Developmental and comparative immunology single-cell transcriptome analysis of the B-cell repertoire reveals the usage of immunoglobulins in the gray short-tailed opossum (Monodelphis domestica). (October 2021)

• Record Type: Journal Article
• Authors: Schraven, Andrea L.; Hansen, Victoria L.; Morrissey, Kimberly A.; Stannard, Hayley J.; Ong, Oselyne TW.; Douek, Daniel C.; Miller, Robert D.; Old, Julie M.
• Is Part Of: Developmental and comparative immunology. Volume 123(2021)
• Publication Date: 2021-10
• Subjects: Marsupial -- B-cells -- IgH -- Igλ -- Igκ; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2021.104141
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: B-cells are key to humoral immunity, are found in multiple lymphoid organs, and have the unique ability to mediate the production of antigen-specific antibodies in the presence of pathogens. The marsupial immunoglobulin (Ig) heavy (H) chain locus encodes four constant region isotypes, IgA, IgG, IgM and IgE, but no IgD, and there are two light (L) chain isotypes, lambda (Igλ) and kappa (Igκ). To gain an understanding of the marsupial humoral immune system, B-cell transcriptomes generated by single-cell RNA sequencing from gray short-tailed opossum ( Monodelphis domestica ) splenocytes, and peripheral blood mononuclear cells were analysed. The cells used were from a single unimmunized animal and the majority of B-cells were transcribing IgM heavy chains. The ratio of Ig light chain use was roughly 2:1, Igλ:Igκ in this individual. This was not predicted due to Igκ being the more complex of the two L chain loci. The variable (V) gene segment pairs used in individual B-cells confirm greater diversity provided by the L chain V. This study is the first to report on using single cell analysis to investigate Ig repertoires in a marsupial and confirms a number of prior hypothesis, as well as revealing some surprises. Highlights: First single-cell transcriptomic investigation of the immunoglobulin repertoire for any marsupial species. The expression of Igλ to Igκ was 65 to 35, despite Igκ being more complex in the opossum genome. IgL variable gene segments made a greater contribution to antibody diversification than IgH.