Genetic susceptibility of chicken macrophages toin vitroinfection with infectious laryngotracheitis virus

Abstract

SUMMARYChicken macrophages are susceptible to infection with infectious laryngotracheitis virus (ILTV), the level of infection being dependent, in part, on the genotype of the host cell. Following infection in vitro a greater proportion of macrophages from the ILTV-resistant J 1 (B 113/113 ) and N 1 (B 114/114 ) inbred lines of chickens were found to be positive for ILTV antigens, than macrophages from the ILTV-susceptible M 1 (B 15/15 ) chickens. The proportion of ILTVpositive macrophages was found to be genetically regulated, in part by the chicken major histocompatibility complex (MHC), although alloantisera to class I and class II MHC antigens did not reduce the number of macrophages infected. Similarly, the phagocytic activity of the cultured macrophages from chickens of different MHC genotype did not correlate with their susceptibility to infection with ILTV.

Aspectos epidemiológicos e laboratoriais da laringotraqueíte infecciosa das aves

“…A idade de maior susceptibilidade seria por volta da 10ª semana e na época de início de produção, entretanto, existem evidências de que galinhas adultas manifestam sinais clínicos mais característicos (GAMA;CANAL, 2009). In vitro, os linfócitos da bolsa de Fabricius, do baço, do timo e do sangue periférico são resistentes à infecção com VLTI, enquanto que os macrófagos de galinhas dos mesmos locais são susceptíveis (LOUDOVARIS et al, 1991). CRUZ, C.A.…”

“…Os mecanismos nãoespecíficos incluem a ação dos macrófagos, complemento, lisozima, e o pH dos fluidos corporais, enquanto os mecanismos específicos são o resultado do sistema imunológico respondendo à infecção. Um dos elementos-chave na regulação genética da resposta imune é o complexo principal de histocompatibilidade do frango, o que tem claramente demonstrado a influência na resistência de diferentes animais a uma variedade de vírus (LOUDOVARIS et al, 1991).…”

Genetic resistance to infectious laryngotracheitis in inbred lines of White Leghorn chickens

“…However, a recent study by Fahey & York (1990) in bursectomised chickens further discounts the role of antibody in recovery or vaccinal immunity to ILTV. The involvement of macrophages in recovery from ILTV has also been suggested from in vitro studies with macrophages from genetically susceptible and resistant chickens (Loudovaris et al, 1990b).…”