Effective gene therapy for pancreatic cancer by cytokines mediated by restricted replication-competent adenovirus

Pancreatic cancer has a poor prognosis even when surgical treatment can be accomplished. Studies have demonstrated that pancreatic cancer is associated with various genetic abnormalities in oncogenes and tumor suppressor genes including p53. New therapeutic approaches for pancreatic cancer can be developed by targeting these genetic alterations. Adenovirus (Adv) lacking the 55-kDa E1B protein (E1B55K) replicates preferentially in p53-deficient cancer cells. We constructed E1B55K-deleted Adv (AxE1AdB), and studied its replication and cytopathic effect on pancreatic cancer cells. AxE1AdB replicated in and caused cell death of the p53-deficient pancreatic cancer cell lines tested (e.g., PANC-1, MIAPaCa-2, SU.86.86, BxPC-3, and PK-1). To enhance its therapeutic effect, we examined the combination of coinfecting this restricted replication-competent adenovirus (RRCA) with other Adv. Coinfection of E1-deficient Adv expressing the reporter lacZ gene (AxCAlacZ) together with AxE1AdB resulted in the replication of both viruses and a marked increase in reporter gene expression. PANC-1 cells coinfected with AxE1AdB and the Adv for human IL-2 (AxCAhIL2), produced 110 times more IL-2 than those infected with AxCAhIL2 alone. Similarly, coinfection of AxE1AdB and Adv for human IL-12 augmented the IL-12 production by 370-fold. Injecting AxE1AdB into the PANC-1 tumor of severe combined immunodeficient mice (SCID mice) resulted in marked reduction of the volume of the tumor. Moreover, injecting AxE1AdB with AxCAhIL2 into the PANC-1 tumor resulted in complete regression of the established tumors. These data suggest that RRCA, which augments the antitumor effect of a viral transgene (i.e., cytokines), may be a powerful tool for treating p53-deficient pancreatic cancer.     

Absence of autoantibodies against neurofilament proteins in the sera of scrapie infected mice

Autoantibodies against neurofilament proteins were not detected in any of the sera from the following scrapie infected mice: 19 mice infected with scrapie agent 139A in pre-clinical stage, 32 histologically confirmed scrapie mice and other 12 clinical scrapie mice infected with various strains. The test sera were assayed against acetone-fixed central neuron cultures from fetal mice by indirect immunofluorescence and immunoperoxidase techniques. The negative result suggests that autoantibodies against neurofilament proteins do not play a role in the pathogenesis of scrapie.     

POSSIBLE ROLE OF INTERFERON IN DETERMINING THE ONCOGENIC EFFECT OF POLYOMA VIRUS VARIANTS

1. Infection of newborn C₃Hf/Bi mice with both the highly oncogenic S variant and the poorly oncogenic M variant of polyoma virus caused significantly fewer tumors than infection with the S variant alone 2. Infection of newborn C₃Hf/Bi mice at birth with either M or S variant caused resistance to infection with a heterologous agent, encephalomyocarditis virus, but the M variant caused a somewhat greater degree of resistance. 3. Extracts of tissues of animals infected at birth with the M variant had measurable levels of interferon, reaching a peak on the 5th day after infection with the virus. Extracts of animals infected with the S variant showed no such activity. 4. The growth curves of the two variants in newborn C₃Hf/Bi mice showed that the S variant grew to a 1000-fold greater titer than did the M variant at 5 days after infection. Samples tested at 10 days showed a 10-fold difference. 5. These findings suggested that the difference between the variants in oncogenic potential might have been due to the greater interferon production induced by infection with the M variant than by infection with the S variant.     

