Brain tumors in owl monkeys inoculated with a human polyomavirus (JC virus).

Owl monkeys were inoculated intracerebrally, subcutaneously, and intravenously with JC, BK, or SV40 virus. Two of four adult owl monkeys inoculated with JC virus, a human polyomavirus, developed brain tumors at 16 and 25 months after inoculation, respectively. A grade 3 to grade 4 astrocytoma (resembling a human glioblastoma multiforme) was found in the left cerebral hemisphere and brainstem of one monkey. The second monkey developed a malignant tumor in the left cerebral hemisphere containing both glial and neuronal cell types. Impression smears prepared from unfixed tissue of this tumor showed cells that contained polyomavirus T antigen. Virion antigens were not detected. Tumor cells cultured in vitro also contained T antigen but were negative for virion antigen. Infectious virus was not isolated from extracts of this tumor.

Depression in lymphocyte response to general mitogens by owl monkeys infected with Herpesvirus saimiri.

The effect of Herpesvirus saimiri (HVS) infection on the response of owl monkey lymphocytes to general mitogens was examined during the development of neoplastic disease. The reactivity of the lymphocytes was then correlated with the clinical condition of the infected monkeys and the content of virus rescued from the peripheral blood lymphocytes (PBL). Eight monkeys developed lymphoma which, in six monkeys, was accompanied by lymphocytic leukemia. All animals that died of HVS-induced neoplasia consistently showed a lack of mitogenic response to phytohemagglutinin and concanavalin A. The response to pokeweed mitogen, while always reduced, was generally less markedly affected than the response to the other two mitogens. Lymphocytes from five of the leukemic animals demonstrated an elevated level of spontaneous DNA synthesis in culture late in the disease. This increased spontaneous DNA synthesis tended to correlate with the rescue of HVS from the PBL as demonstrated by the infective center assay. Although mitogenic hyporesponsiveness corresponded with HVS rescue from PBL in six of nine monkeys, the impairment of normal lymphocyte responsiveness sometimes preceded virus recovery.

Infection of capuchin monkeys (Cebus albifrons) with Herpesvirus saimiri.

Herpesvirus saimiri (HVS) induced persistent, clinically inapparent infections of long-term duration in capuchin monkeys (Cebus albifrons). The infections were characterized by development of antibody to HVS-associated antigens and recovery of low levels of virus-genome-carrying lymphocytes in the peripheral blood. Peripheral lymphocyte counts remained in low-normal to normal ranges and no physical signs of lymphoma were evident. Prednisolone treatment caused immunosuppression in one monkey; this was accompanied by a progressive loss of humoral antibody to HVS-associated antigens, but neoplastic disease did not develop.

Cerebrospinal fluid markers in African Burkitt's lymphoma with central nervous system involvement.

Several cerebrospinal fluid markers were found to be elevated in Burkitt's lymphoma patients with central nervous system (CNS) involvement. Antibody levels to the virus capsid antigen of the Epstein-Barr virus and to the brain cell antigens myelin and cerebroside were elevated during active CNS disease. Immune complexes were present in levels above 100 micrograms/ml in most patients with CNS involvement but tended to be low or negative in patients without CNS disease. Oligoclonal IgG bands were present in 12 of 13 patients with CNS disease and in only 3 of 26 patients with no clinical evidence of disease. None of these markers were present in 6 other tumor patients without CNS disease. The presence of these markers in 12 of 13 patients in whom CNS disease was involved suggests that these markers may be useful in determining the status of the tumor with regard to involvement of the CNS.

Spontaneous lymphoma associated with Herpesvirus saimiri in owl monkeys.

Two cases of lymphoma and one case of lymphoproliferative disease were found in a group of 7 owl monkeys imported into our colony as a single group. Herpesvirus saimiri (HVS) was isolated from the tumor cells of 1 lymphoma by cocultivation and from kidney cell cultures from the monkey with lymphoproliferative disease. Antibody to HVS was found in serum samples from 2 monkeys positive for HVS but not in the sera from the 4 clinically normal monkeys. Antibody to Epstein-Barr virus-infected cells was also found in the serum from the animal with lymphoma.

