Inmunogenicidad de proteínas recombinantes comparada con el empleo de herramientas bioinformáticas / Immunogenicity of recombinant proteins compared with the use of bioinformatics tools

Objetivo: para determinar la utilidad de herramientas inmunoinformáticas para detectar péptidos que puedan ser inmunodominantes, y evaluar las diferencias entre las respuestas inmunes de los modelos animales empleados en los estudios preclínicos y en los humanos. Métodos: se modeló la respuesta frente a dos proteínas exógenas: la estreptocinasa recombinante y el antígeno de superficie de la hepatitis B. A partir de sus secuencias primarias se emplearon algoritmos para identificar epítopes B y T frente a moléculas HLA de clase I y II (HLA-A*0201, HLA-DRB1*0301 y HLA-DRB1*0701) y los haplotipos murinos H2-Kd y H2-Kk. Se seleccionaron los péptidos de más alta puntuación. Resultados: el algoritmo ABCPred mostró una mejor capacidad de predicción de epítopes B, mientras fue mayor la coincidencia para los programas de modelación de la respuesta T. Los epítopes generados para el haplotipo H2-Kk tuvieron una similitud mayor con los presentados por las moléculas HLA seleccionadas. Conclusiones: se presenta una metodología aplicable al desarrollo de vacunas de subunidades y multiepitópicas, así como para otros fármacos biotecnológicos de naturaleza peptídica, que permite optimizar las etapas preclínicas y clínicas, a muy bajo costo, mínimos requerimientos tecnológicos, utilización óptima de medios, recursos y capital humano disponibles en cualquier institución del sistema nacional de salud

Objective: determine the usefulness of immunoinformatics tools to detect potentially immunodominant peptides, and evaluate the differences between the immune responses provided by the animal models used in preclinical and human studies. Methods: modeling was conducted of the response to two exogenous proteins: recombinant streptokinase and hepatitis B surface antigen. Based on their primary sequences, algorithms were used to identify B and T epitopes against HLA class I and II molecules (HLA-A*0201, HLA-DRB1*0301 and HLA-DRB1*0701), and murine haplotypes H2-Kd and H2-Kk. The highest scoring peptides were chosen. Results: ABCPred algorithm showed a better prediction capacity for B epitopes, whereas coincidence was greater in modeling programs for the T response. The epitopes generated for haplotype H2-Kk had greater similitude with those presented by the HLA molecules selected. Conclusions: a methodology is presented which is applicable to the development of subunit and multiepitope vaccines, as well as other peptidic biotechnological drugs. This methodology allows optimization of the preclinical and clinical phases at a very low cost, with minimal technological requirements, optimal use of media, and resources and human capital available at any institution of the national health system

Preparation and immunological evaluation of oral solution of egg yolk-derived hepatitis B virus-specific transfer factor / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare the oral solution of egg yolk hepatitis B virus (HBV)-specific transfer factor (EYHBV-TF) and evaluate its immunological activity as an immune regulator against hepatitis B.</p><p><b>METHODS</b>From hens immunized with the Hepatitis B vaccine the egg yolk was isolated to extract the specific transfer factor EYHBV-TF, and its physicochemical properties were examined. Leukocyte adhesion inhibition test (LAI) was performed to detect the immunogenic activity of EYHBV-TF. The solution of EYHBV-TF was then administered orally in normal mice, and the specific cellular immune activity induced was assayed with delayed type skin hypersensitivity test (DTH), with the non-specific immune activity assessed with immune organ index. The immune responses induced by oral EYHBV-STF solution were compared with those by EYHBV-STF injection and by different dosages (injection and oral) of porcine spleen HBV-specific transfer factor (PSHBV-STF), porcine spleen nonspecific transfer factor, and egg yolk extracts from non-immunized hens.</p><p><b>RESULTS</b>The prepared EYHBV-STF oral solution, which met the standards for biological products, could inhibit leukocyte adhesion in vitro and significantly enhance mouse foot pad swelling, demonstrating its capability of transferring antigen-specific delayed type hypersensitivity reactions to naive recipient. EYHBV-STF oral solution also significantly improved the immune organ index in mice (P<0 01) with similar effects to those caused by EYHBV-STF injections and by PSHBV-STF injection and oral solution.</p><p><b>CONCLUSION</b>Orally administered EYHBV-STF and EYHBV-STF injection both possess hepatitis B antigen-specific cellular immune activity and can significantly enhance specific cellular immune responses.</p>

