Class II MHC Self-Antigen Presentation in Human B and T Lymphocytes

Human CD4[superscript +] T cells process and present functional class II MHC-peptide complexes, but the endogenous peptide repertoire of these non-classical antigen presenting cells remains unknown. We eluted and sequenced HLA-DR-bound self-peptides presented by CD4[superscript +] T cells in order to compare the T cell-derived peptide repertoire to sequences derived from genetically identical B cells. We identified several novel epitopes derived from the T cell-specific proteome, including fragments of CD4 and IL-2. While these data confirm that T cells can present peptides derived from the T-cell specific proteome, the vast majority of peptides sequenced after elution from MHC were derived from the common proteome. From this pool, we identified several identical peptide epitopes in the T and B cell repertoire derived from common endogenous proteins as well as novel endogenous epitopes with promiscuous binding. These findings indicate that the endogenous HLA-DR-bound peptide repertoire, regardless of APC type and across MHC isotype, is largely derived from the same pool of self-protein.National Institutes of Health (U.S.) (grant P01AI039671)National Institutes of Health (U.S.) (P01AI045757

A Kinetic Investigation of Peptidic Hydrogels derived from Semenogelin-­I

Hydrogels have many applications in medical research. They can most generally be defined as a cross-linked polymer network that is able to absorb a large amount of water while retaining a degree of structural integrity. Due to their unique physical and chemical properties, hydrogels are currently being developed for applications in wound treatment, drug delivery and tissue generation. We are investigating the hydrogel forming properties of a series of peptides derived from the protein Semenogelin I, which have been found to form a hydrogel under physiological conditions. We are investigating factors that affect gel formation, including peptide length, concentration and pH. Using size exclusion chromatography, we first isolate the peptide monomer and then perform kinetics studies using thioflavin T fluorescence to follow the aggregation process, which generates entangled fibrils consisting of beta-sheet. Disc centrifugation is used to determine the size of these aggregates. The primary objective of this investigation is to establish a protocol that generates consistent and reliable data with regard to the aggregation. Through a combination of size exclusion chromatography and Thioflavin T fluorescence, we have derived a successful method to study the kinetics of Semenogelin-I hydrogel formation

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

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