Geoffrey Clements

Induction of HLA expression in Daudi cells after cell fusion

The Daudi cell line, established from a Burkitt lymphoma, has recently been found to be HLA- andΒ2-microglobulin-negative, although it expresses B lymphocyte alloantigens. This report is concerned with the reexpression of HLA-A10, B38, and B17 on the Daudi cell, after cell fusion with another human cell line (Raji) or with mouse fibroblasts. In the latter fusion, the same HLA specificities are re-expressed, but not humanΒ2-microglobulin while mouseΒ2-microglobulin andH-2 could be detected. No such reexpression was observed when Daudi was fused with the F9 mouse teratocarcinoma, which lacks mouseΒ2-m andH-2. No HLA activity (alloantigenic and xenogenic activity) was detected in the membrane or cytoplasm of Daudi, using salt extraction and sonication. Therefore we postulate thatΒ2-microglobulin could be necessary for the expression and possible synthesis of the HLA antigen.

Reactivation of latent herpes simplex virus from dissociated identified dorsal root ganglion cells in culture

Herpes simplex virus (HSV) types 1 and 2 reactivate from dissociated cultured dorsal root ganglia of latently infected mice. The neurons in culture were identified morphologically and by using the specific anti-neuronal monoclonal antibody A2B5. HSV antigen expression during reactivation was first seen in neurons on day 3 after dissociation, and infectious virus was released subsequently. Approximately 0.4% of neurons released infectious virus. The presence of neutralizing antibody to HSV did not modify the reactivation process. After infection of mouse neuronal cultures in vitro with HSV, cytopathic effect and viral antigen expression appeared within 18 h predominantly in fibroblastic cells.

Cultured human neural cells accumulate a heat-shock protein during acute herpes simplex virus infection

Herpes simplex virus-1 (HSV-1) infection of cultured human neural cells causes the accumulation of a host cell-encoded nuclear protein identified as a 57,000 mol.wt. stress protein by monoclonal antibody TI56. This protein is cell cycle-related in fibroblast, may mediate host cell control during HSV infection and could play a role in the regulation of HSV latency.

Studies on the pathogenesis of neurological diseases associated with Varicella-Zoster Virus

Immunocytochemical techniques and in situ hybridization with three different Varicella‐Zoster Virus (VZV)‐specific RNA probes have been used to study the pathogenesis of VZV‐associated neurological syndromes. Varicella‐Zoster Virus antigens were not detected using the avidin‐biotin peroxidase technique with a polyvalent anti‐VZV antibody in any of the formalin‐fixed tissue sections from eight cases of VZV‐associated neurological disease (encephalitis, myelitis, ganglionitis); one case was immunosuppressed although inflammatory lesions were present. Intense labelling was detected within the inflammatory lesions in several representative VZV cases with a monoclonal antibody against Class II MHC antigens, whereas cases of Herpes Simplex Virus encephalitis and normal controls were not so labelled.

Spontaneous and induced patterns of the Epstein-Barr virus (EBV) cycle in a new set of somatic cell hybrids.

A somatic cell hybrid line and its subclones obtained by fusing two Burkitt lymphoma lines (Raji and Namalwa) were examined for the expression of EBV-specific antigens both spontaneously and after induction. The hybrids retained spontaneous early antigen (EA) production at the level characteristic of Raji. Similarly the more permissive Raji pattern dominated the induction of EA by IUDR treatment or P3HR-1 virus superinfection. These findings accord with our previous results on independently derived Raji/Namalwa hybrids. Virus capsid antigen was induced in the hybrids by P3HR-1 virus superinfection though at a lower level than in the Raji parental cell.

Stress proteins accumulate in cultured retinal glial cells during herpes simplex viral infection

The production of stress- or heat-shock proteins (SP) which are defined by three monoclonal antibodies (TI56, TG5E and TG7A) were examined in cultured retinal glial cells with and without herpes simplex virus (HSV) infection. Indirect immunofluorescence showed that 80-90% of uninfected cells reacted with anti-glial fibrillary acidic protein (GFAP) and that 10-20% of uninfected cells were weakly labelled with anti-SP antibodies. By 6 hr after HSV infection, the proportion of GFAP labelled cells decreased to 60-70% whereas cells strongly expressing SP antigens were demonstrated. At 24 hr, GFAP+ cells were markedly reduced in number and immunolabelling with anti-SP antibodies was evident in approximately 50% of cells, directly demonstrating the accumulation of SP in cultured retinal cells after HSV infection. Double labelling with GFAP/TI56 indicated that 30% of GFAP+ cells were labelled with TI56 and 30-50% of TI56+ cells were also GFAP+, despite the abrupt loss of GFAP+ cells during HSV infection. These results indicate that SP normally expressed at low level are significantly upregulated in retinal glial cells following HSV infection.

Herpes simplex virus 1 infection upregulates stress protein expression in cultured retinal neurons.

The production of a 57K stress protein (StrP) after herpes simplex virus type 1 (HSV-1) infection was examined in cultured neonatal rat retinal cells. StrP expression in individual cells was identified using a monoclonal antibody, TI56. Indirect immunofluorescence of uninfected retinal cultures showed that approximately 40% of cells expressed neurofilament (NF+) and 5% expressed a low level of StrP. Following HSV infection the proportion of NF+ cells decreased while the proportion of StrP positive cells became greater and the intensity of staining increased. The number of cells labelled with a polyclonal anti-HSV antibody increased with time after infection. Retinal neurons in culture can be infected with HSV, after which StrP expression is significantly upregulated.

A cultured human oligodendroglioma cell line and herpes simplex virus-infected cells share antigenic determinants

Cell cultures derived from 60 different human brain tumors were screened for the presence of HSV infected cell antigens by indirect immunofluorescence using a polyclonal rabbit antiserum reacting with herpes simplex virus (HSV), 3 monoclonal antibodies recognising different HSV specified proteins, and one monoclonal antibody TI81 reacting with a DNA binding protein present in HSV-infected cells. Only one tumor (IN/157), derived from an oligodendroglioma, stained with the polyclonal antiserum. TI81 but none of the other monoclonal antibodies used also specifically reacted with IN/157 cells. High levels of the TI81-defined protein were detected using immunoblotting in HSV-1 infected BHK/21 cells but not in IN/157 cells. T181 may react with either an epitope shared between two different molecules in HSV I infected and IN/157 cells or a cell-specified polypeptide that is upregulated after HSV-1 infection.