ADENO-ASSOCIATED SATELLITE VIRUS INTERFERENCE WITH THE REPLICATION OF ITS HELPER ADENOVIRUS

Adeno-associated satellite virus type 4 interferes with the replication of its helper adenovirus. No interferon-like soluble substance could be detected in satellite-infected cultures and other DNA- and RNA-containing viruses were not inhibited by coinfection with satellite virus under conditions which reduced adenovirus yields by more than 90% in monkey cells. Altering the concentration of adenovirus in the presence of constant amounts of satellite resulted in a constant degree of interference over a wide range of adenovirus inocula and suggested that adenovirus concentration was not a significant factor in the observed interference. The interference with adenovirus replication was abolished by pretreating satellite preparations with specific antiserum, ultraviolet light or heating at 80°C for 30 min. This suggested that infectious satellite virus mediated the interference. Satellite virus concentration was found to be a determinant of interference and studies indicated that the amount of interference with adenovirus was directly proportional to the concentration of satellite virus. 8 hr after adenovirus infection, the replication of adenovirus was no longer sensitive to satellite interference. This was true even though the satellite virus was enhanced as effectively as if the cells were infected simultaneously with both viruses. Interference with adenovirus infectivity was accompanied by reduced yields of complement-fixing antigen and of virus particles which suggested that satellite virus interfered with the formation and not the function of adenovirus products. When cells were infected either with adenovirus alone or with adenovirus plus satellite, the same proportion of cells plated as adenovirus infectious centers. However, the number of plaque-forming units of adenovirus formed per cell in the satellite-infected cultures was reduced by approximately 90%, the same magnitude of reduction noted in whole cultures coinfected with satellite and adenovirus. This suggested that all cells infected with the two viruses were producing a reduced quantity of adenovirus.     

Competition between strains of scrapie depends on the blocking agent being infectious

Compton White mice (Sincs7) were injected twice intraperitoneally, first with the 22A strain of scrapie agent (in brain homogenates) and then, after 105 days, with the 22C strain. Incubation periods were calculated from the time of the first injection. The experiment was designed so that, with no interaction between strains, the second strain (22C) should have produced cases about 300-350 days after the first injection, depending on the dose of 22C. This was well before the limit of 470 days set by the mean incubation period minus 3 SD of 22A alone: a limit which was used to distinguish 22C from 22A clinical cases. In fact, 22A blocked 22C as shown by (i) the lengthening of 22C incubation periods, (ii) the reduced proportion of cases due to 22C, and (iii) the reduced effective titer of 22C. The blocking efficiency of 22A was not greatly reduced by physicochemical treatments that had little or no effect on its infectivity by the intraperitoneal route. However, treatment of 22A homogenates with 6 M urea virtually eliminated infectivity and also abolished blocking ability. It is concluded that competition depends on the infectivity of the scrapie strain used for blocking.     

羊瘙痒因子139A感染引起小鼠脑组织中的1-ACT表达增加

目的 探究1-ACT在羊瘙痒因子139A感染小鼠脑组织中的变化情况。方法 利用蛋白免疫印迹、免疫组织化学、间接免疫荧光及荧光共聚焦方法分析羊瘙痒因子139A感染小鼠脑组织中1-ACT表达的变化和分布特点。结果 蛋白免疫印迹方法显示在羊瘙痒因子139A感染小鼠终末期脑组织中1-ACT的含量较正常对照小鼠明显上调且随着潜伏期的延长而逐渐增加;免疫组织化学方法发现1-ACT主要分布于羊瘙痒因子139A感染小鼠的皮层、丘脑和小脑区域;间接免疫荧光实验显示羊瘙痒因子139A感染终末期小鼠脑组织中补体成分C3含量明显增加,同时荧光共聚焦实验表明1-ACT与补体成分C3存在明显的共定位现象。结论 羊瘙痒因子139A感染终末期小鼠脑组织中1-ACT含量明显增加。     

Preclinical changes in weight of scrapie-infected mice as a function of scrapie agent-mouse strain combination

Several inbred strains of mice were injected with different scrapie agents and their total body weight was monitored throughout the incubation period. As a control, mice were injected with normal mouse brain homogenate. For most combinations of scrapie agent and mouse strain, weights during the preclinical phase were similar to or lower than the average weight of controls. For some combinations there was a significant increase in weight (compared to controls) during the latter part of the preclinical phase of disease. The effect was dependent on both agent and mouse strain, i.e., in some cases a mouse strain showed the increase with one scrapie agent but not another and some scrapie agents caused the increase in one inbred strain of mouse but not in another strain. The increase in weight was due to accumulations of fat rather than a generalized increase in weight of various organs. With one mouse strain (SJL), there was increased vacuolation seen in the hypothalamus of mice injected with scrapie agents that showed the increase in weight compared to the lesion intensity with an agent which did not cause the weight increase.     

