90 Placental transfer of SARS-CoV-2 specific antibodies from mothers to newborns

Shigella is the second leading cause of diarrheal diseases, accounting for >200,000 infections and >50,000 deaths in children under 5 years of age annually worldwide. The incidence of Shigella-induced diarrhea is relatively low during the first year of life and increases substantially, reaching its peak between 11 to 24 months of age. This epidemiological trend hints at an early protective immunity of maternal origin and an increase in disease incidence when maternally acquired immunity wanes. The magnitude, type, antigenic diversity, and antimicrobial activity of maternal antibodies transferred via placenta that can prevent shigellosis during early infancy are not known. To address this knowledge gap, Shigella-specific antibodies directed against the lipopolysaccharide (LPS) and virulence factors (IpaB, IpaC, IpaD, IpaH, and VirG), and antibody-mediated serum bactericidal (SBA) and opsonophagocytic killing antibody (OPKA) activity were measured in maternal and cord blood sera from a longitudinal cohort of mother-infant pairs living in rural Malawi. Protein-specific (very high levels) and Shigella LPS IgG were detected in maternal and cord blood sera; efficiency of placental transfer was 100% and 60%, respectively, and had preferential IgG subclass distribution (protein-specific IgG1 > LPS-specific IgG2). In contrast, SBA and OPKA activity in cord blood was substantially lower as compared to maternal serum and varied among Shigella serotypes. LPS was identified as the primary target of SBA and OPKA activity. Maternal sera had remarkably elevated Shigella flexneri 2a LPS IgM, indicative of recent exposure. Our study revealed a broad repertoire of maternally acquired antibodies in infants living in a Shigella-endemic region and highlights the abundance of protein-specific antibodies and their likely contribution to disease prevention during the first months of life. These results contribute new knowledge on maternal infant immunity and target antigens that can inform the development of vaccines or therapeutics that can extend protection after maternally transferred immunity wanes.

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Placental Transfer of Dengue Virus (DENV)–Specific Antibodies and Kinetics of DENV Infection–Enhancing Activity in Brazilian Infants

The Journal of Infectious Diseases ◽

10.1093/infdis/jiw143 ◽

2016 ◽

Vol 214 (2) ◽

pp. 265-272 ◽

Cited By ~ 24

Author(s):

Priscila M. S. Castanha ◽

Cynthia Braga ◽

Marli T. Cordeiro ◽

Ariani I. Souza ◽

Claudeir D. Silva ◽

...

Keyword(s):

Dengue Virus ◽

Placental Transfer ◽

Denv Infection ◽

Specific Antibodies ◽

Kinetics Of

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Repertoire of naturally acquired maternal antibodies transferred to infants for protection against shigellosis

10.1101/2021.05.21.445178 ◽

2021 ◽

Author(s):

Esther Ndungo ◽

Liana R Andronescu ◽

Andrea G Buchwald ◽

Patricia Mawindo ◽

Miriam K Laufer ◽

...

Keyword(s):

Cord Blood ◽

Placental Transfer ◽

Disease Incidence ◽

Shigella Flexneri ◽

Maternal Serum ◽

Maternal Antibodies ◽

Endemic Region ◽

Specific Antibodies ◽

Maternal Immunity ◽

Epidemiological Trend

Shigella is the second leading cause of diarrheal diseases, accounting for >200,000 infections and >50,000 deaths in children under 5 years of age worldwide. The incidence of Shigella-induced diarrhea is relatively low during the first year of life and increases substantially (reaching its peak) between 11 to 24 months of age. This epidemiological trend hints to an early protective immunity of maternal origin and an increase in disease incidence when maternal immunity wanes. The magnitude, type, antigenic diversity and anti-microbial activity of maternal antibodies transferred via placenta that can prevent shigellosis during early infancy are not known. To address this knowledge gap, Shigella -specific antibodies directed against the lipopolysaccharide (LPS) and virulent factors (IpaB, IpaC, IpaD, IpaH and VirG) and antibody mediated serum bactericidal (SBA) and opsonophagocytic killing antibody (OPKA) activity were measured in maternal and cord blood sera from a longitudinal cohort of mother-infant pairs living in rural Malawi. Protein-specific IgG (very high levels) and Shigella LPS were detected in maternal and cord blood sera; efficiency of placental transfer was 100% and 60%, respectively and was associated with IgG subclass distribution (protein-specific IgG1 > LPS-specific IgG2). In contrast, SBA and OPKA activity in cord blood was substantially lower as compared to maternal serum and varied among Shigella serotypes. LPS was identified as a target of SBA and OPKA activity. Maternal sera had remarkably elevated Shigella flexneri 2a LPS IgM indicative of recent exposure. Our study revealed a broad repertoire of maternally acquired antibodies in infants living in a Shigella-endemic region and highlights the abundance of protein-specific antibodies and their likely contribution to disease prevention during the first months of life. These results contribute new knowledge on maternal infant immunity and target antigens that can inform the development of vaccines or therapeutics that can extend protection after maternal immunity wanes.

