Relationship of antimicrobial cellular immunity to delayed hypersensitivity in Listeriosis

Listeria monocytogenes infection in prosthetic joints

Listeria monocytogenes is increasingly recognised as a cause of prosthetic joint infection. These infections tend to be more insidious and indolent in contrast to similar infections with Staphylococcus aureus. They can occur in patients who are immunocompromised due to malignancy or other illness or in nonimmunocompromised elderly patients. Listeria infections should not be treated with cephalosporins and prolonged antimicrobial treatment is generally advised for prosthetic joint infections. We noted a high affinity of L. monocytogenes for foreign bodies. Three of twenty-seven cases 11%) of listeriosis under the period of investigation were associated with foreign bodies (hip prosthesis, knee prosthesis and arterial graft).

Interleukin-1-induced promotion of T-cell differentiation in mice immunized with killed Listeria monocytogenes

We studied the effects of administration of recombinant interleukin-1 alpha (rIL-1 alpha) to mice after immunization with killed Listeria monocytogenes cells on the promotion of the functional differentiation of T cells in vivo. Mice immunized with killed L. monocytogenes were unable to express cell-mediated immunity to specific antigen in vivo, as determined by delayed-type hypersensitivity (DTH) and acquired cellular resistance (ACR), and splenic T cells obtained from such mice were unable to respond to rIL-2 and specific antigen and to produce IL-2 after antigenic restimulation in vitro. When rIL-1 alpha was given to mice after immunization with killed bacteria. T cells became capable of responding to rIL-2 and specific antigen in vitro. These functions of T cells were similar to those from mice immunized with viable listeriae. Moreover, using a local passive transfer system, it was found that effector T cells mediating DTH but not ACR to L. monocytogenes were generated in mice treated with rIL-1 alpha after immunization with killed bacteria. These T cells were able to produce macrophage chemotactic factor but not macrophage-activating factor or gamma interferon in vitro in response to stimulation with specific antigen. These results suggest that in vivo administration of rIL-1 alpha facilitates the maturation of antigen-specific T cells mediating DTH and that different effector T cells mediating DTH or ACR are involved in cell-mediated immunity to L. monocytogenes.

Induction by killed Listeria monocytogenes of effector T cells mediating delayed-type hypersensitivity but not protection in mice

Using a local passive transfer system, we found that effector T cells mediating delayed-type hypersensitivity (DTH) but not acquired cellular resistance (ACR) to Listeria monocytogenes (strain EGD) were generated in mice immunized with killed Listeria, although immunized mice did not express DTH or ACR. When non-adherent cells of peritoneal, lymph node, or spleen cells from mice immunized with killed Listeria were transferred into the footpad of naive recipient mice along with eliciting antigen, positive delayed footpad reaction (DFR) was elicited. However, there was no evident protection against challenge at the site of the local transfer. Cells from mice immunized with viable Listeria conferred significant degrees of DFR and ACR on the recipients. DFR transferred by cells immunized with killed Listeria was mediated by L3T4+ T cells in an antigen-specific manner. The antigen-specific proliferative response of T cells from mice immunized with killed Listeria was much lower than that of T cells from mice immunized with viable Listeria. The production of macrophage chemotactic factor (MCF) by cells from killed Listeria-immune mice was much the same as that by cells from viable Listeria-immune mice. In contrast, the production of interleukin-2 (IL-2) and macrophage activating factor (MAF) was much lower in cells from killed Listeria-immune mice. The elimination of L. monocytogenes (strain L461), a strain of low virulence, was enhanced at the site of DFR transferred with cells from killed Listeria-immune mice. These results suggest that stimulation with killed bacteria is effective for the generation of DTH-mediating effector T cells, and that different effector T cells mediating DTH or ACR are involved in cell-mediated immunity to L. monocytogenes.

Differential regulation of effector responses of cell mediated immunity in experimental salmonellosis

Delayed type hypersensitivity (DTH) and protective cell mediated immunity showed different profiles with respect to time following intraperitoneal immunization with live Salmonella enteritidis. Whereas the DTH response decreased with time the Protection Index increased. The decline in DTH response was found to be associated with suppressor cells generated by intraperitoneal immunization and could be prevented by cyclophosphamide treatment prior to immunization. It was concluded that the two effector responses of cell mediated immunity were under differential regulation.