STUDIES ON THE TRANSMISSION AND THE EXCRETION OF THE LACTIC DEHYDROGENASE AGENT

The lactic dehydrogenase agent (LDH agent) was found in the urine, feces, and saliva of mice within 24 hours after inoculation. The titer of virus in these materials appears to be directly related to the titer in the plasma. Infection by the oral route occurred only when a high concentration of virus was used. Animals infected prior to mating rarely transmitted the LDH agent to their progeny. However, 91.2 per cent of the progeny of mothers infected during gestation and 51.5 per cent of the progeny of mothers infected within 48 hours after giving birth became infected with the LDH agent. Evidence is discussed which suggests that the transmission of the LDH agent from the infected mother to her offspring is related to the titer of the LDH agent in the maternal circulation.     

Disappearance of scrapie virus from tissues of the mouse

Examination of newborn mice, inoculated intraperitoneally with high doses of scrapie virus, revealed that the virus could not be reisolated from their tissues after about 1 week following inoculation, until almost 1 year later. The inoculum was rapidly removed and was not detectable, although the animals became latently infected. Homogenization of whole inoculated newborn animals showed that only about 3% of virus could be recovered by the 2nd day postinoculation (p.i.). During the first 6 days p.i. the half-life of titratable scrapie was about 15 h. A further study of the rate of disappearance of clarified scrapie virus from blood after intravenous inoculation showed an even more rapid disappearance, with a half-life of 5.16 min. Prior treatment of the recipient mice with either carbon black or silica to block the reticuloendothelial system (RES) did not affect the rate of disappearance. It was concluded that the mouse possesses a very efficient means of scrapie virus removal from the blood which is not dependent upon an active RES. However, after 1 h the rate of disappearance changed dramatically; the residual virus level was very stable, with no significant drop during the next 21 h. This finding was compatible with the possibility that two forms of scrapie virus, with different removal rates, coexisted in the inoculum. Silica treatment caused a shortened scrapie incubation period.     

Pre-existent adenovirus antibody inhibits systemic toxicity and antitumor activity of CN706 in the nude mouse LNCaP xenograft model: implications and proposals for human therapy

Pre-existent humoral antibody to adenovirus potentially confounds human clinical trials involving intravascular administration of adenovirus. Using the LNCaP prostate cancer xenograft model in BALB/c nu/nu mice and the prostate-specific attenuated replication-competent adenovirus (ARCATM) CN706, we developed an animal model that systematically controls both the dose of intravascularly administered adenovirus and the titer of the pre-existent anti-Ad5 antibody, and then measures the virus-induced toxicity as well as antitumor activity. We prepared hyperimmune sera to adenovirus in rabbits, passively injected the purified rabbit anti-Ad5 antibody into tumor-bearing mice, and established measurable humoral anti-Ad5 antibody titers. CN706 was intravenously injected into the tail vein of animals 24 hr after passive anti-Ad5 antibody administration. In the absence of pre-existent antibody, the lethal dose (LD100) for BALB/c nu/nu mice was 2.5x10(11) CN706 particles, whereas 1x10(11) CN706 particles was not lethal. However, in the presence of a 1:80 pre-existent titer of Ad5 neutralizing antibody (NAb), intravenous injection of 5x10(11) CN706 particles was no longer lethal. In addition, pre-existent antibody also prevented antitumor activity in a dose-dependent manner: 1x 10(11) CN706 particles prevented LNCaP xenograft tumor progression, but antitumor activity was eliminated by a pre-existent 1:80 NAb titer. These results led us to propose transient removal of pre-existent adenovirus antibody by immunoapheresis. An affinity column of cloned virus capsid proteins was constructed that was able to specifically remove adenovirus antibody from human clinical serum samples. A 5-min disposable immunoassay was also developed to monitor the level of pre-existent antibody in sera before and after immunoapheresis. Clinically, this approach may enable controlled clinical studies of intravenously administered adenovirus in patients with pre-existent anti-adenovirus antibody.     

Biochemical and pathological evaluation of albendazole/thalidomide co-therapy against eosinophilic meningitis or meningoencephalitis induced by Angiostrongylus cantonensis