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Selective Transfer of Maternal Antibodies in Preterm and Term Children

10.21203/rs.3.rs-1076115/v1 ◽

2021 ◽

Author(s):

Sepideh Dolatshahi ◽

Audrey L Butler ◽

Christian Pou ◽

Ewa Henckel ◽

Anna Karin Bernhardsson ◽

...

Keyword(s):

Placental Transfer ◽

Selective Transfer ◽

Term Infants ◽

Specific Antibodies ◽

Functional Quality ◽

Organ Specific ◽

Functional Antibodies ◽

Cellular Immune ◽

Antibody Levels ◽

Functional Profiles

Abstract Preterm newborns are more likely to suffer from infectious diseases at birth compared to children delivered at term. Whether this is due to compromised cellular, humoral, or organ-specific development remains unclear. Recent studies have shown that while preterm children have an aberrant cellular immune response, these infants receive similar maternal anti-viral IgG repertoires compared to term children, albeit at lower concentrations. These data point to selectivity in placental transfer at distinct gestational ages, to ensure that children are endowed with the most robust humoral immunity even if born preterm. To begin to define the mechanism by which preterm selective transfer may occur, the overall quantity and functional quality of an array of vaccine-, endemic pathogen-, and common antigen-specific antibodies were assessed across a cohort of 11 preterm and 12 term-delivered mother:infant pairs from birth through week 12. Although higher antibody levels were present in term infants, the overall functional profiles of antigen-specific antibodies were very similar. Temporal transfer differences were ascertained across distinct antibody subpopulations, with early transfer of functional antibodies capable of binding to FcRn and FcγR2-3 receptors followed by the transfer of distinct IgG subclasses. These results provide new insights on maternal:fetal immunity, highlighting novel immune axes that may be manipulated to enhance neonatal immune transfer of antibodies through gestation.

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1192: Placental transfer of HSV-specific antibodies from mothers to newborns

American Journal of Obstetrics and Gynecology ◽

10.1016/j.ajog.2019.11.1204 ◽

2020 ◽

Vol 222 (1) ◽

pp. S734

Author(s):

Aakash Mahant ◽

Fatima A. Estrada Trejo ◽

Anayeli Correa ◽

Lip Loh ◽

Benjamin Galen ◽

...

Keyword(s):

Placental Transfer ◽

Specific Antibodies

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Maternal Antibodies to Pneumolysin but Not to Pneumococcal Surface Protein A Delay Early Pneumococcal Carriage in High-Risk Papua New Guinean Infants

Clinical and Vaccine Immunology ◽

10.1128/cvi.00247-09 ◽

2009 ◽

Vol 16 (11) ◽

pp. 1633-1638 ◽

Cited By ~ 36

Author(s):

Jacinta P. Francis ◽

Peter C. Richmond ◽

William S. Pomat ◽

Audrey Michael ◽

Helen Keno ◽

...

Keyword(s):

High Risk ◽

Placental Transfer ◽

Protein A ◽

Surface Protein ◽

Upper Respiratory Tract ◽

Specific Antibodies ◽

Pneumococcal Carriage ◽

Pneumococcal Surface Protein A ◽

Antibody Titers ◽

High Risk Infants

ABSTRACT Immunization of pregnant women can be an efficient strategy to induce early protection in infants in developing countries. Pneumococcal protein-based vaccines may have the capacity to induce pneumococcal serotype-independent protection. To understand the potential of maternal pneumococcal protein-specific antibodies in infants in high-risk areas, we studied the placental transfer of naturally acquired antibodies to pneumolysin (Ply) and pneumococcal surface protein A family 1 and 2 (PspA1 and PspA2) in relation to onset of pneumococcal nasopharyngeal carriage in infants in Papua New Guinea (PNG). In this study, 76% of the infants carried Streptococcus pneumoniae in the upper respiratory tract within the first month of life, at a median age of 19 days. Maternal and cord blood antibody titers to Ply (ρ = 0.824, P < 0.001), PspA1 (ρ = 0.746, P < 0.001), and PspA2 (ρ = 0.631, P < 0.001) were strongly correlated. Maternal pneumococcal carriage (hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.25 to 5.39) and younger maternal age (HR, 0.74; 95% CI, 0.54 to 1.00) were independent risk factors for early carriage, while higher cord Ply-specific antibody titers predicted a significantly delayed onset (HR, 0.71; 95% CI, 0.52 to 1.00) and cord PspA1-specific antibodies a significantly younger onset of carriage in PNG infants (HR, 1.57; 95% CI, 1.03 to 2.40). Maternal vaccination with a pneumococcal protein-based vaccine should be considered as a strategy to protect high-risk infants against pneumococcal disease by reducing carriage risks in both mothers and infants.

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Ribosome Structural Organization

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051670 ◽

1974 ◽

Vol 32 ◽

pp. 332-333

Author(s):

James A. Lake

Keyword(s):

Ribosomal Proteins ◽

Structural Organization ◽

Three Dimensional ◽

Small Subunit ◽

Structural Studies ◽

X Ray Diffraction ◽

Specific Antibodies ◽

X Ray ◽

E Coli ◽

Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

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