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At least 19 recordsLinked to original sources
PubMed1997

Immunization with bacterial antigens: bacterial kidney disease.

Bacterial kidney disease has consistently resisted attempts to control it by prophylactic immunisation. Although successful vaccines have been produced to a number of Gram-negative fish pathogens, the relatively simple method used in these cases have not been successful with Renibacterium salmoninarum. A more circumspect and thorough knowledge of the biological function of R. salmoninarum antigens must be obtained. Also required is a more precise understanding of the role of regional immunity in effective prophylaxis. Aspects of R. salmoninarum's biology provide a provocative challenge to the vaccinologist. Its residence in, and apparent commandeering of the macrophage, indicate that a vigorous cell-mediated response will probably be required to generate protective immunity. Its most biologically potent secreted product, p57, appears to be an aggressin. Further, p57 has the capability of frustrating immunoprophylaxis by either misdirecting the immune response, or by preventing its induction. Many immunization studies have used injection immunization and challenge protocols. It now appears that alternative routes of immunization which had been considered less protective (i.e. oral immunization) may not only be more efficacious, but may be the only route that does not lead to a misdirected and possibly pathological immune response. Also, the general reliance on serum antibodies as the only means to assess immunity is fraught with difficulties, particularly with pathogens such as R. salmoninarum. Recent advances in the analysis of cellular immunity will be a great aid in the design of future vaccines.

Animals↗
PubMed1978

Studies on the subpopulation and function of peripheral lymphocytes, and lymphocyte reactivity to colonic mucosal antigen and bacterial antigen in patients with ulcerative colitis and Crohn's disease.

Immunological studies were carried out in fifteen cases of ulcerative colitis, three cases of tuberculous colitis, four cases of Crohn's disease and one case of Behcet's disease diagnosed by X-ray, endoscopy or biopsy mainly from the standpoint of cellular immunity. In patients with ulcerative colitis the T-cell population and PHA responsiveness of peripheral lymphocytes were both depressed more than in the control group. At different stages of the disease, the deviation of the values of PHA responsiveness of lymphocytes showed a rather wide range in the active stage and there was also immunological instability. However, when the disease entered remission, the immunological conditions settled down and the pathological condition appeared stable. In contrast to the nonspecific immunological conditions mentioned above, characteristically, there were many examples of a positive lymphocyte response to colonic mucosal and bacterial antigens. In all cases of Crohn's disease the lesions are in the small intestine and there was a reduced response to PHA lymphocytic stimulation which was more pronounced than that in patients with ulcerative colitis. PHA response was also high in tuberculous colitis cases.

Adult↗
PubMed1997

Bacterial antigen delivery systems: phagocytic processing of bacterial antigens for MHC-I and MHC-II presentation to T cells.

Using an in vitro model system we have studied parameters of both bacteria and antigen presenting cells that influence peptide presentation by murine major histocompatibility complex class II (MHC-II) and class I (MHC-I) molecules. To study MHC-II presentation, the HEL (52-61) epitope, which binds the murine MHC-II molecule I-Ak, was expressed as the cytoplasmic Crl-HEL fusion protein in S. typhimurium. When murine peritoneal macrophages mediated phagocytic processing of S. typhimurium expressing Crl-HEL, HEL (52-61) was processed and presented on I-Ak more efficiently from heat-killed S. typhimurium than from viable bacteria, and from a rough LPS strain compared to its isogenic smooth LPS counterpart, most likely due to enhanced phagocytosis of the rough LPS strain. Macrophages also processed phoP S. typhimurium strains with greater efficiency for peptide presentation by I-Ak than wild type bacteria while Salmonella constitutively expressing phoP were processed for peptide presentation by I-Ak less efficiently than wild type Salmonella. We have also shown that macrophage phagocytosis of E. coli or S. typhimurium results in presentation of bacterial antigens by MHC-I molecules. To investigate the role of post-Golgi MHC-I molecules in this presentation pathway, peritoneal macrophages from TAP1-/- mice, which are deficient in presenting endogenous antigens on MHC-I and lack significant surface MHC-I expression, were co-incubated with bacteria containing the 257-264 epitope from ovalbumin [OVA(257-264)], which binds the murine class I molecule Kb. Peritoneal macrophages from TAP1-/-/ mice could process bacteria expressing the OVA epitope for recognition by epitope-specific T hybridoma cells. This processing and presentation was reduced in efficiency between three to 100 fold compared to C57BL/6 macrophages, depending on the protein harbouring the OVA (257-264) epitope (Crl-OVA or native OVA). This suggests that the protein context of the OVA (257-264) epitope influences the extent of TAP-independent processing for MHC-I presentation. In addition, we show that murine bone marrow-derived dendritic cells can phagocytose and process viable gram negative bacteria for peptide presentation on MHC-I and MHC-II; inhibition studies showed that acidic compartments in dendritic cells are required for this presentation. These results suggest that dendritic cells may be potential antigen presenting cells used in eliciting specific immune responses against bacteria.

