Increased Vascular Permeability of Brucella Abortus Bacilli in the Thymus of Nzb/W F₁ Mice

Abstract

Various amounts of the bacterium, Brucella abortus (BA) were injected intravenously into autoimmune NZB/W F₁ mice and non-autoimmune BDF, mice and then the localization of BA in the thymus was traced using an immunohistochemical method at 30 min and 3 h after injection. The results showed that a greater amount of BA became consistently localized in the thymic parenchyma in a free form or in a phagocytized form in NZB/W F, mice in comparison with BDF, mice, indicating a marked increase of vascular permeability in the thymus of NZB/W F₁ mice. The extravascular leakage of BA was clearly dose-dependent. The significance of invasion of bacterial antigens from the general circulation into the thymic parenchyma is discussed in relation to autoimmune states.

Key Words:

• Autoimmune NZB/W F₁
• thymus
• vascular permeability
• Brucella abortus bacilli
• immunohistochemistry