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Biomedical subjects

R N Lausch

Publications and source records attributed to R N Lausch.

At least 55 records · Page 3Linked to original sources
PubMed1987

Nucleotide sequences important in DNA replication are responsible for differences in the capacity of two herpes simplex virus strains to spread from cornea to central nervous system.

Two herpes simplex virus (HSV) intertypic recombinants were isolated with genomes composed entirely of HSV-2(186) nucleotide sequences except for a 6.0 kb segment of HSV-1(17) DNA positioned between 0.40 and 0.44 map units. Following corneal infection of mice, HSV-1(17) and the two intertypic recombinants spread from infected eyes into the central nervous system and induced a fatal encephalitis. Ocular infection with the HSV-2(186) parent did not lead to detectable amounts of virus in the brain, and none of the mice developed encephalitis. The 6.0 kb HSV-1(17) DNA inserted within the genome of the two intertypic recombinants contained nucleotide sequences involved in DNA replication. These include the HSV-1(17) oriL, the HSV-1(17) gene for DNA polymerase and portions of the HSV-1(17) gene coding for DNA-binding protein ICP8. Thus, our results indicate that the difference in the capacity of HSV-1(17) and HSV-2(186) to spread from the cornea into the CNS is determined solely by nucleotide sequences associated with DNA replication.

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PubMed1987

Failure of intertypic recombinant constructed from HSV-1 x HSV-2 virulent parents to induce ocular pathology.

An intertypic recombinant constructed from HSV-1 x HSV-2 parents was isolated which failed to induce any overt ocular pathology when inoculated onto the sacrificed cornea of four-week-old SJL/J mice. During the 24-48 hour post-infection period there was transient virus replication but by day 3 the infectious titer in the eye had dropped by greater than or equal to 10(4)-fold, and little or no virus could be recovered thereafter. When immunosuppressed (600 r) mice were infected corneally, virus clearance was delayed several days but again no obvious ocular pathology was seen, and no mice died. By contrast, infection of the cornea with either parent was followed by virus replication and development of clinically apparent pathology which could progress to blinding stromal keratitis. The genome of the intertypic recombinant was analyzed by agarose gel electrophoresis of restriction endonuclease digests and found to consist entirely of HSV-1 DNA except for HSV-2 DNA sequences located between map units 0.10-0.16, 0.41-0.43, and 0.77-1.0. Potential explanations for the loss of virulence are discussed.

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PubMed1987

Superiority of antibody versus delayed hypersensitivity in clearance of HSV-1 from eye.

The contribution that antibody and delayed type hypersensitivity (DTH) make in promoting HSV-1 clearance from the infected cornea was investigated. Balb/c mice were immunized intravenously or subcutaneously with an attenuated strain of HSV-1 to generate hosts which were antibody-producing DTH-tolerant or antibody-producing DTH-responsive. Anti-mu serum treated mice were likewise sensitized intravenously or subcutaneously to obtain hosts which were antibody depressed-DTH tolerant or antibody-depressed DTH-responsive. Eight days after sensitization, these four sensitized groups and unsensitized controls were infected on scarified corneas with a stromal keratitis inducing strain of HSV-1, and the extent of virus replication was determined 1, 3, and 7 days later. Very different results were obtained depending upon the host's immune status. Virus proliferated extensively (greater than 3-4 logs) in the eyes of nonimmune mice and antibody-depressed DTH-tolerant hosts during the first 3 days after infection. In striking contrast, HSV-1 could not be detected even 24 hr post challenge in antibody-producing DTH-tolerant mice. In fact, such mice cleared virus from the eye as efficiently as immunologically intact hosts. However, in mice with the reverse immune status, ie antibody-depressed DTH-responsive, virus growth was clearly evident (greater than 2-3 logs) during days 1-3, and only thereafter did complete clearance occur. These results indicate that in the sensitized host antibody is both independent of and significantly more effective than DTH in promoting HSV-1 eradication from the infected eye.

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PubMed1986

Herpes simplex virus type 1 DNA sequences which direct spread of virus from cornea to central nervous system.