Animals↗
PubMed1981

Whipple's disease: morphologic and immunofluorescence characterization of bacterial antigens.

The bacterial etiology of Whipple's disease is generally accepted. However, the exact identity of the "Whipple bug" has remained elusive. Indeed, the isolation of several types of bacteria from different patients with Whipple's disease has caused some to speculate that Whipple's disease may have polymicrobial etiology. Our light and electron microscopic studies document the presence of bacilliform organisms lying free in the lamina propria of the duodenal mucosa. Intact and partially degraded bacterial organisms were seen in the phagosomes of macrophages. Indirect immunofluorescence studies demonstrated the presence of multiple bacterial antigens in the lamina propria as well as the macrophage granules. This profile of antigens is similar to the profile demonstrated in four other patients in two previous studies. The occurrence of similar profiles of bacterial antigens in the tissues of different patients with Whipple's disease suggests a single microorganism in the etiology of Whipple's disease. Because of the overlapping features of muciphages and Whipple's cells in the rectal biopsy material, the superiority and reliability of proximal small intestinal biopsy in preference to rectal biopsy are re-emphasized.

Adult↗
PubMed1976

Blastogenic response of human lymphocytes to oral bacterial antigens: characterization of bacterial sonicates.

Soluble sonicate supernatant preparations were made from Actinomyces viscosus (ATCC 19246), A. naeslundii (ATCC 12104), two strains of Veillonella alcalescens (strain HV-1 and a human oral isolate), Streptococcus sanguis (ATCC 10556), S. mutans (strain 6715-T2), Bacteroides melaninogenicus (strain K110), and Leptotrichia buccalis (isolated from human dental plaque). These supernatants were characterized with reference to their chemical and antigenic components and their biological activity determined by using in vitro lymphocyte blastogenesis as a measure of the host's cellular immune response. The sonicate supernatant of each bacterium contained protein, neutral sugars, methylpentose, and nucleic acids. Protein was the major component in all except L. buccalis, in which neutral sugars predominated. The antigenic components in each supernatant were detected by using rabbit antisera prepared against the whole bacteria and the sonicate supernatant. The supernatants showed a complex antigenic distribution on immunoelectrophoretic analysis. The supernatants were shown to be antigenic and not mitogenic in nature, since neither cord blood lymphocytes nor all adult lymphocytes were stimulated. The supernatant antigen preparations showed a reproducible, dose-dependent, and kinetic response in vitro, which was similar to that seen with the antigen preparation streptokinase-streptodornase.

Actinomyces↗
PubMedDate not supplied

[Etiology of acute infections of the lower respiratory tract in hospitalized infants: bacterial antigens].

