Proteolytic Activity in the Midgut of Helicoverpa armigera (Noctuidae: Lepidoptera) Larvae Fed on Wild Relatives of Chickpea, Cicer arietinum.

Wild relatives of crops are an important source of resistance genes against insect pests. However, it is important to identify the accessions of wild relatives with different mechanisms of resistance to broaden the basis and increase the levels of resistance to insect pests. Therefore, we evaluated 15 accessions of wild relatives of chickpea belonging to seven species and five genotypes of cultivated chickpea for their resistance to pod borer, Helicoverpa armigera, which is the most damaging pest of chickpea. The test genotypes were evaluated for resistance to H. armigera using detached pod assay. Data were also recorded on activity of the digestive enzymes in the midgut of the larvae fed on different wild relatives of chickpea. All the wild chickpea genotypes suffered lower pod damage and weight gained by the third-instar larvae of H. armigera was lower when fed on them compared with the cultivated chickpea. The accessions, IG 69979 (Cicer cuneatum), PI 599066, IG 70006, IG 70018, IG 70022 (Cicer bijugum), IG 599076 (Cicer chrossanicum), and IG 72933, IG 72953 (Cicer reticulatum), showed high levels of resistance to H. armigera. There were significant differences in protease activity in larval gut of H. armigera fed on different wild relatives of chickpea. Total protease, trypsin, and chymotrypsin activities were lowest in larva fed on PI 599066 (C. bijugum) compared with that in the larvae fed IG 69979 (C. cuneatum) and IG 70022 (C. bijugum). Aminopeptidase activity was highest in the larvae fed on IG 70022 (C. bijugum) and IG 599076 (C. chrossanicum), whereas lowest activity was recorded in the larvae fed on ICC 3137 and KAK 2 (susceptible checks). The variation in protease activities may be due to the presence of protease inhibitors in the wild relatives or hyperproduction of enzymes by the larvae as result of protease inhibitor activity of the wild relatives, resulting in low weight gain by larvae. The results suggested that wild relatives of chickpea with diverse mechanisms of resistance can be exploited to increase the levels and diversify the basis of resistance to H. armigera in cultivated chickpea.

Double-Stranded RNA-Mediated Suppression of Trypsin-Like Serine Protease (t-SP) Triggers Over-Expression of Another t-SP Isoform in Helicoverpa armigera.

High diversity of digestive proteases is considered to be the key factor in the evolution of polyphagy in Helicoverpa armigera. Serine proteases (SPs) contribute ~85% of the dietary protein digestion in H. armigera. We investigated the dynamics of SP regulation in the polyphagous pest, H. armigera using RNA interference (RNAi). HaTry1, an isoform of SP, expressed irrespective of the composition of the diet, and its expression levels were directly proportional to the larval growth rate. Therefore, HaTry1 was silenced by delivering 10 and 20 µg concentrations of double-stranded RNA through semi-synthetic diet. This led to a drastic reduction in the target gene transcript levels that manifested in a significant reduction in the larval weight initially, but the larvae recovered in later stages despite continuous dsRNA treatment. This was probably due to the compensatory effect by over-expression of HaTry13 (31-folds), another isoform of SP. Phylogenetic analysis of H. armigera SPs revealed that the over-expressed isoform was closely related to the target gene as compared to the other tested isoforms. Further, silencing of both the isoforms (HaTry1 and HaTry13) caused the highest reduction in the larval weight and there was no larval growth recovery. These findings provide a new evidence of the existence of compensatory effect to overcome the effect of silencing individual gene with RNAi. Hence, the study emphasizes the need for simultaneous silencing of multiple isoforms.

A randomized placebo-controlled trial to evaluate a novel noninjectable anesthetic gel with thermosetting agent during scaling and root planing in chronic periodontitis patients.

