The Modifying Effect of BCG on the Immunological Induction of T Cells (original) (raw)
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Open Journal of Immunology, 2013
The cellular immune response elicited by Mycobacterium bovis Bacille Calmette-Guérin (BCG) has been carefully investigated, but the humoral immune response has been partially neglected. BALB/c mice were immunized with BCG strain used to immunize humans. Anti-BCG antibodies, as assayed by ELISA, began to appear in the sera after the third week of immunization and plateaued three weeks after the 8 th immunization. The total immunoglobulins (Igs) were purified by caprylic acid method from pooled serum collected after the 8 th immunization. Anti-BCG antigen antibodies were detected in the total Igs preparation as well as in IgG, IgM, IgA, IgG 1 , IgG 2a , and IgG 2b , but not in the IgG 3. Distinct BCG proteins were recognized the IgGs in Western blot analysis. Opsonization of BCG bacilli by the purified Igs potentiated internalization of the bacteria by murine Raw 264.7 macrophages. The intracellular BCG elimination coincided with the induction of NO production, which was more pronounced in cells infected with opsonized BCG compared to those infected with the non-opsonized bacteria. Coincidently, the production of NO was also higher in macrophages infected with opsonized BCG (maximal NO production at 48 h of incubation). The obtained results demonstrate that repeated inoculations of BCG effectively activate the humoral immune response, justifying the use of BCG as a live recombinant vaccine vector to insert genes encoding virulence factors controlled by antibodies.
Brazilian Journal of Medical and Biological Research, 2001
Two attenuated bacillus Calmette-Guérin (BCG) preparations derived from the same Moreau strain, Copenhagen but grown in Sauton medium containing starch and bacto-peptone (onco BCG, O-BCG), or asparagine (intradermal BCG, ID-BCG), exhibited indistinguishable DNA sequences and bacterial morphology. The number of viable bacilli recovered from spleen, liver and lungs was approximately the same in mice inoculated with the vaccines and was similarly reduced (over 90%) in mice previously immunized with either BCG vaccine. The humoral immune response evoked by the vaccines was, however, distinct. Spleen cell proliferation accompanying the growth of bacilli in tissue was significantly higher in mice inoculated with O-BCG. These cells proliferated in vitro upon challenge with the corresponding BCG extract. Previous cell treatment with mAb anti-CD4 T cells abolished this effect. Anti-BCG antibodies, as assayed either in serum by ELISA or by determining the number of antibody-producing spleen cells by the spot-ELISA method, were significantly higher in mice inoculated with ID-BCG. Anti-BCG antibodies were detected in all immunoglobulin classes, but they were more prevalent in IgG with the following distribution among its isotypes: IgG1>(IgG2a = IgG2b)> IgG3. When some well-characterized Mycobacterium tuberculosis antigens were used as substitutes for BCG extracts in ELISA, although antibodies against the 65-kDa and 96-kDa proteins were detected significantly, antibodies against the 71-kDa, 38-kDa proteins and lipoarabinomannan were only barely detected or even absent. These results indicate that BCG bacilli cultured in Sauton-asparagine medium permitted the multiplication of bacilli, tending to induce a stronger humoral immune response as compared with bacilli grown in Sautonstarch/bacto-peptone-enriched medium.
Clinical and Experimental Immunology, 1990
Wild house mice IMus domcsticu.s) captured in a Flemish pigsty were infected intravenously with 4 X 10'' viable units of Mycohacterium bovis BCG and examined by Western blot analysis for IgG seeretion againsl BCG eulture tiltrate (CF) antigens, Wild mice showed a marked individual variation inanlibody pattern when tested 4.6 and 8 weeks after infection. Some animals reacted to a wide range of antigens and others only to a limited number. Most wild mice rceogni/ed preferentially antigens withmolecularweight of24kD. 32kD. .^7 3K 40 kD. 65 kD and H2 kD. i.e. the major CF antigens known lo be reeognized by sera from BCG-infeeted Inbred laboraUiry strains. BALB/e. DBA/2. CBA Ca and C?7BL'6. The 32-kD fibronectin-binding protein and the 65-kD heat-shock prolein appeared as verv immunodominant in wild mice. Furthermore, about 20-25"ii ofthe miee reacled strongly with a unique anligen of. "^5 kD estimated molecular weighl. to which ihe tested inbred laboratory miee did not respond. Monitoring the size of the bacterial population in the spleen indieatcd that the BCG inoeulum did not replieate in wild miee. suggesting that the Bc^ allele is expre.sscd in this population.