Dissociation between enhanced resistance and delayed hypersensitivity induced with subcellular preparations from Listeria monocytogenes and the adjuvant dimethyl-dioctadecyl-ammonium bromide

In this study we investigated the relation between enhanced resistance and delayed hypersensitivity (DH) induced with subcellular preparations from Listeria monocytogenes and the adjuvant dimethyldioctadecylammonium bromide (DDA). Ribosomal RNA as well as cell envelope fragments (fraction I) protected mice against lethal Listeria infection. However, only fraction I induced DH against killed Listeria. For the induction of protection with fraction I or RNA as well as for the induction of DH with fraction I, preparations had to be administered in combination with DDA. Fraction I elicited a DH response in mice immunized with viable Listeria, but RNA did not. These observations pointed to a dissociation between DH and enhanced resistance induced with RNA, and to a dissociation between fraction I and RNA with respect to their ability to induce or elicit DH. Also DH and enhanced resistance induced with fraction I could be dissociated. Intracutaneous administration of fraction I induced high levels of DH without concomitant induction of protection against lethal challenge with Listeria. On the other hand, intraperitoneal administration of fraction I fully protected mice against lethal infection, but only induced a moderate DH response. DH induced with fraction I was largely specific, whereas enhance resistance induced with this preparation was nonspecific. Finally, proteinase K-sensitive proteins were found to be essential for the induction of DH but not for the induction of protection with fraction I.

Adoptive protection of the Mycobacterium tuberculosis-infected lung. Dissociation between cells that passively transfer protective immunity and those that transfer delayed-type hypersensitivity to tuberculin

Adoptive transfer of protective immunity to an aerogenic infection with the facultative intracellular bacterium Mycobacterium tuberculosis was mediated by a population of T cells acquired in the spleen of donor mice at the height of the primary cell-mediated immune response to an immunizing infection with M. bovis bacillus Calmette-Guerin. Successful adoptive immunotherapy was ablated by prior exposure of immune donor cells to ionizing radiation or by treatment of these cells with antibody raised against the Ly-2 marker. In contrast, however, the capacity of immune donor cells to passively transfer delayed-type hypersensitivity (DTH) responses to tuberculin was unaffected by prior treatment with antibody to Ly-2, but was completely ablated by treatment by antibody to Ly-1. These results indicate, that DTH and protective anti-tuberculous immunity are dissociable phenomena, mediated by separate populations of T lymphocytes.

Delayed-type skin hypersensitivity and in vitro lymphocyte immunostimulation responses of swine following inoculation with Mycobacterium avium cell walls and a mycobacterial immunopotentiating glycolipid

Miniature swine (n = 5 per group) were inoculated intradermally with mineral oil-in-water emulsions containing either 150 micrograms of mycobacterial immunopotentiating glycolipid P3 (EP3), 150 micrograms of lyophilized Mycobacterium avium (serotype 8) cell walls (E-MaCW), or 150 micrograms P3 and 150 micrograms M. avium cell walls (EP3-MaCW). Swine vaccinated with E-MaCW and EP3-MaCW developed antigen-sensitive lymphocytes detectable with delayed-type hypersensitivity (DTH) skin tests and lymphocyte transformation assays. Swine injected with EP3 were not sensitized. In general EP3-MaCW evoked a more pronounced in vivo DTH tuberculin skin test and in vitro lymphocyte transformation responses than E-MaCW. Time-course studies indicated a more persistent response in swine injected with EP3-MaCW than in those given E-MaCW. Commercial type Yorkshire swine (n = 5) inoculated intradermally with EP3-MaCW developed cell-mediated immune (CMI) responses to avian tuberculin detectable in vivo with delayed-type skin hypersensitivity and in vitro with lymphocyte immunostimulation responses.

