Biomedical subjects

G Perdigón

Publications and source records attributed to G Perdigón.

At least 19 recordsLinked to original sources

PubMed2006

Escherichia coli with anti-O157:H7 activity isolated from bovine colon.

AIMS: To isolate bacteria from bovine gastrointestinal tract and investigate their inhibitory effect on Escherichia coli O157:H7 in vitro. METHODS AND RESULTS: A total of 2400 bacterial colonies were isolated from cattle colonic mucous membrane. Thirteen strains demonstrated the ability to inhibit the growth of E. coli O157:H7. From these, seven were screened for the presence of virulence factors as: stx(1), stx(2), ehxA, eae, st1a and lt1 by polymerase chain reaction. The selected bacteriocin-producing bacteria showed susceptibility to most of the antibiotics used. CONCLUSIONS: The strains of E. coli isolated, which exhibit inhibitory activity on E. coli O157:H7 growth by the production of inhibitory substances, may be useful in the control of this pathogen in reservoirs. An important characteristic of these strains was the absence of any of the virulence factors assayed and the susceptibility to most of the antibiotics used for Gram-negative bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: These microorganisms might be used as probiotic bacteria to reduce the carriage of E. coli O157:H7 in cattle, thus limiting the contamination of carcasses at slaughter and subsequently the contamination of foods and the transfer of this pathogen to man.

Animals↗

PubMed2006

The probiotic bacterium Lactobacillus casei induces activation of the gut mucosal immune system through innate immunity.

The mechanisms by which probiotic bacteria affect the immune system are unknown yet, but many of them are attributed to an increase in the innate or in the acquired immune response. To study the influence of the probiotic bacterium Lactobacillus casei in the expression of receptors involved in the innate immune response, this bacterium was orally administered to BALB/c mice. After, they were sacrificed; the small intestine and intestinal fluids were collected to measure secretory immunoglobulin A (IgA) specific for L. casei. Mononuclear cells from Peyer's patches were isolated to determine the CD-206 and TLR-2 receptors. In histological slices we determined the number of IgA+, CD4+, CD8+, and CD3+ cells and two cytokines (interleulin-5 [IL-5] and IL-6). CD-206 and TLR-2 increased with respect to the untreated control. We did not observe an increase in the T population or in the IL-5-positive cells. IgA+ cells and IL-6-producing cells increased after 7 days of L. casei administration. We did not find specific antibodies against L. casei. The main immune cells activated after oral L. casei administration were those of the innate immune response, with an increase in the specific markers of these cells (CD-206 and TLR-2), with no modification in the number of T cells.

Administration, Oral↗

PubMed2005

Interference of Lactobacillus plantarum with Pseudomonas aeruginosa in vitro and in infected burns: the potential use of probiotics in wound treatment.

This study evaluated the ability of the probiotic organism Lactobacillus plantarum to inhibit the pathogenic activity of Pseudomonas aeruginosa, both in vitro and in vivo, and investigated the mechanisms involved in such protection. L. plantarum whole cultures, culture filtrates (acid filtrate and neutralised acid filtrate) and isolated, washed cells were tested in vitro for their effects on the production of the P. aeruginosa quorum-sensing signal molecules, acyl-homoserine-lactones (AHLs), and two virulence factors controlled by these signal molecules, elastase and biofilm. All were inhibited by L. plantarum cultures and filtrates, but not by isolated, washed cells. The acid L. plantarum growth medium itself had some inhibitory activity, but the greatest activity was exerted by the whole culture. To test the in-vivo activity of L. plantarum, a burned-mouse model was used in which burns infected with P. aeruginosa were treated with L. plantarum at 3, 4, 5, 7 and 9 days post-infection. Samples from skin, liver and spleen taken after 5, 10 and 15 days demonstrated inhibition of P. aeruginosa colonisation by L. plantarum. There was also an improvement in tissue repair, enhanced phagocytosis of P. aeruginosa by tissue phagocytes, and a decrease in apoptosis at 10 days. These results indicate that L. plantarum and/or its by-products are potential therapeutic agents for the local treatment of P. aeruginosa burn infections.

Animals↗

PubMed2005

Reduction of beta-glucuronidase and nitroreductase activity by yoghurt in a murine colon cancer model.

