Monocytoid B cells: an enigmatic B cell subset showing evidence of extrafollicular immunoglobulin gene somatic hypermutation.
Scand J Immunol
; 75(5): 500-9, 2012 May.
Article
em En
| MEDLINE
| ID: mdl-22486786
ABSTRACT
Monocytoid B cells are IgM(+) , IgD(-/+) , CD27(-) B cells, localized in the perisinusoidal area of the lymph node. These cells are especially prominent in infections such as those caused by toxoplasma and HIV. The ontogeny of monocytoid B cells with respect to B cell maturation is incompletely known. We analysed clonal expansion, somatic hypermutation and expression of activation-induced cytidine deaminase (AID) in monocytoid B cells. Sequence analysis of the rearranged immunoglobulin heavy chain genes amplified from microdissected monocytoid B cell zones with a high proportion of proliferating cells reveals the presence of multiple clones with low-level ongoing mutations (mean frequency 0.46 × 10(-2) per bp). Mutation analysis of these ongoing mutations reveals strand bias, a preference of transitions over transversions as well as the occurrence of small deletions, as observed for somatically mutated immunoglobulin genes in the human germinal centre. Proliferation, ongoing mutation as well as expression of AID, combined, is evidence that monocytoid B cells acquire the mutations in the extrafollicular perisinusoidal area of the lymph node and pleads against a postgerminal centre B cell origin.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Subpopulações de Linfócitos B
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Cadeias Pesadas de Imunoglobulinas
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Citidina Desaminase
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Hipermutação Somática de Imunoglobulina
Limite:
Humans
Idioma:
En
Revista:
Scand J Immunol
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Noruega