# IMMUNOREGULATORY MECHANISMS IN THE RHEUMATIC DISEASES

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 1987 · $167,141

## Abstract

The objective has been to characterized immunoregulatory abnormalities in
patients with connective tissue diseases.  Our studies originally focused
on a subset of human blood lymphocytes with high density Fc receptors for
IgG which we called "L cells."  These lymphocytes are part of a larger
population characterized by a unique morphological appearance and which
react with monoclonal antibodies which recognize the Type III complement
receptor (CR3).  We plan to separate L cells and other CR3+ lymphocyte
subsets, determine their relationship with T cells and determine their
regulatory effects on B cell activity in patients with Systemic Lupus
Erythematosus.

We have recently observed that lymphocytes from patients with both active
and inactive SLE have an impaired capacity to produce interleukin 2 in
vitro.  Moreover, these patients have spontaneously activated T8+
lymphocytes that inhibit IL-2 production.  We plan to determine whether
this is an inherited, primary immunologic defect in SLE or whether it is a
secondary manifestation of the disease.  This will be accomplished by a
study of Twins with SLE.

Our last objective is to determine the relationship of the IL-2 defect and
B lymphocyte hyperactivity in SLE.  This will be accomplished by
determining the effects of interleukin 2 on lymphocytes which regulate the
production of B cell growth factors and which have direct effects on B cell
functions.  We will determine whether CR3+ lymphocytes are involved in
these regulatory circuits.  These studies should lead to a better
understanding of pathogenetic mechanisms in patients with the connective
tissue diseases.

## Key facts

- **NIH application ID:** 3155707
- **Project number:** 5R01AR029846-07
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **SAM.gov UEI:** G88KLJR3KYT5
- **Principal Investigator:** DAVID A HORWITZ
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $167,141
- **Award type:** 5
- **Project period:** 1980-09-01 → 1989-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155707

## Citation

> US National Institutes of Health, RePORTER application 3155707, IMMUNOREGULATORY MECHANISMS IN THE RHEUMATIC DISEASES (5R01AR029846-07). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155707. Licensed CC0.

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