Figure 13-4.

Damage to tissue may be initiated by response to released viral antigens and to viral antigens presented by major histocompatability complex molecules on the surface of infected host cells. Released antigens allow development of antibody responses (left side), leading to deposition on the surface of infected targets and cellular destruction by complement mediation. T helper cells release cytokines that assist cytotoxic lymphocytes to induce killing of target cells (right side). During both processes, bystander killing of surrounding tissue may occur, leading to manifestation of pathology. TCR, T-cell receptor.