Yoghurt feeding inhibits induced colon cancer in mice. Several studies showed the immunomodulatory effect of yoghurt which can explain this inhibition. It is possible that yoghurt bacteria can also affect gut flora enzymes related to colon carcinogenesis as reported for other probiotics in different animal tumours. The aim of this work was to evaluate the role of yoghurt starter bacteria and their cell-free fermentation products on the reduction of procarcinogen enzyme activities (beta-glucuronidase and nitroreductase). Mice injected with 1,2-dimethylhydrazine (DMH) and fed with yoghurt were used for this study. Mice given milk or yoghurt supernatant (cell free extract) were used to evaluate if the yoghurt antitumour effect is due to the starter bacteria or other components released during fermentation, that could inhibit these enzymes. We determined that yoghurt by itself maintained enzymes activities similar or lower than non-treatment control group, and the enzyme activity was also lower than milk or yoghurt supernatant groups. DMH increased the activity of the enzymes. Mice injected with DMH and fed cyclically with yoghurt presented lower enzymes activities than the tumour control group. Feeding yoghurt decreased procarcinogenic enzyme levels in the large intestine contents of mice bearing colon tumour. The results of this study provide another mechanism by which yoghurt starter bacteria interact with the large intestine of the mice and prevent colon cancer.

1,2-Dimethylhydrazine↗

PubMed2004

Relationship between interaction sites in the gut, hydrophobicity, mucosal immunomodulating capacities and cell wall protein profiles in indigenous and exogenous bacteria.

AIMS: To investigate whether there is a relationship between interaction sites in the gut, hydrophobicity, mucosal immunomodulating capacities and cell wall protein profiles in lactobacilli, bifidobacteria and enterococci. METHODS AND RESULTS: Hydrophobicity, cell wall protein profiles and sites of interaction in the gut (by using fluorescein isothiocyanate-labelled bacteria) were determined for Lactobacillus casei, L. acidophilus, L. fermentum, Bifidobacterium bifidum, B. animalis and Enterococcus faecalis. We also determined the number of immunoglobulin (Ig)A+, tumour necrosis factor (TNF)alpha+, interleukin (IL)-6+ and IL-10+ cells after oral administration of the above bacteria to BALB/c mice. All strains assessed were found to interact with the sites of induction of the immune response in the gut. No correlation with hydrophobicity was observed. When some strains at certain doses were administered to mice, bacterial translocation to liver was observed. The oral administration of indigenous (104 cells day(-1)) and exogenous (107 cells day(-1)) bifidobacteria and lactobacilli for 5 consecutive days activated the systemic and intestinal mucosal immune response in a strain-specific way, independently whether the strain was indigenous or exogenous in relation to the host. The differences in the immunopotentiating capacity of the various strains might be related to the differences in their cell wall protein profiles. CONCLUSIONS: Indigenous bacteria activated the mucosal immune response at a dose significantly smaller than the one required for probiotic exogenous bacteria. However, probiotic exogenous bacteria can be used at high concentrations in fermented dairy products with a great impact on the immune system, favouring its immunomodulation. SIGNIFICANCE AND IMPACT OF THE STUDY: The immunomodulation capacity of probiotic bacteria is strain specific and independent of the specificity of the host. The ability of certain strains to down-regulate the production and release of IL-6 by IL-10 may have potential implications in their use in cases in which cytokine deregulation or excessive production at the mucosal level can be the cause of tissue damage.

Animals↗

PubMed2004

Role of viability of probiotic strains in their persistence in the gut and in mucosal immune stimulation.

AIMS: To determine how probiotic bacteria contact with intestinal epithelial and immune cells and the conditions to induce a good mucosal immune stimulation. METHODS AND RESULTS: Lactobacillus casei was studied by transmission electron microscopy (TEM) to determine its interaction with the gut. We compared the influence of viable and nonviable lactic acid bacteria on the intestinal mucosal immune system (IMIS) and their persistence in the gut of mice. TEM showed whole Lact. casei adhered to the villi; the bacterial antigen was found in the cytoplasm of the enterocytes. Viable bacteria stimulated the IMIS to a greater extent than nonviable bacteria with the exception of Lact. delbrueckii subsp. bulgaricus. For all the strains assayed at 72 h no antigenic particles were found in the intestine. CONCLUSION: Antigenic particles but not the whole bacteria can enter to epithelial cells and contact with the immune cells. Bacterial viability is a condition for a better stimulation of the IMIS. SIGNIFICANCE AND IMPACT OF THE STUDY: We demonstrated that only antigenic particle interact with the immune cells and their fast clearance from the gut agrees with those described for the particulate antigens. The regular consumption of probiotics should not adversely affect the host.

