Stimulation of a memory B cell response does not require primed helper T cells

Abstract

The use of universally immunogenic T cell epitopes, such as those identified in tetanus toxin or malaria circumsporozoite protein, could represent a major improvement in the development of synthetic vaccines. However, one limitation of this approach is the lack of T cell cross-reactivity between the vaccine and the pathogen. To determine whether the memory B cell response elicited by immunization with a synthetic peptide containing a B cell epitope linked to a T cell epitope can be restimulated by the same B cell epitope linked to different T cell epitope(s), we used a synthetic peptide which contains non-overlapping B and T cell determinants from hepatitis B surface antigen (HBsAg) of hepatitis B virus (HBV). The results of this study clearly show that primed T cells can increase the antibody response against a B cell epitope linked to the priming T cell determinant. However, the antibody response obtained was weaker than that obtained after two injections of the peptide containing both B and T cell epitopes, showing the important role played by memory B cells in secondary antibody responses. Moreover, a strong antibody response against the B cell epitope was elicited by boosting mice with the B cell epitope linked to a heterologous carrier, thus demonstrating that a strong B cell memory response can be revealed in the absence of primed T cells. These results therefore provide new important information for the design of synthetic or recombinant vaccines.

Long-Term Humoral and Cellular Immune Response to Hepatitis B Vaccine in High-Risk Children 18–20 Years After Neonatal Immunization

“…Yet, only 50% of seropositive participants displayed specific IFN-g-producing cells. This observation did not come as a surprise because the stimulation of a memory B-cell response does not require primed T helper cells (12). In this study we did not observe any association between the level of anti-HBs and the presence of the T-helper type 1 cytokine, IFN-g (Table 1), in contrast to the findings of the study of Lu et al (15), who found a positive correlation between post-booster ELISPOT assay results and anti-HBs titers.…”

Long-Term and Memory Immune Responses in Mice against Newcastle Disease Virus-Like Particles Containing Respiratory Syncytial Virus Glycoprotein Ectodomains

“…Similarly, a complex of ovalbumin and alum, which forms a particulate antigen, did not require T cell help for the activation of memory B cells (21). These results led MacLeod et al to suggest that requirements for T cells in activation of memory B cells vary with the form of the antigen and that stimulation of B cell memory responses to particulate antigens may be T cell independent (22).…”

Assessing the Binding of FourPlasmodium falciparumT Helper Cell Epitopes to HLA-DQ and Induction of T-Cell Responses in HLA-DQ Transgenic Mice

“…Since T-cell epitopes have to be presented by HLA class II molecules in order to be recognized by T cells, it is essential to include a combination of peptides or a promiscuous peptide that can be bound by at least one HLA molecule expressed in an individual in order for the peptide to generate an effective immune response. The inclusion of such a T helper epitope(s) linked to an appropriate B-cell determinant can potentially induce antibody responses in a genetically heterogeneous human population (17).…”