Investigation of the role of complement and complement receptors in the modulation of B cell activation by a Paracoccidioides brasiliensis cell wall fraction.
F1 fraction from Paracoccidioides brasiliensis is a potent activator of the complement system. Considering that complement receptors CR1 and CR2 are involved in the regulation of B cell response, we evaluated the in vitro effect of the F1 in the activation of B lymphocytes, as well as the participation of complement receptors in this process. Murine splenocytes were cultured in order to evaluate the expression of CD40, CD45RB and CD69 on B lymphocyte, and IgG and IgM were quantified in the culture supernatant. F1 participated in the activation of B cells, showing a positive modulation effect on all markers analyzed. An increase in the production of IgG was detected in the supernatants when the opsonized F1 fraction was present. Complement receptor blockade with monoclonal antibodies led to a partial reduction in immunoglobulin secretion, suggesting that these receptors, especially CR2, play a role in modulating the function of B lymphocyte stimulated with the opsonized F1 fraction. These results may contribute for a better understanding of the B cell activation and differentiation processes in response to the F1 fraction from P. brasiliensis.
de Agostino Biella
Carla
C
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas-Faculdade de Ciências Farmacêuticas de Ribeirão Preto-Universidade de São Paulo, Avenida do Café, S/N, B. Monte Alegre, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil.
Uecker
Marilei
M
Fernandes da Silva
Marcelo
M
Barbosa
José Elpidio
JE
Silva
Célio Lopes
CL
Crott
Luciana Simon Pereira
LS
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology*; D002473:Cell Wall / Q000276:immunology*; D002474:Cell-Free System / Q000276:immunology; D002478:Cells, Cultured; D003165:Complement System Proteins / Q000502:physiology*; D007136:Immunoglobulins / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010228:Paracoccidioides / Q000276:immunology*; D011951:Receptors, Complement / Q000502:physiology*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D047071:beta-Glucans / Q000276:immunology
D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D007136:Immunoglobulins; D011951:Receptors, Complement; D047071:beta-Glucans; D003165:Complement System Proteins