OBJECTIVES: To evaluate the curative effect of albendazole/thalidomide co-therapy on eosinophilic meningitis in BALB/c mice caused by Angiostrongylus cantonensis. METHODS: Male mice were infected with 50 A. cantonensis larvae and treated with albendazole (5, 10 or 20 mg/kg per day) alone, thalidomide (25, 50 or 100 mg/kg per day) alone, or a combination of albendazole (10 mg/kg per day) and thalidomide (50 mg/kg per day) for 7 consecutive days on days 5, 10 and 15 post-inoculation (PI), respectively. RESULTS: Indicators used to measure this effect included: (i) worm recovery; (ii) histopathological score of meningitis; (iii) eosinophil counts; (iv) level of pro-inflammatory cytokines, such as tumour necrosis factor-alpha, interleukin-1beta and interleukin-5; (v) activity of enzymes, such as tissue-type plasminogen activator, urokinase-type plasminogen activator and matrix metalloproteinase-9; and (vi) CSF/serum albumin ratio. The results showed that albendazole/thalidomide co-therapy significantly decreased (P < 0.05) these factors when treatment was initiated on days 5 or 10 PI compared with treatment initiated on day 15 PI. CONCLUSIONS: The timing of medication use is important and is closely related to the anthelmintic efficacy of a drug. For a given dosage, earlier medication use is more effective. This novel approach to treating parasitic meningitis may suggest other new methods of treatment.     

Activity of gatifloxacin alone or in combination with pyrimethamine or gamma interferon against Toxoplasma gondii

The activity of gatifloxacin against Toxoplasma gondii, either alone or in combination with pyrimethamine or gamma interferon (IFN-gamma), was examined in vitro and in vivo. In vitro, gatifloxacin significantly inhibited intracellular replication of tachyzoites of the RH strain with a 50% inhibitory concentration of 0.21 microg/ml at 48 h after addition of the drug to the cultures. Toxicity for host cells was not observed at this concentration. A synergistic effect (combination indices < 0.5) was demonstrated in vitro following 48 h of treatment with the combination of gatifloxacin and pyrimethamine (1:1 ratio). Doses of gatifloxacin of 100 and 200 mg/kg of body weight/day administered orally to mice for 10 days resulted in significant (P values of 0.056 and <0.0001, respectively) prolongation in time to death following infection with a lethal inoculum of tachyzoites. A dose of 400 mg/kg resulted in 20% survival (P = 0.0001). Mortality was 100% in untreated control mice and in mice treated with 25 or 50 mg/kg/day. Treatment of infected mice with a combination of gatifloxacin at 200 mg/kg/day and pyrimethamine at 12.5 mg/kg/day resulted in 85% survival, whereas 100 and 80% of mice treated with gatifloxacin alone or pyrimethamine alone, respectively, died (P < 0.0001). Moreover, a gatifloxacin dose of 200 mg/kg/day administered orally for 10 days plus 2 microg of recombinant murine IFN-gamma/day administered intraperitoneally for 10 days resulted in significant survival compared with IFN-gamma alone (P < 0.0001) or gatifloxacin alone (P < 0.007).     

Alpha interferon and acyclovir treatment of herpes simplex virus in lymphoid cell cultures.

The T-lymphoblastoid cell line CEM, persistently infected with herpes simplex virus type 1, has been used to examine the antiviral efficacy of human alpha interferon and acyclovir, both alone and in combination. Acyclovir and interferon each produced dose-dependent decreases in virus titer at concentration ranges of 1 to 100 microM (approximately 0.225 to 22.5 micrograms/ml) and 10 to 10,000 U/Ml, respectively. Mean reductions in titer of 1.9 and 4.2 log10 PFU/ml were observed with 100 microM acyclovir and 10,000 U of interferon per ml, respectively, on day 10 of treatment. The combination of 100 microM acyclovir and 10,000 U of interferon per ml produced the most rapid fall in virus titer of all regimens examined and elimination of infections virus by day 7. Prolonged treatment (greater than 10 days) with acyclovir or alpha interferon was accompanied by a gradual return of virus titer to control levels despite the continuous presence of drug. Virus preparations isolated from such cultures were tested for antiviral agent sensitivity by a plaque reduction method. Acyclovir-exposed isolates were found to be acyclovir resistant, with 50% inhibitory doses of greater than 200 microM, and to be thymidine kinase deficient. Alpha interferon-exposed isolates were not interferon resistant. These results suggest that, in persistently herpes simplex virus-infected CEM cells: (i) combination treatment with 100 microM acyclovir and 10,000 U of alpha interferon per ml is more effective in reducing virus titer than either agent alone; (ii) prolonged exposure to drug may result in development of resistance by either the virus strain or the host cell system; and (iii) development of acyclovir resistance by herpes simplex virus in lymphoid cells is mediated by thymidine kinase.     