AIM: To study the efficacy of a noninjectable anesthetic gel with a thermosetting agent in the reduction of pain during scaling and root planing (SRP) in untreated chronic periodontitis patients. MATERIALS AND METHODS: This study is a randomized, double-masked, split-mouth, placebo-controlled trial. Thirty patients were enrolled who underwent SRP in a split-mouth (right side/left side) manner. Before commencement of SRP, both quadrants on each side were isolated and had a randomized gel (either placebo or test gel) placed in the periodontal pockets for 30 s. The pain was measured using numerical rating scale (NRS) and verbal rating scale (VRS). RESULTS: The median NRS pain score for the patients treated with the anesthetic test gel was 1 (range: 0-4) as opposed to 5 (range: 3-7) in the placebo treated patients. The mean rank of pain score using NRS in test gel was 16.18 as compared to 44.82 in placebo treated sites. Hence, significant reduction in pain was found in test gel as compared to placebo using NRS (P < 0.001). The VRS showed that the majority of patients reported no pain or mild pain with a median of 1 as compared to placebo treated sites with a median of 2 suggestive of moderate pain. CONCLUSIONS: The NRS and VRS pain scores showed that the side treated with anesthetic gel was statistically more effective than the placebo in reducing pain during SRP.

Hepatitis E virus infection and acute-on-chronic liver failure in West Africa: a case-control study from The Gambia.

BACKGROUND: In sub-Saharan Africa, it is unknown whether hepatitis E virus (HEV) infection is a common precipitating event of acute-on-chronic liver failure (ACLF). AIMS: To estimate the prevalence of HEV infection in general population and assess whether HEV is a common trigger of ACLF in cirrhotic patients in The Gambia, West Africa. METHODS: We first conducted an HEV sero-survey in healthy volunteers. We then tested cirrhotic patients with ACLF (cases) and compensated cirrhosis (controls) for anti-HEV IgG as a marker of exposure to HEV, and anti-HEV IgA and HEV RNA as a marker of recent infection. We also described the characteristics and survival of the ACLF cases and controls. RESULTS: In the healthy volunteers (n = 204), 13.7% (95% CI: 9.6-19.2) were positive for anti-HEV IgG, and none had positive HEV viraemia. After adjusting for age and sex, the following were associated with positive anti-HEV IgG: being a Christian, a farmer, drinking water from wells, handling pigs and eating pork. In 40 cases (median age: 45 years, 72.5% male) and 71 controls (39 years, 74.6% male), ≥70% were infected with hepatitis B virus. Although hepatitis B flare and sepsis were important precipitating events of ACLF, none had marker of acute HEV. ACLF cases had high (70.0%) 28-day mortality. CONCLUSIONS: Hepatitis E virus infection is endemic in The Gambia, where both faecal-oral route (contaminated water) and zoonotic transmission (pigs/pork meat) may be important. However, acute HEV was not a common cause of acute-on-chronic liver failure in The Gambia.

Elimination of Gut Microbes with Antibiotics Confers Resistance to Bacillus thuringiensis Toxin Proteins in Helicoverpa armigera (Hubner).

Helicoverpa armigera is one of the most important pests worldwide. Transgenic crops with toxin genes from Bacillus thuringiensis (Bt) have been deployed on a large scale to control this pest. The insecticidal activity of Bt is probably influenced by the insect midgut microbes, which vary across crop hosts and locations. Therefore, we examined the role of gut microbes in pathogenicity of Bt toxins in the H. armigera. Antibiotic cocktail was used for the complete elimination of the H. armigera gut microbes. Activated Cry1Ac, Bt formulation, and transgenic cotton resulted in larval weight loss and increase in mortality, but pretreatment of larvae with antibiotic cocktail significantly decreased larval mortality and increased the larval weight gain. Activated Cry1Ac and Bt formulation inhibited the activity of proteases in midgut of H. armigera larvae but showed no such effect in the larvae pretreated with antibiotic cocktail. Five protease bands in activated Cry1Ac and two in Bt formulation-treated larvae were inhibited but no such effect in the larvae pretreated with antibiotic cocktail. Cry1Ac protein was detected in Bt/Cry1Ac protoxin-fed larval gut extract in the absence of antibiotic cocktail, but fewer in larvae pretreated with antibiotic cocktail. The activity of antioxidant enzymes and aminopeptidases increased in larvae fed on Bt toxin, but there was no significant increase in antioxidant enzymes in larvae reared on toxin protein in combination with antibiotic cocktail. The results suggest that gut microbes exercise a significant influence on the toxicity of Cry1Ac and Bt formulation in H. armigera larvae. The implications of these results have been discussed in relation to development of insect resistance to Bt transgenic crops deployed for pest management.

