Changes in macrophages in spleen and lymph nodes during acute African swine fever: expression of cytokines F.J. Salguero 1 , E. Ruiz-Villamor, M.J. Bautista, P.J. Sa Ânchez-Cordo Ân, L. Carrasco, J.C. Go Âmez-Villamandos * Departamento de Anatomõ Âa y Anatomõ Âa Patolo Âgica Comparadas, Facultad de Veterinaria, Universidad de Co Ârdoba, Campus Universitario de Rabanales, 14014 Co Ârdoba, Spain Received 8 November 2001; received in revised form 15 May 2002; accepted 8 July 2002 Abstract TogainfurtherinsightintothepathogenesisofAfricanswinefever(ASF),thecytokineexpressionbymacrophagesinspleen andlymphnodeswereexamined.Twenty-onepigletswereinoculatedwiththehighlyvirulentisolateSpain-70ofASFvirusand killed in groups at 1±7 post-inoculation days (pid). An increase in the immunohistochemical detection of proin¯ammatory monokines in spleen and renal and gastrohepatic lymph nodes is reported, along with an increase in the serum levels of TNF-a andIL-1b.Theexpressionofthesecytokinesisdetectedsimultaneouslyintimeandspacewiththeviralprotein73(vp73)ofthe ASFvirusdetection.Ourresultsdemonstratethatmononuclearphagocytesystemcellactivationresultsinthereleaseofseveral cytokines that could induce apoptosis of lymphocytes and haemodynamic changes. # 2002 Elsevier Science B.V. All rights reserved. Keywords: African swine fever; Pathogenesis; Macrophage; Cytokines 1. Introduction Monocyte-macrophage (m-Mf) is a pluripotential cell, responsible of the modulation of immune and in¯ammatory response in a number of infectious dis- eases. This modulation is carried out by synthesis and secretion of chemical mediators (Arai et al., 1990; Baarsch et al., 1995; Murtaugh et al., 1996; Sato et al., 1997; Andrews et al., 1978; Conaldi et al., 1995; Geisbert et al., 2000; Herna Ândez-Casellez and Stutman, 1993; Haagmans et al., 1994; Lechner et al., 1996;Molinasetal.,1989;Petersetal.,1989),andhas been suggested that these chemical mediator or cyto- kines may be involved in the pathogenesis of several viral diseases of swine (Van Reeth et al., 1998; Van Reeth and Nauwynck, 2000; Go Âmez-Villamandos et al., 2000), including African swine fever (ASF) (Go Âmez-Villamandos et al., 1995a,b; Go Âmez del Moral et al., 1999). Among these monokines (cyto- kines synthesized by monocyte-macrophages), TNF- a, IL-1a, IL-1b and IL-6 are present (Le and Vilcek, 1987; Arai et al., 1990; Murtaugh et al., 1996). African swine fever is a fatal disease that affects animals of Suidae family (Montgomery, 1921; Ward- ley et al., 1983) and caused by the only virus that belongs to the recently created family Asfarviridae (VanRegenmorteletal.,2000).Themaintargetcellof ASFvirus(ASFV)isthem-Mf (Mebus, 1988), being Veterinary Immunology and Immunopathology 90 (2002) 11±22 * Corresponding author. Tel.: 34-957-218162; fax: 34-957-218847. E-mail address: jcgomez@uco.es (J.C. Go Âmez-Villamandos). 1 Present address: Centro de Investigacio Ân en Sanidad Animal (CISA-INIA), Valdeolmos, 28130 Madrid, Spain. 0165-2427/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII:S0165-2427(02)00225-8