Demonstration of bacterial antigens in biological fluids has been used for early detection of bacterial infections. Recent evidence suggests that higher detection rates of these antigens can be obtained from concentrated urine than from serum samples of patients. Evidence of bacterial infection by antigen detection was looked for from 50 fold concentrated urine samples by means of an ultrafilter system (Minicom) and latex agglutination for Haemophilus influenzae B (HiB) and Streptococcus pneumoniae (Sp) in three groups of patients. Group A (Positive controls), included 7 patients whose blood culture were positive for HiB (n = 5) and Sp (n = 2). Group B (Healthy controls) involved 16 children without clinical and laboratory signs of infection, coming from ambulatory well baby clinics and surgical wards, and group C was formed by 77 patients with negative blood cultures but with clinical and X ray evidence of lower respiratory tract infection. The corresponding antigen was demonstrated in urine samples from all group A patients. Three group B subjects gave positive results for HiB antigen. HiB antigen was detected from 10 and Sp antigen from 2 group C patients. These results suggest that the search for bacterial antigens in urine would be useful for etiological diagnosis and management of patients with bacterial pneumoniae. There is no definite explanation for the finding of HiB antigen in urine from apparently healthy children but the possibility of previous or actual asymptomatic infections must be taken into account.

Antigens, Bacterial↗
PubMed1976

Hypersensitivity to bacteria in eczema. I. Bacterial culture, skin tests and immunofluorescent detection of immunoglobulins and bacterial antigens.

A study was made of the cytotoxic effect of antibacterial antibody and complement reacting with bacterial antigens firmly adsorbed to epidermal cells. It is believed that this phenomenon enhances the severity of the lesions and their spread in some cases of disseminated eczema. In this first part of the study it is confirmed that Staphylococcus aureus and micrococci are frequently present on lesions and 'unaffected' skin of patients with disseminated eczema. Intradermal skin tests with antigens of staphylococci and micrococci on 122 eczematous patients elicited immediate, or combined immediate and 4 h (Arthus-like) responses, in a large proportion, but few showed uncombined 4 h responses or delayed hypersensitivity, in contrast to findings reported by others. Immunofluorescence tests on skin of thirty patients showed that IgG and IgM diffused into the epidermis, sometimes to the skin surface, of lesional skin, and more immunoglobulin was found in skin of 'unaffected' areas than in skin of normal healthy persons, indicating that clinically unaffected skin in patients with disseminated eczema is abnormal. IgD was present in three of eight samples of unfixed, and six of eight samples of fixed eczematous skin. Staphylococcal and micrococcal antigen was shown on the skin surface and also diffusely in the cytoplasm of cells in the dermis beneath the surface deposits, indicating percutaneous absorption. Further small amounts of antigen were adsorbed to some epidermal cells. These results show that the predisposing conditions for a cytotoxic reaction mediated by hypersensitivity to bacteria do occur. Increased growth of staphylococci and micrococci on eczematous skin would result in increased deposits of antigen. Bacterial antigens are absorbed into the skin and bind with epidermal cells, and immunoglobulins diffuse into the epidermis. Furthermore, skin tests showed that many eczematous patients were hypersensitive to bacteria. Studies on the nature of the antibacterial antibody will be published in the succeeding reports.

Antigens, Bacterial↗
PubMed1995

Quality assurance study of bacterial antigen testing of cerebrospinal fluid.

Bacterial antigen testing (BAT) of cerebrospinal fluid (CSF) by latex agglutination is a low-yield procedure in patients whose CSF specimens have normal laboratory parameters. Between August 1992 and August 1994, we evaluated 287 bacterial antigen (BA) test requests to determine whether yields could be improved and whether patient costs could be reduced by cancelling BAT for those patients with normal CSF parameters (cell count, protein, glucose) after consultation with physicians. A total of 171 (68%) BA tests were canceled by this approach. None of these CSF specimens was culture positive for an organism detectable by BAT. Of the remaining 116 CSF specimens tested, only 3 were positive by BAT, one each for Neisseria meningitidis, Streptococcus pneumoniae, and group B streptococcus. Only 43 of the CSF specimens tested had at least two abnormal parameters; the 3 positive CSF specimens were included in this group. In light of the low rate of positivity, the number of BA tests can be further reduced by establishing criteria that must be met before a CSF specimen is accepted for BAT. After review of our data and the literature concerning this topic, we concluded that only specimens with leukocyte counts of > or = 50 cells per mm3 should be tested. Of 287 specimens evaluated in our study, only 36 met this criterion, including the 3 BA-positive specimens. Enacting such a restriction would have reduced the total number of BA tests by 251 (87%) without compromising patient care. A laboratory cost savings of $6,500 per year would have been realized, with a substantial reduction in the cost per positive test. Patient charges would have been reduced by $12,500 per year.

