Hepatitis B virus (HBV)-specific in vitro antibody production by peripheral blood mononuclear cells (PBMC) after vaccination by recombinant hepatitis B surface antigen (rHBsAg)

Abstract

SUMMARYTo study the immunization induced by rHBsAg, we analysed the in vitro antibody production (IVAP) to HBsAg by PBMC from 18 subjects vaccinated by two injections on days 0 and 30. HBsAg-specific IVAP was detectable in all subjects after both the first and the second injection, and lasted for about 10 days and then disappeared. However, when the spontaneous HBsAg-specific IVAP became negative, HBsAg stimulation of PBMC cultures induced again a specific HBsAg IVAP. Cultures of cell populations separated by erythrocyte rosetting or Percoll density centrifugation showed that the cells responsible for spontaneous secretion, after in vivo stimulation, were low-density B lymphocytes. Highdensity B lymphocytes were involved in anti-HBs production induced by in vitro stimulation when spontaneous secretion disappeared. These data suggest that the IVAP test could be a source of important information along with serologic analysis for exploration of the immune response to hepatitis B vaccine.

A new vaccine escape mutant of hepatitis B virus causes occult infection

“…Thus, viral mutations in CTL epitopes were able to evade cellular immunity and contribute to persistency. [17][18][19] The aa 171-179 20,21 and aa175-184 22,23 is the antigenic epitopes of HBV presented by HLA class I molecules. In this region, we found 3 new mutations (S171F, S174N and Q181R) on HBV which infected patient X.…”

Induction of a specific antibody response to Bordetella pertussis antigens in cultures of human peripheral blood mononuclear cells

“…In a similar way, antibody production to rHBsAg in vitro has been proposed as a useful mean of exploration of the immune response to hepatitis B vaccine [31]. Further work is necessary to fully define and to exploit the possibilities provided by this approach and, in particular, to estimate whether it can help to define the state of memory induced by natural exposure or by primary vaccination in infants.…”

HBsAg Variants: Common Escape Issues

“…The humoral response to HBsAg is T cell-dependent. At least four regions within the HBsAg present epitopes for MHC class II restricted CD4+ T cells (Table 2) (35,36).…”

“…Similarly, the MHC class I-restricted CDB+CTL response plays a key role in suppressing HBV infections. Schirmbeck et al (38) showed that in H-2b mice even small changes in amino acid residues within the two different CTL epitopes that mimic natural variants of adw2, ayr and adr, completely (Table 2) (35,36,40,41). In general, viral mutations in CTL epitopes were able to evade cellular immunity and thus contribute to persistency (42,43).…”