Protection of mice against vaccinia virus by bacterial infection and sustained stimulation with specific bacterial antigens

Lack of detectable circulating interferon in mice protected against vaccinia virus by induction and elicitation with bacterial systems

Mice which had been subjected to mycobacterial infection and specific elicitation were bled from the orbital sinus at the time the mice were challenged intravenously with vaccinia virus. Assays of the sera were negative for interferon. Sera of rabbits sensitized with staphylococci and elicited by Staphage Lysate also lacked detectable circulating interferon.

CD4 T-cell-mediated heterologous immunity between mycobacteria and poxviruses

The bacillus Calmette-Guerin (BCG) strain of Mycobacterium bovis is used in many parts of the world as a vaccine against Mycobacterium tuberculosis. Some epidemiological evidence has suggested that BCG immunization may have unpredicted effects on resistance to other pathogens. We show here in a mouse model that BCG immunization followed by antibiotic treatment to clear the host of the pathogen rendered three strains of mice partially resistant to infection with vaccinia virus (VV) but not to lymphocytic choriomeningitis virus (LCMV). VV-challenged BCG-immune mice developed a striking splenomegaly and elevated CD4 and CD8 T-cell responses by 6 days postinfection (p.i.). However, resistance to VV infection could be seen as early as 1 to 2 days p.i. and was lost after antibody depletion of CD4 T-cell populations. BCG- but not LCMV-immune memory phenotype CD4 T cells preferentially produced gamma interferon (IFN-gamma) in vivo after VV challenge. In contrast, LCMV-immune CD8 T cells preferentially produced IFN-gamma in vivo in response to VV infection. In BCG-immune mice the resistance to VV infection and VV-induced CD4 T-cell IFN-gamma production were ablated by cyclosporine A, which inhibits signaling through the T-cell receptor. This study therefore demonstrates CD4 T-cell-mediated heterologous immunity between a bacterium and virus. Further, it poses the question of whether BCG immunization of humans alters resistance to unrelated pathogens.

Peripheral corneal disorders

The peripheral cornea is anatomically and physiologically distinct from its central counterpart. The major differences relate to the gradual transition of corneal tissues to those of the conjunctiva, episclera, and sclera; furthermore, the vascular structures, lymphatics, and inflammatory cells from these neighboring structures are intimately associated with the limbus and periphery of the cornea. The peripheral cornea is thereby predisposed to three main classes of disorders which do not normally involve the central cornea. First, local conditions affecting the sclera and conjunctiva may secondarily spread to involve the limbus and peripheral cornea. These include several infectious diseases, as well as hypersensitivity conditions, mass lesions, and degenerations. Second, due to the associated blood vessels and lymphatics, the peripheral cornea may be involved in a variety of systemic diseases, including vasculitides, autoimmune disorders, and abnormal metabolic conditions. Finally, there are several conditions, such as the noninflammatory peripheral degenerations, which primarily affect the peripheral cornea without associated ocular or systemic changes. In this review, we present a classification and discussion of the various disorders which may involve the peripheral cornea.

Staphage lysate: an immunomodulator of the primary immune response in mice

The immunological enhancing activity of staphage lysate on the primary immune response of mice as reflected by specific heteroantibody production to a single antigenic stimulus and on immunoglobulin synthesis was determined. Staphage lysate was administered at different periods in relation to time of sheep erythrocyte injection so that both the inductive and the productive phase of the immune response could be evaluated. Treatment with staphage lysate induced pronounced enhancement of the hemagglutinin response by day 14 regardless of the dose or the time of its administration. Significantly higher antibody levels in the test groups were observed when compared with the control animals, peak antibody titers being 21 days following antigenic challenge. Furthermore, staphage lysate administered without an accompanying antigen evoked a heightened serum immunoglobulin level in mice for a period of more than 14 days after injection. IgG1, IgG2a and IgG2b were significantly elevated as a direct result of this treatment. This increased output of immunoglobulin synthesis and heightened hemagglutinin titers demonstrate that staphage lysate is not only an immunomodulator of cell-mediated immunity, as previously reported, but also an effective immunoadjuvant of the humoral antibody response capability in the host.

