# ROLE OF FOLLICULAR ANTIGEN-BINDING DENDRITIC CELLS

> **NIH NIH R01** · VIRGINIA COMMONWEALTH UNIVERSITY · 1991 · $147,435

## Abstract

Our work focuses on one of the most basic questions in immunology--what
happens to the immunogen during the induction of a secondary response?
In immune animals Ag encounters Ab and is almost instantaneously
converted into Ab-Ab complexes. These complexes are quickly trapped,
endocytosed, and catabolized by macrophages.  This process occurs
quickly and by 48 hours after immunization very little Ag persists in or
on these macrophages.  However, some immune complexes enter an
"alternative" follicular dendritic cell (FDC) dependent pathway which
serves to utilize Ag efficiently and preserves some Ag for months and
perhaps years.  For several days after secondary challenge, the
dendritic processes of FDC form and release immune complex coated bodies
or "iccosomes" which are endocytosed by germinal center B cells.  Major
tenets of the basic hypothesis are FDC present Ag to specific follicular
B cells and that follicular B cells endocytose the iccosomes then
process and present Ag to follicular T cells.  The T cells provide
factors needed for formation of the germinal center, production of Ab,
and B memory cells.  Although FDC release iccosomal Ag for a few days
after challenge, most Ag persists on the FDC and functions in
conjunction with an Ab feedback system to maintain immune responses.
The feedback system determines when and how much is released from the
FDC for processing.  In this application we propose to study both the
induction maintenance of anamnestic responses in mice lacking FDC.  If
our hypotheses are correct, anamnestic responses should be grossly
aberrant. Iccosomal Ag appears to be highly immunogenic.  We propose to
establish the relative immunogenicity of iccosomal Ag, Ag-Ab complexes
and free Ag and determine the role of the sIg B cell receptor in the
uptake of iccosomes.  Finally, we propose to study regulation of the
germinal center reaction by T cells.  The immunological significance of
FDC and iccosomes is only beginning to be understood.  Clearly more
information is needed but only a few groups around the world are
focusing on FDC and their products.

## Key facts

- **NIH application ID:** 3126988
- **Project number:** 2R01AI017142-12
- **Recipient organization:** VIRGINIA COMMONWEALTH UNIVERSITY
- **SAM.gov UEI:** MLQFL4JSSAA9
- **Principal Investigator:** John G Tew
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $147,435
- **Award type:** 2
- **Project period:** 1980-09-01 → 1996-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126988

## Citation

> US National Institutes of Health, RePORTER application 3126988, ROLE OF FOLLICULAR ANTIGEN-BINDING DENDRITIC CELLS (2R01AI017142-12). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126988. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*