Selective lymphocyte depletion during the early stage of the immune response to foot-and-mouth disease virus infection in swine

Foot-and-mouth disease virus (FMDV) is the causative agent of a highly contagious vesicular disease of cloven-hoofed animals. In the present study we use FMDV serotype C infection of swine to determine, by analytical techniques, the direct ex vivo visualization of virus-infected immune cells during the first 17 days of infection. We report, for the first time, that FMDV C-S8c1 can infect T and B cells at short periods of time postinoculation, corresponding with the peak of the viremia. There is a significant lymphopenia that involves CD3+ CD4- CD8+/-, CD3+ CD4 - CD8+Tc, and CD3+ CD4+ CD8 + memory Th but not CD3+ CD4+ CD8- naïve Th lymphocytes. In addition, a profound depletion of the vast majority of peripheral T cells in lymph nodes and spleen is observed. This selective depletion of T cells is not due mainly to in situ death via apoptosis as visualized by the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) technique. Thus, early infection of T cells by FMDV may be the main cause of the observed T-cell depletion. Importantly, this lack of T cells is reflected in a reduced response to mitogen activation, which in many cases is totally eliminated. These data suggest a mechanism by which the virus causes a transient immunosuppression, subvert the immune systems, and spreads. These results have important implications for our understanding of early events in the development of a robust immune response against FMDV. Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Bibliographic Details

Main Authors:	Díaz-San Segundo, F., Salguero, F. J., de Avila, A., Fernández de Marco, M. M., Sánchez-Martín, M. A., Sevilla, N.
Format:	journal article biblioteca
Language:	eng
Published:	2006
Online Access:	http://hdl.handle.net/20.500.12792/5041
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