Increased survival of patients with end-stage hepatocellular carcinoma due to intake of ONCOXIN®, a dietary supplement.

BACKGROUND AND AIMS: Treatment and management of patients with end-stage hepatocellular carcinoma (HCC) represents a formidable challenge to contemporary branches of medical sciences. The study presented here was conducted to assess the utility of nutrient supplement, if any, for management of patients with end-stage HCC. MATERIALS AND METHODS: A total of 19 patients with end-stage HCC (Barcelona Clinic Liver Cancer [BCLC] staging D) were provided with ONCOXIN® for 3 months. Another 10 patients with end-stage HCC (BCLC stage D) with similar clinical conditions received conservative management, but they did not give consent for taking ONCOXIN® (non-ONCOXIN® group). All patients of both groups were followed on regular basis until their death. STATISTICAL ANALYSIS: The results were expressed as mean and standard deviation. Comparison between groups was performed using Student's t-test or the Mann-Whitney U test. For categorical data, Chi-square or Fisher exact test was applied. RESULTS: All patients of the control group (non-ONCOXIN® group) (10 of 10 patients) died within 2 months after study commencement. On the other hand, 10 of 19 patients receiving ONCOXIN® died within 2 months (less than 53% patients) after the start of taking ONCOXIN® (P < 0.05, compared with patients of non-ONCOXIN® group). Five more patients died within 5 months after the start of intake of ONCOXIN®. Four patients receiving ONCOXIN® survived for more than 6 months after study commencement. CONCLUSIONS: Although this is a preliminary report, it inspires considerable optimism about safety and efficacy of a food supplement for management of patients with end-stage HCC.

Hepatic necroinflammation and severe liver fibrosis in patients with chronic hepatitis B with undetectable HBV DNA and persistently normal alanine aminotransferase.

Both consensus and controversy remains regarding surrogacy of hepatitis B virus (HBV) deoxyribonucleic acid (DNA) and alanine aminotransferase (ALT), however, these markers are used to ascertain the extent of liver damages and to guide therapeutic options in patients with chronic hepatitis B. However, little is known about liver histology of patients with chronic hepatitis B with undetectable HBV DNA and persistently normal ALT. Thirty-five incidentally-detected patients with chronic HBV infection (assessed by expression of hepatitis B surface antigen for more than 6 months) with undetectable HBV DNA and normal serum ALT were enrolled in this study. Liver biopsy specimens were taken from all patients and the extent of hepatic necroinflammation and liver fibrosis were evaluated. Moderate degree of hepatic necroinflammation was detected in 2 of 35 patients and severe hepatic fibrosis was seen in 6 of 35 patients. Two patients with undetectable HBV DNA and sustained normal ALT had moderate hepatic necroinflammation and severe hepatic fibrosis. In spite of undetectable HBV DNA for prolonged period and persistently normal ALT, some patients with chronic hepatitis B express evidences of progressive liver diseases. Large scale studies in different races and geographical regions should be accomplished to develop insights about management of these patients. Studies about extent of liver diseases in these patients should be accomplished in Treatment recommendation and management strategies should be developed for these patients.

Interaction of plant cell signaling molecules, salicylic acid and jasmonic acid, with the mitochondria of Helicoverpa armigera.

