Dynamic of Immune Response induced in Hepatitis B Surface Antigen-transgenic Mice Immunized with a Novel Therapeutic Formulation.

Unlabelled: The development of therapeutic vaccines against chronic hepatitis B requires the capacity of the formulation to subvert a tolerated immune response as well as the evaluation of histopathological damage resulting from the treatment. In the present study, the dynamicity of induced immune response to hepatitis B surface antigen (HBsAg) was evaluated in transgenic mice that constitutively express the HBsAg gene (HBsAg-tg mice). After immunization with a vaccine candidate containing both surface (HBsAg) and core (HBcAg) antigens of hepatitis B virus (HBV), the effect of vaccination on clearance of circulating HBsAg and the potential histological alterations were examined.

HBV genotypic variability in Cuba.

The genetic diversity of HBV in human population is often a reflection of its genetic admixture. The aim of this study was to explore the genotypic diversity of HBV in Cuba. The S genomic region of Cuban HBV isolates was sequenced and for selected isolates the complete genome or precore-core sequence was analyzed.

Two mucosal-parenteral schedules to coadminister a multiantigenic formulation against HIV-1 in Balb/c mice.

Previous studies showed that simultaneous immunization through the nasal (IN) and subcutaneous (SC) route of a multiantigenic formulation induced a Th1 anti-HIV humoral and cellular immune responses. The formulation was comprised of a recombinant protein of HIV-1 (named CR3; Cellular Response number 3) and the surface and nucleocapsid antigens of hepatitis B virus. This study asks whether four times simultaneous administration through the IN and SC routes (SC+IN) of the multiantigenic formulation induces a similar systemic and mucosal immune responses than two sequential IN priming and two SC boosting (2IN&2SC) inoculations in mice.

The effect of the parenteral route of administration on the immune response to simultaneous nasal and parenteral immunizations using a new HBV therapeutic vaccine candidate.

Chronic hepatitis B is a major health problem, with more than 350 million people infected worldwide. Available therapies have limited efficacy and require long-term continuous and expensive treatments, which often lead to the selection of resistant viral variants and rarely eliminate the virus. Immunotherapies have been investigated as a promising new approach.

Anti-HIV-1 and anti-HBV immune responses in mice after parenteral and nasal co-administration of a multiantigenic formulation.

The cell-mediated immune response to HIV-1 is an essential element of the mechanisms for viral replication control. Currently, most of the vaccine candidates in clinical trials were developed to stimulate HIV-1-specific CD8+ cytotoxic (CTL) and CD4+ T helper (Th) lymphocytes. We have been working on a novel approach to develop a vaccine formulation for HIV-1 using a recombinant multiepitopic protein (named CR3), which comprises CTL and Th epitope-rich regions of HIV-1 from several subtype B isolates, co-inoculated with the hepatitis B virus surface (HBsAg) and core (HBcAg) antigens of the hepatitis B virus (HBV) as adjuvant.

Influence of aluminum-based adjuvant on the immune response to multiantigenic formulation.

Several adjuvants have been described and tested in humans. However, the aluminum-based adjuvants remain the most widely used component in vaccines today. Emerging data suggest that aluminum phosphate and aluminum hydroxide adjuvants do not promote a strong commitment to the helper T cell type 2 (Th2) pathway when they are coadministered with some Th1 adjuvants.

Coinoculation with hepatitis B surface and core antigen promotes a Th1 immune response to a multiepitopic protein of HIV-1.

It has been defined that strong and multispecific cellular immune responses correlate with a better prognosis during the course of chronic diseases. A cross-enhancing effect on the resulting immune response obtained by the coadministration of recombinant hepatitis B virus (HBV) surface and core Ag was recently observed. With the objective of studying the effect of such Ag on the immune response to coinoculated heterologous Ag and vice versa, several formulations containing the recombinant HBV Ag and a multiepitopic protein (CR3) composed by CTL and Th epitopes from HIV-1 were evaluated by s.