- Age influences antibody production, with some antibodies increasing or decreasing by viral target region
- Biological sex and genetics affect antibody quantity and specific viral regions targeted
- The study analysed 1,000 individuals' antibody responses and related genetic, lifestyle factors
Age could be a dominant factor in influencing antibody production in response to a virus -- for a given virus, certain antibodies increase with age while others decrease, depending on which part of the virus is targeted, researchers have found. The team, including researchers from Institut Pasteur at France's National Centre for Scientific Research, have shown that when attacked by the same virus, individuals can produce antibodies that target different parts of the virus. Biological sex and genetic factors of the host are also important factors which determine not only the quantity of antibodies produced but also the specific viral regions they target, the team found. The findings, published in the journal Nature Immunology, could have major implications for developing treatments better tailored to an individual's profile.
The researchers analysed data from the Milieu Intérieur study, launched 15 years ago and aimed at dissecting the interplay between genetics and environment and its impact on the immune system.
One thousand healthy individuals were enrolled whose socio-economic status, lifestyle, medical history, and biological markers were included in the study.
The authors "demonstrate that age, sex and continent of birth extensively affect not only the viruses but also the specific viral epitopes targeted by the antibody repertoire." An epitope is a region on an antigen or substance triggering an immune response where an antibody attaches itself.
"Furthermore, we identify strong associations between antibodies against 34 viruses and genetic variants at HLA, FUT2, IGH and IGK loci, some of which increase autoimmune disease risk," the authors said.
"A major strength of this study is its exhaustive quantification of the antibody repertoire. We were able to characterize exactly which parts of viral proteins are targeted by antibodies in each individual," author Etienne Patin, research director in the human evolutionary genetics laboratory at the Institut Pasteur, said.
The researchers found that more than half of the antibody repertoire produced as part of an immune response varied depending on age.
For influenza H1N1 and H3N2, antibodies in young adults were found to mainly target a part of the viral surface protein known as hemagglutinin, which evolves rapidly, whereas antibodies among older individuals tended to target a more stable region of the same protein known as the stalk domain, the team said.
Further, women were found to produce more antibodies against hemagglutinin while antibodies among men tended to target other viral proteins, despite comparable vaccination rates between the two sexes, the study found.
Host genetic factors further shape antiviral immunity.
"We identified mutations in genomic regions known to encode the immunoglobulin repertoire. These variants determine which genes are used to produce antibodies," Patin said.
The study was also extended to include an African cohort, where the researchers found that for a given virus such as the Epstein-Barr, antibodies can recognise varied viral proteins depending on the geographical and epidemiological context.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
