# PHYSICOCHEMICAL STUDIES OF IMMUNE COMPLEXES

> **NIH NIH R01** · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · 1990 · $185,379

## Abstract

Immune complexes (IC) are formed in the circulation or in tissue
fluids as a consequence of the interaction between antigens and
their corresponding antibodies (Ab).  Many properties of IC,
including clearance from the circulation, complement fixation, and
adherence to phagocytes, depend on IC size and composition.  The
chronic presence of IC has been implicated in the pathology of
several diseases including systemic lupus erythematosus, rheumatoid
arthritis, and neoplastic disease.  The demonstration that activity
which blocks the immune response to tumors can be removed by
incubation of serum with protein A has motivated studies of plasma
adsorption onto immobilized protein A in a number of tumor systems.
Excellent success has been reported in treatment of lymphosarcoma
and leukemia in FeLV-infected cats, and variable success has been
reported in clinical studies with humans having a variety of
neoplastic disease.  No systematic study to delineate the myriad
reactions occurring during immunoadsorption treatment of plasma has
been undertaken.  A more complete understanding of the phenomena
must be attained if this technique is to be advanced in application
to IC and Ab-mediated diseases.  Our research objectives are to:
(1) determine the parameters that govern size, composition, and
structure of IC, (2) investigate and dependence of IC size and
composition on binding and activation of complement, and (3) define
the reactions that occur upon contact of IC with immunoadsorbents
such as immobilized protein A.  Model IC constructed from two or
more monoclonal Ab and bovine serum albumin will be characterized
in terms of a variety of physicochemical properties, including
molecular weight and size distribution, composition, overall
structure, and mean hydrodynamic radius using electron microscopy,
quasi-elastic and classical light scattering, small angle neutron
scattering, high performance liquid chromatography,
radioimmunoassays, and mathematical models.  Purified complement
components will be incubated with model IC; the dependence of
complement fixation and activation on IC size, structure, and com-
position will be measured.  Similarly, IC will be incubated with
immunoadsorbents to analyze adsorption effects.  These fundamentals
studies will provide the basis for experiments using IC isolated
from sera of FeLV-infected cats.  The proposed research will
enhance our understanding of IC formation and behavior and will
provide a rational basis for development and design of
immunoadsorption techniques which may be applied diagnostically or
therapeutically to a variety of disease states.

## Key facts

- **NIH application ID:** 3171715
- **Project number:** 5R01CA033956-06
- **Recipient organization:** MASSACHUSETTS INSTITUTE OF TECHNOLOGY
- **SAM.gov UEI:** E2NYLCDML6V1
- **Principal Investigator:** CLARK K COLTON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $185,379
- **Award type:** 5
- **Project period:** 1987-07-01 → 1991-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3171715

## Citation

> US National Institutes of Health, RePORTER application 3171715, PHYSICOCHEMICAL STUDIES OF IMMUNE COMPLEXES (5R01CA033956-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3171715. Licensed CC0.

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