The cotton bollworm, Helicoverpa armigera is a polyphagous pest in Asia, Africa, and the Mediterranean Europe. Salicylic acid (SA) and jasmonic acid (JA) are the cell signaling molecules produced in response to insect attack in plants. The effect of these signaling molecules was investigated on the oxidative phosphorylation and oxidative stress of H. armigera. SA significantly inhibited the state III and state IV respiration, respiratory control index (RCI), respiratory complexes I and II, induced mitochondrial swelling, and cytochrome c release in vitro. Under in vivo conditions, SA induced state IV respiration as well as oxidative stress in time- and dose-dependent manner, and also inhibited the larval growth. In contrast, JA did not affect the mitochondrial respiration and oxidative stress. SA affected the growth and development of H. armigera, in addition to its function as signaling molecules involved in both local defense reactions at feeding sites and the induction of systemic acquired resistance in plants.

Hepatitis B surface antigen-negative, but HBV DNA-positive patients in Bangladesh.

Hepatitis B surface antigen (HBsAg) is regarded as sole marker of hepatitis B virus (HBV) infection in Bangladesh and most other developing countries. However, some HBV-negative subjects may harbor HBV DNA and transfusion of their blood may cause HBV infection in recipients. HBV DNA was checked in 20 patients with cryptogenic liver cirrhosis, 10 patients with hepatocellular carcinoma without any known etiology, and 10 apparently healthy subjects with elevated levels of serum alanine aminotransferase (ALT). HBV DNA was detected in 8 of 20 patients with cryptogenic liver cirrhosis, 1 of 10 patients with hepatocellular carcinoma, and 2 of 10 apparent healthy subjects with elevated ALT. However, all of them were negative for HBsAg in the sera. This study indicates that some additional mechanisms should be developed for detection of HBsAg-negative HBV-infected subjects for efficient control and management of HBV infection in Bangladesh.

Immunosuppressive functions of hepatic myeloid-derived suppressor cells of normal mice and in a murine model of chronic hepatitis B virus.

The immunosuppressive state of tumour-bearing hosts is attributable, at least in part, to myeloid-derived suppressor cells (MDSC). However, the role of MDSC in physiological conditions and diseases other than cancer has not been addressed. As the liver is a tolerogenic organ, the present study attempted to localize and assess functions of hepatic MDSC in a normal liver and in a murine model of chronic hepatitis B virus (HBV) infection. MDSC was identified in the liver of normal mice and HBV transgenic mice (TM) as CD11b(+) Gr1(+) cells by dual-colour flow cytometry. Highly purified populations of MDSC and their subtypes were isolated by fluorescence-activated cell sorting. The functions of MDSC and their subtypes were evaluated in allogenic mixed lymphocyte reaction (MLR) and hepatitis B surface antigen (HBsAg)-specific T cell proliferation assays. Normal mice-derived liver MDSC, but not other myeloid cells (CD11b(+) Gr1(-) ), suppressed T cell proliferation in allogenic MLR in a dose-dependent manner. Alteration of T cell antigens and impaired interferon-γ production seems to be related to MDSC-induced immunosuppression. In HBV TM, the frequencies of liver MDSC were about twice those of normal mice liver (13·6±3·2% versus 6·05±1·21%, n=5, P<0·05). Liver-derived MDSC from HBV TM also suppressed proliferative capacities of allogenic T cells and HBsAg-specific lymphocytes. Liver MDSC may have a critical role in maintaining homeostasis during physiological conditions. As liver MDSC had immunosuppressive functions in HBV TM, they may be a target of immune therapy in chronic HBV infection.

Mechanism of restoration of immune responses of patients with chronic hepatitis B during lamivudine therapy: increased antigen processing and presentation by dendritic cells.