Adolescent↗
PubMed1994

The role of bacterial antigen detection tests in the diagnosis of bacterial meningitis.

We sought to determine the circumstances under which cerebrospinal fluid (CSF) bacterial antigen detection tests. (BADT) are indicated. The medical records of 146 consecutive patients with bacterial meningitis seen from 1986 to 1991 were reviewed retrospectively (mean age 16 months; median eight months). Bacterial meningitis was defined as a positive CSF culture or a positive CSF BADT, in association with the clinical presentation and response to antibiotic treatment consistent with bacterial meningitis. Before lumbar puncture, 61/146 (42%) of meningitis patients had received treatment with antibiotics. CSF BADT was performed on 56/61 (92%) of pretreated patients; of these, 48 (87%) were positive, and 8 (13%) were negative. In this group, 15/61 (25%) of pretreated patients had a negative CSF culture but a positive CSF BADT. All 85 patients who did not receive antibiotics before lumbar puncture had positive CSF cultures and 52/75 (69%) had positive CSF BADT. Because prior antibiotic therapy may impair bacterial growth from the CSF, a CSF BADT should be performed whenever the patient has received prior antibiotic treatment.

Adolescent↗
PubMed1985

The effect of phospholipids from Listeria monocytogenes and Aspergillus fumigatus on degradation of bacterial antigens by mouse peritoneal macrophages.

Investigations were carried out on an influence of phospholipids from L. monocytogenes and A. fumigatus on the degradation of Streptococcus faecalis cell walls by mouse peritoneal macrophages. It has been found, that macrophages from mice stimulated with phospholipids under studies degraded streptococcal cell walls labeled with DL-alanine-I-14C more efficiently than normal macrophages. Activated macrophages degraded also more rapidly antigenic structures of bacterial cell walls reacting with specific fluorescein-labeled antibodies. Moreover, the increase in activity of lysosomal acid hydrolases in stimulated macrophages was observed. The experiments performed suggest that increased ability of macrophages to degradation of bacterial antigens may be connected with a primary augmentation of lysosomal enzyme activity.

Animals↗
PubMed2006

Comparison of gene expression by co-cultured WC1+ gammadelta and CD4+ alphabeta T cells exhibiting a recall response to bacterial antigen.

Immunization of cattle with a Leptospira borgpetersenii serovar hardjo-bovis vaccine results in the development of a recall response by WC1(+) gammadelta T cells and CD4(+) alphabeta T cells characterized by proliferation and interferon-gamma production. It was hypothesized that these two T cell subpopulations had largely redundant effector functions, principally differing in their requirements for activation. To test this, gene expression in cells proliferating to antigen were compared utilizing RT-PCR and bovine microarrays. Both T cell populations had similar transcript profiles for effector molecules, including IFN-gamma, FasL and granzyme B. In contrast, transcripts for costimulatory receptors and ligands were notably different following activation, as WC1(+) T cells expressed no or lower levels of transcripts for CD28 and CD40L, while CD4(+) T cells expressed substantial levels of both. However, both cell types had high levels of CTLA-4 transcript suggesting the cells may be regulated similarly following activation but differ in their need for and ability to provide costimulation. Microarray analyses to extend the number of genes examined revealed that while both subpopulations upregulated anti-apoptotic genes as well as those involved in cell activation and protein biosynthesis, overall there were limited differences between the two antigen-activated cell populations. Those genes that did differ were involved in cell signaling, protein production and intracellular protein trafficking. These results strengthen the hypothesis that these particular activated WC1(+) and CD4(+) T cells have overlapping effector functions and therefore may differ principally with regard to how they are recruited into immune responses.

