Tetsutaro Sata

Growth of Measles Virus in Epithelial and Lymphoid Tissues of Cynomolgus Monkeys

The pathogenesis of measles virus infection is not yet clearly understood, but clinical and pathological findings as well as experimental studies in monkeys indicate the invasion of measles virus through the respiratory epithelium and initial multiplication in the regional lymphoid tissues spreading into the reticuloendothelial system, and subsequent infection of the epithelial tissues including the trachea and skin. Thus both the lymphoreticular cells and epithelial cells are major sites for measles virus replication (4). In vitro growth of measles virus in the lymphoid cells has been used as the model of virus growth in these target cells in vivo (1, 2, 5). However, there is no report of a comparison of the in vivo growth of measles virus in epithelial and lymphoid cells. In the present study, characteristics of the growth of wild measles virus in the epithelial and lymphoid cells of cynomolgus monkeys (Macaca lascicularis) were compared by the immunofluorescence (IF) technique and electron microscopy. Pooled throat washings obtained from several patients with measles a few days after the onset of rash were used as the source of wild measles virus as described previously (9). Two cynomolgus monkeys free of measles-virus neutralizing antibody were subcutaneously inoculated with the throat washings. Seven days later, they were euthanasized by anesthetization with ketamine hydrochloride, and the brain, trachea, lungs, thymus, lymph nodes, spleen, kidneys, heart, and liver were removed. For the IF technique, the tissues were quickly frozen in n-hexane in a dry-ice-acetone bath. Thin sections made with a cryostat were fixed in acetone, and mixed with monoclonal antibodies against the Edmonston strain of measles virus including three clones against hemagglutinin (H) protein, one clone against nucleocapsid-associated phosphorylated (P) protein, one clone against nucleocapsid (NP) protein, two clones against fusion (F) proteins and two clones against membrane (M) protein (8), and then with goat anti-mouse IgG conjugated with fluorescein

Hair follicle involvement in herpes zoster : pathway of viral spread from ganglia to skin

Herpes zoster is caused by reactivation of varicella-zoster virus (VZV) persisting in dorsal root or trigeminal ganglia. To clarify the pathway of viral spread from the ganglia to skin, 16 biopsy specimens of early skin lesions of herpes zoster obtained from the face and trunk of 13 patients were studied histologically and immunohistochemically using monoclonal antibodies to the structural proteins of VZV. VZV-infected cells were detected in the hair follicles in 10 of the 16 specimens and in the epidermis in 2 specimens. Infected cells were localized in the isthmus of every involved follicle (12/12), frequently in the stem (8/10) and infundibulum (6/10), and never in the bulb. The high frequency of follicular involvement in herpes zoster suggests that VZV spreads to the area of skin innervated by myelinated nerves, which end around the isthmus of hair follicles and sebaceous glands.

Analysis of viral antigens in giant cells of measles pneumonia by immunoperoxidase method.

The localization of measles virus proteins was analyzed by immunoperoxidase method using both monospecific and monoclonal antibodies. In Vero cells infected with the Edmonston or EB-L strain, the former being a laboratory strain and the latter a fresh isolate from a measles patient, nucleocapsid protein was located in the nuclei, and matrix protein, phosphoprotein, haemagglutinin and fusion protein were located in the cytoplasm. In the lung tissues of eight cases with measles giant cell pneumonia, the similar findings were obtained. The presence of haemagglutinin on the surface of giant cells at the luminal side was also noticed. Histopathologically, measles giant cells had nuclear and cytoplasmic eosinophilic inclusion bodies with some differences in appearance. The significance of localization of viral proteins is discussed in comparison with histopathological findings in measles giant cells.

A comparative study of congenital and postnatally acquired human cytomegalovirus infection in infants : lack of expression of viral immediate early protein in congenital cases

Postmortem tissues from infants with congenital and postnatally acquired human cytomegalovirus (HCMV) infection were examined by routine histology, immunohistochemistry (IHC) and in situ hybridization (ISH) to determine the dynamics of viral replication in vivo. Histologically, infants in both groups showed characteristic inclusion-bearing cells most commonly in lung, kidney, liver and pancreas. IHC for late proteins using a rabbit polyclonal antibody and ISH for viral genomes detected most of the infected cells as nuclear and/or cytoplasmic signals. However, immunostaining with a monoclonal antibody against viral immediate early (IE) proteins was variable depending on the stage of viral replication within an individual infected cell. In tissues of infants with postnatal HCMV infection, many cells harboured IE antigens, while in tissues from congenital cases most of the affected cells lacked IE antigens and only a few showed cytoplasmic staining. The difference was not caused by the antigenic diversity among viral strains as confirmed by in vitro study. Our findings suggested that congenital infections exhibited uniformly late stage proteins with inactive viral replication at death, while acquired ones remained active. The different viral activity may reflect the immune status of congenital and acquired HCMV infections.

GIANT CELL PNEUMONIA IN LETTERER‐SIWE DISEASE

An 8‐month‐old girl suffered from Letterer‐Siwe disease since one week after birth. During the chemotherapy, giant cell pneumonia caused by measles virus infection developed and led rapidly to her death. Histopathologically, alveolar spaces were lined by multi‐nucleated giant cells with intranuclear and intracytoplasmic eosinophilic inclusion bodies. Electronmicroscopical examination of the lung revealed intranuclear inclusion bodies full of rod‐shaped structures characteristic to paramyxoviruses, and irregular electron‐dense materials compatible with nucleocapsid protein antigens in the cytoplasm. Additionally these giant cells were observed in the salivary glands, thyroid gland, thymus and lymph nodes. The measles virus antigen was detected immunohistochemically in these giant cells in the lungs and other organs. The specific antibody of measles virus is helpful to study the pathogenesis of giant cell pneumonia.