Exploring the Leishmania Hydrophilic Acylated Surface Protein B (HASPB) Export Pathway by Live Cell Imaging Methods

Abstract

Leishmania major is a human-infective protozoan parasite transmitted by the bite of the female phlebotomine sand fly. The L. major hydrophilic acylated surface protein B (HASPB) is only expressed in infective parasite stages suggesting a role in parasite virulence. HASPB is a "nonclassically" secreted protein that lacks a conventional signal peptide, reaching the cell surface by an alternative route to the classical ER-Golgi pathway. Instead HASPB trafficking to and exposure on the parasite plasma membrane requires dual N-terminal acylation. Here, we use live cell imaging methods to further explore this pathway allowing visualization of key events in real time at the individual cell level. These methods include live cell imaging using fluorescent reporters to determine the subcellular localization of wild type and acylation site mutation HASPB18-GFP fusion proteins, fluorescence recovery after photobleaching (FRAP) to analyze the dynamics of HASPB in live cells, and live antibody staining to detect surface exposure of HASPB by confocal microscopy.

In silico designing of a novel polyvalent multi-subunit peptide vaccine leveraging cross- immunity against human visceral & cutaneous leishmaniasis: An Immunoinformatics-based approach

“…Heat shock proteins (HSPs) are highly conserved molecules which are highly immunogenic too inducing both MHC-I and MHC-II pathways of adaptive immunity and are thought to have a pertinent role in vaccine development against infectious leishmaniasis (Holakuyee et al 2012). Leishmania Hydrophilic Acylated Surface Protein-B (HASP-B) is expressed only in infective parasites suggesting a role in parasite virulence and therefore, a potential vaccine candidate (MacLean et al 2016). Kinetoplastid para agellar rod (PFR) proteins are also of therapeutic and prophylactic importance due to their restricted evolutionary distribution, high order organization and high immunogenicity (Maharana et al 2015).…”