Association between HLA-DRB1* polymorphisms and hepatitis B infection in a brazilian population / Associação entre polimorfismos HLA-DRB1* e infecção por hepatite B em uma população brasileira

OBJECTIVE: The aim of the present study was to determine the genotype association for alleles of class II human leukocyte antigens (HLA) in the DRB1* locus among blood donors at the Fundação Hemope (Brazil) infected by or immunized for the hepatitis B virus (HBV). METHODS: A case-control study was performed, comprising a group of individuals infected by HBV and a control group of immunized individuals at a proportion of 1:4. Blood samples were taken for the HLA typing of the DRB1* locus. Univariate and multivariate analyses were performed for the assessment of associations between the categorical variables using the chi-squared test and Fisher's exact test. RESULTS: A total of 320 blood donors were analyzed (241 males [75%] and 79 females [25%] with a mean age of 39 years). The case group consisted of 64 HBV-infected donors and the control group was composed of 256 HBV-immunized donors. The multivariate analysis stratified by gender revealed that the DRB1*09 allele was associated with infected male donors (p = 0.016) and the DRB1*08 allele was associated with infected donors aged 39 years or younger (p = 0.031). CONCLUSION: The results of the present study reveal that younger blood donors and male blood donors who respectively exhibit the DRB1*08 and DRB1*09 alleles are more susceptible to intensification of HBV infection.

OBJETIVO: O objetivo do presente estudo foi determinar a associação genotípica dos alelos de classe II dos antígenos leucocitários humanos (HLA) presentes no locus DRB1* entre doadores de sangue da Fundação Hemope (Brasil), infectados pelo ou imunizados contra o vírus da hepatite B (HBV). MÉTODOS: Estudo caso-controle foi realizado com um grupo de indivíduos infectados pelo HBV e um grupo controle composto de indivíduos imunizados na proporção de 1:4. Amostras de sangue foram coletadas para a tipagem HLA do locus DRB1*. Análises univariada e multivariada foram realizadas para a avaliação de associações entre as variáveis categóricas pelo teste do qui-quadrado e teste exato de Fisher. RESULTADOS: Um total de 320 doadores de sangue foram analisados (241 homens [75%] e 79 do sexo feminino [25%], com idade média de 39 anos). O grupo de casos consistiu de 64 doadores infectados pelo HBV e o grupo controle foi composto de 256 doadores imunes ao HBV. A análise multivariada estratificada por sexo revelou que o alelo DRB1*09 foi associado com os doadores infectados do sexo masculino (p = 0,016) e do alelo DRB1*08 foi associado com os doadores infectados com idade entre 39 anos ou mais jovens (p = 0,031). CONCLUSÃO: Os resultados do presente estudo revelam que doadores de sangue mais jovens e doadores de sangue do sexo masculino que exibem, respectivamente, os alelos DRB1*08 e DRB1*09, são mais suscetíveis à cronificação da infecção pelo HBV.

Production of immunoglobulin Y (IgY) against synthetic peptide analogs of the immunogenic epitopes of the hepatitis B surface antigen

Introduction. Several studies have been conducted on the use of Immunoglobulin Y (IgY) technology in the fields of diagnostics and therapeutics. IgY is the avian counterpart of the mammalian immunoglobulin G (IgG) which is exclusively transferred from the hen to the yolk thus conferring passive immunization to the growing embryo. However, despite the advantages it offers over the use of mammalian immunoglobulin, IgY technology has remained underutilized. Objective. The objective of this study is to produce an IgY with activity against synthetic peptide analogs of known immunogenic epitopes of the Hepatitis B Surface Antigen (HBsAg) - a molecular marker of Hepatitis B infection. Methods. Chickens were immunized with synthetic peptide analogs of previously reported immunogenic epitopes of the S and the pre-S1 regions of the Hepatitis B surface antigen (HBsAg). IgY specific for the synthetic peptides was isolated by delipidation and salt precipitation and was further purified by affinity chromatography. Purity and molecular weights of the whole IgY molecule and its subunits were assessed and determined by SDS-PAGE. Anti-peptide activity and specificity were determined by indirect ELISA. The study was approved by the Ethical Review Board (ERB) and Technical Review Board of the Research Implementation and Development Office (RIDO), University of the Philippines Manila. Results and Conclusion. The IgY that was purified in this study had an approximate molecular weight of 165 kilodaltons. The heavy and light chains are 60 and 28 kilodaltons, respectively. The affinity purified IgY demonstrated anti-peptide antibody activity against synthetic peptide analogs of known immunogenic epitopes of the HBsAg. Specific binding against a battery of synthetic peptides also revealed that the affinity purified IgY specifically binds to the known immunogenic epitope of the HBsAg.