The normal immune response and what can go wrong. A classification of immunologic disorders

It is difficult to summarize any discussion of a subject when its vitality and growth increases and changes almost daily. It has been clearly demonstrated that the immune response is important in all organ systems of the body. Although we have learned a great deal about cellular recognition and the regulatory aspects of immunity, we are literally only scratching the surface of its complexity and applicability. A totally comprehensive review of the immune response is impossible in this short space. We do hope, however, that we have set the stage for the following in-depth reviews of the immunologic disorders in adults.

Effects of mycobacterial fractions and muramyl dipeptide on the resistance of mice to aerogenic influenza virus infection

The nonspecific protective effect in mice of pre-exposure to mycobacterial components and muramyl dipeptide three weeks before aerosol infection with influenza virus A/PR/8/34 (H1N1) was studied. Muramyl dipeptide, when combined with trehalose dimycolate and emulsified in an oil-in-water emulsion, conferred complete protection comparable to specific immunization with a high dose of formalin inactivated A/PR/8/34 influenza viral vaccine. Animals pre-exposed to muramyl dipeptide plus trehalose dimycolate showed a marked reduction in lung virus titres, an earlier clearance of detectable infectious virus, and an earlier onset of antibody production in comparison to control mice. Resistance to infection was also observed with BCG-cell wall skeleton combined with trehalose dimycolate and trehalose dimycolate alone when given as oil-in-water preparations. The route of administration of nonspecific stimulants was crucial. Only intravenous but not intradermal inoculation produced significant protection.

Phlyctenular keratoconjunctivitis

There is growing evidence that a variety of corneal disorders may be expressions of altered immune mechanisms. Phlyctenular keratoconjunctivitis is probably such a condition. Typically described as arising from hypersensitivity to tuberculin protein, other antigens clearly may participate, particularly staphylococcus products. When corneal involvement occurs, it need not be confined to the peripheral cornea. The symptoms of the process may be disproportionate to obvious findings and so exaggerated as to suggest a psychiatric disorder. Resultant visual deficits, if the disease is corneal, progressive, unrecognized, and untreated may be profound. Representative examples of this disease are cited. Immune mechanisms are reviewed. The importance of recognizing the characteristic sign and symptom complex is stressed. Appropriate diagnostic studies and treatment regimens are presented.

Specific and nonspecific immune resistance enhancing activity of staphage lysate

The immunopotentiating activity of staphage lysate (SPL) was evaluated in terms of its immune protection against lethal bacterial infection and its antitumor activity. Mice were pretreated weekly with 10(8) viable, Staphylococcus aureus, strain 18Z for 3 weeks (Induction), followed by intraperitoneal SPL injections (Elicitation) at various times in relation to infectious challenge or tumor implantation. Induction without elicitation, or elicitation alone failed to provide protection against Klebsiella pneumoniae infection and resulted in only 30-40% survival against homologous infection with pathogenic S. aureus type III, whereas combined induction and elicitation produced enhanced resistance induction and elicitation regimens resulted in 50% and 80-100% survival in mice inoculated with K. pneumoniae and S. aureus, respectively. SPL had no antitumor effect in mice implanted with median survival time resulting from induction and elicitation in animals implanted which Ehrlich's ascites. This enhancement of immune resistance may possibly be related to activation of thymus-modulated lymphocytes and macrophages by SPL.

The effect of BCG-vaccination on vaccinia virus infections in mice

Pretreatment with BCG yielded a high degree of protection against experimental vaccinia virus infections in mice. Corynebacterium parvum and Aristolochia acid were less protective; other immunostimulants were ineffective.

Induction and specificity of delayed hypersensitivity to Staphylococcus aureus in mice

The induction and specificity of delayed hypersensitivity (DH) to Staphylococcus aureus in mice was evaluated in vivo by the footpad (FP) assay and in vitro by spleen cell stimulation. Repeated infections result in a biphasic DH response. The first DH response, observed following three subcutaneous injections, was route and antigen specific, required viable organisms, and could not be enhanced by the incorporation of bacteria in adjuvants. Footpad reactivity was transferred to non-injected recipients by spleen cells but not serum and was inhibited by anti-thymocyte serum but not by cyclophosphamide. Spleen cell stimulation was maximal with homologous antigen, but, some cross reactivity was observed when cells were stimulated with hererologous gram-positive antigens. No cross reactivity was observed when antigens from gram-negative bacteria were used to stimulate spleen cells. The FP reactivity to homologous antigen following 7 injections, the second DH response, is of longer duration than that following 3 injections. Mice given seven injections exhibit a greater degree of cross reactivity to heterologous gram-positive but not gram-negative bacterial antigens. Similar results were observed when spleen cells from mice receiving 7 injections were simulated with gram-positive antigens. Furthermore, the degree of spleen cell stimulation following three of seven injections could be increased by elicitation prior to the vitro experiments.