Animals↗

PubMed2002

Role of yoghurt in the prevention of colon cancer.

The beneficial effect of yoghurt consumption on health and on the improvement of the mucosal immune system is well established, as is the diet-associated risk of colon cancer. In an experimental model in BALB/c mice we demonstrated that yoghurt added to the diet for 10 consecutive days, with the procedure repeated each 10 days for 6 months, inhibited the development of a colorectal carcinoma induced by 1,2 dimethylhydrazine (DMH). The immunoregulatory mechanisms involved in the inhibition of tumour growth by yoghurt were also examined in these studies. We determined B lymphocytes IgA(+) and IgG(+), as well as CD4(+) and CD8(+) T cells in the large intestine. We measured cellular apoptosis and the cytokines TNF-alpha, IFN-gamma and IL-10. An increase in the number of IgA(+) (P<0.01) was observed, but not in IgG(+) (P<0.01), or in the CD4(+) population (P<0.01) in the mice treated with DMH and yoghurt. While in the group with the carcinogen there was an enhancement in the IgG(+) B cells (P<0.01) and CD8(+) T cells (P<0.01). Yoghurt increased the number of apoptotic cells and induced IFN-gamma and TNF-alpha cytokine release, their production being regulated by an increase in IL-10 (P<0.001). We demonstrated that yoghurt may exert antitumour activity by a decrease in the inflammatory immune response mediated by IgA(+) increase, apoptosis induction and IL-10 release.

Animals↗

PubMed2002

Interaction of lactic acid bacteria with the gut immune system.

Health claims of lactic acid bacteria (LAB) used in functional foods and pharmaceutical preparations are based on the capacity of these microorganisms to stimulate the host immune system. In this study, the antigenic effect of LAB (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) on the gut immune system of BALB/c mice was evaluated. A dose-dependent increase of the Bcl2 protein was observed with all LAB assayed. Furthermore, the analysis of cytokine-producing cells in the lamina propria of gut showed that TNFalpha and INFgamma values, determined in macrophages cultured from Peyer patches, were enhanced for all the LAB assayed. An important increase of interleukins IL-10 and IL-4 was observed mainly in mice fed with Lactobacillus delbrueckii ssp. bulgaricus or Lactobacillus casei, while a significant induction of IL-2 and IL-12 was only observed with L. acidophilus (P<0.01). These effects were dose dependent. The role of produced cytokines in the balance Th1/Th2 was determined by a systemic antibody response against parenterally injected ovoalbumin. L. casei, L. delbrueckii ssp. bulgaricus and L. acidophilus enhanced the IgG1 response favouring Th2 balance, while L. acidophilus also increased the IgG2a response inducing Th1 balance. S. thermophilus did not influence the balance Th1/Th2. Our studies showed that lactic acid bacteria induce distinct mucosal cytokine profiles showing different adjuvant capacity among them. Thus, selection of probiotic strain with immunological properties must be well defined to influence cytokine expression that favour the claimed immune response.

Animals↗

PubMed2001

Enteric bifidobacteria: isolation from human infants and challenge studies in mice.

Bifidobacteria from breast-fed infants, formula-fed infants, or premature babies fed by parenteral methods were isolated and identified. The persistence of these microorganisms in the gastrointestinal tract of mice, after oral administration, was studied to determine the optimal dose and frequency of translocation to the liver and spleen. The rate of isolation among infants varied between 19 and 82% depending on the origin of the samples, with the highest values seen in breast-fed babies. The predominant species found in all cases was Bifidobacterium adolescentis. The optimal dose for oral administration of bifidobacteria to mice was 10(7) cells per day per animal for up to 2, 5, or 7 days. These bacteria remained up to 5 days postfeeding, even if feeding was interrupted. The results of bacterial translocation assays showed differences for the different strains and doses tested.

Animals↗

PubMed2001

Lactic acid bacteria and their effect on the immune system.

Lactic acid bacteria (LAB) are present in the intestine of most animals. The beneficial role played by these microorganisms in the humans and other animals, including the effect on the immune system, has been extensively reported. They are present in many foods and are frequently used as probiotics to improve some biological functions in the host. The activation of the systemic and secretory immune response by LAB requires many complex interactions among the different constituents of the intestinal ecosystem (microflora, epithelial cells and immune cells). Through different mechanisms they send signals to activate immune cells. Thus the knowledge of the normal intestinal microflora, the contribution of LAB and their role in the numerous functions in the digestive tract as well as the functioning of the mucosal immune system form the basis for the study and selection of a probiotic strain with immunostimulatory properties. In the selection of LAB by their immunostimulatory capacity it helps to know not only the effect which they have on the mucosal immune system, but the specific use to which these oral vaccine vectors are being put. Although there are reports of the protection of animals and humans against diseases such as microbial infections and cancer, more work remains to be done on the factors affecting the design of oral vaccine vectors and the use of LAB for therapeutic purposes. The basic knowledge of LAB immunostimulation and the criteria for selection of LAB by their immunostimulatory capacity, will be extensively discussed and appraised in this review.

