|Functional consequences of impaired autophagy in aging|
Mechanisms of Antigen Processing and Presentation in Aging Dendritic Cells
» Autophagy and Antigen
» Characterization of lysosomal processing compartments
Project 2 will investigate different aspects of antigen processing and presentation during immunosenescence.
In particular we will determine:
Endogenous and exogenous antigens delivery pathways
We recently were able to elute peptides from MHC class II proteins affinity purified from endosomal compartments. Several of these peptides derived from processed endogenous proteins entering lysosomal compartments through MA or CMA. These sequenced peptides represent the first processed antigens eluted directly from endosomal compartments and not from total cell lysates.
Efficiency of antigen loading will also be determined in a quantifiable manner using a conformational specific antibody which recognizes specific MHC class II molecules loaded with the relevant peptide.
We will determine efficiency of T cell responses in each age group as well
as possible differences in T cell clonal selection by Vb and Va
spectratyping. Such analysis is particularly important because it would
allow the determination of whether an homogeneous quantitative reduction
in the T cell repertoire is accountable for the decreased immunological
response in aged mice or whether a decrease in selected populations is
observed. More importantly T cell spectratyping performed on antigen
specific T cells from immunized mice will determine whether the clonal TCR
expansion and immunological memory to the immunizing antigens is the same
or different in each age group. This information will prove particularly
useful in vaccine design for an aging population.
Dr. Laura Santambrogio
Immunolocalization of HLA-Dr in multilamellar bodies in dendritic cells.
convergence of the autophagic and endocytic compartment in old dendritic cells green: mitotracker red: BSA-Tx Red