The virulence of a herpes simplex virus (HSV) intertypic recombinant possessing HSV-1 DNA sequences from map units 0.31 to 0.44 and HSV-2 sequences from map units 0 to 0.30 and 0.45 to 1.0 were compared with the virulence of the two parental strains. Following ocular inoculation, both the intertypic recombinant and the HSV-1 parent replicated at the infection site and spread to the peripheral and central nervous system (CNS) to produce fatal encephalitis. The HSV-2 parent also replicated at the infection site but failed to progress to the CNS. However, when inoculated intracerebrally, the HSV-2 strain was as lethal as the HSV-1 parent. Furthermore, the HSV-2 strain could produce thymidine kinase at 37 and 39 degrees in levels comparable to the HSV-1 strain. The results indicate that transfer of the HSV-1 DNA sequences imparted to the recombinant virus the necessary genetic information to spread from the cornea into the central nervous system.

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PubMed1985

Resolution of HSV corneal infection in the absence of delayed-type hypersensitivity.

The role of delayed-type hypersensitivity (DTH) in the resolution of herpes simplex virus type 1 (HSV-1) ocular infection was examined. Infection of Balb/c mice on the sacrificed cornea with HSV-1 resulted in sensitization for DTH. This response, demonstrable by swelling of the ear following inoculation with ultraviolet-irradiated virus, was optimal 7 days postinfection. The reaction was immunologically specific and characterized histologically by a predominately mononuclear cell infiltrate. DTH responsiveness could be completely abrogated if the mice were inoculated intravenously with an attenuated strain of HSV-17 days before corneal infection. DTH-unresponsive mice were, nevertheless, resistant to corneal challenge with sublethal or lethal doses of HSV-1. Resistance was accompanied by a greater than 30-fold reduction in infectious virus in the eye 24 hr post challenge. A cellular infiltrate characteristic of a DTH response was not observed within the cornea during virus clearance. Tolerance was restricted to DTH, as antibodies to HSV antigens could be readily demonstrated 6-7 days after intravenous virus immunization. These antibodies may have contributed to the resistance observed. The results establish that neither a systemic nor local DTH response is required by the host to resist HSV-1 ocular infection.

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PubMed1984

Identification of infected cell-specific monoclonal antibodies and their role in host resistance to ocular herpes simplex virus type 1 infection.

Monoclonal antibodies 35S and 55S, specific for herpes simplex virus type 1 (HSV-1) glycoproteins gB and gD respectively, were found to react with infected cell membranes but not cell-free virions. This indicates that the spectrum of viral determinants detectable on the infected cell surface is not identical to that detectable on the virion envelope. The monoclonal antibody 35S could promote recovery from ocular HSV-1 infection in mice. Thus, antibody reactive with infective cell-specific determinants can play a significant role in host resistance to HSV-1 infection.

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PubMed1984

Monoclonal antibodies suppress replication of herpes simplex virus type 1 in trigeminal ganglia.

The effect of monoclonal antibodies on the growth of herpes simplex virus type 1 in trigeminal ganglia was investigated. Four-week-old mice were infected on an abrased cornea with herpes simplex virus type 1. Forty-eight hours after infection, trigeminal ganglia ipsilateral with infected eyes were removed and placed in culture. Incubation of infected ganglia in the presence of a pool of nonneutralizing monoclonal antibodies specific for glycoproteins of gB and gE suppressed virus growth by greater than 90%. This was comparable to the amount of suppression observed when infected ganglia were incubated in hyperimmune serum. Individual monoclonal antibodies were less efficient, being able to inhibit virus growth by only two- to threefold. The mechanism of suppression was examined. Reduction in virus growth was observed under conditions in which all susceptible ganglion cells were infected in vitro before nonneutralizing monoclonal antibody was added. Similar results were obtained in tests with virus-infected neuroblastoma cells. Furthermore, suppression of infectious progeny was seen in the absence of complement and immunologically reactive cells. Thus, neither virus neutralization nor immunocytolysis could account for the effects of antibody on virus growth. Rather, the data suggest that antibody can bind to herpes simplex virus type 1-infected neuronal cells and suppress intracellular virus replication.

