L-plastin associated syndrome of immune deficiency and hematologic cytopenia.
J Allergy Clin Immunol
; 154(3): 767-777, 2024 Sep.
Article
in En
| MEDLINE
| ID: mdl-38710235
ABSTRACT
BACKGROUND:
LCP1 encodes L-plastin, an actin-bundling protein primarily expressed in hematopoietic cells. In mouse and fish models, LCP1 deficiency has been shown to result in hematologic and immune defects.OBJECTIVE:
This study aimed to determine the nature of a human inborn error of immunity resulting from a novel genetic variant of LCP1.METHODS:
We performed genetic, protein, and cellular analysis of PBMCs from a kindred with apparent autosomal dominant immune deficiency. We identified a candidate causal mutation in LCP1, which we evaluated by engineering the orthologous mutation in mice and Jurkat cells.RESULTS:
A splice-site variant in LCP1 segregated with lymphopenia, neutropenia, and thrombocytopenia. The splicing defect resulted in at least 2 aberrant transcripts, producing an in-frame deletion of 24 nucleotides, and a frameshift deletion of exon 8. Cellular analysis of the kindred revealed a proportionate reduction of T and B cells and a mild expansion of transitional B cells. Similarly, mice carrying the orthologous genetic variant exhibited the same in-frame aberrant transcript, reduced expression Lcp1 and gene dose-dependent leukopenia, mild thrombocytopenia, and lymphopenia, with a significant reduction of T-cell populations. Functional analysis revealed that LCP1c740-1G>A confers a defect in platelet development and function with aberrant spreading on collagen. Immunologic analysis revealed defective actin organization in T cells, reduced migration of PBMCs from patients, splenocytes from mutant mice, and a mutant Jurkat cell line in response to CXCL12; impaired germinal center B-cell expansion after immunization; and reduced cytokinesis during T cell proliferation.CONCLUSIONS:
We describe a unique human hematopoietic defect affecting neutrophils, lymphocytes, and platelets arising from partial LCP1 deficiency.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Microfilament Proteins
Limits:
Animals
/
Female
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Humans
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Male
Language:
En
Journal:
J Allergy Clin Immunol
Year:
2024
Type:
Article
Affiliation country:
Australia