Prophylactic effect of administration of human gamma globulins in a mouse model of tuberculosis

The protective effect of human gamma globulins on Mycobacterium tuberculosis infection was evaluated in a mouse model of intratracheal infection. Animals receiving human gamma globulins intranasally, 2h before intratracheal challenge showed a significant decrease in lung bacilli load compared to non-treated animals in different time intervals of up to 2 months after challenge. The same effect was obtained when M. tuberculosis was pre-incubated with the gamma globulin before challenge. The protective effect of the gamma-globulin formulation was abolished after pre-incubation with M. tuberculosis. These results suggest a potential role of specific antibodies in the defence against mycobacterial infections.