Th1 and Th2 cytokines differentially regulate the transformation of Kupffer cells into multinucleated giant cells but similarly enhance the Kupffer cell-induced hepatic stellate cell proliferation

Application of TGF-β1, TIMP-1 and TIMP-2 small interfering RNAs can alleviate CCl4-induced hepatic fibrosis in rats by rebalancing Th1/Th2 cytokines

The present study aimed to investigate the effects of TGF-β1, tissue inhibitor of metalloproteinase (TIMP)-1 small interfering (si)RNA and TIMP-2 siRNA on hepatic fibrosis in rats and explore the T helper (Th)1/Th2 balance. Moreover, IFN-γ, IL-4 and IL-13 are the main cytokines associated with Th1/Th2 responses and have significant influence on the progression of hepatic fibrosis. The expression levels of IFN-γ, IL-4 and IL-13 in rats with hepatic fibrosis that were treated with siRNAs against the aforementioned molecules were measured using various techniques including immunohistochemical staining, western blotting and reverse transcription-quantitative PCR. The principal outcomes revealed the downregulation of IFN-γ and the upregulation of IL-4 and IL-13 in the model group compared with the normal group. Moreover, the expression of IFN-γ was significantly increased, while IL-4 and IL-13 demonstrated no significant difference in the TGF-β1 siRNA treatment group compared with the model group. The TIMP-1 and TIMP-2 siRNA treatment groups exhibited significantly increased expression levels of IFN-γ, but lower expression levels of IL-4 and IL-13 compared with the model group. These results indicated that TIMP-1 and TIMP-2 were improved antifibrotic targets compared with TGF-β1.

Relationship between serum cytokine levels and histopathological changes of liver in patients with hepatitis B

AIM: To investigate whether there was a relationship between the liver functions and fibrosis scores of hepatitis B patients and their TNF-α, IFN-γ, IL-4, and TGF-β₁ serum levels based on the studies of liver biopsies.

METHODS: Thirty patients with chronic hepatitis B (CHB) receiving no treatment and 30 healthy individuals with negative hepatitis serology and normal values of liver biochemistry were studied. After serum samples of the patients were collected, liver needle biopsy was performed on each patient. Cytokine levels were studied by ELISA. The biopsy materials were scored based on Knodell’s histological activity index.

RESULTS: In comparison of cytokine levels between CHB patients and control group, TNF-α, IL-4, and TGF-β₁ levels of the patients were higher in CHB patients than in the controls, while IFN-γ level was lower in the patients than in the controls. There were significant differences between the groups in TNF-α, IL-4, TGF-β₁, and IFN-γ (P<0.005, 0.03, 0.002, 0.0001, respectively). There was a negative correlation between TGF-β₁ and IL-4 and IFN-γ (P<0.05), TNF-α and the other cytokines and IFN-γ and IL-4 were not correlated (P>0.05). TGF-β₁ was correlated with fibrosis (P<0.05). Liver necroinflammatory activity and fibrosis and TNF-α, IL-4, and IFN-γ were not correlated (P>0.05).

CONCLUSION: In the course of HBV infection and its chronic progress, cytokines play an important role. IL-4 and IFN-γ are effective in the chronic progression, while TGF-β₁ is effective in the development of fibrosis. Serum cytokine levels may be effective tools in the estimation of chronic progression and fibrosis development.

The detection of IRF-1 promoter polymorphisms and their possible contribution to T helper 1 response in chronic hepatitis C

We described the interferon (IFN) regulatory factor-1 (IRF-1) promoter single nucleotide polymorphisms (SNPs), and the clinical and immunologic implications of these SNPs have been investigated. We successfully determined the mutation at -300 of the IRF-1 promoter by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and this mutation linked with other mutations in the promoter region. In our Japanese population, the frequency of the type -300*A/A was 11.9%, type A/G was 54.2%, and type G/G was 33.9%. We found no significant difference without IFN stimulation in the production levels of IFN-gamma and interleukin-10 (IL-10) from peripheral blood mononuclear cells (PBMC) between subjects with -300*A/A and those with other types. IFN-alpha stimulation, however, increased the levels of IFN-gamma significantly and decreased the IL-10 production level significantly only in the subject with -300*A/A type. Flow cytometric analysis showed that the Th1-type CD4(+) cell population was significantly increased by IFN-beta administration only in the patient with chronic hepatitis C with -300*A/A type. These results suggest that the IRF-1 promoter SNP types are positively involved in Th1-type response and, consequently, the -300*A/A type may be beneficial for viral elimination in chronic hepatitis C and IFN therapy.