Exploring the Association of Surface Plasmon Resonance with Recombinant MHC:Ig Hybrid Protein as a Tool for Detecting T Lymphocytes in Mice Infected withLeishmania (Leishmania) amazonensis

Abstract

A surface plasmon resonance- (SPR-) based recognition method applying H-2 Ld:Ig/peptides complexes for ex vivo monitoring cellular immune responses during murine infection with Leishmania (Leishmania) amazonensis is described. Lymphocytes from lesion-draining popliteal lymph nodes were captured on a carboxylated sensor chip surface previously functionalized with H-2 Ld:Ig (DimerX) protein bound to synthetic peptides derived from the COOH-terminal region of cysteine proteinase B of L. (L.) amazonensis. In computational analysis, these peptides presented values of kinetic constants favorable to form complexes with H-2 Ld at neutral pH, with a Gibbs free energy ΔG° < 0. The assayed DimerX:peptide complexes presented the property of attaching to distinct T lymphocytes subsets, obtained from experimentally infected BALB/c mice, in each week of infection, thus indicating a temporal variation in specific T lymphocytes populations, each directed to a different COOH-terminal region-derived peptide. The experimental design proposed herein is an innovative approach for cellular immunology studies of a neglected disease, providing a useful tool for the analysis of specific T lymphocytes subsets.

Insights into the tracking of the cysteine proteinase B COOH-terminal polypeptide of Leishmania (Leishmania) amazonensis by surface plasmon resonance

“…In macrophages, amastigote Cyspep is released during the maturation of pro-CPB and is directed to intracellular processing pathways of the mouse MHC system. Taken together, these findings suggest that the parasite may use protein processing products to establish an infection in the vertebrate host by modulating the type 1 or type 2 immune response (Alves et al 2004;Pereira et al 2011;Souza-Silva et al 2014;Da Silveira-Júnior et al 2017).…”

Combining Well‐Tempered Metadynamics Simulation and SPR Assays to Characterize the Binding Mechanism of the Universal T‐Lymphocyte Tetanus Toxin Epitope TT830‐843

“…DimerX was bound to the COOH5 chip by the Fc region and exhibited an average binding rate of 4548 RU/s ( Figure 8(a) ). Therefore, the α 1 and α 2 domains of the H-2D b protein were free to interact with the peptide in solution, as previously shown to identify H-2 epitopes and detect specific CD8 + T-lymphocytes in the immune response of Leishmania ( Leishmania ) amazonensis cysteine proteinase B [ 46 , 47 ].…”

Reactivity of sera from dogs living in a leishmaniasis-endemic area to the COOH-terminal region of cysteine proteinase B

“…As most cases in the Montes Claros region are cases of L. (L.) infantum and L. (V.) braziliensis infection, it is possible that the assessed dog sera may content antibodies that recognized the linear sequence of amino acids or specific adjacent amino acid strings at different points in folded cyspep protein. 25 , 33 , 34 …”

“…Additionally, as cyspep is released by amastigotes during pro-CPB maturation, 21 it is plausible that the parasite may use cyspep to establish infection in the dog host by modulating the humoral and cellular immune responses, as proposed for natural human infection 20 and experimental mouse infection. 22 , 34 Thus, the clinical presentation and evolution of canine leishmaniasis could be a consequence of interactions between parasite products, such as cyspep, and dog immune components.…”