Lack of correlative enhancement of passive transfer of delayed-type hypersensitivity and antilisterial resistance when using concanavalin A-stimulated primed spleen cells

The adoptive transfer of resistance to Listeria monocytogenes can be significantly enhanced by in vitro incubation of primed murine spleen cells with concanavalin A (ConA) before transfer into syngeneic recipients. The level of transferred resistance, as measured by clearance of infectious organisms, can approach that observed in actively immunized mice. When delayed-type hypersensitivity (DTH) responses of passive transfer recipients were compared, there was no difference in the level of hypersensitivity exhibited by mice receiving either nonstimulated or ConA-stimulated, Listeria-immune spleen cells. In addition, the level of these adoptively transferred responses never approached the level of DTH observed in actively immunized mice. This inability of ConA-stimulated cells to enhance passive DTH in recipient mice was not dependent on the antigenic preparation of Listeria used to elicit the DTH response. Transfer of cultured, ConA-stimulated, Listeria-immune spleen cells did not lead either to specific or to nonspecific suppression of DTH responsiveness in actively immunized mice. These results indicate the possible existence of antigen-specific T-cells subpopulations which, after stimulation with ConA, exhibit differing efficiencies when responding in assays of cell-mediated immunity.

A functional relationship between delayed hypersensitivity and antibacterial immunity

The injection of living Listeria Monocytogenes into the site of a delayed hypersensitivity reaction in the footpads of mice resulted in inactivation of the organism. No such inactivation occurred when L. monocytogenes was injected into normal footpads. A correlation was observed between the magnitude of the delayed hypersensitivity reaction and the level of antibacterial resistance expressed within the delayed hypersensitivity site.

Transfer of immunity to cryptococcosis by T-enriched splenic lymphocytes from Cryptococcus neoformans-sensitized mice

Splenic enriched T-cells and sera were obtained from inbred CBA/J mice injected 7 or 35 days earlier with either 10(3) viable Cryptococcus neoformans or sterile physiological saline. The transfer of enriched T-cells collected 7 days after immunization or of normal enriched T-cells did not transfer immunity to C. neoformans or delayed-type hypersensitivity responsiveness to cryptococcal culture filtrate (CneF) antigen to the recipients. However, enriched T-cells harvested 35 days after immunization, when transferred to recipient mice, were able to confer immunity as indicated by the reduction in numbers of C. neoformans cells in the tissues, and they also transferred delayed-type hypersensitivity responsiveness to CneF antigens. Sera from either sensitized or normal mice were unable to transfer immunity to recipient animals. These results suggested that there was a time requirement for development of the immune response in the donor mice and that T-cells were crucial in the host defense against a cryptococcal infection. Culturing of day-35 C. neoformans-sensitized T-cells in the presence of homologous antigen (CneF) but not in the presence of heterologous antigen (purified protein derivative or 2, 4-dinitro-1-fluorobenzene) induced the production of migration inhibition factor, thus indicating that lymphocytes from C. neoformans-injected mice were specifically sensitized to CneF antigen.

Mechanisms of protective immunogenicity of microbial vaccines: effects of cyclophosphamide pretreatment in Venezuelan encephalitis, Q fever and tularaemia

Administration of high-dose (250 mg/kg) cyclophosphamide (CY) to guinea-pigs and mice 3 days prior to immunization with inactivated vaccine derived from Venezuelan encephalitis virus (VE), Coxiella burnetii and Francisella tularensis resulted in accentuated and prolonged delayed-type hypersensitivity (DTH) and in vitro cellular immunity (CMI) to specific antigen. Humoral antibody were either absent or significantly lower in CY-pretreated animals compared to immunized non-pretreated controls. CY pretreatments precluded protection in the VE virus model, suggesting that resistance is related to antibody. In the Q fever model, the protective immunogenicity of vaccine was preserved or increased by CY pretreatment suggesting that cell-mediated immunity is the important factor. In the tularaemia bacterial system, there was a complex effect of CY pretreatment on the low-grade protection afforded by killed vaccine against virulent infection. These findings suggest that the inability of killed vaccines to induce high-grade resistance against tularaemia and Q fever may be due in part to a suppressive B cell response which is eliminated by CY. These studies have given useful information on the relative significance of components of the specific immune response and may lead to an increased understanding of the mechanisms of action of vaccines and adjuvants.

