Neonatal immunization prevents the development of a chronic autoimmune response against CD4 caused by HIV-1 gp120 in rats

The AIDS autoimmune hypothesis suggests that suppression of the autoimmunity against CD4 T lymphocytes should positively affect the course of HIV infection. The aim of this study was to determine whether neonatal immunization can be used to prevent induction of anti-CD4 autoimmune response triggered by HIV-1. The induction of anti-CD4 lymphocytes in HIV infection proceeds via their idiotypic interactions with anti-gp120 lymphocytes; therefore, the creation of tolerance to gp120 by means of neonatal immunization with gp120 may prevent subsequent induction of anti-CD4 lymphocytes. Neonatal immunization with CD4 may also be effective, since it can increase natural tolerance to CD4 and prevent its subsequent breakdown by gp120. Thus, anti-gp120 lymphocytes and anti-CD4 lymphocytes are potential neonatal stimulation targets. To determine which of these targets can be manipulated during the neonatal period, a computer model of the immune network was used. The computer model predictions were tested in a rat model of autoimmune CD4 T lymphocytopenia induced by gp120. The in silico studies predicted that stimulating a clone against an external antigen that is in idiotype-anti-idiotype interactions with an autoclone, when stimulation is performed during the time that the dynamic behavior type of the immune network is being established, changes the autoimmune response from self-perpetuating to transient. Experimental studies confirmed the predictions of the computer model and showed that neonatal immunization with gp120 suppresses anti-CD4 autoantibody production and prevents the development of autoimmune CD4 T lymphocytopenia triggered in adult rats by gp120. Neonatal HIV-1 gp120 immunization enhances natural tolerance to CD4.