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PubMed1988

Genetic restriction and fine specificity of human T cell clones reactive with rabies virus.

Rabies virus-specific T cell clones isolated from a human vaccine recipient were studied for their fine specificity and genetic restriction using synthetic peptides of the viral Ag and mouse fibroblasts transfected with human MHC genes. Two clones were found to react with an epitope present in the rabies glycoprotein, which was presented by the HLA-DR7 molecule. Other T cell clones recognized synthetic epitopes corresponding to the rabies nucleoprotein in association with the HLA-DR7 or HLA-DQw3 molecule, and one clone responded to the viral nucleocapsid Ag in the presence of HLA-DPw4. T cell clones that exhibited different cross-reactivity patterns among several virus strains were found to recognize closely situated epitopes (within 15 amino acid residues), which were presented in the context of the same MHC molecule. The lack of recognition of a particular virus strain by a T cell clone was attributable in some cases to amino acid variations of the Ag that appear to affect the T cell's receptor for Ag specificity and not the ability of that epitope to associate with the corresponding MHC molecule. Comparisons of the T cell cross-reactivity patterns with various rabies and rabies-related viruses, the fine antigenic specificity, and MHC restriction may aid in understanding the role of individual amino acid variations among virus strains in the induction of cross-protective immunity.

Amino Acid Sequence↗

PubMed1989

Rabbit pasteurellosis: respiratory and renal pathology of control and immunized rabbits after challenge with Pasteurella multocida.

Gross and microscopic lesions of pasteurellosis were studied in control and immunized pasteurella-free rabbits after challenge with virulent Pasteurella multocida. Pathologic responses were compared in rabbits immunized intravenously or mucosally with P. multocida or with J5, a cross protective core LPS mutant of E. coli. All rabbits were challenged conjunctivally with approximately 2xLD50 of P. multocida. Rabbits were necropsied and examined for histopathology of the respiratory tract and kidneys. Lung lesions varied in severity depending on the duration of the disease, the route of vaccination, and the vaccine used. The most severe lung lesions occurred in rabbits vaccinated intravenously with P. multocida and challenged with the same strain. Some of these rabbits had purulent bronchopneumonia and pleuropneumonia. Lung lesions were absent or less severe in rabbits vaccinated by a mucosal (aerosol, conjunctival) route and in unvaccinated controls. In these animals there was no bronchopneumonia or pleuropneumonia, and bronchiolitis, if present, was less severe. Kidney lesions were found only in rabbits vaccinated intravenously. There was an interstitial nephritis, some collagen deposition, mononuclear cell infiltration, and a loss of tubular architecture in the cortex. Some glomeruli were affected. These results indicate that intravenous immunization contributes to the formation of lesions whereas mucosal immunization prevented lesion formation to some degree.

Aerosols↗

PubMed1989

Immunity of tick-exposed seronegative and seropositive small stock challenged with two stocks of Cowdria ruminantium.

Nineteen per cent and 32% of serologically positive sheep and goats in heartwater endemic areas of the Republic of South Africa were susceptible to challenge with, respectively, the Ball 3 and Welgevonden stocks of Cowdria ruminantium. There was good correlation between the results of the indirect fluorescent antibody test and immunity, since without exception all the seronegative animals reacted when they were challenged. The fact that only 74% of the seropositive sheep and goats were immune to challenge can probably be ascribed to the poor cross-protection between stocks of C. ruminantium and not to false positive serological reactions.

Animals↗

PubMed1985

Specific immunity in rats inoculated with Trypanosoma brucei brucei derived from tsetse salivary glands and cultured in vitro.

Twenty rats were each immunized intraperitoneally with 1.25 X 10(7) formalin-fixed Trypanosoma brucei brucei (Stock EATRO 1969) derived from tsetse salivary glands and propagated in culture at 29 degrees C in their infective form for more than 1000 days. Another group, consisting of 10 rats, was similarly immunized with parasites of stock EATRO 999 derived from salivary glands of a tsetse fly and propagated in culture for more than 360 days. Immunized animals were resistant to homologous challenge with 10(4) cultured infective parasites. There was no cross protection between stocks and animals were susceptible to homologous infective tsetse bite challenge.

Animals↗

PubMed1988

Evidence for multiple tachykinin receptor subtypes on the rabbit iris sphincter muscle.