Cell-mediated immunity to intestinal infection

Specified pathogen-free B6D2F1 mice were orally infected with various doses of Listeria monocytogenes. Oral inocula containing more than 2.5 X 10(8) live organisms consistently initiated infection in the Peyer's patches (PP) of the small intestine. At lower doses the infection was sporadic, with many mice showing no apparent infection in the PP. The PP appeared to be the only site of tissue invasion and L. monocytogenes survival in the intestinal tissues, as no organisms were recovered from mucosa dissected free of all visible PP. Within the PP, the bacteria multiplied and the infection then disseminated to the mesenteric lymph node (MLN), liver, and spleen. However, bacteria were almost completely eliminated from all tissues, both systemic and gut-associated by 6 days postinfection. Mice given a primary L. monocytogenes infection by the oral route were highly resistant to subsequent intravenous or oral challenge. Likewise, sublethal intravenous infection rendered mice highly resistant to subsequent oral infection. In addition, lymphocytes from the PP, MLN, and spleens of mice recovering from a primary oral infection were able to adoptively transfer immunity to normal recipients. Finally, after oral infection, mice did not display peripheral delayed hypersensitivity to L. monocytogenes antigens until the organisms had penetrated to the spleen.

Effect of visceral leishmaniasis on congenitally athymic mice

Congenitally athymic mice were more susceptible to challenge with amastigotes of Leishmania donovani than were their thymus-intact littermates. This increased susceptibility correlated with a lack of Arthus and delayed-type responses when animals were skin tested with leishmanial antigen.

Acquired cellular resistance, delayed hypersensitivity, and altered macrophage migration in Listeria monocytogenes-infected guinea pigs

A Listeria monocytogenes infection in guinea pigs was used to study the interrelationship between antigen-induced macrophage migration inhibition, delayed-type hypersensitivity, and acquired cellular resistance. Early after infection (at 2 and 7 days), very significant enhancement of macrophage migration was observed. Migration inhibition was detected beginning on day 14 and was uniformly observed only on day 21 of the infection, after which a shift again to enhancement was seen. The early detection (by day 2) of migration enhancement suggested that this assay may be more sensitive than assessment of delayed type hypersensitivity in vivo, which in this system was first detectable only on day 4. Acquired cellular resistance, as measured by enhanced survival following a high dose challenge with Listeria, was present from day 7 after infection until at least day 60. By splenic clearance studies, however, acquired cellular resistance was present only until day 14 after infection, suggesting that in this system splenic clearance was not a very reliable criterion for measuring acquired cellular resistance.

Interactions between salmonellae and macrophages of guinea pigs. IV. Relationship between migration inhibition and antibacterial action of macrophages

The in vitro macrophage migration inhibition test was used to detect the development of delayed-type hypersensitivity in guinea pigs infected with Salmonella typhimurium. Four different preparations from supernatants of S. typhimurium cultures were used as the antigens in this test. They included the concentrated bacterial antigens, the high-molecular-weight (>50,000) antigens, the ammonium sulfate-precipitated antigens, and the ribonuclease-treated antigens. All four antigen preparations were shown to inhibit the migration of peritoneal macrophages of salmonella-infected (immune) guinea pigs from capillary tubes, in comparison with cells of normal control animals. By use of the high-molecular-weight antigens and the ammonium sulfate-precipitated antigens, the production of the migration inhibition factor(s) was elicited from cultures of lymphocytes obtained from the peripheral blood of immune guinea pigs. The activity of the migration inhibition factor(s) was demonstrated by its ability to inhibit the migration of peritoneal macrophages of normal guinea pigs from capillary tubes. In contrast, normal peritoneal macrophages exposed to products of antigen-stimulated immune lymphocytes did not exhibit an enhanced phagocytic or bactericidal action against virulent S. typhimurium as compared with those of the normal control. The present study indicated that the bacterial antigens responsible for the elicitation of the production of the migration inhibition factor from lymphocytes of immune guinea pigs are inactivated by proteolytic enzymes, but not by ribonuclease, and have molecular weights of >50,000.

