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Published on: January 19, 2017
B cell and immunoglobulin heterogeneity in carp (Cyprinus carpio L.); an immuno(cyto)chemical study
J C Koumans-van Diepen1, E Egberts, B R Peixoto
1Department of Experimental Animal Morphology and Cell Biology, Agricultural University, Wageningen, The Netherlands.
Insights
This study reveals distinct B cell subpopulations in carp (Cyprinus carpio L.) using monoclonal antibodies, showing heterogeneity in immunoglobulin expression during development. These findings highlight the complexity of fish immune systems.
Area of Science:
- Immunology
- Ichthyology
- Cell Biology
Background:
- Immunoglobulin (Ig) heterogeneity is crucial for adaptive immunity.
- Understanding B cell subpopulations in fish, like carp (Cyprinus carpio L.), is vital for fish immunology.
- Previous research has not fully characterized B cell heterogeneity in carp.
Purpose of the Study:
- To investigate B cell and immunoglobulin heterogeneity in carp.
- To identify and characterize distinct B cell subpopulations using monoclonal antibodies (MAbs).
- To analyze the ontogenetic changes in these B cell subpopulations.
Main Methods:
- Production and use of two MAbs (WC14, WCI12) against carp Ig.
- Immunochemical analysis, immunofluorescence microscopy, and flow cytometry.
- ELISPOT assay for antibody-secreting cells, affinity chromatography, and immunoprecipitation.
- Analysis of B cell subpopulations during carp ontogeny.
Main Results:
- Identified three distinct B cell subpopulations: WCI4+12-, WCI4-12+, and WCI4+12+.
- Demonstrated heterogeneity in Ig heavy chains (approx. 70,000 Da).
- Observed a significant ontogenetic shift in WCI4+12- and WCI4-12+ cell percentages in spleen and pronephros, with WCI4-12+ cells becoming dominant later in development.
Conclusions:
- Carp exhibit significant B cell and Ig heterogeneity.
- Distinct B cell subpopulations change in proportion during carp development.
- This heterogeneity likely plays a role in the adaptive immune response of carp.
Abstract:
B cell and immunoglobulin (Ig) heterogeneity was demonstrated in carp, Cyprinus carpio L., using two monoclonal antibodies (MAbs; WC14, WCI12) produced against carp serum Ig. Immunochemical results showed that both WCI4 and WCI12 react with a protein determinant on the heavy chain of Ig (relative molecular mass approximately 70,000). Immunofluorescence microscopic and flow cytometric analyses of lymphoid cells suggest three distinct subpopulations of B cells and plasma cells: WCI4+12- cells, WCI4-12+ cells, and WCI4+12+ cells. WCI4-12+ and WCI4+12+ anti-DNP antibody-secreting cells were also demonstrated with the ELISPOT assay in pronephros and spleen cell suspensions from primary immunised carp. Affinity chromatography of carp serum and sequential immunoprecipitation of 125I-labelled peripheral blood leucocyte (PBL) membrane proteins only indicated the presence of two antigenically different Ig molecules, i.e., WCI4-12+ and WCI4+12+ molecules. WCI4+12- molecules could not be detected by affinity chromatography or immunoprecipitation. During ontogeny, a shift in percentages of WCI4+12- and WCI4-12+ cells was found in the spleen and the pronephros. In these organs, WCI4+12- cells formed the majority of B cells at 2 weeks of age, but the percentages of this cell type decreased during ontogeny. On the other hand, the percentages of WCI4-12+ cells increased during development, and these cells became the major population of B cells from 13 weeks onward. The proportion of WCI4+12+ cells remained almost constant during ontogeny. The distribution of B cell subpopulations in blood was more or less stable at all ages. The functional significance of Ig heterogeneity in fish and in particular carp is discussed.