Animals↗

PubMed2000

Gut mucosal immunostimulation by lactic acid bacteria.

The beneficial properties of lactic acid bacteria (LAB) on human health have been frequently demonstrated. The interaction of LAB with the lymphoid cells associated to the gut to activate the mucosal immune system and the mechanisms by which they can exert an adjuvant effect is still unclear, as well as if this property is common for all the LAB. We studied the influence of the oral administration of different geneous of LAB such as Lactobacillus casei, L. acidophilus, L. rhamnosus, L. delbrueckii subsp. bulgaricus, L. plantarum, Lactococcus lactis and Streptococcus thermophilus. We determined if the LAB assayed were able to stimulate the specific, the non-specific immune response (inflammatory response), or both. We demonstrated that all the bacteria assayed were able to increase the number of IgA producing cells associated to the lamina propria of small intestine. This effect was dose dependent. The increase in IgA+ producing cells was not always correlated with an increase in the CD4+ T cell number, indicating that some LAB assayed only induced clonal expansion of B cells triggered to produce IgA. Most of them, induced an increase in the number of cells involved in the inflammatory immune response. CD8+ T cell were diminished or not affected, with exception of L. plantarum that induced an increase at low dose. This fact would mean that LAB are unable to induce cytotoxicity mechanisms. We demonstrated the importance in the selection of LAB to be used as gut mucosal adjuvant. The different behaviours observed among them on the gut mucosal immune response, specially those that induce inflammatory immune response, show that not all the LAB can be used as oral adjuvant and that the beneficial effect of them can not generalized to genous or specie. The immunoadjuvant capacity would be a property of the strain assayed.

Adjuvants, Immunologic↗

PubMed1999

Study of the possible mechanisms involved in the mucosal immune system activation by lactic acid bacteria.

The induction of a mucosal immune response is not easy due to the development of oral tolerance, but under some conditions, bacteria can activate this immune system. Antigens administered orally can interact with M cells of Peyer's patches or bind to the epithelial cells. We have demonstrated that certain lactic acid bacteria are able to induce specific secretory immunity, and others will enhance the gut inflammatory immune response. The aim of this work was to establish the reason for these different behaviors and to define possible mechanisms involved in the interaction of lactic acid bacteria at the intestinal level. We studied IgA+ and IgM+ B cells comparatively in bronchus and intestine and CD4+ T cells and IgA anti-lactic acid bacteria antibodies in the intestinal fluid, induced by oral administration of Lactobacillus casei, Lb. delbrueckii ssp. bulgaricus, Lb. acidophilus, Lb. plantarum, Lb. rhamnosus, Lactococcus lactis, and Streptococcus salivarius ssp. thermophilus. The increase in the IgA+ B cells in the bronchus means that these lactic acid bacteria were able to induce the IgA cycle by interaction with M cells from Peyer's patches or intestinal epithelial cells. The IgM+ cells increased when the stimulus did not induce the switch from IgM+ to IgA+. The increase in the CD4+ cells suggests interaction of Peyer's patches and enhancement of the B- and T-cell migration. The anti-lactic acid bacteria antibody is related to the processing and presentation of the microorganisms to the immune cells. We demonstrated that Lb. casei and Lb. plantarum were able to interact with Peyer's patch cells and showed an increase in IgA-, CD4+ cells, and antibodies specific for the stimulating strain. Lactobacillus acidophilus induced gut mucosal activation by interaction with the epithelial cells without increase in the immune cells associated with the bronchus. Although Lb. rhamnosus and Strep. salivarius ssp. thermophilus interact with epithelial cells, they also induced an immune response against their epitopes. Lactococcus lactis and Lb. delbrueckii ssp. bulgaricus induced an increase of IgA+ cells entering the IgA cycle but not CD4+ cells; thus, these bacteria would have been bound to epithelial cells that activated B lymphocytes without processing and presenting of their epitopes. We did not determine specific antibodies against Lc. lactis or Lb. bulgaricus.