The actions of mammalian tachykinins (substance P, substance K/neurokinin a, neuromedin K/neurokinin b) and non-mammalian tachykinins (eledoisin, kassinin, physalaemin) were compared on the rabbit pupillary sphincter. All acted as direct spasmogens with potencies in the order: eledoisin greater than physalaemin = neurokinin b = substance P greater than kassinin greater than neurokinin a. However, their actions could be divided into at least two categories on the basis of similar kinetics of contractions, differential sensitivity to the tachykinin antagonist (D-Arg1, D-Pro2, D-Trp7,9, Leu11) substance P and specific cross-protection against phenoxybenzamine inactivation by structurally related tachykinins. The relationship between these observations and the suggested "P" and "E" subtypes of tachykinin receptors is discussed.

Animals↗

PubMed1986

Structure and antigenicity of the phosphorylated lipopolysaccharide antigens from the leprosy and tubercle bacilli.

A family of major arabinose- and mannose-containing phosphorylated lipopolysaccharides was isolated from Mycobacterium leprae and Mycobacterium tuberculosis. The only antigenic member of the family, lipoarabinomannan (LAM)-B, was purified by anion exchange and gel filtration chromatography in detergent and recovered in large quantities (15 mg/g of bacteria). It yielded a broad diffuse band on polyacrylamide gel electrophoresis but appeared homogeneous by this criterion and gel filtration. Besides arabinose and mannose, it contained glycerol and a polyol phosphate and was acylated by lactate, succinate, palmitate, and 10-methyloctadecanoate. The phosphate was released by alkalinolysis and identified by thin layer chromatography and gas chromatography-mass spectrometry as myoinositol 1-phosphate. Thus, the group-specific "arabinomannan" of the genus Mycobacterium in the native state is acylated, contains the substituents of phosphatidylinositol, and is apparently membrane associated. LAM-B is one of the dominant immunogens of the leprosy bacillus reacting readily with antibodies from lepromatous leprosy patients and monoclonal antibodies in plate and nitrocellulose enzyme-linked immunosorbent assay and on electrophoretic immunoblots. It is immunologically cross-reactive with a like product from M. tuberculosis. LAM-B is clearly the pervasive "glycoprotein" antigen of the leprosy bacillus and may be the long sought lipoteichoic acid-like polymer of Mycobacterium with a role in cell wall physiology, macrophage recognition, and perhaps an involvement in cross-protective immunity.

Antigens, Bacterial↗

PubMed1987

Failure of anti-Fasciola antisera to induce antibody-dependent, eosinophil-mediated killing of Schistosoma mansoni schistosomula.

Sera from rabbits or humans infected with Fasciola hepatica were tested for their ability to kill Schistosoma mansoni schistosomula in an antibody-dependent, eosinophil-mediated in vitro assay. In addition, anti-F. hepatica antisera raised in rabbits or calves, including one to a Fasciola/Schistosoma cross-reactive, cross-protective defined immunity antigen, were also tested for their killing ability. None of these antisera induced damage to S. mansoni schistosomula in vitro, even when enhanced with mononuclear cell supernatants containing eosinophil-activating factor. Serum from humans with S. mansoni did induce schistosomulum killing in vitro when tested under these same conditions. These results suggest that the mechanism of immunity to schistosomes induced by Fasciola antigens at the level of the schistosomula is mediated by factors other than eosinophils.

Animals↗

PubMed1988

Genetics of resistance to the African trypanosomes. VII. Trypanosome virulence is not linked to variable surface glycoprotein expression.

