# PROCESSING OF IA MOLECULES IN B CELLS AND MACROPHAGES

> **NIH NIH R01** · WASHINGTON UNIVERSITY · 1987 · $146,444

## Abstract

Ia molecules are polymorphic glycoproteins which regulate the major
histocompatibility complex (MHC)-restricted recognition of the cooperating
cells that bear them with a class of T cells (Class II restricted) that
includes the bulk of the TH (helper cell) population.  On the surface of
the antigen-presenting cell (APC), Ia molecules are recognized together
with processed exogenous antigen, and thereby trigger the T cell to a
differentiative response resulting in "activation," i.e., capability to
deliver help in an antigen-restricted (Ir-gene controlled) fashion. On the
surface of the cell receiving help, Ia molecules promote recognition by the
antigen-activated TH cell, resulting in delivery of a signal to
differentiate.

The differential capacities of Ia molecules to promote response to a
particular antigenic determinant (Ir gene effect) is dependent on variation
in Ia primary structure (amino acid sequence). In addition, there is
evidence that secondary structural features (post-translational
modifications) of Ia molecules, which vary on functionally different cell
types, influence the recognition of Ia by T cells.  This work involves:
(1) description of secondary structural features of Ia, such as N-linked
oligosaccharide, in functionally different cell populations; (2)
correlation of such structural features with functions such as
antigen-specific T-cell binding and proliferation; and (3) intentional
modification of the secondary structure to generate changes in function.
We will also be examining the role of a newly discovered chondroitin
sulfate proteoglycan (CSPG) specifically associated with Ia in modifying
the interaction of Ia with T cells.  Methods to be employed are T cell
binding and proliferation assays, serial lectin affinity chromatography,
exoglycosidase sequencing, and in situ manipulations of la expression or
structure by pharmacological, enzymatic, or other approaches.  (AG)

## Key facts

- **NIH application ID:** 3171371
- **Project number:** 5R01CA033529-06
- **Recipient organization:** WASHINGTON UNIVERSITY
- **SAM.gov UEI:** L6NFUM28LQM5
- **Principal Investigator:** SUSAN E CULLEN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $146,444
- **Award type:** 5
- **Project period:** 1982-07-01 → 1990-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3171371

## Citation

> US National Institutes of Health, RePORTER application 3171371, PROCESSING OF IA MOLECULES IN B CELLS AND MACROPHAGES (5R01CA033529-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3171371. Licensed CC0.

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