Animals↗

PubMed1998

Antitumour activity of yogurt: study of possible immune mechanisms.

The effect of yogurt on the inhibition of colon tumours induced by 1,2-dimethylhydrazine in BALB/c mice has been studied, and the hypothesis examined that yogurt induces a great reduction in the inflammatory immune response and inhibits tumour growth. Mice were assigned to five experimental groups: a control group fed with a conventional balanced diet, and four other test groups that received yogurt supplements for 2, 5, 7 or 10 consecutive days. At the end of each feeding period, mice were given subcutaneous injections of 1,2-dimethylhydrazine (20 mg/kg) once a week for 8 weeks. After tumour induction, yogurt was given again for 2, 5, 7 or 10 consecutive days each 10 d for 20 weeks. By week 20, 70% of the animals in the control group had developed colorectal tumours. From week 8, there was a considerable infiltration of mononuclear cells into the lamina propria of the large intestine. There was an increase in the number of IgG-producing cells and a slight increase in the IgA-secreting cells, and of CD8+ but not CD4+ T lymphocytes, a high level of beta-glucuronidase activity in the intestinal fluid and leucocytosis with neutrophilia in the blood. However, in the test groups given yogurt tumour growth was inhibited, the effect being more evident with 7 or 10 d treatment. The inflammatory immune response as measured by the characteristics we assessed was also reduced, with an increase in the IgA-secreting cells and in CD4+ T lymphocytes. The blood count was similar to that of normal animals and no colorectal tumours were observed in week 20. We suggest that one of the mechanisms by which yogurt exerts antitumour activity is through its immunomodulator activity, by reducing the inflammatory immune response, which was markedly increased when the carcinogen was administered.

1,2-Dimethylhydrazine↗

PubMed1994

Effect of yogurt feeding on the small and large intestine associated lymphoid cells in mice.

The effect of giving yogurt supplements to BALB/c mice on the various gut-associated lymphoid cells was studied. Animals were fed for 2, 5, 7 and 10 consecutive days. The different lymphoid cell types were identified and counted by haematoxylin-eosin staining of histological slices. The numbers of cells secreting IgA, IgG and IgM and the numbers of T lymphocytes were determined by direct immunofluorescence. The degree of activation of the intestinal macrophages in the small intestine was assessed by measuring the beta-glucuronidase (EC 3.2.1.31) released into the intestinal fluid, and also by a histochemical method. Throughout the feeding period, there were no histological alterations in the gut, but there was marked cell infiltration, mainly of plasma cells and lymphocytes. The number of macrophages on the small intestine increased significantly after feeding for 2 d, while the beta-glucuronidase activity was only slightly higher that of the controls. After a 7 d feeding period, the number of IgA secreting cells increased, while the values for cells secreting IgM and IgG and for T lymphocytes remained similar to those of the controls. The effect of giving yogurt on lymphoid cells associated with the large intestine was mainly on the numbers of IgA secreting B cells and T lymphocytes, with a marked increase during the whole feeding period in the latter type of cell. Since giving yogurt mainly enhanced the IgA secreting B cells in both small and large intestines, this increase would strengthen the host's defence mechanisms in the intestinal mucosa. Although the number of macrophages was increased, there was no enhancement in their activity, which might have harmed the host by producing an inflammatory response.

Animals↗

PubMed1991

Immunoadjuvant activity of oral Lactobacillus casei: influence of dose on the secretory immune response and protective capacity in intestinal infections.

Lactobacilli, often used as effectors of host functions, could play an important role in maintaining human health by controlling other intestinal microorganisms capable of producing harmful effects. Using an experimental model, we studied the effect of different oral doses of Lactobacillus casei on the secretory IgA response and the protective capacity of the microorganism in preventing intestinal infections. The optimization of the protective dose of Lb. casei by previous feeding and the use of the lactobacillus as an immunological way to control enteric infections were investigated. We found that conventional mice were protected against infection with Salmonella typhimurium and Escherichia coli by previous feeding for 2 consecutive days with a daily Lb. casei dose of 1.2 x 10(9) cfu/mouse. Previous feeding for 7 d proved less effective, and feeding for 5 d afforded no protection at all. We were also able to demonstrate that the protective effect of Lb. casei against Sal. typhimurium and Esch. coli was connected mainly with the high level of IgA antipathogen antibodies present in intestinal secretions. beta-Glucuronidase (EC 3.2.1.31) and beta-galactosidase (EC 3.2.1.23) activities, measured both in the intestinal fluid and histological samples, showed a marked increase in intestinal inflammatory response on day 5 of feeding. These results show that Lb. casei plays an important role in the prevention of enteric infections, a low dose being enough for protection against intestinal infections by increasing IgA secretion into the intestinal lumen, thus providing adequate defences for the mucosal surface. A previously administered dose of this magnitude could therefore be used as an oral adjuvant in preventing enteric infections.