Restoration of host immunity has been reported in patients with chronic hepatitis B (CHB) after treatment with lamivudine; however, the underlying mechanisms of this treatment have not been determined. This study examined the role of antigen-presenting dendritic cells (DC) in restoration of host immunity. Circulating DC were isolated from peripheral blood of 23 patients with CHB before and 1, 3, and 12 months after starting lamivudine therapy. The non-antigen-specific proliferation of DC was assessed in allogenic mixed leucocyte reaction. Dendritic cells were cultured with hepatitis B surface antigen (HBsAg) to prepare HBsAg-pulsed DC. Proliferative capacity and production of interleukin (IL)-12 and interferon (IFN)-γ of HBsAg-pulsed DC were evaluated. Circulating unpulsed DC and HBsAg-pulsed DC showed significantly higher levels of T-cell proliferation capacities 1 month after lamivudine therapy compared to proliferation levels before therapy (P<0.05). HBsAg-pulsed DC also produced significantly higher levels of IL-12 and IFN-γ with lamivudine therapy compared to levels before therapy (P<0.05). HBsAg-pulsed DC from lamivudine-treated patients induced proliferation of T cells of patients with CHB in an antigen-specific manner (P<0.05). However, T-cell stimulatory capacity of DC did not increase significantly 3 and 12 months after lamivudine therapy compared to 1 month after lamivudine therapy. Immune restoration as a result of lamivudine therapy is regulated at least in part by activation of DC. However, progressive activation of DC was not seen as treatment duration progressed, indicating the limitations of this mechanism of viral clearance.

Safety and immunogenicity of hepatitis B surface antigen-pulsed dendritic cells in patients with chronic hepatitis B.

The immune modulator capacity of antigen-pulsed dendritic cells (DC) has been documented in patients with cancers and in animal models of chronic viral infections. Cancer antigen-pulsed DC are now used for treating patients with cancer. But viral antigen-pulsed DC are not used in chronic viral-infected patients because safety of antigen-pulsed DC has not been evaluated in these patients. DC were isolated from human peripheral blood mononuclear cells by culturing with human-grade granulocyte-macrophage colony stimulating factor and interleukin-4. Human blood DC were cultured with hepatitis B surface antigen (HBsAg) for 8h to prepare HBsAg-pulsed DC. After immunogenicity assessment of HBsAg-pulsed DC in vitro, five million HBsAg-pulsed DC were administered intradermally to five patients with chronic hepatitis B (CHB) 1-3 times. HBsAg-pulsed DC were immunogenic in nature because they produced significantly higher levels of interleukin-12 and interferon-γ compared to unpulsed DC (P<0.05). Also, HBsAg-pulsed DC induced proliferation of HBsAg-specific T lymphocytes in vitro. CHB patients injected with HBsAg-pulsed DC did not exhibit generalized inflammation, exacerbation of liver damage, abnormal kidney function, or features of autoimmunity. Administration of HBsAg-pulsed DC induced anti-HBs in two patients and HBsAg-specific cellular immunity in 1 patient. This is the first study about preparation of antigen-pulsed DC using human consumable materials for treating patients with CHB. Because HBsAg-pulsed DC were safe for all patients with CHB and had immune modulation capacity in some patients, phase I and phase II clinical trials with antigen-pulsed DC in CHB and other chronic infections are warranted.

Combination therapy of lamivudine and interferon-alpha in pediatric patients with chronic hepatitis B in Bangladesh: a safe and effective therapeutic approach for pediatric CHB patients in developing countries.

Hepatitis B virus (HBV) is mainly transmitted during birth or perinatal period, however, treatment is not usually recommended for pediatric patients with chronic hepatitis B (CHB). Twelve pediatric patients with CHB in Bangladesh were treated with both lamivudine and interferon. Lamivudine was given at a dose of 3 mg/kg, daily for 12 months. Two months after commencement of lamivudine therapy, all patents were given interferon-alpha (3 million IU/square meter of body surface area) three times weekly, subcutaneously for 10 months. Combination therapy was safe for all pediatric CHB patients. The levels of serum HBV DNA became undetectable (less than 500 copies/ml) in 8 patients and reduced in 4 patients after the end of therapy. Anti-HBe was detected in 10 of 12 patients at this time point. The levels of serum alanine aminotransferase (ALT) were significantly reduced in these patients (p less than 0.05) due to therapy. Neither flare of HBV DNA nor elevation of serum ALT were detected during follow-up. In conclusion, combination therapy with lamivudine and interferon-alpha represents a new and novel therapeutic option for treatment of pediatric CHB patients.

Swine influenza (H1N1) pandemic: developing countries' perspective.