Impaired defense against vaccinia in a child with T-lymphocyte deficiency associated with inosine phosphorylase defect

A case of progressive vaccinia associated with a profound deficiency of cellular immunity and a defect in inosine phosphorylase is described. A striking contrast was observed between humoral immunity, which showed little if any impairment, and a severe cellular defect affecting both markers and functions of T lymphocytes. The child died despite treatment with methosazone, levamisole, transfer factor, irradiated blood transfusions, and a thymus graft. An adequate serum level of antibody to vaccinia virus was obtained by transfer of specific immunoglobulins, but this failed to stop the progression of the disease. This observation suggests that host defense against vaccinia infection is mainly mediated by cellular immunity.

Enhanced resistance against encephalomyocarditis virus infection in mice, induced by a nonviable Mycobacterium tuberculosis oil-droplet vaccine

Female C57B1/10 mice injected intravenously (i.v.) with nonviable Mycobacterium tuberculosis Jamaica cells associated with oil-droplet emulsions (WCV) were highly resistant to the i.v. injection of encephalomyocarditis virus (EMCV). Resistance to infection (87% survival) was detected from 1 week to at least 12 weeks after injection of WCV. Mice vaccinated i.v. also were resistant to intraperitoneal, subcutaneous, or intramuscular virus challenge, but were not resistant to intracranial challenge. Mice vaccinated intraperitoneally also were resistant to virus infection, whereas WCV administered intramuscularly or subcutaneously did not protect mice from virus injected by any route. Less than 50% of WCV mice that survived virus challenge possessed serum anti-EMCV-neutralizing antibody (less than 1:10), and none had detectable (less than 1:10) serum interferon. Interferon was not detected in sera of WCV mice from 4 to 144 h after i.v. injection of EMCV. Studies concerning the effects of WCV on EMCV infection suggest that mice may be protected by mechanisms that inhibit early viral replication and spread of virus to the central nervous system.

Nonspecific resistance to Escherichia coli in mice

Nonspecific cell-mediated immunity to a relatively virulent strain of Escherichia coli was studied in mice infected with Staphylococcus aureus and elicited with specific antigens. The infected and elicited mice were protected against as intraperitoneal challenge by E. coli for an observation period of 7 days, whereas normal mice, given the same number of bacteria, died within 18 to 24 h. However, the amount of time elapsing between elicitation and challenge greatly affected the rate of protection. Little or no protection was observed in mice injected with S. aureus but not elicited or in mice injected with staphylococcal antigens but not infected with staphylococci.

Nonspecific resistance to Listeria monocytogenes in mice infected and elicited with Staphylococcus aureus

Normal mice and mice displaying delayed hypersensitivity to Staphylococcus aureus were challenged with a lethal dose of Listeria monocytogenes. Nonspecific antimicrobial activity was assessed by inhibition of bacterial growth in the spleen and by increased survival rates. Administration of specific staphylococcal antigen prior to challenge was a prerequisite for the induction of nonspecific resistance. Both the time of administering eliciting antigen and the route were important consideration for evoking the response. Similar responses were seen in 3 strains of inbred mice following immunization with both encapsulated and nonencapsulated staphylococci. Although enhanced resistance as measured by viable counts in the spleens was achieved after 2 injections, protection as measured by survival required 4 injections of S. aureus followed by elicitation with staphylococcal antigens. Nonspecific resistance could be detected as late as 9 weeks after the disappearance of delayed hypersensitivity.

Effect macrophage activation on infection with Treponema pallidum

Infection of rabbits with Treponema pallidum induces nonspecific acquired cellular resistance (ACR) to Listeria monocytogenes. This resistance can be adoptively transferred using thymus-dependent lymphocytes. Since infections that induce ACR are usually brought under control by cellular mechanisms, we sought to determine whether induction of ACR in rabbits stimulates resistance to challenge with T. pallidum. When BCG-infected rabbits which suppressed the growth of Listeria were challenged intravenously with T. pallidum, lesions appeared at the same time and progressed in a fashion similar to that in non-BCG-infected controls. There was a tendency for syphilitic lesions to disseminate more widely in BCG-infected animals and for the lesions to necrose more rapidly in controls. T. pallidum may resist phagocytosis by macrophages, as has been suggested previously, or macrophages may fail to be activated locally in the dermis. Although syphilitic infeciton appears to stimulate ACR, activation of the macrophages may not contribute significantly to the ability of the host to suppress T. pallidum.