Adjuvants, Immunologic↗

PubMed1991

Piroxicam, indomethacin and aspirin action on a murine fibrosarcoma. Effects on tumour-associated and peritoneal macrophages.

Growth of a methylcholanthrene-induced fibrosarcoma in BALB/c mice was accompanied by an increase in the activation state of tumour-associated macrophages (TAM), as measured by their FcIgG receptor expression, phagocytic index and beta-glucuronidase levels. All of these parameters were markedly higher in TAM than in peritoneal macrophages (PM) derived from the same animal. On the other hand, PM from tumour-bearing mice showed lower activation parameters than PM from normal animals. We also studied the effect on tumour development of three inhibitors of prostaglandin synthesis: indomethacin, piroxicam and aspirin. Intraperitoneal administration of these drugs during 8 d was followed by the regression of palpable tumours. Indomethacin (90 mg/d) induced 45% regression, while with piroxicam (two 400 mg/d doses and six 200 mg/d doses) and aspirin (1 mg/d) 32% and 30% regressions, respectively, were observed. The growth rate of nonregressing tumours, which had reached different volumes by the end of the treatment, was delayed to a similar extent by the three anti-inflammatory non-steroidal drugs (NSAID). With respect to TAM, the treatment did not induce any significant change in their activation state, though both piroxicam and indomethacin increased slightly the TAM number. In contrast, NSAID administration was followed by a remarkable increase in the activation parameters of PM when compared with PM from tumour-bearing mice receiving no treatment. Indeed, these parameters were in some cases higher than those of PM from normal mice. The leukocytosis (60,000/microliters) with neutrophilia (80%) induced by tumour growth on peripheral blood leukocytes (PBL) was reversed by the treatment to values close to normal, in parallel with the reduction of tumour size. A drop in haematocrit was also noted which was most probably a consequence of tumour growth rather than of the treatment. This study reveals that the three NSAID tested have a remarkable antitumour activity, which correlates with the restoration of PM activity and PBL values.

Animals↗

PubMed1989

Immune response in mice infected with Candida albicans in the mycelial form.

The effect of the infection with the mycelial form of a Candida albicans strain (Mycology Dept.) upon the immune system in mice was studied. BALB/c mice were infected intraperitoneally in a single dose of a 3 x 10(6), 6 x 10(6) and 12 x 10(6) cell suspension of the strain. Macrophages's activity was studied the days 7, 14, 21, 28, 35, and 42 after inoculation, by the following assays: phagocytosis in vitro, mononucleated phagocytic system by the colloidal carbon clearance technique, the lymphocyte's activity by the direct plaque forming cells technique (PFC) and delayed hypersensitivity (DTH). Infection with the mycelial form did not affect the peritoneal macrophage's phagocytic ability, neither modified the delayed hypersensitivity to sheep red blood cells (SRBC). However, a slight and transient depression of the lymphocyte stimulation was found. Suppression of PFC to SRBC was high when a 12 x 10(6) cell suspension was used in contrast to the infection with blastospores. These results suggest that systemic infection by Candida albicans in its mycelial form do not induce a non specific immunosuppression.

Animals↗

PubMed1988

Systemic augmentation of the immune response in mice by feeding fermented milks with Lactobacillus casei and Lactobacillus acidophilus.

This study investigates the effect of feeding fermented milks with Lactobacillus casei, Lactobacillus acidophilus and a mixture of both micro-organisms on the specific and non-specific host defence mechanisms in Swiss mice. Animals fed with fermented milk for 8 days (100 micrograms/day) showed an increase in both phagocytic and lymphocytic activity. This activation of the immune system began on the 3rd day, reached a maximum on the 5th, and decreased slightly on the 8th day of feeding. In the 8-day treated mice, boosted with a single dose (100 micrograms) on the 11th day, the immune response increased further. The feeding with fermented milk produced neither hepatomegaly nor splenomegaly. These results suggest that L. casei and L. acidophilus, associated with intestinal mucosae, can influence the level of activation of the immune system. The possible clinical application of fermented milks as immunopotentiators is also discussed.

Animals↗