Changes

[[Image:B Cell viral response.jpg|thumb|right|200px|B Cell Immunity to Viruses - B. Catchpole, RVC 2008]]

[[Image:B Cell viral response.jpg|thumb|right|200px|B Cell Immunity to Viruses - B. Catchpole, RVC 2008]]

*Antibodies- these are particularly important in preventing the spread of the virus in the bloodstream

*Antibodies - these are particularly important in preventing the spread of the virus in the bloodstream

**[[IgA]] production is increased at mucosal surfaces- helps prevent reinfection

**[[IgA]] production is increased at mucosal surfaces- helps prevent reinfection

**Although antibodies that target any viral protein can be produced, only those directed against proteins found in the virion envelope or infected cell membrane will be effective

**Although antibodies that target any viral protein can be produced, only those directed against proteins found in the virion envelope or infected cell membrane will be effective

**When targeting virus-infected cells, they aid antibody-dependent cell-mediated cytotoxicity by NK cells, macrophages and [[Neutrophils|neutrophils]]

**When targeting virus-infected cells, they aid antibody-dependent cell-mediated cytotoxicity by NK cells, macrophages and [[Neutrophils|neutrophils]]

*Complement- although not considered a major factor in defence against viruses, complement is able to damage the virion envelope (virolysis)

*Complement - although not considered a major factor in defence against viruses, complement is able to damage the virion envelope (virolysis)

**Coupled with antibody, complement is also able to:

**Coupled with antibody, complement is also able to:

***block the virus receptor

***block the virus receptor

[[Image:T Cell viral response.jpg|thumb|right|200px|T Cell Immunity to Viruses - B. Catchpole, RVC 2008]]

[[Image:T Cell viral response.jpg|thumb|right|200px|T Cell Immunity to Viruses - B. Catchpole, RVC 2008]]

*T cells

*T cells

**CD8+ cytotoxic T cells are particularly important as nearly all the cells in the body express MHC class I. They tend to focus at the site of viral replication and destroy virus-infected cells.

**CD8⁺ cytotoxic T cells are particularly important as nearly all the cells in the body express MHC class I. They tend to focus at the site of viral replication and destroy virus-infected cells.

**CD4+ T cells are important in the recruitment of macrophages, using cytokines such as IFN-γ and TNF, and the induction of CD8+ cytotoxic T cells

**CD4⁺ T cells are important in the recruitment of macrophages, using cytokines such as IFN-γ and TNF, and the induction of CD8⁺ cytotoxic T cells

**The presence of CD4+ T cells is also vital for the antibody response, i.e. class-switching and affinity development

**The presence of CD4⁺ T cells is also vital for the antibody response, i.e. class-switching and affinity development

*For more on the adaptive response to viruses, see [[Adaptive Immunity to Viruses]]

*For more on the adaptive response to viruses, see [[Adaptive Immunity to Viruses]]