethanol or isocaloric control diets were fed to wild-type and CCR5 knockout mice for 10 days and gavaged with a single dose of ethanol or isocaloric maltose dextrin at 11th day. Cytokine, chemokine, and reactive oxygen species levels were measured in liver tissues to study the role of CCR5 in alcoholic fatty liver disease.

RESULTS:C-C chemokine receptor type 5 knockout mice exacerbated ethanol-induced liver injury. Serum levels of aspartate aminotransferase and alanine aminotransferase were higher in CCR5 knockout mice than wild-type mice, and CCR5 knockout mice showed more severe lipid accumulation in liver tissue than wild-type mice after ethanol feeding. Increased expressions of pro-inflammatory cytokines TNF-α and IL-6 and chemokines CCL2, CCL3, CCL4, and CCL5 result in exacerbation of hepatitis in CCR5 knockout mice after ethanol feeding. Oxidative stress induced by reactive oxygen species was more severe in CCR5 knockout mice, and increasing level of fatty acid import and decreasing level of lipid degradation resulted in lipid accumulation in ethanol-fed CCR5 knockout mice.

CONCLUSION:　Deficiency of CCR5 exacerbates alcoholic fatty liver disease by hepatic inflammation induced by pro-inflammatory cytokines and chemokines and oxidative stress.

CCR5缺乏加重酒精性脂肪肝。
2)

Oncotarget. 2016 Mar 15;7(11):11984-99. doi: 10.18632/oncotarget.7453.

CCR5 deficiency accelerates lipopolysaccharide-induced astrogliosis, amyloid-beta deposit and impaired memory function.

Hwang CJ¹, Park MH¹, Hwang JY¹, Kim JH¹, Yun NY¹, Oh SY¹, Song JK¹, Seo HO¹, Kim YB², Hwang DY³, Oh KW¹, Han SB¹, Hong JT¹.

Abstract

Chemokine receptors are implicated in inflammation and immune responses. Neuro-inflammation is associated with activation of astrocyte and amyloid-beta (Aβ) generations that lead to pathogenesis of Alzheimer disease (AD). Previous our study showed that deficiency of CC chemokine receptor 5 (CCR5) results in activation of astrocytes and Aβ deposit, and thus memory dysfunction through increase of CC chemokine receptor 2 (CCR2) expression. CCR5 knockout mice were used as an animal model with memory dysfunction. For the purpose LPS was injected i.p. daily (0.25 mg/kg/day). The memory dysfunctions were much higher in LPS-injected CCR5 knockout mice compared to CCR5 wild type mice as well as non-injected CCR5 knockout mice. Associated with severe memory dysfuction in LPS injected CCR5 knockout mice, LPS injection significant increase expression of inflammatory proteins, astrocyte activation, expressions of β-secretase as well as Aβ deposition in the brain of CCR5 knockout mice as compared with that of CCR5 wild type mice. In CCR5 knockout mice, CCR2 expressions were high and co-localized with GFAP which was significantly elevated by LPS. Expression of monocyte chemoattractant protein-1 (MCP-1) which ligands of CCR2 also increased by LPS injection, and increment of MCP-1 expression is much higher in CCR5 knockout mice. BV-2 cells treated with CCR5 antagonist, D-ala-peptide T-amide (DAPTA) and cultured astrocytes isolated from CCR5 knockout mice treated with LPS (1 μg/ml) and CCR2 antagonist, decreased the NF-ĸB activation and Aβ level. These findings suggest that the deficiency of CCR5 enhances response of LPS, which accelerates to neuro-inflammation and memory impairment.
CCR5缺乏增強個體對LPS的反應性，從而加重炎症和記憶損害。

3)

J Neuroinflammation. 2015 Dec 15;12:233. doi: 10.1186/s12974-015-0447-9.

CCR5 limits cortical viral loads during West Nile virus infection of the central nervous system.

Durrant DM¹, Daniels BP², Pasieka T³, Dorsey D⁴, Klein RS^5,6,7.

Abstract

BACKGROUND:Cell-mediated immunity is critical for clearance of central nervous system (CNS) infection with the encephalitic flavivirus, West Nile virus (WNV). Prior studies from our laboratory have shown that WNV-infected neurons express chemoattractants that mediate recruitment of antiviral leukocytes into the CNS. Although the chemokine receptor, CCR5, has been shown to play an important role in CNS host defense during WNV infection, regional effects of its activity within the infected brain have not been defined.

METHODS:We used CCR5-deficient mice and an established murine model of WNV encephalitis to determine whether CCR5 activity impacts on WNV levels within the CNS in a region-specific fashion. Statistical comparisons between groups were made with one- or two-way analysis of variance; Bonferroni's post hoc test was subsequently used to compare individual means. Survival was analyzed by the log-rank test. Analyses were conducted using Prism software (GraphPad Prism). All data were expressed as means ± SEM. Differences were considered significant if P ≤ 0.05.

RESULTS:As previously shown, lack of CCR5 activity led to increased symptomatic disease and mortality in mice after subcutaneous infection with WNV. Evaluation of viral burden in the footpad, draining lymph nodes, spleen, olfactory bulb, and cerebellum derived from WNV-infected wild-type, and CCR5(-/-) mice showed no differences between the genotypes. In contrast, WNV-infected, CCR5(-/-) mice exhibited significantly increased viral burden in cortical tissues, including the hippocampus, at day 8 post-infection. CNS regional studies of chemokine expression via luminex analysis revealed significantly increased expression of CCR5 ligands, CCL4 and CCL5, within the cortices of WNV-infected, CCR5(-/-) mice compared with those of similarly infected WT animals. Cortical elevations in viral loads and CCR5 ligands in WNV-infected, CCR5(-/-) mice, however, were associated with decreased numbers of infiltrating mononuclear cells and increased permeability of the blood-brain barrier.

CONCLUSIONS:These data indicate that regional differences in chemokine expression occur in response to WNV infection of the CNS, and that cortical neurons require CCR5 activity to limit viral burden in this brain region.
尼羅河病毒感染時神經細胞需要CCR5的活性限製病毒感染