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PubMed1984

Lyt-1+ T cells participate in recovery from ocular herpes simplex virus type 1 infection.

Herpes simplex virus type 1 (HSV-1) inoculated on the abrased cornea of 4-week-old irradiated (450 R) SJL/J mice spread to the brain and produced a fatal viral encephalitis by 10-12 days post-infection. Adoptive transfer of 2-3 X 10(7) virus-sensitized non-adherent spleen cells 24 hrs before virus challenge led to recovery from infection. Recovery was due to suppression of HSV-1 replication in the brain rather than prevention of virus spread from the cornea to the central nervous system. If the immune cells were treated with monoclonal anti-Thy 1.2 and complement before transfer the protective effect was lost. Pretreatment of the virus-sensitized spleen cells with monoclonal antibody to the Lyt-1 membrane antigen also significantly reduced or completely abrogated the protective effect. In contrast, depletion of Lyt-2 bearing cells resulted in a less-pronounced and not statistically significant loss of protection. It was further observed that spleen cell reconstituted, virus challenged mice had considerably higher serum antibody titers (greater than 10-fold) than unreconstituted virus challenged controls. The results indicate that lymphocytes with a Thy 1.2+, Lyt-1+, Lyt-23- phenotype play a predominant role in promoting recovery following corneal HSV-1 infection.

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PubMed1982

Use of monoclonal antibodies for analysis of antibody-dependent immunity to ocular herpes simplex virus type 1 infection.

Monoclonal antibodies specific for the five major glycoproteins of herpes simplex virus type 1 (HSV-1) were tested for their capacity to mediate immunity to ocular HSV-1 infection. The specificity of the immunoglobulin made by each monoclone was determined by immunoprecipitation of [14C]glucosamine-labeled polypeptides from detergent-solubilized HSV-1-infected cells. Of the five monoclonal antibodies studied, two immunoprecipitated glycoproteins gA/B, one immunoprecipitated glycoprotein gC, one immunoprecipitated glycoprotein gD, and one immunoprecipitated glycoprotein gE. All five were effective in passively transferring immunity to mice when they were given 4 to 24 h after HSV-1 infection on an abraded cornea. Four of the monoclonal antibodies were also evaluated for their capacity to neutralize HSV-1 and to promote complement-mediated cell lysis and antibody-dependent cellular cytotoxicity. It was found that none of these in vitro assays correlated with the protective activity of the antibodies in vivo. In fact, one of the monoclonal antibodies was unreactive in all three immunological reactions, even though it was highly effective in promoting recovery from HSV-1 induced ocular disease in vivo. The results suggest that antibodies can interact in vivo with virus-specific glycoproteins gA/B, gC, gD, and gE to initiate recovery from HSV-1-induced ocular disease, and that the therapeutic effectiveness of a specific monoclonal antibody does not correlate with its immunological reactivity in vitro.

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PubMed1981

Role of Fc fragments in antibody-mediated recovery from ocular and subcutaneous herpes simplex virus infections.

The contributions of the Fc fragment of virus-specific antibody in the resistance of mice to peripheral herpes simplex virus infection were investigated. Rabbit anti-herpes simplex virus-specific F(ab')2 fragments prepared by pepsin digestion of immune immunoglobulin G (IgG) were found to be inactive in complement-mediated cytolysis while retaining their capacity to neutralize virus infectivity in vitro. When F(ab')2 fragments were passively transferred either before or simultaneously with virus inoculation, they were as efficient as intact IgG was in protecting animals from virus challenge. However, if passive transfer was delayed until 8 h after herpes simplex virus infection, only IgG antibody was protective. The loss of protective activity could not be attributed to a rapid disappearance of F(ab')2 fragments, because comparable levels of F(ab')2 fragments and IgG antibody were maintained in the blood of recipients during the time that antibody mediated its protective effects. The inability of F(ab')2 subunits to activate complement was also not a factor, because complement-deficient A/J mice and complement-sufficient SJL/J mice recovered from herpes simplex virus infection after the passive transfer of IgG. We concluded that the Fc component of the antibody molecule is needed to resolve intracellular infection and that the mechanism by which antibody mediates recovery remains undefined but does not appear to involve virus neutralization or complement activation.

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PubMed1980

Expression of type-common envelope antigens by herpes simplex virus type 2-transformed hamster cells.

At least ten polypeptides were detected on the surface of the herpes simplex virus type 1 (HSV-1) virion. Two of these polypeptides, having molecular weights of 30,000 and 33,000, were identified in two herpes simplex virus type 2-transformed cell lines (333-8-9 and 333-2-29) by immunoprecipitation and SDS-PAGE. The same two virion polypeptides previously were shown to be present in an HSV-1-transformed cell line (14-012-8-1, T-10). These observations suggest that genetic information coding for these polypeptides is in close proximity to that portion of the virus genome involved in transformation.

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PubMed1979

Uninhibited growth and metastases of herpes simplex virus-transformed cells in virus-sensitized hosts.

Four established tumour lines of hamster cells transformed by herpes simplex virus (HSV) but not shedding the virus were examined for continued expression of virus-associated antigens. Hamster or rabbits, appropriately immunized to the tumour cells, produced virus-neutralizing antibody. The serum titres were invariably low, suggesting that only small quantities of virion antigen were present in the cells. Hamster sensitized to HSV and resistant to virulent virus challenge did not reject low numbers of tumour cells, nor was the incidence of lung metastases significantly reduced. Virus-sensitized lymph-node cells, readily cytotoxic for HSV-infected hamster embryo fibroblasts, did not lyse any of three transformed lines tested in an 18-h 51chromium release test. Animals that had their tumour excised demonstrated no or only modest resistance to tumour rechallenge. Thus, virus-specific transplantation rejection antigen could not be detected in the HSV tumour lines although low levels of virus structural antigens were present.

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PubMed1979

Cellular immune response to human cytomegalovirus. I. Lymphocyte transformation studies in the rabbit.

The lymphocyte transformation assay was used to monitor the cellular immune response of rabbits sensitized to cytomegalovirus (CMV). Peripheral blood lymphocytes from animals inoculated with purified virus were specifically stimulated by crude or twice-banded CMV. Blood cells from rabbits immunized to herpes simplex virus type 1 (HSV-1) responded to that antigen but not to CMV. Viable or heated CMV preparations stimulated unwashed blood cells as efficiently as washed cells. Furthermore, preincubation of stimulating antigen with anti-CMV serum did not prevent lymphocyte activation. Lymphoid cells readily stimulated by virus antigen were not stimulated by cells transformed by CMV or HSV-1.

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PubMed1979

Inability of antiserum active in antibody-dependent cellular cytotoxicity and arming tests to protect against simian virus 40 tumor cell challenge.

Previous studies have shown that simian virus 40 (SV40) hamster tumor cells that were pretreated with antiserum from syngeneic hosts sensitized to SV40 were killed following exposure to nonsensitized spleen cells. In this study preincubation of nonadherent spleen or lymph node cells with SV40 antiserum rendered the cells specifically cytotoxic for the SV40-transformed fibroblasts. The capacity of a particular antiserum to "arm" (i.e., to be made specifically cytotoxic) was comparable with its ability to mediate antibody-dependent cellular cytotoxicity (ADCC). Experiments were performed to determine if the SV40 antiserum had prophylactic activity. Two hours after passive transfer of serum, cytotoxic effector cells could be demonstrated in the blood, spleen, and mesenteric lymph node, and the recipients' sera were active in ADCC tests. Nevertheless, such hosts were not resistant to challenge with small numbers of SV40 tumor cells that were given intradermally or intracardiacly, nor was tumor growth suppressed by addition of normal lymph node cells to the antiserum-pretreated tumor cell inoculum. Thus SV40 antiserum, active at high titer in ADCC and arming assays, did not prevent or delay growth of SV40 tumor isografts.

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