Immune CD4+ T cells promote the clearance of influenza virus from major histocompatibility complex class II -/- respiratory epithelium.
The experiments described establish that CD4+ T-cell-dependent effector mechanisms can eliminate an H3N2 influenza A virus from lung cells that are unable to express class II major histocompatibility complex (MHC) glycoproteins. Radiation chimeras were made by using CD4+ T cells and bone marrow from CD8-depleted, MHC class II +/+ mice and irradiated (950 rads) MHC class II -/- recipients. The influenza virus-specific CD4+ T-cell responses in these +/+-->-/- mice were not obviously different from those in the +/+-->+/+ controls: the cytokine profiles, the spectra of plasma cells producing the various immunoglobulin isotypes, and the frequencies of virus-specific CD4+ T cells were similar for the two groups. Expression of class II MHC glycoproteins on stimulator cells, B lymphocytes, and monocytes/macrophages is apparently sufficient for CD4+ T cells to terminate influenza virus infection of MHC class II -/- respiratory epithelium. A possible explanation is that the local spread of this lytic virus in the lung is limited by cytokines and/or antibody.
Topham
D J
DJ
Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
Tripp
R A
RA
Sarawar
S R
SR
Sangster
M Y
MY
Doherty
P C
PC
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D009980:Influenza A virus / Q000276:immunology*; D008168:Lung / Q000276:immunology* / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL
D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II