Animals↗
PubMed1985

In situ enzyme immunodetection of surface or intracellular bacterial antigens using nitrocellulose sheets.

We describe an immunological method which allows the in situ colorimetric detection of translated DNA fragments in bacteria. In the absence of lysis only cell surface proteins are detected. For cytoplasmic proteins, lysis is required. The procedure comprises the following steps: bacteria are lysed, the proteins are transferred onto a disc of nitrocellulose sheet, the remaining protein sites are blocked, the disc is successively soaked in a solution of antibodies specific for the protein to be detected and in a solution of peroxidase-labelled anti-IgG antibody solution. Finally, the immune complexes are made visible by enzyme substrate incubation. We describe the application of this method to the detection of the LamB protein, the LacZ protein, and a LamB-polio VP1 chimera translated from cloned DNA fragment in E. coli.

Antigens, Bacterial↗
PubMed2003

Immune changes in lymph nodes after skin grafting. I. Effects of bacterial antigens.

Transplantation of skin brings about response of the regional lymph nodes. Lymph node cells (B and T lymphocytes, dendritic cells, imigrating monocytes, high endothelial venous cells) respond to three types of antigens: allogeneic, bacterial and self-antigens. Allogeneic reaction is induced by contact of antigen presenting cells (APC) with donor antigens. Bacteria penetrate rejecting graft epidermis and travel along lymphatics to the nearest lymph node. Rejecting graft debris is phagocytized by macrophages and dendritic cells and transported to lymph nodes. These different type antigens induce different reaction of node cells. In this review we present data from literature and own studies on the effect of bacteria normally residing on skin surface on lymph node after penetration of epidermis. Further reviews will be dealing with the response of lymph nodes to allo- and autoantigens.

Animals↗
PubMed1995

Analysis of the natural human IgG antibody repertoire: life-long stability of reactivities towards self antigens contrasts with age-dependent diversification of reactivities against bacterial antigens.

We used a quantitative immunoblotting technique to analyze the repertoires of IgG antibody reactivities in the serum of healthy young children, young adult males and aged males with self and non-self antigens. Densitometric patterns of reactivity of purified IgG with self antigens were highly conserved between individuals within a given age group and across age groups. Inter-individual differences were observed, however, upon analysis of self reactivities of IgG in whole serum. A striking heterogeneity between individuals within a given age group and across age groups characterized the reactivity of purified IgG and of IgG in whole serum with bacterial antigens. Inter-individual differences were more marked among aged individuals than among individuals of other age groups. Analysis of variances of reactivities of IgG with bacterial antigens further demonstrated an increased diversity of repertoires of aged donors compared with those of young adults and children. Our results document the stability of the self-reactive repertoires of IgG throughout life, which contrasts with the diversification of the repertoire of IgG antibody reactivities directed toward foreign antigens with aging. These findings support the concept that self-reactive antibody repertoires are positively selected throughout life by a restricted set of self antigens shared by all individuals.

Adult↗
PubMed1979

[Role of T- and B-lymphocytes in the heterogeneity of human cell-mediated reactions to bacterial antigens].

Leucocytes from 30 patients with allergy to tuberculin and bacterial antigens were treated with antithymus (ATS) and anti-immune globulin (AIGS) sera. The leucocyte migration inhibition test (LMIT) was performed with these antigens. ATS abolished the LMIT induced by tuberculin and sometimes by bacterial antigens (staphylococcal, streptococcal etc.). AIGS frequently abolished the LMIT induced by bacterial antigens, but not by tuberculin. In some cases the treatment with any serum abolished the LMIT induced by the antigens, or, on the contrary, it was abolished only by a successive treatment with both sera. The lymphocyte types (T or B) determining the secondary immune response to the same antigen are different in various patients, as well as they differ in the same patients in relation to diverse antigens. Five types of lymphocyte - antigen interrelation in the LMIT have been distinguished.

Adult↗