Serum levels of anti-PspA and anti-PspC IgG decrease with age and do not correlate with susceptibility to experimental human pneumococcal colonization

Autor: Elissavet Nikolaou, Hugh Adler, Adriano P. Araujo, Maria Leonor S. Oliveira, Gabriela B. C. Colichio, Daniela M. Ferreira, Eliane N. Miyaji, Tao Chen, Esther L. German
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Serotype
Male
Aging
Physiology
Biochemistry
Geographical locations
law.invention
Basal (phylogenetics)
Elderly
law
Immune Physiology
Medicine and Health Sciences
Colonization
Enzyme-Linked Immunoassays
Multidisciplinary
Immune System Proteins
wc_217
Middle Aged
Antigenic Variation
Antibodies
Bacterial
Recombinant Proteins
Pneumococcal infections
Recombinant DNA
Medicine
Female
Disease Susceptibility
Antibody
Brazil
Research Article
qw_520
Adult
Adolescent
Science
Immunology
Biology
Research and Analysis Methods
Antibodies
Pneumococcal Infections
Antigen
Protein Domains
Bacterial Proteins
medicine
Antigenic variation
Adults
Humans
Antigens
qw_571
Immunoassays
Aged
Biology and Life Sciences
Proteins
South America
medicine.disease
Age Groups
People and Places
biology.protein
Immunologic Techniques
Population Groupings
qw_142
Zdroj: PLoS ONE
PLoS ONE, Vol 16, Iss 2, p e0247056 (2021)
ISSN: 1932-6203
Popis: Older adults are at increased risk of pneumococcal disease. This work aims to evaluate whether there is any decrease in serum IgG against variants of the antigens Pneumococcal surface protein A (PspA) and Pneumococcal surface protein C (PspC) in healthy adults with increasing age. Levels of IgG against PspA and PspC variants were determined by ELISA in serum samples comparing volunteers 18–30 years of age with volunteers who were 50–70+ before and after an experimental pneumococcal colonization challenge. The serotype 6B strain used in the challenge belongs to a minor group of pneumococcal isolates expressing two PspC variants. There was a decrease in levels of IgG with increasing age for the most common PspA variants and for all PspC variants analyzed. No correlation was found between basal levels of IgG against these antigens and protection against colonization. There was an increase in levels of IgG against PspA variants that are more cross-reactive with the variant expressed by the challenge strain post challenge in younger individuals who became colonized. Since the challenge strain used in our study expresses two different PspC variants, an increase in serum IgG against all PspC variants tested was observed in younger individuals who became colonized. For some of the antigen variants tested, a decrease in serum IgG was observed in young volunteers who were challenged but did not become colonized. Serum IgG antibodies against PspA and PspC variants thus decrease with age in healthy adults, but there is no correlation between levels of IgG against these antigens and protection against human experimental colonization. Though no correlation between naturally induced serum IgG antibodies against PspA and PspC and protection against colonization was observed, these results do not rule out the protective potential of these antigens as vaccines against pneumococcal infections.
Databáze: OpenAIRE
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