# PHYSICOCHEMICAL STUDIES OF IMMUNE COMPLEXES

> **NIH NIH R01** · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · 1987 · $278,839

## 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
treament 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 dependance 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 composition 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:** 3171711
- **Project number:** 2R01CA033956-04
- **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:** 1987
- **Award amount:** $278,839
- **Award type:** 2
- **Project period:** 1987-07-01 → 1990-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3171711

## Citation

> US National Institutes of Health, RePORTER application 3171711, PHYSICOCHEMICAL STUDIES OF IMMUNE COMPLEXES (2R01CA033956-04). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3171711. Licensed CC0.

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