Pilot studies with human interferon in Herpesvirus saimiri-induced lymphoma in owl monkeys.

The nature of Herpesvirus saimiri-induced disease in owl monkeys is described with emphasis on those biological parameters useful in monitoring the disease. These parameters are lymphocyte response to general mitogens, lymphocyte-infective centers, and antibody to virus-associated early antigen. Human interferon was used in treating owl monkeys with virus-induced leukemia. In 2 animals evidence was obtained that suggested a positive antileukemic effect.

Oligoclonal IgG in CSF of patients with African Burkitt's lymphoma.

Oligoclonal IgG bands were detected in CSF from 12 of 13 patients with African Burkitt's lymphoma (BL) who exhibited neurologic signs or symptoms of CNS involvement. Twenty-three of 26 patients free of neurologic involvement with this tumor were found to lack the oligoclonal IgG bands in their CSF. None of six patients with non-BL included in this study had these bands in their CSF. None of six patients with non-BL included in this study had these bands in their CSF samples. These findings suggest that detection of these bands may be a useful adjunct for determining the presence of African BL that invades the CNS.

Coronavirus antibodies in sera from patients with multiple sclerosis and matched controls.

Sera from patients with multiple sclerosis and carefully matched controls were tested for antibodies to three strains of coronavirus. There was no significant difference in the levels of antibody in the patients vs the controls. We conclude that unless the strains of coronaviruses recently reported to have been isolated from patients with multiple sclerosis express important serological differences from those used in these studies, coronaviruses are not associated with the cause of multiple sclerosis.

Measles and canine distemper antibody. Presence in sera from patients with multiple sclerosis and matched control subjects.

Antibody to measles virus and canine distemper virus (CDV) was demonstrated in sera from patients with multiple sclerosis (MS) and from carefully matched control subjects. Elevated measles and CDV antibody titers were found in patients with MS when compared with the matched control subjects. The correlation between the measles and CDV antibody titers was quite high, suggesting that the antibody levels between the two viruses are very closely related. Based on the results of our study and a review of the literature, our conclusion is that the CDV antibody levels in patients with MS and matched control subjects are associated with occurrence of measles virus antibodies.

Suppressor cell activity in multiple sclerosis.

Patients with multiple sclerosis and matched controls were tested for lymphocyte stimulation response and induction of suppressor cell activity in response to concanavalin A (Con A) and antigens from axolemma or myelin. Of 17 stable patients, 6 failed to have a suppressor cell response activated by one of these brain cell antigens. Among the patients who lacked these suppressor responses, five had lymphocyte stimulation responses to the same antigens. All matched controls except for one had suppressor cell responses to these antigens and none responded with a positive cellular immune reaction. We found no difference in lymphoproliferative responses to Con A in patients and controls. The level of suppressor cell activity induced by Con A in the stable MS patients varied but did not differ significantly from that of controls.

Management of genital herpes simplex virus infection during pregnancy.

The clinical course and outcome of 58 pregnancies in 57 women with culture-verified genital herpes simplex virus (HSV) infection during gestation are reported. In 19 cases (33%) an active genital HSV infection was present within 1 week of delivery. Of the 60 infants delivered, 58 survived. No maternal or perinatal morbidity or mortality was attributable to HSV. This experience suggests that weekly culturing of the cervix and all other previously infected genital sites from the 36th week of gestation until delivery is an acceptable plan for managing such pregnancies. Women without evidence of infection at the onset of labor can be allowed to deliver vaginally. With appropriate precautions, breast-feeding by mothers with genital HSV infections is not contraindicated.

Scanning and transmission electron microscopy study of antibody-dependent lymphocyte-mediated cytotoxicity on measles virus-infected cells.

