Recovery of an Antiviral Antibody Response following Attrition Caused by Unrelated Infection

Dorothy H. L. Ng, John J. Skehel, George Kassiotis, Jean Langhorne

PLoS Pathog. (2014) 10(1): e1003843.

Speaker: Chung-Lin Li (利宗霖)                                          Time: 15:10~16:00, May 14, 2014

Commentator: Dr. Trai-Ming Yeh (葉才明老師)                Place: Room 601

Abstract

Adaptive immune system plays an important role in anti-viral response. Production of antigen-specific antibodies (Abs) can be detected in the circulation for decades. For example, Abs against Influenza A virus can be detected in humans for over 90 years (1). The production of these long-term Abs depends on the maintenance of antigen-specific memory B cells (MBCs) and long-lived plasma cells (LLPCs). A previous study showed that infection with the malaria parasite, Plasmodium, will cause a reduction in pre-established Abs response. (2). Other study indicated thatTrypanosome brucei infection in mice caused a reduction in pre-estabilshed MBCs and LLPCs (3). To investigate whether malaria parasite would affect pre-established humoral immunity to Influenza A virus, the authors first infected mice with Influenza A/Puerto Rico/8/34 (PR8). HA-specific Abs increased and remained stable in serum but were significantly reduced after infection with P. chabaudi. The authors further determined the number of HA-specific Ab-secerting cells (ASC) as a measure of pre-established LLPC. HA-specific ASCs also decreased when PR8-immune mice were infected with P. chabaudi. The decrease in LLPCs were induced by an FcγRIIB-mediated apoptosis. Interestingly, after P. chabaudi infection, a gradual return of HA-specific IgG and HA-specific ASCs were observed at later time points. This phenomenon may be due to continuous conversion of HA-specific MBCs into LLPCs that eventually resulted in the recovery of HA-specific IgG and ASCs. In conclusion, this study demonstrates the importance of MBCs not only in the anamnestic response but also in the general maintenance of long-lived serum Abs in the absence of re-infection.

References:

1.     Yu X, Tsibane T, McGraw PA, House FS, Keefer CJ, et al. (2008) Neutralizing antibodies derived from the B cells of 1918 influenza pandemic survivors. Nature 455: 532–526.

2.     Goumard P, Vu DN, Maurois P, Camus D (1982) Influence of malaria on a preexisting antibody response to heterologous antigens. Ann Immunol (Paris) 133: 313–326.

3.     Radwanska M, Guirnalda P, De Trez C, Ryffel B, Black S, et al. (2008) Trypanosomiasis-induced B cell apoptosis results in loss of protectiveantiparasite antibody responses and abolishment of vaccine-induced memory responses. PLoS Pathog 4: e1000078.