Since the first case of the current pandemic (H1N1) 2009 virus reported to WHO on 24 April 2009 on the American continent, the virus has spread in 160 countries and territories. By mid-2009, there were 135,000 cases and 816 deaths recorded. Pandemic preparedness is not advanced in most developing countries. Effective and essential measures include heightened surveillance, early detection and appropriate medical care. The use of local resources and capacity building with the assistance of developed nations will reduce the impact of this pandemic in the developing world.

Dendritic cell-based therapy as a multidisciplinary approach to cancer treatment: present limitations and future scopes.

Existence of residual cancers and recurrence of cancers are two major limitations of conventional therapies against cancers. A naturally-occurring defense system against tumor may be established in cancer patients by induction of antitumor immunity. Both polyvalent and tumor antigen-defined vaccines have been administered to cancer patients to accomplish this. However, the efficacy of these approaches is not promising. Dendritic cells (DCs) are regulator of the immune system. Antigens loaded on DCs (antigen-pulsed DCs) are able to induce immune responses when this can not be achieved by administration of antigens or vaccines only. Tumor antigen-pulsed DCs are now used for treatment of patients with cancers. But, it is unlikely that the present regimen of DC-based therapy would be an independent anticancer therapeutic approach. However, the therapeutic potentials of tumor antigen-pulsed DCs can be accentuated in cancer patients if this immune therapy is performed as part of multidisciplinary therapeutic approaches. In this review, we will describe about the concept and limitations of the present regimen of tumor antigen-pulsed DC-based therapy in cancer patients. We will further discuss how DC-based therapy can be applied as a multidisciplinary approach to cancer treatment.

Administration of dendritic cells in cancer nodules in hepatocellular carcinoma.

Dendritic cells (DCs), the most potent antigen-presenting cells in vivo, are now used for cancer immunotherapy during which they are usually administered to the blood of patients with cancer. However, the route of administration of DCs affects the magnitude of immune responses. This study was conducted to assess the safety of the direct administration of DCs into cancer nodules. DCs were generated by culturing peripheral blood mononuclear cells with granulocyte-macrophage colony-stimulating factor and interleukin-4 for 7 days. After confirming the phenotype and function, one hundred thousand DCs were injected directly into the cancer nodules of 4 patients with hepatocellular carcinoma (HCC) under ultrasonography guidance 48 h after the administration of 100% ethanol. All patients were monitored for any alteration in generalized condition, signs of inflammation, and liver and kidney function for the next 14 days. In addition, the final assessment of the safety of the administration of DCs into cancer nodules was performed 6 months after therapy commencement. The injection of 100% ethanol disrupted the HCC nodules in all 4 patients. DCs were distributed uniformly in the cancer nodules as assessed by ultrasonography. The administration of DCs into cancer nodules was well tolerated by all patients and there were no immediate or delayed side effects. The tumor marker decreased in one patient after the direct administration of DCs. Direct administration of DCs into the cancer nodules of patients with HCC was safe.

The quantification of cytochrome P-450 (CYP 3A4) mRNA in the blood of patients with viral liver diseases.

OBJECTIVE: We quantified cytochrome P-450 (CYP) 3A4 mRNA in the blood and liver of patients with viral liver diseases to determine whether CYP 3A4 expression is related to disease progression. DESIGN AND METHODS: Total RNA was extracted from 10 mL of blood from 12 normal volunteers, from 6 patients with acute hepatitis, 17 with chronic hepatitis, 12 with liver cirrhosis, and 16 with hepatocellular carcinoma. Total RNA from 1 mg of liver tissue was extracted simultaneously in 10 patients. CYP 3A4 mRNA was quantified by competitive reverse-transcription polymerase chain reaction and expressed as log copies/microliter. RESULTS: The CYP 3A4 mRNA titer in blood correlated with that of the liver (r = 0.65, P < 0.05). The CYP 3A4 mRNA titer was 1.6 +/- 0.4 in normal controls, 1.0 +/- 0.5 in acute hepatitis, 0.7 +/- 0.2 in chronic hepatitis, 0.5 +/- 0.2 in liver cirrhosis, 0.5 +/- 0.2 in hepatocellular carcinoma, and decreased with progression of liver disease (P < 0.05). CONCLUSION: These data suggest that the CYP 3A4 mRNA level in blood relates to progression of liver disease.