Kinetics and maintenance of acquired resistance in mice to Listeria monocytogenes

In the mouse system, acquired resistance to Listeria monocytogenes can only be demonstrated after immunization with viable microorganisms. A successful state of immunity cannot be elicited with formalin-killed organisms or bacterial cell-derived products. Viable, serologically cross-reactive organisms (not mouse pathogenic) do not induce a state of immunity as measured by acquired resistance. The duration of immunity, once established, is dose independent, and the absolute interval of its existence is not extended by secondary challenge with large numbers of viable organisms. The decline of immunity in actively immunized animals is not altered by antigenic challenge with formalin-killed cells or cell products. This indicates that the cellular requirements for the development of host resistance are similar for induction as well as maintenance. In vitro measurements of cellular immunity by migration inhibition indicate that formalin-killed organisms as well as cell products were recognized by actively sensitized lymphocytes obtained from immune animals.

Enhanced primary resistance to Listeria monocytogenes in T cell-deprived mice

The present studies reinvestigate the role of the T cell in the development of resistance to Listeria monocytogenes. Doubly thymus-deprived adult thymectomized irradiated bone marrow-reconstituted mice (D-AT × BM) were prepared using anti-theta serum-treated bone marrow from AT × BM donors for reconstitution. The growth of the bacteria in spleens and livers of D-AT × BM was inhibited and such animals survived infection with doses which were lethal to normal mice. Since the D-AT × BM animals were T cell-depleted, as evidenced by (a) absence of theta-positive cells in their spleens; (b) inability to mount a primary humoral response to a T-dependent antigen and (c) failure to reject H-2 incompatible skin allografts, their antibacterial resistance was not due to the presence of a residual T-cell population. Further evidence of T-cell depletion in these animals was furnished by the findings that, despite their resistance to L. monocytogenes, they failed to exhibit a delayed hypersensitivity reaction to Listeria antigens, their splenocytes were unable to transfer resistance to naïve hosts and they did not develop an anamnestic response upon secondary challenge.

We concluded from these findings that primary antibacterial resistance to L. monocytogenes need not necessarily depend on the development of specific cell-mediated immunity although under normal circumstances these two processes develop in chronological association. The increased resistance of D-AT × BM animals is interpreted as being due to the enhancement of bactericidal activity of mononuclear phagocytes, possibly caused by the removal of a regulatory T-cell population. This population seems to be radiosensitive and spleen-seeking and requires an intact spleen to mediate its effect.

Cell-mediated immunity in experimental Nocardia asteroides infection

Experimental mycetoma-like lesions developed in guinea pigs after subcutaneous injection of Nocardia asteroides. Although delayed hypersensitivity appeared earlier, increased macrophage migration inhibition and microbicidal activity appeared after 7 weeks. When the lesions healed, high cell-mediated immunity was present. Cell-mediated immunity was transferred to normal recipient guinea pigs from healed donor guinea pigs by spleen cell transfer. Recipient guinea pigs showed marked protection against challenge with N. asteroides.

Macrophage migration inhibitory activity of mycobacterial growth inhibitory factor and the effect of a number of factors on mycobacterial growth inhibitory factor activity

Mycobacterial growth inhibitory factor (MycoIF), which inhibits the intracellular multiplication of virulent tubercle bacilli within normal peritoneal macrophages in vitro, was tested for its ability to inhibit the migration of normal peritoneal exudate cells. The migration of peritoneal exudate cells was not inhibited by MycoIF. It was also shown that normal peritoneal macrophages infected with virulent Mycobacterium tuberculosis, strain H37Rv, required 72 h of incubation with spleen cell culture supernatant fluids containing MycoIF in order to inhibit intracellular bacillary multiplication. Treatment of infected macrophages with trypsin before their exposure to MycoIF abolished the ability of MycoIF to inhibit intracellular mutiplication of tubercle bacilli. Incubation of infected macrophages with goat anti-mouse globulin before their exposure to MycoIF also blocked the action of MycoIF.