The structural events related to antibody-dependent lymphocyte-mediated cytotoxicity (ADLC) have been studied on measles virus-infected cells using human peripheral blood lymphocytes (PBL) and anti-measles virus serum. The first event in ADLC was a recognition process occurring with 15 min after contact between the infected cells and lymphocytes. Plasma membrane and microvilli of adsorbed PBL were specifically attached to virus-induced ridges over nucleocapsids and to viral buds. After 30 min, a fraction of adsorbed PBL (K cells) changed shape and extended long filipodia toward the target cells which, in turn, showed long villi contacting the PBL. At 4 h, when cytotoxicity as measured by chromium release was maximum, K cells had flattened and numerous blebs and ruffles formed on their surface. The K-cell alterations varied in intensity with the type of measles-infected target cell, but frequently the K cells appeared irreversibly damaged. T- and non-T-cell fractions were separated, and in situ erythrocyte rosettes were used as markers for subpopulations which were easily recognized by scanning electron microscopy. Most of the cytotoxic K cells were identified as non-T cells carrying Fc receptors for immunoglobulin G. However, a small subpopulation of cells bearing both sheep erythrocyte and Fc receptors was also found to be involved in ADLC by chromium release assay as well as by electron microscopy. Some of these interacting T cells extended a long uropod on the target cell, but their intracellular structure remained unaltered through ADLC, in contrast with the other T cells and the non-t killer cells. This suggests that perhaps some T killer cells might remain functional after the cytotoxic interaction with a target cell.

Evidence for suppressor cell activity associated with induction of Herpesvirus saimiri-induced lymphoma.

Peripheral blood lymphocytes (PBL) from Herpesvirus saimiri (HVS) infected owl monkeys lose their ability to respond to PHA during the development of lymphoma. In this study, five HVS-infected owl monkeys were examined for their ability to respond to PHA and to confer this loss of PHA reactivity to normal lymphocytes. Four of the monkeys developed HVS-induced disease and lost their ability to respond to PHA. Although less affected, reduced responses were also found with PWM. The animals which developed disease and suppressed PHA responses were found to be able to confer this loss of PHA reactivity to normal lymphocytes. One HVS-infected monkey did not develop disease or loss of PHA reactivity and did not confer a loss of PHA reactivity to normal lymphocytes. In the four affected monkeys, the conference of suppression to PHA was not accompanied by a concomitant reduction in response to PWM by the normal lymphocytes, demonstrating some specificity in the suppressor cell activity. Thus, the presence of suppressor cell activity appears to be associated with the inhibition of T-cell function and possibly the eventual development of lymphoma.

Stimulation of Herpesvirus saimiri expression in the absence of evidence for type C virus activation in a marmoset lymphoid cell line.

Nucleic acid base analogues were used to examine a Herpesvirus saimiri (HVS)-infected marmoset lymphoid cell line (MLC-1) for possible association with type C viruses. Synthetic templates poly(rA).d(pT)(10) and poly(dA).d(pT)(10) were used to detect RNA-directed DNA polymerase activity in 100-fold concentrated tissue culture fluids. HVS was monitored by immunofluorescence for early, late, and membrane antigens. MLC-1 cells were exposed to 30 mug of 5-bromo-2'-deoxyuridine (BUdR) per ml for 24 h and examined daily. Similar experiments used 5-iodo-2'-deoxyuridine (IUdR) (20 mug/ml) for 30 h or IUdR (20 mug/ml) for 3 days followed by 2% dimethyl sulfoxide for 4 days. Results of these experiments failed to show any type C virus-like polymerase; however, HVS expression was greatly stimulated. BUdR and IUdR enhanced expression of HVS-associated antigens five- to sevenfold, with maximal stimulation being observed 3 to 4 days after removal of the analogue. IUdR-dimethyl sulfoxide treatment was generally less effective. Although more cells showed HVS antigens, the treatments did not increase cell-free infectious virus. The data suggest that HVS-infected lymphoid cells can be stimulated to express virus in a manner similar to that of the Epstein-Barr virus in Burkitt's lymphoma cells. No evidence of type C virus was found in stimulated cultures.

Detection of soluble antigen of Epstein-Barr virus by the enzyme-linked immunosorbent assay.