The question of linkage of virulence traits to variable surface glycoprotein (VSG) expression in African trypanosomiasis was addressed. Previously we demonstrated that daughter cells arising in mice infected with a genetically homogeneous trypanosome population of Trypanosoma brucei rhodesiense were more virulent than the infecting population (J. A. Inverso and J. M. Mansfield, J. Immunol. 130:412, 1983). These virulent trypanosomes expressed differences in surface phenotype compared with the infecting variant types, and we proposed that virulence may be "linked" to VSG expression. In the present study, however, we have shown that expression of virulence is independent of the VSG phenotype displayed by trypanosome populations. A VSG-identical but highly virulent subpopulation of T. b. rhodesiense LouTat 1 was derived by rapid subpassage and subcloning in immunosuppressed mice. The virulent LouTat 1A subclone derived in this manner killed B10.BR/SgSnJ mice in 3 to 4 days postinfection compared with approximately 60 days for the parent clone, LouTat 1. The virulent subclone LouTat 1A appears to express the same VSG as the less virulent LouTat 1 population, as determined by polyspecific and monoclonal antibody-binding assays, cross-protection tests, and amino acid sequence analyses of the N-terminal portion of the VSG molecules. When LouTat 1 and subclone LouTat 1A were injected into a heterologous host species, multiple variant antigenic types (VATs) arising from each inoculum were isolated and characterized. VATs derived from the virulent subclone were as uniformly virulent for B10.BR mice as LouTat 1A. In summary, these results demonstrate that trypanosome virulence, once expressed, is a stable phenotype that does not seem to be associated with a particular VSG phenotype, nor does virulence change with the expression of different VSG genes.

Amino Acid Sequence↗

PubMed1988

Radiation-induced lymphoblastic lymphomas/leukemias and sarcomas of mice express conserved, immunogenic 44-kilodalton oncofetal antigen.

X-ray-induced, lymphoblastic, T-cell lymphoma/leukemias from irradiated RF mice were observed to uniformly expressed a 44-kd oncofetal antigen (OFA). The OFA polypeptide was detected by flow cytometry, affinity column SDS-PAGE analysis, and immunoblotting with monoclonal antibody (MAb) 115 prepared against syngeneic mouse fetus. X-ray and ultraviolet (UV) induced murine fibrosarcoma cell lines, used as classic models in radiation biology, were also found to express the OFA, which suggested that the 44-kd OFA was a general transformation marker of tumors. Adult mouse thymocytes and other adult tissues expressed no OFA. The 44-kd polypeptide was located at the surface membrane of the tumors examined. In contrast to other reports, lymphoblastic lymphoma cell lines expressed the OFA as a cross-protective, rather than an individually-specific, tumor-associated transplantation antigen. Pronase treatment removed OFA from the surface of living lymphoma cells, whereas collagenase, neuraminidase, and hyaluronidase did not. The OFA was rapidly reexpressed upon culture of the pronase-treated cells. Taken together, these results suggest that the 44-kd OFA polypeptide described here may provide a useful cell surface marker for future radiation carcinogenesis studies. MAb 115 is a promising reagent for detecting tumor-associated 44-kd OFA, for assessing immunoregulatory perturbations to the OFA caused by radiation damage and for investigating the immunopathology of OFA-associated radiation damage.

Animals↗

PubMed1986

Generation of tumor-specific transplantation antigens by UV radiation can occur independently of neoplastic transformation.

The purpose of this study was to determine whether the UV-associated antigens present on tumors induced in mice by chronic UV irradiation could be induced by in vitro irradiation of cells that were already tumorigenic, or whether their occurrence was associated with the primary neoplastic transformation event. Cells of a nonantigenic, spontaneous fibrosarcoma cell line were exposed to UV radiation in vitro, were cloned, and were tested for antigenic properties. A large number of the clones obtained after UV irradiation of the fibrosarcoma cells were highly antigenic (20 of 39), whereas clones derived from unirradiated cultures were not (0 of 10). The antigenic variants did not induce cross-protection among themselves, but induced only variant-specific immunity in vivo. Several antigenic variants were tested for susceptibility to the action of UV-induced suppressor cells, which seem to recognize a common determinant shared among UV-induced tumors. The variants tested were indeed subject to the activity of the UV-induced suppressor lymphocytes. These results demonstrate that the unique antigenic properties exhibited by UV-induced murine skin cancers are also exhibited by cells exposed to UV radiation in vitro. In addition, they imply that the UV-associated antigens arise as a consequence of exposing cells to UV radiation and that they can occur independently of an initial neoplastic transformation event.

Animals↗

PubMed1985

Tumour cell variants with increased immunogenicity obtained by mutagen treatment.

