# OPSONINS IN NEONATAL IMMUNITY TO GROUP B STREPTOCOCCI

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 1991 · $131,464

## Abstract

The proposed studies will further elucidate the mechanisms by which group B
streptococci (GBS) interact with host defense components which mediate
their opsonization and clearance.  The aim of these studies is to prove the
hypothesis that physiologic maturation of one or more immune mechanisms
during the first months of life provides an explanation for the
age-specific interval of infant susceptibility to invasive GBS infection.
The binding of human plasma fibronectin (FN) to GBS and relevance of the
maturation of plasma FN levels to opsonic efficiency for GBS in infancy
will be defined by:  (1) employing radiolabeled FN chromatographically
purified to determine the strain and serotype specificity of FN binding to
GBS; (2) exploring the role of proteins, sialic or lipotechoic acid as
receptors for FN binding and the influence of purified opsonins (Clq and
specific antibody) in modulating binding; and (3) correlating plasma FN
levels with maturation of opsonic efficiency for GBS in relationship to the
maturation of complement and specific antibody in the first six months of
life.  These studies will employ opsonically defined sera from normal
infants and a group surviving GBS disease.  The reticuloendothelial system
(RES) clearance of GBS will be characterized using a neonatal guinea pig
(GP) model of infection by (1) determining the efficiency of bloodstream
clearance and RES localization (hepatic and splenic) by GBS serotype in
normal and C4-deficient GP; (2) defining the roles of terminal sialic acid
residues and the sufficiency of the alternative complement pathway (ACP) in
modulating RES clearance; and (3) blocking selectively hepatic
asialoglycoprotein or phagocytic Fc receptors to determine the mechanism by
which RES clearance occurs in neonates.  Finally, the evolution of
immunospecific IgG subclass antibodies to Ia and III-GBS will be determined
between birth and six months of age by ELISA to establish their
relationship to invasive disease vs. colonization and their influence on
the development of functional activity.

## Key facts

- **NIH application ID:** 3129227
- **Project number:** 5R01AI019800-09
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **SAM.gov UEI:** FXKMA43NTV21
- **Principal Investigator:** MORVEN S EDWARDS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $131,464
- **Award type:** 5
- **Project period:** 1983-04-01 → 1993-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129227

## Citation

> US National Institutes of Health, RePORTER application 3129227, OPSONINS IN NEONATAL IMMUNITY TO GROUP B STREPTOCOCCI (5R01AI019800-09). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3129227. Licensed CC0.

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