Positive and negative effects of immune responses

    Antibody
    Beneficial effects
• Neutralising antibody (demonstrated in vitro only) might prevent primary infection and destroy some infectious particles
• Evidence for beneficial effect of passive transfer of antibody in man requires confirmation
Harmful effects
• Antibody may also help the virus to enter cells with Fc receptors
• Immune complexes may cause tissue damage, anemia and neutropenia

Cellular immune responses
Beneficial effects
• A strong CD8 response is correlated with primary resistance in some individuals and with long-term survival
• Cytotoxic T-cells may delay the progress of disease by killing infected cells.
• They produce CD8 T-cell anti-viral factor (CAF) which inhibits viral replication and may be important in slowing disease progression

Harmful effects
• They may kill uninfected cells which take up shed gp120
• Abnormal cytokine secretion may cause immunopathology (perhaps including encephalopathy)