By treating mouse tumour cells in vitro with mutagens it is possible to obtain at high frequency variants that are rejected by normal syngeneic mice. Such variants have been designated 'tum-' to distinguish them from the original tumorigenic (tum+) cell lines. Most tum- variants appear to express new, individual antigens that can be defined in vivo by cross-protection experiments or in vitro by cytolytic T lymphocytes. The failure of tum- variants to form progressive tumours is apparently the result of an immune rejection response. Mice that have rejected a tum- variant clone are often protected against a subsequent challenge with the original tum+ cells. This was even demonstrated for two spontaneous mouse tumours for which no immunogenicity could be demonstrated otherwise. An analysis of 21 variants derived from mastocytoma P815 with cytolytic T lymphocyte populations showed that the repertoire of tum- antigens probably exceeds 50 specificities. No two variants have been found to express the same new antigen. Variant-specific long-term cytolytic T lymphocyte clones were isolated and used for the immunoselection of secondary antigen-loss variants that could then be analysed for the presence of previously undefined residual variant antigenic determinants. Somatic cell hybrids were prepared between different P815 tum- variants or between tum- variants and the original P815 cells. An analysis of the hybrids with variant-specific cytolytic T lymphocyte clones showed that the expression of tum- antigens was dominant. The intriguing paradox of the high frequency of tum- variants in populations of mutagen-treated tumour cells may require new genetic and immunological approaches before being understood.

Animals↗

PubMed1985

Cellular immune response to Mycobacterium bovis (BCG) in genetically-susceptible and resistant congenic mouse strains.

Congenic Bcgr (C.D2, resistant) and Bcgs (BALB/c, susceptible) mice were infected intravenously with Mycobacterium bovis (BCG, strain Montreal) in order to establish the relationship between different indicators of the cell-mediated immune response and the bacterial load attained in the host. There was a correlation between the bacterial burden and the splenomegaly response, granuloma formation in the liver and cross-protection against an heterologous pathogen (Listeria monocytogenes) in Bcgr and Bcgs mice. No relationship was found between bacterial load or granuloma formation and the development of specific acquired protection against an homologous organism (BCG or M. tuberculosis, H37Rv) as assessed by the level of resistance attained in BCG-primed mice challenged with virulent H37Rv or by the adoptive immunity conferred by BCG-primed spleen cells transferred to naïve irradiated recipients challenged with BCG.

Animals↗

PubMed1979

Immunogenicity of Clostridium septicum in guinea pigs.

Five strains of Clostridium septicum were used to prepare bacterins, bacterin-toxoids, toxoid, and combinations of bacterins or bacterin-toxoids. These preparations were tested for immunogenicity in guinea pigs vaccinated subcutaneously with 1.0 ml of product. Usually, a second vaccination was given 21 to 24 days later. The immunity of groups of vaccinated guinea pigs was challenged with as many as 22 strains of C septicum. When challenge exposed with homologous strains at 21 to 24 days after one vaccination or 10 t0 18 days after a second vaccination, 60% to 100% of the guinea pigs in each group survived. Demonstrable cross-protection among strains of C septicum varied from none to 100% protection in vaccinated guinea pigs. A combination of bacterin-toxoid prepared from four selected strains protected 70% to 100% of the vaccinated guinea pigs challenge exposed with 21 strains. Duration-of-immunity studies demonstrated a twofold to fourfold decrease in protection when the vaccination-to-challenge interval was extended an additional 3 weeks. Strains of C septicum do not have an effective common immunogen and the stimulated immunity appears to be of short duration. Antitoxin was demonstrated to be less important than other factors in protecting against C septicum infection.

Animals↗

PubMed1979

[Relations between the fungi Gaeumannomyces graminis and Phialophora radicicola when growing together outside the host (author's transl)].

In laboratory model experiments, numerous hyphal adhesions were found to take place between a severe wheat pathogen, G. graminis var. tritici, and a weak wheat pathogen, P. radicicola var, radicicola, and therefore the linear growth of the both fungi is inhibited. When both fungi occur concurrently side by side on celophane, the hyphae of one fungus do not occupy the place colonized before by the other fungus, due to mutual contact. It can be presumed that also direct interaction between hyphae of both fungi participates in cross protection mechanism of the take-all fungus G. graminis with P. radicicola.

Antibiosis↗

PubMed1984

Serologic and clinical responses of premunized, vaccinated, and previously infected cattle to challenge exposure by two different Anaplasma marginale isolates.

