Infection of APC by human cytomegalovirus controlled through recognition of endogenous nuclear immediate early protein 1 by specific CD4(+) T lymphocytes.
Infections by human CMV are controlled by cellular immune responses. Professional APC such as monocytes and macrophages can be infected in vivo and are considered as a reservoir of virus. However, CMV-specific CD4(+) responses against infected APC have not been reported. To develop a model of CD4-infected APC interaction, we have transfected the U373MG astrocytoma cell line with the class II transactivator (CIITA). Confocal microscopy experiments showed that U373MG-CIITA cells expressed markers characteristic of APC. Functional assays demonstrated that infected U373MG-CIITA APC processed and presented both exogenous and endogenously neosynthesized nuclear immediate early (IE) protein 1 through the MHC class II pathway. More importantly, endogenous presentation of IE1 by infected APC lead to efficient control of CMV infection as revealed by decreased viral titer. Thus, these results describe the endogenous presentation of a nuclear viral protein by the MHC class II pathway and suggest that IE1-specific CD4(+) T cells may play an important role in CMV infection by directly acting against infected APC.
Institut National de la Santé et de la Recherche Médicale, Toulouse, France.
Emmanuelle
E
Le Roy
Michel
M
Baron
Wolfgang
W
Faigle
Danièle
D
Clément
David M
DM
Lewinsohn
Daniel N
DN
Streblow
Jay A
JA
Nelson
Sebastian
S
Amigorena
Jean-Luc
JL
Davignon
D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000821:virology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D003587:Cytomegalovirus / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D017874:Immediate-Early Proteins / Q000276:immunology*; D009687:Nuclear Proteins; D015534:Trans-Activators / Q000502:physiology; D014764:Viral Proteins
C088645:IE1 protein, cytomegalovirus; D017874:Immediate-Early Proteins; C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D015534:Trans-Activators; D014764:Viral Proteins