PUBLICATION
Leukolectins support lifelong innate immunity in lower vertebrates, and reveal dichotomies of several leukocytic lineages
- Authors
- Miftari, M.H., Riste, T.B., Walther, B.T.
- ID
- ZDB-PUB-240611-11
- Date
- 2024
- Source
- Fish & shellfish immunology 151: 109685 (Journal)
- Registered Authors
- Keywords
- LL-positive leukocytes, Leukolectins, TECPR-domains, TRMs, compartmentalization, dual ISH, innate immunity, lectocytes, lectophages, tectonins
- MeSH Terms
-
- Animals
- Immunity, Innate*/genetics
- Zebrafish*/genetics
- Zebrafish*/immunology
- Fish Proteins/genetics
- Fish Proteins/immunology
- Salmo salar*/genetics
- Salmo salar*/immunology
- Leukocytes*/immunology
- Chickens/genetics
- Chickens/immunology
- PubMed
- 38857816 Full text @ Fish Shellfish Immunol.
Citation
Miftari, M.H., Riste, T.B., Walther, B.T. (2024) Leukolectins support lifelong innate immunity in lower vertebrates, and reveal dichotomies of several leukocytic lineages. Fish & shellfish immunology. 151:109685.
Abstract
Innate immunity is vital for animal homeostasis and survival. First-line immuno-defense for fish larvae involves mucus enriched with leukolectin (LL) secreted by dermal lectocytes. Later during the critical transition from yolk-nutrition to feeding, additional larval immuno-protection in zebrafish (zF) is provided by macrophages containing LL. This work investigated new LL-expression in embryos and in blood, structures of fish leukocytic LL and LL-genes, and LL- presence in chicken leukocytes. In zF-embryos, lectophages appear ∼10 hpf, while later cells co-expressing myeloperoxidase- and LL-mRNA were detected (∼19 hpf). Furthermore, protein-extracts of Atlantic salmon (Ssal) leukocytes contained LL-proteins, compartmentalized in the cytosol. Cloning and sequencing revealed 94 % nt-sequence identity between variants of Ssal-leukolectins. Highly conserved LLs allowed production of epitope-specific anti-LL IgGs. Immuno-fluorescence-analysis demonstrated that most Ssal-bloodcells were LL-negative, but both some large cells with protrusions and some small, rounded cells did express LL. Immunoperoxidase-staining method confirmed LL-expression in some Ssal-leukocytes, identified as macrophages, PMN-leukocytes, thrombocytes and dendritic cells. However, closer examination revealed a dichotomy of these cell-categories into either LL-positive, or LL-negative variants. In situ hybridization demonstrated profuse LL-expression in Ssal head kidney interstitial tissue, while LL-transcripts were absent in large kidney tubules. Both hematopoietic (non-pigmented) marrow cells and melano-macrophages expressed LL-mRNA, implying that leukolectins provide lifelong innate immuno-protection. PCR-amplification using Ssal-leukocytic DNA as template, and direct sequencing yielded a leukocytic LL-gene. Some cells in salmon, cod, halibut, oikopleura and zebrafish embryos express LL-proteins and/or LL-mRNA, and LL-mRNA is detected in salmon, cod and chicken leukocytes. However, current genomes for these species lack recognizable LL-loci except the Ssal_v3.1 Genome-assembly. The data demonstrate an unexpected dichotomy of some leukocyte lineages into LL-positive or LL-negative cell-variants. Such dichotomies suggest exploring differential impacts from the duplicated leukocyte-lineages in health and disease.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping