M. Mohamadzadeh et al., FRESHLY ISOLATED MOUSE 4F7(-CELLS() SPLENIC DENDRITIC CELLS PROCESS AND PRESENT EXOGENOUS ANTIGENS TO T), European Journal of Immunology, 24(12), 1994, pp. 3170-3174
The antibody 4F7 was reported to recognize an epitope expressed on den
dritic cells (DC) from various tissues. To study the ability of spleni
c 4F7(+) dendritic cells to process antigen for presentation to CD4(+)
T cells, DC were enriched using a separation procedure avoiding overn
ight culture which could lead to an altered phenotype. These DC were u
sed as antigen-presenting cells (APC) in stimulation cultures of major
histocompatibility complex class II-restricted T cells. It was found
that they induce antigen-dependent lymphokine production by T cells an
d therefore could present exogenous antigens. These processing takes p
lace intracellularly, because fixation abrogates presentation to T cel
ls. Moreover, antigen presentation needs intracellular processing with
in endo- or lysosomes as chloroquine-treatment prevents T cell activat
ion. Titration of APC numbers revealed that contaminating APC most lik
ely did not account for antigen-specific T cell activation by DC. No e
vidence was found for release of antigenic peptides or for partial ant
igen processing possibly done by cell surface located enzymes on DC. I
n conclusion, these results indicate that freshly enriched DC are able
to process antigens similarly to other APC.