The enzym-linked immunosorbent assay (ELISA) was compared with the microcomplement-fixation test for sensitivity and reliability in detection of antibody to soluble antigen of Epstein-Barr virus. ELISA was found to be more sensitive (up to 160 times more antibody) in detecting levels of antibody than the complement-fixation assay. The ELISA test was shown also to be comparably reliable to the complement-fixation assay in detecting immunity to this antigen; only one false-positive response was found in tests of 21 sera. Because this assay is completely quantifiable, it provides an easy, rapid, and highly sensitive technique for the detection of antibody to antigen of Epstein-Barr virus.

Epstein-Barr virus infection following bone-marrow transplantation.

A 12-year-old patient with acute lymphoblastic leukemia received a bone-marrow transplant (BMT) from a matched sibling donor. Nine weeks prior to transplant the donor experienced Epstein-Barr virus (EBV)-induced infectious mononucleosis. The bone-marrow recipient was EBV-negative at the time of transplant; however, 4 weeks post transplant the recipient developed clinical symptoms of graft-verus-host disease (GVHD) coincident with serological evidence of acute EBV infection. In addition, a lymphoblastoid cell line positive for Epstein-Barr nuclear antigen was established from a bone-marrow sample obtained at the onset of symptoms compatible with GVHD. Sera obtained from the recipient over the ensuing 2 months showed the appearance of antibodies to specific EBV antigens consistent with a primary immune response to EBV infection. This association of acute EBV infection with symptoms of GVHD in a BMT recipient suggests a need for further investigation of the epidemiology of EBV infections in human bone-marrow transplantation and the relationship between EBV infection and GVHD.

Inhibition of the mitogenic response of normal peripheral lymphocytes by extracts or supernatant fluids of a Herpesvirus saimiri lymphoid tumor cell line.

A Herpesvirus saimiri-infected marmoset lymphoid cell line (MLC-1) was examined for the presence of soluble factors which might affect lymphocyte functions and, therefore, relate to the pathogenesis of lymphoma in vivo. MLC-1 cells, cell extracts, and culture fluids were shown to reduce the spontaneous deoxyribonucleic acid (DNA) synthesis of normal peripheral blood lymphocytes and to completely inhibit their response to phytohemagglutinin (PHA). Suppression of PHA response was demonstrated against a variety of human and nonhuman primate species, with 90 to 95% inhibition occurring at dilutions of extract as great as 1:5,120. Inhibition of this type was also demonstrated using extracts of two of five other lymphoblastoid cell lines tested. Physical-chemical characteristics of the active factor(s) revealed a non-sedimentable, non-dialyzable, trypsin-resistant molecule, which was stable at 56 C for 30 min but inactivated at 80 C for 30 min. The factor(s) also exerted an effect on some but not all established lymphoblastoid cell lines, where DNA, ribonucleic acid, and protein synthesis were all inhibited, with DNA synthesis being the most affected (95% suppression). Cellular respiration was not affected by the presence of the factor(s), and the inhibition of DNA synthesis was reversible after 24 h. Purified human interferon did not reduce the PHA response of normal owl monkey peripheral blood lymphocytes and was less effective against an established lymphoblastoid cell line than the MLC-1 extract. Antiviral activity was also demonstrated in the preparations and may represent interferon, which these cells are known to produce at low levels.

Lymphocyte functions and subpopulation distribution in marmosets.

Marmoset lymphocytes were highly reactive to general mitogens, participate in direct cytotoxicity (purportedly mediated by T-cells) and particpate in an antibody dependent lymphocyte cytotoxicity assay (K-cell). The distribution of lymphocyte subpopulations among various species showed that the percent T-cells ranged from 46.4 to 66.6% in different species while complement receptor cells ranged from 10.3 to 19.0%. Surface immunoglobulin (SIg) stable B-cells ranged from 10.6 to 16.4% while the SIg labile L-cells ranged from 26.9 to 37.5%. A fourth receptor, Fc, was demonstrated on 23.7 to 31.7% of the marmoset lymphocytes.