Clinical and Experimental Immunology, 2000
In order to investigate the ability of Mycobacterium bovis BCG vaccination to induce immune responses toward different classes of mycobacterial antigens and the cell populations involved in such responses, proliferation of distinct human lymphocyte subsets from BCG-vaccinated donors in response to different subcellular fractions of BCG was analysed and compared with that of not sensitized subjects. Proliferation of different cell subsets was evaluated by¯ow cytometric determination of bromodeoxyuridine incorporated into DNA of dividing cells and simultaneous identi®cation of cell surface markers. Although a certain degree of variability was observed among different donors, after 6 days of in vitro stimulation BCG-vaccinated subjects displayed, as a mean, a stronger blastogenic response to all the classes of antigens compared with non-sensitized ones. PPD, culture ®ltrates and membrane antigens induced a predominant proliferation of CD4 T cells. In contrast, preparations enriched in cytosolic antigens elicited strong proliferation of gd T cells which, as a mean, represented 55% of the proliferating cells. Although to a lesser extent, proliferation of gd T cells was also elicited by preparations enriched in membrane and cell wall antigens. In response to the latter preparation proliferation of CD4 T cells and CD16 /CD3 À (natural killer (NK)) cells was observed, as well. In particular, cell wall antigens were found to induce signi®cantly higher levels of proliferation of NK cells compared with all the other classes of antigens.
FEMS Immunology & Medical Microbiology, 2009
During the serial passage of Mycobacterium bovis bacillus Calmette-Guérin (BCG) in different countries after initial seed distribution from the Pasteur Institute, specific insertions and deletions in the genome among BCG substrains were observed and speculated to result in differences in immunological activities. 'Earlyshared strains' of BCG (Russia, Moreau, Japan, Sweden, Birkhaug), distributed by the Pasteur Institute, which conserve three types of mycolate (a, methoxy, keto) in cell wall, exhibited stronger activities of induction of nitric oxide, interleukin-1b (IL-1b), IL-6, IL-8, IL-12 and tumor necrosis factor (TNF)-a, from human epithelial cell line A549, human myelomonocytic cell line THP-1 and mouse bone marrow cells in the presence of interferon-g (IFN-g) than did 'late-shared strains' of BCG (Danish, Glaxo, Mexico, Tice, Connaught, Montreal, Phipps, Australia, Pasteur). The stronger induction of IL-12 and TNF-a in the presence of IFN-g was also observed by trehalose 6,6 0 -dimycolate (TDM) extracted from BCG-Japan than by TDM from BCG-Connaught, which lacks the methoxymycolate residue. These results suggest that 'early-shared strains' are more potent immunostimulating agents than 'late-shared strains' , which could be attributed partially to methoxymycolate. Our study provides the basic information for immunological characterization of various BCG strains and may contribute to a re-evaluation of them as a reference strain for vaccination against tuberculosis.
Vaccine, 2000
After oral or intragastric administration of BCG to mice, comparable numbers of IFN gamma and TNF gamma producing cells were detected in both local (Peyer's patches) and central (spleen) lymphoid organs. Similar levels of precursors of CD8+ cytotoxic T lymphocytes specific for mycobacterial antigens were also found in the spleen and the mesenteric lymph nodes. These immune responses remained high over the course of 3 months, the duration of observation. Oral administration of BCG led to an enlargement of the cervical lymph nodes, which contained high levels of viable bacteria. In contrast, no adverse effects were observed in mice given the BCG via the intragastric route. These two routes of immunization induced similar levels of protective immunity to those observed in mice immunized via the subcutaneous route against a challenge with a virulent Mycobacterium tuberculosis strain (H37Rv).
Virulence of six strains of Mycobacterium bovis (BCG) in mice
Infection and immunity, 1973
The abilities of six strains of Mycobacterium bovis strain BCG to replicate in vivo and to cause spleen enlargement in the CDF(1) male mouse were compared. The strains were grown in synthetic medium and harvested soon after complete pellicles were produced on liquid medium. In addition, two freeze-dried commercially available preparations were tested. The comparisons were made on the basis of injecting equal numbers of colony-forming units. Strain differences were marked. The Brazil strain was most effective in stimulating spleen enlargement, and the Japan strain was the least effective. This correlated with the number of colony-forming units isolated from the spleen.
Infection and Immunity, 1979
Resistance and susceptibility to mycobacterial infection in the Biozzi high and low lines of mice which were genetically selected for their responses to heterologous erythrocytes have been found to be related to the innate ability of nonimmune macrophages to kill or inhibit the growth of the organisms during the first two weeks after infection and to their ability to mount specific and nonspecific immune responses. High antibody-producer mice were more capable of expressing cell-mediated immune parameters than low antibody-producer mice. A direct relationship was observed between the ability of bacteria (BCG vaccine) to multiply inside the reticuloendothelial system and the development of cell-mediated immunity, as measured by the delayed local reaction at the injection site, the lymphoproliferative response in the draining nodes, the tuberculin delayed-type hypersensitivity, the acquired resistance, and the adjuvant effect after BCG inoculation. In high line mice, apart from the in...