Characterization of hepatitis B virus antigen expression in vitro and in vivo transduced by different transfer plasmids carrying HBV infectious genome / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To character HBV antigen expression in vitro and in vivo transduced by different transgenic plasmids carrying infectious genome of hepatitis B virus (HBV).</p><p><b>METHODS</b>We constructed four different lentiviral transfer plasmids (carrying 1.3 full-length genome of HBV, by replacing the EGFP express box in pCS-CG plasmid with HBV genome and with different structural element, named as pCS-HBV1.3 (pCS-HBV1.3 X, pCS-HBV1.3 P, pCS-HBV1.3 N and pCS-HBV1.3 K). We detected the expression of HBsAg and HBeAg by ELISA in different time after transfected Huh 7 cells or hydrodynamic injection into C57 BL/6 mice with transfer plasmids pCS-HBV, respectively.</p><p><b>RESULTS</b>We detected significant expression of HBsAg over 5 days after transfected Huh 7 cells (in vitro) or hydrodynamic injection into C57 BL/6 mice (in vivo) with transfer plasmids pCS-HBV1.3 X, pCS-HBV1.3 P and pCS-HBV1.3 K. The expression level and dynamics of HBsAg and HBeAg in the sera of mice is consistent with that of in the supernatant of Huh-7 cell. Furthermore, the expression of HBV antigens were modulated by the direction and position of HBV insert, also by some lentiviral vector cis-elements (cPPT and RRE).</p><p><b>CONCLUSION</b>The optimal lentiviral transfer plasmids (pCS-HBV1.3 X, pCS-HBV1.3 P and pCS-HBV1.3 K) could be further used for establishment and application of HBV transgenic cell or animal model.</p>

The analysis of hepatitis delta virus infective markers in the hepatitis is B virus infective people / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the distribution of hepatitis delta virus (HDV) marker among hepatitis B virus (HBV) infected patients and to reveal its clinical significance.</p><p><b>METHOD</b>To collect the clinical data and sera samples of HBV infected patients and to detect HDAg, Anti-HDV as well as HBV infection markers by means of enzyme-linked immunosorbnent assay. These data combined with clinical diagnostic results and biochemical index were then analyzed.</p><p><b>RESULT</b>462 samples of HBV infected patients were collected including 210 HBV carriers without symptom, 175 chronic HBV infections, 35 acute HBV infections and 42 liver fibrosis. The HDV infection rate was 4.8% overall. The highest infection rate of 9.5% was found in the group of liver fibrosis whereas the lower rate of 6.9% was found in HBV chronic carriers. HDV infection rate was 7.8% among the population of 40-60 years old, obviously higher than any other age groups.</p><p><b>CONCLUSION</b>HDV infection was significantly higher in the chronic HBV patients and liver fibrosis patients. Because HDV infection was highly associated with the progress of liver disease, we suggest the screen of HDV markers among hepatitis patients and discriminate whether the patient was co-infected with HDV.</p>

Seroprevalencia de hepatitis viral B en estudiantes universitarios en Abancay, Perú / Seroprevalence of viral hepatitis B in university students in Abancay, Perú

Para determinar la prevalencia de marcadores serológicos de hepatitis viral B en estudiantes universitarios de la ciudad de Abancay, realizamos un estudio transversal en 240 estudiantes de tres universidades, entre enero a octubre de 2010. Previo consentimiento informado, se llenó, por cada estudiante, una ficha epidemiológica y se tomó una muestra sanguínea para determinar la presencia de HBsAg, anti-HBcAg total, anti-HBe, HBeAg e IgM anti-HBc por el método de ELISA. Se encontró una prevalencia de 2,5 por ciento (seis seropositivos) para el HBsAg y 28,3 por ciento (68 seropositivos) para los anticuerpos Anti-HBcAg. El sexo masculino estuvo asociado con la presencia del anti-HBcAg (OR = 2,0; IC 95 por ciento, 1,2- 3,6). No se encontró la presencia del HBeAg e IgM anti-HBc; los seis portadores del HBsAg fueron anti-HBe positivos. En conclusión, la infección por hepatitis B sigue siendo un problema de salud pública en Abancay, con una prevalencia importante en estudiantes universitarios.

