14.1 Virus response against apoptosis

Virus inhibits the apoptosis by interrupting the various stages of transcription and translation. Herpes and poxviruses are evolved in a way to modulate the apoptosis by blocking the activation of caspases. SV40 T antigen and E1 protein of adenovirus are known to bind with p53 and target it for proteasomal degradation. Although many viruses prevent apoptosis, herpes virus can selectively cause apoptosis in the lymphocytes in order to delay their removal from the host cell.

14.2 Virus response against host immune system

Many viruses come up with a system to reduce the expression of MHC-I molecules over the virus infected host cell surface. This explains the important role of MHC-I towards viral invasion into the susceptible host cells.

HIV, adenovirus, and herpesvirus inhibits the translocation of peptide within the endoplasmic reticulum, which is a necessary step for the loading and trafficking of the peptide over the MHC-I molecules. Cytomegalovirus produces a homologues of MHC-I molecule to decoy the host immune system.

Herpes simplex virus express a “glycoprotein E” that binds to the immunoglobulin molecules and prevents the activation of antibody mediated immune response.  

 

Table 14.1 Inhibition of viral antigen presentation by MHC-I: