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Biomedical subjects

B T Rouse

Publications and source records attributed to B T Rouse.

At least 73 records · Page 4Linked to original sources
PubMed1996

HSV-1-mediated modulation of cytokine gene expression in a permissive cell line: selective upregulation of IL-6 gene expression.

Pathological effects of herpes simplex virus (HSV) can result due to a combination of direct viropathic effects and immunological reactions to viral antigens. The immunological reactions are orchestrated by a variety of cytokines and chemokines released by the host cells. Therefore, the cytokine gene expression in response to HSV-1 infection in a permissive murine cell line was investigated. The data demonstrate that HSV-1 induced a selective activation of IL-6 gene expression at the mRNA and protein levels, in the permissive cell line. The cell line used was capable of expressing IL-1, IL-7, and IL-10 in addition to IL-6, upon lipopolysaccharide stimulation. UV or heat-inactivated viruses were unable to upregulate IL-6 expression. However, mutant HSV-1 strains lacking fully functional ICP0, ICP4, ICP8, or ICP27 genes, thereby rendering them replication incompetent or impaired in in vitro cell growth (ICP0), enhanced IL-6 expression selectively. Considering the role of IL-6 in inflammation, immune response, and its known association with increased levels of MyD116 and GADD 34 mRNAs (genes involved in the prevention of apoptotic death of cells), the present data may have relevance to HSV-1-mediated diseases as well as to the prevalence of HSV-1 in the host.

Animals↗
PubMed1996

Herpes simplex virus type 1-mediated up-regulation of IL-12 (p40) mRNA expression. Implications in immunopathogenesis and protection.

In this report we investigated whether induction of IL-12 occurs in response to herpes simplex virus (HSV) infection of the mouse eye, which may serve to regulate the nature of the subsequent immune response. The data show early induction and continued maintenance of IL-12 (p40) mRNA in the cornea and draining lymph node upon ocular infection with HSV. Using a very sensitive radioimmunoassay technique, IL-12 (p40) protein also was detected in the cornea upon ocular HSV infection. Unfractionated splenocytes and enriched populations of dendritic cells, macrophages, and neutrophils all responded to HSV infection in vitro by up-regulating the expression of IL-12 (p40) mRNA. However, cultured corneal cells failed to generate IL-12 (p40) upon exposure to HSV. The data indicate that inflammatory cells that infiltrate the cornea in response to HSV-1 infection are the main source of IL-12 in the eye. Our results are consistent with the hypothesis that IL-12 induction in the eye acts as a triggering event that biases HSV-specific immunity to a type 1 T cell response, which, in the environment of the eye, culminates in an immunopathologic disease.

Animals↗
PubMed1996

Disease in the scurfy (sf) mouse is associated with overexpression of cytokine genes.

The murine X-linked lymphoproliferative disease scurfy is similar to the Wiskott-Aldrich syndrome in humans. Disease in scurfy (sf) mice is mediated by CD4+ T cells. Based on similarities in scurfy mice and transgenic mice that overexpress specific cytokine genes, we evaluated the expression of cytokines in the lesions of sf mice by Northern blotting, quantitative reverse-transcription polymerase chain reaction (RT-PCR) and by hybridization in situ. Overall, the phenotypic characteristics of scurfy disease correlated well with increased interleukin (IL)-4 (lymphadenopathy), IL-6 (B cell proliferation, hypergammaglobulinemia), IL-7 (dermal inflammatory cell infiltration), and high levels of tumor necrosis factor-alpha (wasting).

Animals↗
PubMed1996

Role of interferon-gamma in immunity to herpes simplex virus.

Removal of herpes simplex virus (HSV)-infected cells from peripheral sites such as the skin is mainly an activity of T cells, particularly the CD4+ T subset. Such cells orchestrate an inflammatory response with interferon-gamma (IFN-gamma) appearing to play the essential role in viral clearance. In accordance with this hypothesis, we show that infection of BALB/c background mice expressing the knockout phenotype for IFN-gamma (GKO mice) are significantly more susceptible to the development of cutaneous zosteriform lesions than are wild-type. However, following HSV immunization, GKO mice become solidly immune to the development of zosteriform lesions. In addition, the transfer of T cells from immune GKO mice to nude mice recipients renders them resistant to zosteriform lesions. Our results are discussed in terms of the major and compensatory mechanisms available to the body to effect immunity to viral infections.

Adoptive Transfer↗
PubMed1996

The role of the innate immune system in the reconstituted SCID mouse model of herpetic stromal keratitis.

Herpetic stromal keratitis (HSK) has an immunopathological basis, thought primarily to involve a CD4+ T cell-mediated immune response to viral antigen. Other cell types, however, particularly those involved in nonspecific immunity, such as natural killer (NK) cells or neutrophils, may also contribute to tissue destruction in the cornea. The reconstituted SCID mouse model of HSK provides a powerful system in which to study the interactions of the innate and adaptive immune responses to herpes simplex virus type 1 corneal infection. In the present study, reconstituted SCID mice depleted of NK cells had a reduced incidence and severity of clinical and histopathological HSK. The levels of T cell cytokine protein and message in restimulated splenocytes and cytokine message in corneas did not differ between experimental groups. However, significantly fewer neutrophils were seen within the inflamed corneas of NK-depleted SCID mice. Therefore, endogenous NK cells may indirectly influence the severity of HSK in reconstituted SCID mice by affecting neutrophil migration into the cornea.

Animals↗
PubMed1996

Cytokine expression in the gut associated lymphoid tissue after oral administration of attenuated Salmonella vaccine strains.

The use of attenuated Salmonella vaccine vectors as delivery vehicles for heterologous antigens has been extensive. The majority of work has analyzed the specific immune responses to the recombinant antigen in question. In addition, most analysis has been performed on animals maintained with sterile food, water, and bedding. This report defines the Salmonella specific cytokine responses in the gut associated lymphoid tissue after oral immunization with two highly publicized attenuated Salmonella carrier strains in animals maintained with nonsterile food, water, and bedding. Increases in expression of both IL-4 and IFN-gamma occur following immunization with either Salmonella construct. In addition, other cytokines (IL-6, IL-7, IL-12) increase at similar levels in either BRD509 or KR1 dosed animals. Proinflammatory cytokines IL-1 and TNF-alpha are also present but unchanged at early time points (6, 24, and 72 hours), increasing only after 7 days postimmunization. These data have implications in the generation of immunity to recombinant antigens since the response to Salmonella will dictate the direction of responses in terms of CD4 T cell activation.

Administration, Oral↗
PubMed1996

Viral replication is required for induction of ocular immunopathology by herpes simplex virus.

Corneal infection of BALB/c mice with herpes simplex virus type 1 results in a chronic inflammatory response in the stroma termed herpetic stromal keratitis (HSK). This disease is considered to be immunopathological and mediated primarily by CD4+ T cells of the type 1 cytokine profile. However, the nature of the antigens, virus or host derived, which drive the inflammatory response remains in doubt. In this study, the relevance of infection with replicating virus for the subsequent development of HSK was evaluated with immunocompetent mice as well as with SCID mice reconstituted with herpes simplex virus-immune CD4+ T cells. In the corneas of immunocompetent mice, infectious virus, viral antigen, and mRNA expression were detectable for only a brief period of time (< or = 7 days postinfection), and all were undetectable by the time clinical lesions were evident (10 to 15 days). Viral replication, however, was necessary for the development of HSK in both models, since infection with UV-inactivated virus or with mutant viruses which were incapable of multiple rounds of replication in vivo failed to induce HSK. The inactivated and mutant viral preparations did, however, stimulate T-cell immune responses in immunocompetent mice. The results are discussed in terms of possible involvement of host antigens exposed in response to transient progeny virion replication in the immune-privileged cornea.

Animals↗
PubMed1995

Characterization of herpes simplex virus type-1 infection and herpetic stromal keratitis development in IFN-gamma knockout mice.

Herpetic stromal keratitis (HSK) has an immune-mediated pathogenesis that involves T cells that have a type 1 cytokine profile. IFN-gamma is suspected to be the type 1 cytokine involved in ocular pathology, and to test this notion more directly the pathogenesis of HSK was compared in mice deficient in the IFN-gamma gene (gamma knockout or gko) and control mice (wild-type littermates or BALB/c mice). The clinical course of HSK in gko mice closely paralleled that in control mice, yet virus persisted in the corneas of gko mice for an extended period of time, severe periocular skin lesions developed, and gko mice were far more susceptible to encephalitis. Delayed-type hypersensitivity to viral Ag was present, though diminished, in knockout mice, and serum herpes simplex virus-specific IgG isotypes indicated a Th2 shift. No differences existed in proliferative responses to in vitro Ag stimulation in gko vs control mice nor in T cell or proinflammatory cytokine mRNA levels in the corneas of infected mice. However, up-regulation of Th2 cytokine mRNA did occur in in vitro Ag-stimulated gko immune splenocytes. Histopathologic lesions were not statistically different between any of the groups of mice analyzed. These observations indicate that although IFN-gamma plays an important role in the clearance of virus from the eye, the pathogenesis of HSK lesions most likely involves additional cytokines, inflammatory mechanisms, or immune responses to nonviral Ags.

Animals↗
PubMed1995

Lymphotoxin-alpha-deficient mice. Effects on secondary lymphoid organ development and humoral immune responsiveness.

Targeted mutagenesis in embryonic stem cells was used to generate mice deficient in lymphotoxin-alpha (LT-alpha). Mice lacking LT-alpha -/- (LT-alpha -/- mice) exhibit a phenotype dominated by defects in secondary lymphoid organ development. LT-alpha -/- mice lack lymph nodes and Peyer's patches, and possess spleens in which the usual architecture is disrupted. However, in a few of the mutants, abnormal lymph node-like structures were observed, mainly within the mesenteric fat. Abnormal clusters of lymphocytes were also found to accumulate in the periportal and perivascular regions of the liver and lung of LT-alpha -/- mice. Yet, lymphocytes from LT-alpha -/- mice appeared phenotypically normal, expressing the expected ratios of B and T cell surface markers as well as the lymphocyte homing marker, L-selectin. In addition, bone marrow cells from LT-alpha -/- mice were able to successfully reconstitute the lymphoid organs of severe combined immunodeficient mice. However, LT-alpha -/- mutant mice examined for humoral immune responsiveness were found to be impaired in their ability to respond to different Ag. These data illustrate the utility of this mouse model as a system for understanding lymphoid organ development and its effects on immune responsiveness.

Animals↗
PubMed1995

Genetic immunization against herpes simplex virus. Protection is mediated by CD4+ T lymphocytes.

Plasmid DNA encoding proteins represent a convenient novel approach to vaccination. We have investigated this "genetic immunization" approach as a means to protect against herpes simplex virus (HSV) infection using a mouse zosteriform model that mimics several aspects of reactivated HSV infection of humans. After i.m. immunization with plasmid DNA-encoding glycoprotein B (gB), (pc-gB), 80% of BALB/c mice were completely protected and lesions were delayed in the remaining animals. Upon pc-gB vaccination, the animals developed both gB- and HSV-specific IgG Ab response and the isotype examination revealed a predominance of IgG2a. These mice also have low levels (1/16) of HSV-neutralizing Abs. Immune splenocytes obtained from pc-gB-immunized mice, when restimulated in vitro with HSV resulted in production of type 1 cytokines. Evidence for CD(8+)-mediated cytotoxic T lymphocyte response was equivocal. Protection could be adoptively transferred to nude mice recipients by CD4+ T cells from pc-gB-immunized mice but not by CD8+ T cells. Our results demonstrate that genetic immunization is a potent means of inducing protection against HSV and that the mechanism of immunity responsible for clearing virus from cutaneous sites is principally by CD4+ T cells. It is likely that these cells are Th1 cells because type 1 cytokines were the major cytokines detected upon in vitro Ag stimulation.

Animals↗
PubMed1995

T cell cytokine mRNA expression during the course of the immunopathologic ocular disease herpetic stromal keratitis.

Corneal infection with herpes simplex virus in mice induces an inflammatory response in the stroma (herpetic stromal keratitis (HSK)) that appears to represent an immunopathologic reaction in which T cells of the CD4+ subset act as the essential participants. To assess the role of T cell cytokines at different clinical phases of HSK, corneas and draining lymph node (DLN) cells were collected and the levels of mRNA thought to be representative of type 1 and type 2 T cells were quantitated by reverse transcription-PCR. In the corneas collected before the onset of clinical disease, IFN-gamma and IL-4 mRNA were detectable, with levels of IFN-gamma 5- to 15-fold higher than IL-4. During the onset and peak expression of clinical disease, type 1 cytokines IFN-gamma and IL-2 were predominant in the corneas, and IL-4 levels were either very low or undetectable. Neither IL-10 nor IL-5 mRNA was present. After 3 wk postinfection, when some animals with mild disease began to recover, high levels of type 2 cytokine mRNA, particularly IL-10, were present. In addition, only during the recovery phase was IL-10 mRNA present in DLN samples. Levels of transcriptional activity for cytokine mRNA during clinical HSK were higher in corneas than in the corresponding DLN samples. The results indicate that IL-10 may be involved in HSK resolution and that the stimuli for cytokine induction in the cornea may differ from those in the DLN.

Animals↗
PubMed1995

Expression of cytokine mRNA in murine splenic dendritic cells and better induction of T cell-derived cytokines by dendritic cells than by macrophages during in vitro costimulation assay using specific antigens.

Among antigen-presenting cells dendritic cells (DC) have the unique ability to generate primary T cell response. The reasons for the superior inductive property of DC still remain obscure. The explanations offered include higher expression of CD80, MHCII, and ICAMI on DC surface which allows effective cluster formation with T cells. It is also possible that additional cellular characteristics of DC, i.e., their ability to release critical mediators involved in the induction of effective immune response, are important. We examined the ability of DC to express IL-1, IL-6, and IL-12 using the highly sensitive reverse transcription-quantitative polymerase chain reaction. Our data show that highly purified (97-99% pure) murine splenic DC were capable of expressing IL-1, IL-6 and IL-12 mRNA upon stimulation with lipopolysaccharide. We also compared the ability of DC and macrophages to induce T cell-derived cytokines IL-2 and IFN-gamma in an in vitro antigen-specific costimulation assay. In naive T cells stimulated with antigen presented via DC or macrophages, the levels of mRNA for IL-2 and IFN-gamma were 2- to 4-fold higher when cells were stimulated with DC. Overall, our data add additional support to the description of DC as superior antigen-presenting cells for the activation of naive T cells.

Animals↗
PubMed1995

Priming for virus-specific CD8+ but not CD4+ cytotoxic T lymphocytes with synthetic lipopeptide is influenced by acylation units and liposome encapsulation.

Synthetic peptides of the herpes simplex virus glycoprotein B synthesized either as a free form or derivatized with one (PAM1) or three palmitic acids (PAM3Cys) were used to assess the in vivo priming efficacy of high affinity virus-specific CTL induction. The peptide and its derivatives were delivered in vivo with or without liposome encapsulation. Neither the free peptide nor the PAM1 derivative primed for high affinity virus specific CD8+ CTL induction, whether delivered via liposomes or not. On the other hand, the PAM3Cys derivative was able to prime for low levels of high affinity virus specific CD8+ CTL induction in the absence of liposome encapsulation. However, the efficiency of virus-specific CD8+ CTL induction with PAM3Cys derivative was enhanced following encapsulation in the liposomes. In contrast, all forms of the peptides induced both CD4+ T cell proliferative response as well as high affinity virus-specific CD4+ CTL. In addition, the efficiency of the PAM3Cys derivative to prime for CD4+ or CD8+ CTL was found to be influenced by the liposome encapsulation. When delivered via liposomes, the PAM3Cys derivative effectively primed for CD8+ CTL. However, liposomal delivery was not necessary for efficient priming for CD4+ CTL induction. Thus, both the acylation units as well as liposomal delivery appear to influence the in vivo priming of CD4+ and CD8+ T cell responses with synthetic peptides.

Acylation↗
PubMed1995

Induction of protective immunity against herpes simplex virus with DNA encoding the immediate early protein ICP 27.