To determine the prevalence of serological markers of viral hepatitis B in university students of the city of Abancay, we performed a cross-sectional study on 240 students from three universities, from January to October 2010. Informed consent was requested to every student, an epidemiological record was filled, and a venous blood sample was drawn to determine the presence of HBsAg, total anti - HBcAg, anti - HBe, HBeAg and IgM Anti - HBc by ELISA. A prevalence of 2.5 percent (six positive samples) was found for HBsAg and of 28.3 percent (68 positive samples) for anti - HbcAg antibodies. The male sex was associated with the presence of anti - HBcAg (OR = 2.0, 95 percent CI, 1.2 to 3.6). We did not found HBeAg or IgM anti - HBc, however, the 6 HBsAg carriers were anti - HBe positive. In conclusion hepatitis B infection is still a public health problem in Abancay, with a significant prevalence in university students.

Non-association of IL-12 +1188 and IFN-gamma +874 polymorphisms with cytokines serum level in occult HBV infected patients

Occult hepatitis B infection [OBI] is identified as a form of hepatitis in which despite the absence of detectable HBsAg, HBV-DNA is observed in peripheral blood of patients. The main aim of this study has been to investigate the association between polymorphisms in +874 of IFN-gamma and +1188 of IL-12 with their serum level in patients suffering from OBI. In this experimental study, plasma samples of 3700 blood donors were tested for the presence of hepatitis B surface antigen [HBsAg] and anti-HBc by ELISA. The HBsAg[-]/anti-HBc[+] samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases and ARMS-PCR techniques were performed to examine the two known polymorphisms within IL-12 and IFN-gamma. In addition, the serum levels of IL-12 and IFN-gamma were also determined by ELISA. Results of this study demonstrated that, 352 [9.5%] out of 3700 blood samples were HBsAg[-]/anti-HBc[+]and HBV-DNA was detected in 57/352 [16.1%] of HBsAg[-]/anti-HBc[+] samples. Our results showed that groups showed significant difference in CC allele of +1188 region of IL-12 and no difference was observed in the other evaluated genes. Our results also showed that the alleles of +1188 region of IL-12 and alleles of +874 of IFN-gamma were also not associated with serum level of cytokines. According to the results of this study, it may be concluded that the polymorphisms in +1188 region of IL-12 and +874 region of IFN-gamma would not affect the expression of both cytokines at serum level in OBI patients

Study on HBV antigens and IL-12 affecting T cell-mediated immunity in HBsAg carriers / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effect of HBV antigens and pathological mechanism of chronic HBV infection by analyzing the cellular immune function of peripheral blood mononuclear cells (PBMCs) from HBsAg carriers.</p><p><b>METHODS</b>PBMCs were prepared from individuals with chronic asymptomatic HBV infection and cultured in the presence of different antigens and/ or cytokines. The levels of cytokines in culture supernatants were detected by ELISA method. The phenotype of the cells was detected by FACS.</p><p><b>RESULTS</b>The levels of IFN y secreted by PBMCs from HBsAg carriers were (48.3+/-19.8) pg/ml, significantly lower than that from healthy controls (t = 3.023, P less than 0.05); The IFN y produced by PBMCs from HBeAg positive patients due to HBsAg and HBcAg stimulation were (50.4+/-51.6) pg/ml and (63.2+/-36.9) pg/ml, significantly lower than that of HBeAg negative patients (t = 2.468 and 3.184, P less than 0.05, respectively). The IL-12p70 secreted by PBMCs from HBeAg positive patients was also significantly lower than that of HBeAg negative patients (P less than 0.05); Exogenous IL-12 promoted significantly PBMCs to secrete IFN y (P less than 0.01) and IL-12 combined with HBV antigens activated CD8+CD45RA+CCR7+ and CD8+CD45RA-CD62L+ cells. IL-12 secreted by PBMCs decreased in HBeAg positive patients, which may be the crucial reason of viral persistence in chronic HBV carriers. Exogenous IL-12 combined with specific HBV antigen could promote the central memory CD8+ T cells to produce IFN y.</p>