Cell-mediated immune responses in Staphylococcus aureus infections in mice

Delayed hypersensitivity to staphylococcal antigens was shown in mice repeatedly infected with Staphylococcus aureus. It was characterized by footpad swelling at 48 hours with a mononuclear cell infiltrate and could be transferred to non-infected recipients by T lymphocytes from infected animals, but not by serum. Recipients of immune T cells produced very severe necrotic lesions when challenged with staphylococci. This was in contrast to the protection against necrosis in recipients afforded by serum from infected donors. When both serum and cells were transferred into the same mouse the humoral effects overshadowed or perhaps inhibited those mediated by cells with resultant protection against staphylococcal dermonecrosis.

The immune response to infection with vaccinia virus in mice. II. Appearance of hypersensitivity, production of macrophage migration inhibitory factor and transformation of spleen cells in response to virus antigens

The appearance of specific hypersensitivity to virus antigens was examined in mice infected intravenously with vaccinia virus. Both immediate hypersensitivity, transferable by serum, and delayed-type hypersensitivity, transferable only by cells, were apparent 8 days after infection and demonstrable for at least a further 130 days. Production of macrophage migration inhibitory factor by lymphocytes from infected mice was measured directly in terms of inhibition of migration by antigen or indirectly by determining the effect of soluble factors elaborated by the stimulated lymphocytes. The irregular results may have been the resultants of antigen-mediated macrophage stimulation, toxicity and induction of migration inhibitory factor. Transformation of spleen cells - presumably lymphocytes - from infected mice could be induced in vitro by virus antigens for at least 139 days after infection. Virus/lymphocyte interaction appears to be a particularly fruitful area for further study.

The immune response to infection with vaccinia virus in mice. I. Infection and the production of antibody neutralizing cell-associated and cell-free virus

The onset, duration and magnitude of antibody responses to a poxvirus infection were examined. Mice were inoculated intravenously with the WR strain of vaccinia virus and developed pocks on their tails. The number of pocks was related to the size of the inoculum. Virus was detectable in the spleen and infected mice were subsequently immune to intravenous and intra-nasal challenge. Sera of infected animals neutralized both cell-free and cell-associated virus. Antibody against cell-free virus appeared first; maximum titres were reached sooner but were lower than those of antibody neutralizing cell-associated virus. Titres remained high for at least 100 days after infection.

Specific and nonspecific cell-mediated resistance to influenza virus in mice

We found that influenza virus had the capacity to replicate in the peritoneal macrophages of normal mice, as revealed by the development of hemadsorption and the appearance intracellularly of S and V antigens. Cell-mediated resistance was studied in mice infected with influenza virus or a bacterial sytem of induction-elicitation. In the homologous system, mice were injected intraperitoneally or exposed by aerosol to a sublethal dose of an egg-adapted swine strain of influenza virus. In the heterologous system, they were infected repeatedly with Staphylococcus aureus and elicited by subcutaneous or aerosol administration of staphylococcal antigens. The peritoneal macrophages from mice specifically or nonspecifically immunized were significantly more resistant than those from normal mice. Also longer survival to in vivo challenge by the mouse-adapted virus, as compared with normal mice, was indicated in bacterially stimulated mice.

Detection of nonspecific resistance to Listeria monocytogenes in rabbits infected with Treponema pallidum

Several lines of evidence suggest that cell-mediated immunity (CMI) is suppressed in the early stages of infection caused by Treponema pallidum and becomes activated at the time that latency is induced. In the studies reported in this paper, rabbits were infected intravenously with T. pallidum and subsequently challenged with Listeria monocytogenes. Enhanced ability to suppress the growth of Listeria was detected in their livers between 3 and 5 weeks after infection with T. pallidum, corresponding to the onset and regression of the generalized syphilitic eruption. A second infection of T. pallidum 4 weeks after the first, at a time when suppression was beginning to wane, prolonged the listericidal activity. These observations support the hypothesis that infection by T. pallidum stimulates CMI, which, in turn, may play a role in inducing latency.