# FACTORS INFLUENCING COMPLEMENT LYSIS OF RED CELLS

> **NIH NIH R01** · UNIVERSITY OF ROCHESTER · 1987 · $185,200

## Abstract

Emerging from a broad interest in the biological functions of the
complement system, this proposal focuses on the cytolytic action of human
complement from two standpoints:  (1) the reciprocal interplay between the
C5b-9 membrane attack mechanism and properties of a target membrane
influencing susceptibility to lysis; (2) the lysis-inhibiting action of
human high density lipoproteins (HDL) and their apoproteins on the terminal
events of complement (C) lysis.  Within this framework we propose a
detailed, quantitative analysis of the interaction of late-acting C
components with selected cell types:  (a) human erythrocytes from normal
donors and patients with paroxysmal nocturnal hemoglobinuria (PNH), as well
as normal human red cells chemically modified to produce "PNH-like" lytic
sensitivity; (b) guinea pig erythrocytes (also highly vulnerable to human
C5b-9); and (c) sheep erythrocytes, for reference.  The basis for the
differing sensitivity to C lysis of these cell types will be sought by
quantitative complement techniques, biophysical probes, chemical analyses,
and studies with resealed ghosts and erythrocyte-derived lipid vesicles.
The mechanism and precise site of action of the lysis-inhibiting effect of
HDL apoproteins will be sought, as will an explanation for their differing
effectiveness as inhibitors with the above-listed red cell types.  The
physiologic significance of this newly recognized function of HDL will be
explored with HDL-depleted serum.

## Key facts

- **NIH application ID:** 3129130
- **Project number:** 5R01AI019738-05
- **Recipient organization:** UNIVERSITY OF ROCHESTER
- **SAM.gov UEI:** F27KDXZMF9Y8
- **Principal Investigator:** JOHN P LEDDY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $185,200
- **Award type:** 5
- **Project period:** 1983-02-01 → 1989-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129130

## Citation

> US National Institutes of Health, RePORTER application 3129130, FACTORS INFLUENCING COMPLEMENT LYSIS OF RED CELLS (5R01AI019738-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3129130. Licensed CC0.

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