The influence of HBV and its antigens on the expressions of JAK-STAT signal transduction pathway molecules and antiviral proteins of IFN alpha / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the possible influence of HBV and its antigens on the expressions of JAK-STAT signal transduction pathway molecules and the antiviral proteins of IFN alpha.</p><p><b>METHODS</b>The HepG2 cells were transfected with pSM2, pHBS2-S and pHBc-EGFP plasmids which express HBV whole particles or S-antigen, Pre-S antigen and core antigens. The infectious supernatant from HepG2.2.15 cells and the pured HBV proteins which contained the S, Pre-S antigens were used to treat the HepG2 cells. Northern blot and RT-PCR were applied to analyse the expressions of the antiviral proteins MxA, 2' -5' OAS, 9-27 and the JAK-STAT signal transduction pathway molecules STAT1 in HepG2 cells responded to the IFN alpha treatment.</p><p><b>RESULTS</b>The HepG2 cells transfected with pSM2, pHBS2-S and pHBc-EGFP plasmids could express whole HBV particles and HBsAg, Pre-S antigen and HBcAg. The quantitation of expressed HBV particles and antigens increased significantly during the course of transfection. Northern blot hybridization analysis indicated that the HepG2 cells expressed IFN alpha antiviral proteins MxA, 2' -5' OAS and 9-27. When transfected with pHBV-dimer, pHBS2-S, pHBc-EGFP plasmids, the IFN/A antiviral proteins MxA, 2' -5' OAS and 9-27 in transfected cells were reduced greatly as compared to the un-transfected HepG2 cells, and the expressed antiviral proteins decreased sharply with the development of transfection time. Furthermore, the expression of IFN alpha JAK-STAT signal transduction pathway molecule STAT1 was also inhibited with the expression of HBV particles and HBV antigens in transfected HepG2 cells.</p><p><b>CONCLUSIONS</b>The HBV and its antigens influence the expressions of IFN alpha JAK-STAT signal transduction pathway molecules and antiviral proteins in the hepatocellular models in vitro. It is indicated that HBV might possess the activity to antagonise or counteract the IFN alpha antiviral action.</p>

Immunosuppressant dexamethasone can significantly extend the expression of hepatitis B virus antigens in the HBV mouse model by hydrodynamic transfection method / 病毒学报

To develop a HBV infection mouse model by hydrodynamic-based transfection and further to optimize the method of development of HBV infection mouse model. We first developed a construct which contained inverted terminal repeat elements (ITR) of adeno-associated virus (AAV) and 1. 3 copies of HBV genome (ayw subtype). The pAAV-HBV1. 3 DNA was then injected hydrodynamically into the tail veins of C57BL/6 mice in 5 seconds. The virus load in serum and liver was assayed by ELISA and Real-time PCR. The expression of virus antigen and the pathologic changes of liver were analyzed by HE and immunohistochemical staining. Meanwhile, to develop HBV transfected immunosuppressied mouse, mice were injected intraperitoneally triple with 0.2 ml dexamethason (50 mg/kg) every two days before HBV transfection. The levels of HBsAg and HBeAg were assayed by ELISA. Our data showed: (1) HBsAg and HBeAg were positive (100%) in serum and liver of experimental normal mouse at day 10 after HBV transfection, and became negative at day 30 and day 60. Meanwhile the viral load in serum and liver in experimental group was significantly higher than that in control group at day 10, 30 and 60 after HBV transfection (P < 0.01, P < 0.05, respectively). (2) HBsAg and HBeAg in serum in immunosuppressed mouse model were positive until 60 days. In conclusion, a HBV infection mouse model was developed successfully by hydrodynamic-based transfection. By suppressing the immune status of mice injected with dexamethasone, the expression of HBV antigens was extended longer than that in normal adult mice. These models pave a way for HBV research and evaluation of HBV vaccine and drug development.