Impaired functional capacities of liver dendritic cells from murine hepatitis B virus (HBV) carriers: relevance to low HBV-specific immune responses.

The chronic hepatitis B virus (HBV) carrier exhibits ongoing replication of HBV and expresses abundant amounts of HBV-related antigens in the liver. However, HBV-specific immune responses are either absent or narrowly focused in these subjects. With the postulation that impaired functional abilities of liver dendritic cells (DCs) might be responsible for this, we assessed the functions of liver DCs in HBV transgenic mice (HBV-TM), an animal model of the HBV carrier state. Liver DCs were isolated from normal C57BL/6 mice and HBV-TM without the use of cytokines or growth factors. Lymphoproliferative assays were conducted to evaluate the ability of liver DCs to induce the proliferation of allogenic T lymphocytes and hepatitis B surface antigen (HBsAg)-enriched T lymphocytes. Liver DCs were stimulated with viral and bacterial products to assess their cytokine-producing capacities. In comparison to liver DCs from normal C57BL/6 mice, liver DCs from HBV-TM exhibited significantly decreased T cell proliferation-inducing capacities in allogenic mixed leucocyte reaction (P <0.05) and HBsAg-enriched T lymphocytes proliferation assays (P <0.05). Liver DCs from HBV-TM produced significantly lower levels of interleukin-12p70, tumour necrosis factor-alpha, interferon-gamma, and interleukin-6 (P <0.05) compared to liver DCs from normal C57BL/6 mice. This study provides evidence that liver DCs from HBV-TM had impaired ability to induce both innate and adaptive immune responses. This might account for a weak and almost undetectable HBV-specific immune response in chronic HBV carriers. This inspires hope that up-regulation of the functions of liver DCs in situ may have therapeutic implications in chronic HBV carriers.

Production of hepatitis B surface antigen-pulsed dendritic cells from immunosuppressed murine hepatitis B virus carrier: evaluation of immunogenicity of antigen-pulsed dendritic cells in vivo.

Vaccines containing hepatitis B surface antigen (HBsAg) induce antibody to HBsAg (anti-HBs) in most normal individuals and protects them from hepatitis B virus (HBV) infection. However, these vaccines are not efficient at inducing anti-HBs in immunosuppressed individuals, especially in immunosuppressed HBV carriers. The aim of this study was to prepare and to assess the efficacy of a dendritic cell (DC)-based vaccine in an immunosuppressed HBV transgenic mouse (HBV-Tg), an animal model of the HBV carrier state. In order to prepare immunosuppressed HBV-Tg, HBV-Tg were injected with FK-506, an immunosuppressive agent, once daily, intraperitoneally for 15 days. Spleen cells of immunosuppressed HBV-Tg expressed very little mRNAs for interleukin-2 and interferon-gamma. DCs were isolated from the spleen of immunosuppressed HBV-Tg and cultured with HBsAg (100 microg) for 48 h to prepare HBsAg-pulsed DCs. Immunosuppressed HBV-Tg expressing HBsAg in the sera were administered with HBsAg-pulsed DCs or unpulsed DCs or HBsAg in adjuvant for different durations. Immunosuppressed HBV-Tg (n = 8) twice administered with HBsAg-pulsed DCs expressed anti-HBs in the sera within 6 weeks of first injection. Seven of eight immunosuppressed HBV-Tg remained positive for anti-HBs in the sera for the next 12 weeks of observation in spite of receiving daily injection of FK-506 for the entire duration. However, immunosuppressed HBV-Tg administered with unpulsed DCs or HBsAg in adjuvant did not express anti-HBs in the sera. The data show that DCs from immunosuppressed HBV-Tg can be loaded with HBsAg to prepare immunogenic HBsAg-pulsed DCs. HBsAg-pulsed DCs induced anti-HBs in immunosuppressed HBV-Tg. This approach may be of use to induce and maintain anti-HBs in immunosuppressed human HBV carriers.