IMMUNOHISTOCHEMICAL INVESTIGATION OF THE TISSUE DISTRIBUTION OF MANNAN-BINDING LECTIN IN NONINFECTED AND VIRUS-INFECTED CHICKENS

This-paper describes the results of immuno-histochemical staining for chicken mannan-binding lectin (MBL) in formalin-fixed tissue sections from non-infected chickens, and from chickens infected with infectious laryngotracheitis virus (ILTV) or infectious bursal disease virus (IB DV). In the non-infected chickens, MBL was detected in the cytoplasm o f a few hepatocytes and in the germinal centres of the caecal tonsils, whereas sections of kidney, heart muscle, spleen, cerebrum, thymus, a drenal gland, bursa of Fabricius, bone marrow and trachea were without staining. In the ILTV-infected chickens, an intense staining reaction for MBL was detected in the cytoplasm of all hepatocytes and on the s urface of, and inside, ILTV-infected cells. Also in the IBDV-infected chickens, an intense staining reaction for MBL was detected in the cyt oplasm of all hepatocytes. No staining was seen in the follicles of th e bursa of Fabricius, but MBL was present in non-identified cells in t he interstitium, and in the cytoplasm of macrophage-like cells, locate d peripheral to the ellipsoid of the spleen. These findings indicate t he liver as the primary site of MBL synthesis, and points to up-regula tion as a result of the viral infections. The location outside the liv er could indicate a role of MBL in the immune defence.