Two Anaplasma marginale isolates, one originating in Florida (FAM) and the other from Virginia (VAM), were compared immunologically by cross-challenge exposure of 14 Anaplasma carrier cattle, 8 previously infected cattle, and 6 splenectomized carrier calves. In addition, 28 cattle vaccinated with a commercially available adjuvant killed vaccine and 22 nonvaccinated cattle were challenge exposed with either FAM or VAM. A detectable clinical response was not produced by either FAM or VAM challenge exposure in carrier and previously infected cattle; however, evidence of A marginale growth as characterized by low percentages of parasitemia and increased serum complement-fixation titers was seen in carrier cattle given a heterologous challenge organism and in previously infected cattle inoculated with either homologous or heterologous organisms. Among splenectomized calves, there was virtually no cross protection to the heterologous challenge exposure, whereas a homologous challenge failed to elicit any detectable response. Vaccinated cattle were resistant to VAM exposure, but the clinical response to FAM exposure was severe with a 47% mortality. Most of these cattle displayed typical acute anaplasmosis that was only marginally less severe than that encountered in nonvaccinated cattle.

Anaplasma↗

PubMed1984

Pathogenicity studies of feline coronavirus isolates 79-1146 and 79-1683.

Two feline coronavirus isolates were characterized by their disease-causing potential in cats. The 79-1683 feline coronavirus isolate caused an inapparent-to-mild enteritis when given oronasally to specific-pathogen-free kittens and was not a cause of feline infectious peritonitis (FIP). Target tissues for the virus were the mature apical epithelium of the small intestine, mesenteric lymph nodes, tonsils, thymus, and (to a lesser extent) the lungs. Inoculated kittens shed high numbers of virus in their feces for 14 to 17 days, but remained infectious to susceptible kittens for longer periods of time, as evidenced by contact-exposure studies. Because the 79-1683 isolate induced only enteritis, it was designated feline enteric coronavirus (FECV) 79-1683. The 79-1146 feline coronavirus isolate induced effusive abdominal FIP in specific-pathogen-free kittens after oronasal and intraperitoneal inoculation. Clinical signs of disease appeared within 12 to 14 days in almost all inoculated kittens. Because this isolate caused FIP, it was designated FIP virus (FIPV) 79-1146. Cross-protective immunity was not induced by the various coronavirus infections. Kittens preimmunized with the UCD strain of FECV (FECV-UCD) or with FECV-79-1683 were not immune to infection with FIPV-79-1146. Likewise, kittens previously inoculated with FECV-79-1683 were not immune to infection with FIPV-UCD1. In fact, preexisting heterologous FECV-79-1683 immunity often accelerated and enhanced the severity of disease caused by inoculation with FIPV-UCD1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1984

Characterization of antigenic variation among mink enteritis virus isolates.

Three antigenic forms of natural field isolates of mink enteritis virus were revealed with a panel of monoclonal antibodies generated against the closely studied feline panleukopenia virus and canine parvovirus-2 virus. Two types (types 2 and 3) were shown to be closely related by agar-gel precipitin tests and by restriction enzyme mapping. However, types 2 and 3 differed from the type 1 isolates in the same tests. In cross-protection studies, inactivated viral vaccines made from any one of the 3 variant types of mink enteritis virus protected mink against challenge exposure by the homologous, as well as the heterologous, antigenic types.

Animals↗

PubMed1984

Immunotherapy of tumor-bearing mice with chemically modified tumor membrane fractions of two syngeneic tumor cell lines.

The effects of chemical modification on the immunogenicity of plasma membrane fractions of virus-induced and chemically induced tumor cell lines were tested in syngeneic tumor-bearing mice. The immunotherapeutic effects were dependent on (1) the chemical nature of the modifying reagent, which also determines the molecular site of modification in the membrane components, (2) the degree of modification, (3) the immunizing dose of modified membranes, and (4) the time schedule of immunization. Best results were obtained when the immunizing membrane samples were modified by methylation or acetylation using immunizing doses of membrane equivalents corresponding to 10(3)-10(4) cells. Up to 30% of the animals remained tumor-free and the observed survival of the animals was different from that of the control when immunotherapy was started five days after tumor transplantation. A delayed start of immunotherapy, or simultaneous immunization with tumor transplantation, or immunizations with nonmodified membrane samples led to reduced observed survival. The therapeutic effects were specific for each individual cell line. Cross-protection was not observed when mice bearing chemically induced tumors were treated with modified membrane samples derived from a syngeneic virus-induced tumor cell line.

Animals↗