Recombinant adenovirus-mediated expression of 1.2-copy hepatitis B virus DNA in three hepatocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To study hepatitis B virus (HBV) expression in 3 hepatocytes infected with recombinant adenovirus containing 1.2-copy HBV DNA.a</p><p><b>METHODS</b>A chicken hepatoma cell line and two human hepatocytes were infected by the recombinant adenovirus containing 1.2-copy HBV DNA at 25 pfu/cell. HBV-specific mRNA was detected by RT-PCR 3 days after the infection, and HBsAg and HBeAg were detected by ELISA and HBV DNA by real-time PCR daily after the infection.</p><p><b>RESULTS</b>HBV mRNA expression was detected in all the 3 cells after recombinant adenovirus infection, and the quantities of HBV DNA and HBV antigens in the culture supernatant increased with the passage of time.a</p><p><b>CONCLUSION</b>Infection with the recombinant adenovirus containing 1.2-copy HBV DNA can mediate HBV infection in the 3 cells in vitro.</p>

A construct competent to support the replication of hepatitis B virus of genotype B / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To construct a vector that is competent to support the replication of hepatitis B virus (HBV) of genotype B.</p><p><b>METHODS</b>The HBV genome of genotype B was amplified by PCR and ligated into pBlueskript II KS(+) vector, the resulting plasmid was verified by enzyme digestion and DNA sequencing. After transfection of this plasmid into Huh7 cells, the HBsAg and HBeAg antigens in culture medium were quantified by ELISA, the transcripts and replication intermediates of HBV were detected by northern blot and southern blot respectively. On the other hand, the plasmid was hydrodynamically injected into BALB/cJ mice via tail vein. Then the HBV DNA in serum was quantified by real-time PCR, and HBcAg expression in liver tissue was detected by immunohistochemistry.</p><p><b>RESULTS</b>After transfection of the plasmid into Huh7 cells, the HBsAg and HBeAg antigens were detected in the culture medium, the transcripts and replication intermediates of HBV were detected in the cells. High titer of HBV DNA was detected in the serum of hydrodynamic-injected mice. Immunostaining indicated that HBcAg was expressed in hepatocytes of injected mice.</p><p><b>CONCLUSION</b>This construct is competent to support the replication of hepatitis B virus of genotype B.</p>

Pregnant women hepatitis B markers investigation and analysis of intrauterine infection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the hepatitis B virus (HBV) infection in pregnant women and intrauterine infection in local region.</p><p><b>METHODS</b>The markers of hepatitis B (HBVM) were determined by time-resolved fluoroimmunoassay and HBV-DNA were determined by FQ-PCR.</p><p><b>RESULTS</b>A total of 1262 pregnant women were examined the HBVM, 2.6%, 38.2%, 0.9%, 22.6%, 23.1% subjects were identified HBsAg, HBsAb, HBeAg, HBeAb, HBcAb positive respectively. In 33 cases of serum HBsAg-positive pregnant women, HBV-DNA were observed in most of 11 cases of pregnant women with HBeAg-positive and intrauterine infection rates were 6/11. In contrast, 22 cases of pregnant women with HBeAg negative, HBV-DNA were detected lowly-loaded and intrauterine infection rates were 2/22 (P < 0.01). Intrauterine infection rates of HBV in pregnant women with HBsAg-positive were 24.2% (8/33).</p><p><b>CONCLUSION</b>HBV infective rates in pregnant women in the local region were low. Pregnant women with serum HBeAg positive and HBV-DNA high-loaded were prone to intrauterine infection.</p>

Detection of peripheral blood HBV-LHBs transactivation function and its relationship with anti-viral efficacy / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Explore the serum of patients with CHB of HBV large envelope protein (HBV-LHBs) trans-activation function and antiviral therapy effect relationship.</p><p><b>METHODS</b>60 cases of anti-viral treatment of patients with chronic hepatitis B to take every 3 months HBVDNA, HBV-LHBs, as well as detection of hepatitis B immune markers to observe the changes in indexes.</p><p><b>RESULTS</b>Income group 60 cases of anti-virus group HBVDNA with HBV-LHBs have a higher detection rate of the consistency of the results found no statistical significance (P > 0.05), HBV-LHBs-positive rate and positive rate of HBeAg differences (chi2 = 4.08, P < 0.05). After 24 months of antiviral therapy HBV-LHBs expression always HBVDNA in 29 cases of which occurred 24 months after the negative reaction of the 20 cases, continuous positive were seven cases of non-negative. 60 cases of patients 24 months found no HBsAg seroconversion, four cases of emergence of HBeAg seroconversion.</p><p><b>CONCLUSION</b>(1) detection of serum HBV-LHBs to reflect the hepatitis B virus replication with HBVDNA good correlation. (2) anti-viral treatment of dynamic observation of the process of HBV-LHBs expression can predict the effectiveness of anti-viral therapy.</p>

