MORÓN VÍCTOR GABRIEL
Congresos y reuniones científicas
Título:
Lsp1-/- DENDRITIC CELLS HAVE SIMILAR MHC II KINETICS DESPITE THEIR IMPAIRED ABILITY TO PRESENT ANTIGENS TO CD4+ LYMPHOCYTES.
Autor/es:
NICOLAS DANIEL DHO; MERCEDES PASCUAL; MARÍA INÉS CRESPO; BELKYS A. MALETTO; G MORON
Lugar:
virtual
Reunión:
Congreso; LXIX REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI); 2021
Institución organizadora:
SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI)
Resumen:
Leukocyte-specific protein 1 (LSP1) is a 52kDa cytoplasmic F-actin
binding phosphoprotein expressed in all human and murine
leukocytes and endothelial cells. LSP1 is an important regulator
of actin cytoskeleton remodelling. We have previously shown that
Lsp1-/- dendritic cells (DCs) have a defective antigen presentation
to CD4+ T cells compared to DCs from wild type (WT) mice. In order
to study whether defective antigen presentation in Lsp1-/- mice
is due to alteration in MHC class II dynamics, we evaluated I-Ab
kinetics expression on cell surface and intracellulary in Lsp1-/- DCs
upon activation with CpG-ODN. DCs were in vitro derived from bone marrow precursors with Flt3-L and stimulated with CpG-ODN 1826,
at different times (1-2-3-4-8-12 and 18h) they were collected and
stained with anti-I-Ab antibody (Ab) either permeabilized or not,
to measure total or cell surface content of I-Ab and analyzed by
flow cytometry. We found that total and cell surface I-Ab molecules
increases in Lsp1-/- DCs upon stimulation similar than DCs from
Lsp1+/+ mice, with a peak in both cases at 3h. Intracellular content
of I- Ab increased more than cell surface expression in both
groups and remained high for at least 18h. Analyzing the kinetics of
peptide-I-Ab complexes on DC surface by incubating DCs with the
Ea52-68 peptide (which binds to I-Ab) and then labeling them with
Y-Ae Ab (which recognizes I-Ab-Ea52-68 complex) by flow cytometry,
we observed that these complexes remained stable up to 24h
after on surface in Lsp1-/- and Lsp1+/+ stimulated DCs at similar
levels. These results suggests that the altered antigen presentation
in Lsp1-/- DCs could be related to other steps in Ag processing and
not to MHC II dynamics.
binding phosphoprotein expressed in all human and murine
leukocytes and endothelial cells. LSP1 is an important regulator
of actin cytoskeleton remodelling. We have previously shown that
Lsp1-/- dendritic cells (DCs) have a defective antigen presentation
to CD4+ T cells compared to DCs from wild type (WT) mice. In order
to study whether defective antigen presentation in Lsp1-/- mice
is due to alteration in MHC class II dynamics, we evaluated I-Ab
kinetics expression on cell surface and intracellulary in Lsp1-/- DCs
upon activation with CpG-ODN. DCs were in vitro derived from bone marrow precursors with Flt3-L and stimulated with CpG-ODN 1826,
at different times (1-2-3-4-8-12 and 18h) they were collected and
stained with anti-I-Ab antibody (Ab) either permeabilized or not,
to measure total or cell surface content of I-Ab and analyzed by
flow cytometry. We found that total and cell surface I-Ab molecules
increases in Lsp1-/- DCs upon stimulation similar than DCs from
Lsp1+/+ mice, with a peak in both cases at 3h. Intracellular content
of I- Ab increased more than cell surface expression in both
groups and remained high for at least 18h. Analyzing the kinetics of
peptide-I-Ab complexes on DC surface by incubating DCs with the
Ea52-68 peptide (which binds to I-Ab) and then labeling them with
Y-Ae Ab (which recognizes I-Ab-Ea52-68 complex) by flow cytometry,
we observed that these complexes remained stable up to 24h
after on surface in Lsp1-/- and Lsp1+/+ stimulated DCs at similar
levels. These results suggests that the altered antigen presentation
in Lsp1-/- DCs could be related to other steps in Ag processing and
not to MHC II dynamics.