Infected splenic dendritic cells are sufficient for prion transmission to the CNS in mouse scrapie

Transmissible spongiform encephalopathies display long incubation periods at the beginning of which the titer of infectious agents (prions) increases in peripheral lymphoid organs. This "replication" leads to a progressive invasion of the CNS. Follicular dendritic cells appear to support prion replication in lymphoid follicles. However, the subsequent steps of neuroinvasion remain obscure. CD11c(+) dendritic cells, an unrelated cell type, are candidate vectors for prion propagation. We found a high infectivity titer in splenic dendritic cells from prion-infected mice, suggesting that dendritic cells carry infection. To test this hypothesis, we injected RAG-1(0/0) mice intravenously with live spleen cell subsets from scrapie-infected donors. Injection of infected dendritic cells induced scrapie without accumulation of prions in the spleen. These results suggest that CD11c(+) dendritic cells can propagate prions from the periphery to the CNS in the absence of any additional lymphoid element.     

Prophylactic effect of dietary seaweed Fucoidan against enteral prion infection

Dietary seaweed fucoidan delays the onset of disease of enterally infected mice with scrapie when given orally for 6 days after infection, but not when given before the infection. This effect was not modified at a tested fucoidan dose range and appeared to reach the maximum level at a concentration of 2.5% or less in feed. Daily uptake of fucoidan might be prophylactic against prion diseases caused by ingestion of prion-contaminated materials, although further evaluation of its pharmacology remains to be done.     

Treatment of hepatitis C in HIV-coinfected patients

OBJECTIVE: To review the current management of hepatitis C virus (HCV) in persons coinfected with HIV. DATA SOURCES: A MEDLINE search (1966-February 2006) was conducted, using key words such as HIV, human immunodeficiency virus, hepatitis C, interferon, pegylated interferon, and therapy. Article bibliographies and conference abstracts were also reviewed to identify relevant studies. STUDY SELECTION AND DATA EXTRACTION: Studies that examined HCV treatment in individuals coinfected with HIV and articles that focused on HCV/HIV coinfection were considered for this review. DATA SYNTHESIS: Coinfection with HIV leads to a more rapid and severe course of HCV-related liver disease. Treatment of HCV with pegylated interferon (PEG-IFN) and ribavirin therapy is relatively well tolerated in individuals coinfected with HIV, with overall sustained virologic response (SVR) rates of 27-40%. High relapse rates and poor response in HCV-genotype 1 contribute to the lower SVR in coinfected individuals compared with HCV monoinfection. Treatment of HCV is more complicated in HIV-infected persons due to increased risk of myelosuppression, drug interactions, hepatotoxicity of antiretroviral therapy, and the relative contraindication to interferon therapy in advanced HIV disease. Current guidelines recommend that all HIV-positive patients with chronic HCV infection be considered as treatment candidates for anti-HCV therapy due to the higher risk of liver disease progression. Further studies are needed, however, to define the appropriate dose and duration of therapy in HCV/HIV-coinfected individuals. CONCLUSIONS: Response to treatment with PEG-IFN and ribavirin is poorer in patients coinfected with HCV/HIV than in those infected with HCV alone. The benefits of anti-HCV therapy, including viral eradication, need to be weighed against the risks of adverse effects and drug-drug interactions between anti-HCV and antiretroviral medications.     

动力相关蛋白Drp1在羊瘙痒因子139A感染小鼠脑组织中变化的研究

目的 研究动力相关蛋白1(Drp1)在羊瘙痒因子139A感染的小鼠脑组织中的变化。方法 采用Western Blot方法检测Drp1在羊瘙痒因子139A感染的脑组织匀浆中的含量变化及其亚硝基化水平。采用组织免疫荧光方法检测Drp1在脑组织中的分布。结果 在羊瘙痒因子139A感染终末期小鼠脑组织匀浆中,Drp1总量略有降低。对感染不同时间点的动态分析结果显示Drp1含量呈逐渐降低趋势,终末期稍有回升。感染终末期脑组织中亚硝基化水平明显增高。组织免疫荧光显示正常和羊瘙痒因子139A感染终末期小鼠脑组织中,Drp1与神经元细胞存在共定位现象。结论 Drp1在小鼠中枢神经系统中主要分布于神经元细胞,在羊瘙痒因子139A感染的小鼠脑组织中,Drp1总量略有降低,另外亚硝基化水平明显增高,提示在羊瘙痒病感染的小鼠脑组织中,线粒体动力相关蛋白的表达量及翻译后修饰水平出现了变化,在感染过程中起着重要作用。     