Situación actual de la hepatitis B en Chile / Present situation of hepatitis B in Chile

Background: Hepatitis B virus infection generates carriers and 8 percent will evolve to a chronic phase. Aim: To perform a compilation of studies on hepatitis B in Chile and other sources of information to estímate the impact of this disease in our country. Material and methods: Published and unpublished evidence about the infection, in the general population and risk groups in our country, was compiled and reviewed critically. Informal interviews to experts, revisión of the mandatory notification book of the Ministry of Health and collection of data from laboratories that study hepatitis B virus, were also carried out. Results: The seroprevalence of chronic carriers in blood donors is nearly O.3 percent. Among risk groups such as health care personnel, the figure is O.7 percent, among homosexuals 29 percent, among HIV positive patients 30 percent, among sexual workers 2 percent and among children with chronic hemodialysis, 9 percent. Prevalence rate according to notified cases in 2004 was 1.8 x 100,000 habitants. Detection of viral hepatitis B surface antigen in ¡aboratories occurs in 0.2 percent of donors and 1.396 of non donors. Conclusions: The seroprevalence of hepatitis B virus, the lack of notification, and the introduction of hepatitis B vaccine to our Regular Program of Immunizations, are arguments to develop in Chile a hepatitis B and C surveillance system.

Estudos de expressão do HBsAg: hepatite B oculta, genótipos do HBV e quimeras de HBV e HCV / Studies of expression of the HBsAg: occult hepatitis B, genotypes of the HBV and chimeras of HBV and HCV

Introdução: O vírus da hepatite B (HBV) é classificado em oito genótipos (A-H), que apresentam uma distribuição geográfica característica nas diferentes regiões do mundo. No Brasil, são encontrados principalmente os genótipos A, D e F. A infecção pelo HBV é comumente diagnosticada pela presença do antígeno de superfície viral (HBsAg) no soro de indivíduos infectados. Mutações no HBsAg podem afetar os níveis de secreção deste antígeno, bem como, alterar a sua conformação, e conseqüentemente, inibir a sua detecção pelos testes imunoenzimáticos. A detecção do DNA viral em pacientes com sorologia negativa para o HBsAg caracteriza a ocorrência de infecção oculta pelo HBV. Partículas híbridas de HBsAg, também denominadas quimeras, têm sido utilizadas com bastante eficiência na apresentação de epítopos exógenos. Objetivos: Realizar estudos de expressão in vitro do HBsAg em células eucarióticas visando (i) associar infecção oculta pelo HBV com mutações de aminoácidos no HBsAg; (ii) avaliar possíveis diferenças na detecção do HBsAg relacionadas aos diferentes genótipos do HBV; e (iii) possibilitar a construção de quimeras de HBV e do vírus da hepatite C (HCV) para produção de proteínas híbridas imunizantes. Metodologia: A clonagem das regiões genômicas do envelope do HBV foi realizada utilizando-se os vetores de expressão em células eucarióticas pcDNA3 e/ou pCI. Para a inserção do segmento de HCV no HBsAg, foi utilizado um sítio de restrição natural localizado na região do epítopo neutralizante do HBsAg. Ensaios de transfecção transitória foram realizados em células CHO e/ou HuH7. O meio de cultura e os extratos celulares foram analisados quanto à detecção de HBsAg por ensaios imunoenzimáticos. Ensaios de imunofluorescência, utilizando um anticorpo monoclonal anti-HBs, foram realizados para detectar a localização intracelular do HBsAg. Resultados: 1) A infecção oculta pelo HBV foi detectada em 6/43 (14por cento) pacientes infectados pelo HIV. A ocorrência de...HBsAg.