Jornal de Imunologia Clínica e Celular
Acesso livre

Abstrato

Early IgM Antibody Response in Chandipura Virus Infection: T cell-Independent Activation of B-cells

Anukumar Balakrishnan and Prajakta Shahir

The T cell-independent B-cells activation by Chandipura virus is not known. In the current study, T cellindependent activation of B-cells by Chandipura virus was studied. The activation of B-cells was studied in the experiments determining the membrane expression of CD25 and CD69 markers, proliferation and virus specific IgM antibody secretion. Activation and proliferation of B-cells, and IgM secretions could be observed from the cells exposed to live virus. In case of B-cells treated with inactivated virus proliferation and IgM secretion was not observed. In order to determine the role of TLR4 in B-cell activation, the membrane TLR4 on B-cells were blocked with anti TLR4/MD2 antibody and exposed to live virus. Like inactivated virus, the antibody blocked cells were not showed proliferation and IgM secretion. In in vivo mice experiment, the T cell deficient nude mice were exposed to Chandipura virus. No significant difference could be observed in the level of IgM secretions between virus exposed nude and wild type mice. However, virus specific IgG was detected in wild type mice but not in nude mice. All the nude mice infected with Chandipura virus through intra-cerebral route were succumbed to infection. No clinical signs or death could be observed in wild type mice. In conclusion, we demonstrated that CHPV directly activates the B-cells. However, for proliferation and secretion of virus specific IgM, live virus and/or signalling via TLR4 is necessary. IgM antibody alone may not be sufficient to protect the mice from the infection and the CMI and/or virus specific IgG is necessary to confer protection from disease.