Understanding the Role of B Cells in Cross Presentation of Antigen to CD8+ T Cells

Abstract

To elicit robust T-cell response, antigen presenting cells (APCs) play a crucial role in antigen (Ag) presentation. In liver-stage malaria, CD8α+ DCs have been shown to play an essential role in the induction of CD8+ T-cell responses. They have also shown to activate CD8+ T cells upon being licensed with cognate help of CD4+ T-cells via CD40 signaling. Like the DCs have the ability to process the exogenous Ag through the MHC Class-I pathway, Ag specific B cells are shown to regulate or activate CD8+ T-cells. It is yet to be fully understood whether B cells can cross present the Ag to liver-stage specific CD8+ T cells. The whole sporozoite vaccine (WSV) is able to induce sterile immunity in humans and it is found that important immune effectors are antibodies that target sporozoites while entering liver, and T-cells that target infected hepatocytes. This lead us to think that B cell might be involved in the cross priming of CD8+ Tcell against liver stage specific Ag. Present study focuses on studying the induction of CD8+ T cells to chicken ovalbumin (OVA) and Plasmodium falciparum circumsporozoite protein (Pf- CSP) through BCR mediated antigen uptake by B cells or Ag-Ab immune-complex.