Portal de Periódicos da CAPES

Induction and characterization of delayed‐type hypersensitivity to influenza virus in mice

1979; Wiley; Volume: 9; Issue: 10 Linguagem: Inglês

10.1002/eji.1830091008

1521-4141

Foo Y. Liew, Stuart Russell, Colin M. Brand,

interferon and immune responses

Abstract Mice infected with an aerosol of influenza virus or immunized with purified UV‐ inactivated whole virus or viral subunits developed delayed‐type hypersensitivity (DTH) to influenza virus. The level of DTH was greatly enhanced when mice were injected intraperitoneally 2 days prior to immunization with 200 mg/kg of cyclophosphamide. The reaction peaked at 24 h after elicitation, had the classical DTH histology, and was transferable by immune cells but not by immune serum. DTH induced in cyclophosphamide‐pretreated mice persisted for at least 40 days after sensitization. DTH induced by deoxycholate‐treated subviral particles (DC particles) or the matrix protein of the influenza virus was type‐specific, i.e. DTH induced by DC particles or matrix protein of type A virus cross‐reacted only with type A virus and not with type B virus. DTH induced by purified hemagglutinin (HA) subunits, on the other hand, showed subtype specificty. Thus, DTH induced by HA of X 31 virus (H3) did not cross‐react with PR 8 virus (H 0). However, DTH induced by HA of one subtype cross‐reacted significantly with the variants of the same subtype. Thus, it appears that the effector T cells of DTH do not discriminate between the antigenic variants of influenza virus that are distinguishable by serology. DTH induced by purified, UV‐ inactivated whole virus showed extensive cross‐reactivity. This nonspecific reaction was shown to be due to host‐derived material, the lipid bilayer. ‐ The theoretical and practical implications of these findings are discussed.