Using a mouse zosteriform model that mimics human herpes simplex virus (HSV) infection in several aspects, the effectiveness of plasmid DNA encoding the immediate early protein ICP 27 was evaluated as a vaccine. Animals were immunized intramuscularly twice with DNA, then either challenged with virus or killed, and the nature of the immune response induced was measured. After intramuscular injection with plasmid DNA encoding ICP 27 (pc-ICP 27), solid protection was evident in 70-80% of mice and the lesions were delayed in the remaining animals. Immune splenocytes obtained from pc-ICP 27 immune mice showed HSV-specific lymphoproliferation, MHC-class I restricted cytotoxic T-lymphocyte (CTL) activity, and type 1 cytokine production. These animals also exhibited delayed-type hypersensitivity (DTH) reactions. Adoptive transfer studies conducted on syngeneic nude mice revealed that those recipients of immune CD4+ T cells, but not CD8+ T cells, were protected from subsequent HSV-1 (strain 17) challenge. Thus pc-ICP 27 DNA immunization protected the mice principally by CD4+ T cells and it is likely that these cells were Th-1 type because only type 1 cytokines were detectable after in vitro antigen stimulation. Our results indicate the potential value of DNA encoding nonstructural viral proteins as vaccines against HSV.

Animals↗
PubMed1995

Role of macrophages and dendritic cells in primary cytotoxic T lymphocyte responses.

The successful induction of class I restricted cytotoxic T lymphocytes (CTL) responses with soluble non-replicating antigens relies upon vehicles which deliver antigen in vivo appropriately to antigen presenting cells (APC), which for CTL may be dendritic cells (DC). In this study, we have followed the distribution of liposomes and their incorporated antigen and compared the efficacy of splenic macrophages (Mo) and DC at inducing primary CTL responses in vitro. Our results show that whereas liposomes locate predominantly in the splenic red pulp and marginal zone locations, some of their soluble antigen contents redistribute to the central white pulp, comprising mainly DC and T cells. Such antigen redistribution was most apparent following administration of pH-sensitive liposomes. In comparisons of the APC activity of Mo and DC taken at various times post-injection, DC were always superior to Mo. However, if Mo were depleted prior to antigen exposure, DC were ineffective APC for CTL induction. Furthermore, addition of supernatant from OVA-liposome treated Mo to naive DC-T cell cultures in vitro resulted in OVA-specific T cell responses. These studies indicate a role for Mo in enhancing the antigen presenting function of DC.

Animals↗
PubMed1995

Differential induction of carrier antigen-specific immunity by Salmonella typhimurium live-vaccine strains after single mucosal or intravenous immunization of BALB/c mice.

In this study, we constructed strain KR21 (chi 4550 delta cya delta crp delta asd/pYA292asd(+)-toxC+) and compared it with BRD847 (aroA aroD/pnirB-toxC) for the ability to induce humoral and cellular immunity after a single oral or intravenous immunization in 3- to 4-week-old BALB/c mice. ToxC-specific serum immunoglobulin G (IgG) was detectable in animals orally immunized with either BRD847 or KR21. However, after intravenous immunization, IgG was detected only in BRD847-immunized animals. Measurement of immunoglobin types IgG1 and IgG2a suggests that a Th1 cellular response is prominent after immunizations with either system. ToxC-specific IgA was detected in fecal and vaginal samples of animals immunized orally and intravenously with BRD847, while those immunized with KR21 failed to show fecal or vaginal IgA responses. Delayed-type hypersensitivity was used as a measure of induction of T-cell responses in vivo. Mice immunized either orally or intravenously with BRD847 showed significant ear swelling responses after ToxC injections, while KR21-immunized animals failed to show a cellular response. These data indicate that the aroA aroD/pnirB system holds greater potential for inducing global immunity after a single dose when directly compared with the balanced lethal system (delta cya delta crp delta asd/pYA292asd+).

Administration, Oral↗
PubMed1995

Roles of different T-cell subsets in control of herpes simplex virus infection determined by using T-cell-deficient mouse-models.

Herpes simplex virus infection of the scarified dermis results in infection of the nervous system and, subsequently, a cutaneous lesion in the innervated dermatome. We compared the pathogenesis of such zosteriform lesions in mice lacking or severely depleted of CD4+ or CD8+ T cells because of targeted gene disruption. Mice without CD4+ cells showed markedly increased susceptibility, whereas beta 2 microglobulin knockout mice lacking CD8+ T cells were as resistant to challenge as were immunocompetent mice with the same genetic background. Our results demonstrate that CD4+ T cells are of primary importance in the control of herpes simplex virus infections of the skin and nervous system.

Animals↗