STUDIES ON THE MULTIPLICATION AND THE PROPERTIES OF THE LACTIC DEHYDROGENASE AGENT

The procedure used to determine the infective titer of the LDH agent, the reproducibility of this assay, and the relationship between virus dose and plasma enzyme activity were described. Multiplication of the LDH agent began within 6 hours after infection and reached 10^10.8 ID₅₀/ml of plasma within 24 hours. The titer rapidly decreased over the next 72 hours but viremia persisted for at least 16 months with titers as high as 10^5.2 ID₅₀/ml. The appearance of the LDH agent in the circulation preceded the first noticeable rise in plasma LDH activity by close to 24 hours. After 10 months, when the plasma titer of the LDH agent had decreased nearly one millionfold, the plasma enzyme LDH had decreased by less than 50 per cent. The LDH agent is inactivated by ether but withstands lyophilization, and freezing and thawing. It is stable at low temperatures. Ultracentrifugation at 105,000 G for 2 hours leaves less than 0.1 per cent of the LDH agent in the supernatant fluid and filtration through gradocol membranes suggesst that the upper size of the LDH agent is about 55 mµ. Spread of the LDH agent from infected to uninfected mice kept in the same cage and transmission from mothers (infected prior to mating) to their offspring was relatively low.     

CXCL1/CXCR2在羊瘙痒因子感染小鼠脑组织中的分布特征研究

目的 探究朊病毒感染小鼠脑组织CXC趋化因子配体1 (CXCL1)与CXC趋化因子受体2 (CXCR2)的分布特征。方法 通过免疫组织化学、免疫组织荧光双染实验明确羊瘙痒因子139A及ME7感染终末期小鼠脑组织中CXCL1/CXCR2的分布特征,确定CXCL1/CXCR2的靶细胞及与羊瘙痒因子样朊蛋白(PrPSc)沉积的关系。结果 通过全脑区免疫组化染色发现,CXCL1/CXCR2在羊瘙痒因子139A及ME7感染终末期小鼠脑组织中的含量明显升高,主要分布在海马、皮层、丘脑、小脑及延髓5个脑区。CXCL1与小胶质细胞和神经元细胞存在共定位,而CXCR2与神经元细胞存在共定位。在羊瘙痒因子139A及ME7感染终末期小鼠脑组织中CXCL1、CXCR2和PrP^Sc三者存在明显共定位。结论 CXCL1/CXCR2分布于朊病毒感染小鼠脑组织中朊病毒病理特征集中的脑区。     

Naive HIV/HCV-coinfected patients have higher intrahepatic pro-inflammatory cytokines than coinfected patients treated with antiretroviral therapy

In the era of antiretroviral therapy, liver disease has emerged as an important cause of morbidity and mortality in HIV/hepatitis C virus (HCV) coinfected patients. It is believed that HCV is a non-cytopathic virus and that T-cell-mediated events (including the production of pro-inflammatory cytokines) have an important role in promoting both liver damage and viral clearance. Whether HIV coinfection or antiretroviral therapies influence such events is still unclear. In the current study, we compared the expression of NKp46 (a natural killer cell marker), CD3 (a T-cell marker), interferon-gamma (IFN-gamma), tumour-necrosis factor-alpha (TNF-alpha; pro-inflammatory cytokines) and interleukin-10 (IL-10; an anti-inflammatory cytokine) mRNA in the liver of naive HIV/HCV-coinfected patients (group one, n=14), coinfected patients treated with antiretroviral therapy (group two, n=23) and naive HCV mono-infected patients (group three, n=24). All three groups had comparable HCV viremia, with coinfected patients showing similar and relatively high CD4+ T-cell counts and significantly different HIV vireamia. Interestingly, when compared to groups two and three, group one showed significantly higher intrahepatic mRNA levels for CD3, IFN-gamma and TNF-alpha, whereas the expression of NKp46 and IL-10 were comparable in all three groups. Further, higher histopathological grading scores within each group were independently associated with higher mRNA contents for CD3 and IFN-gamma and higher serum alanine aminotransferase levels at the time of liver biopsy. Together, these results suggest that HIV infection may exacerbate the immune-mediated inflammatory response in the liver of patients chronically infected with HCV and antiretroviral therapy may prevent this effect.