Figure 1.

CD4 T cell function, differentiation, and regulation during persistent viral infections. (A) Latent persistent viral infections. In the left panel aspects of CD4 T cell immune responses with specificity for antigens of latent persistent viral infections are summarized: direct antiviral effector functions (discussed in paragraph Direct Antiviral Effector Functions of CD4 T Cells in Latent Persistent Viral Infections), support of CD8 T cell responses (CD4 T Cells Support Virus-Specific CD8 T Cells During Latent Persistent Viral Infections), support of B cell responses (CD4 T Cells Support Humoral Responses During Latent Persistent Viral Infections), immune regulation (Regulatory CD4 T Cells in Latent Persistent Viral Infections), and immunopathology (Role of CD4 T Cells in Latent Persistent Viral Infections and IL-10 Producing CD4 T Regulatory Cells). In the right panel viral strategies leading to escape from CD4 T cell responses are summarized (discussed in paragraph Viral Escape from CD4 T Cells). (B) Chronic active viral infections. In the left panel aspects of CD4 T cell immune responses with specificity for antigens of chronic viral infections are summarized: direct antiviral effector functions (discussed in paragraph CD4 T Cells Promoting Control of Chronic Viral Infection), support of CD8 T cell responses (CD4 T Cells Promoting Control of Chronic Viral Infections), support of B cell responses (Differentiation of CD4 T Cells During Active Chronic Viral Infections), immune regulation (T_regs and Chronic Viral Infections), and immunopathology (CD4 T Cell Mediated Pathology During Chronic Viral Infections). In the right panel viral strategies leading to escape from CD4 T cell responses are summarized (discussed in paragraphs CD4 T Cells Promoting Control of Chronic Viral Infection, Differentiation of CD4 T Cells During Active Chronic Viral Infections, and T_regs and Chronic Viral Infections).