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Results for “Immune System”

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At least 37 records · Page 2Linked to original sources

PubMed1975

Effects of aging on the differentiation and proliferation potentials of cells of the immune system.

An attempt has been made here to show that the immune system can begin to decline in function shortly after an individual reaches maturity. The decline is due in part to changes in the environment of the cells but primarily to changes in the precursor cells of the system. This is reflected in their inability to proliferate and possibly differentiate efficiently. These findings show that the immune system can serve as an excellent model to study how aging can perturb the process of cells undergoing proliferation and differentiation.

Aging↗

PubMed1978

[Antireticular cytotoxic serum as an agent for stimulating the immunity system].

The changes in the immunological indices characterizing the T and B immunity system and also in biological resistance of atherosclerosis patients were studied under conditons of the use of the antireticular cytotoxic serum microdoses. A possibility of employing the ACS for stimulation of the immune system was demonstrated.

Adult↗

PubMed1978

Local and systemic immunity to influenza infections in ferrets.

To establish whether immunity to influenza infection in the ferret is local or systemic, two sites of challenge were utilized: the nose and the anatomically isolated tracheal pouch. Infection of either site did not spread to the other site, and challenge of either site resulted in seroconversion by 13 days. Simultaneous challenge of both sites 21 days after the primary infection revealed that prior infection of the pouch prevented subsequent reinfection of the pouch, but not infection of the nose. Thus, systemic immunity did not prevent the initiation of nasal influenza infection in the ferret. However, the duration of virus shedding from the nose was reduced to half of that seen when ferrets were infected for the first time, showing that the prior pouch infection did lead to a more rapid recovery from the subsequent nasal infection. Passively administered anti-influenza antibody did not prevent or modify the nasal infection, but it did prevent the pouch infection. This is consistent with the observation that an initial infection of the nose prevented pouch infection upon challenge 21 days later. The prior nasal infection also prevented the subsequent nasal infection. These data suggest that immunity to acquisition of influenza infection in the ferret is a local phenomenon, whereas recovery from active infection is influenced by systemic immune mechanisms.

Animals↗

PubMed1977

Abnormalities of the local immune system in intestinal neoplasia: a morphological study.

In colonic adenocarcinomata abnormalities have been noted in all morphological aspects of the local immune system of the bowel; thus, in such tumours there is a defective production of secretory IgA, a diminished content of secretory component (SC) and a marked decrease in intraepithelial lymphocytes. By contrast, no such abnormalities were noted in the non-neoplastic areas of the bowel, either immediately adjacent to, or some distance from, the carcinoma. These findings suggest that there is not usually any generalised morphological abnormality of the local immune systems in intestinal neoplasia and that the immunological abnormalities noted within the tumour are a result of the changed nature of the epithelium, thus altering, or interfering with, the normal interactions between epithelial and lymphoid tissue in the gut.

Adenocarcinoma↗

PubMed2025

Bacterial immune systems as causes and consequences of microbiome structure.

Attacks from molecular parasites such as mobile genetic elements (MGEs) have driven the evolution of defense systems in bacterial genomes. Yet, despite significant advances in understanding the molecular mechanisms of these bacterial immune systems, we have only a rudimentary understanding of their ecology and evolution. Bacteria exist as part of complex microbiomes, but community ecology and microbiome research has yet to characterize the impacts of interactions between MGEs and defense mechanisms upon the structure, dynamics and evolution of microbiomes. This Essay introduces and discusses the interplay between bacterial community dynamics and bacterial immune systems, speculating about how these reciprocal interactions may shape microbial community structure and function.

Bacteria↗

PubMed1975

The secretory immune system and renal disease.

An immunopathological analysis of renal tissue from 105 patients was undertaken: (1) to clarify the relationship of the secretory immune system to renal diseases in which glomerular deposits of immunoglobulin A, (alpha chain), occurred; (2) to determine the lower nephron localization of secretory component and alpha chain in renal disease. This study, which included twenty-four patients with glomerular deposits of alpha chain, failed to reveal glomerular localization of secretory IgA. Secretory component was not found in renal tubular cells in kidneys with normal or minimally abnormal renal histology. In contradistinction to these findings, significant amounts of secretory component were found in tubular epithelial cells and casts in tissue from fifty-one patients with morphological evidence of significant renal damage; this localization had no correlation with glomerular deposits of IgA, IgM or other immunoreactants. Alpha Chain was rarely found in the tubular epithelium or in interstitial round cells; fifteen patients had alpha chain in casts. We conclude that the glomerular localization of immunoglobulin in glomerulonephritis is not derived from the secretory immune system, and the IgA present in glomeruli is not secretory IgA. The finding of secretory component in tubular cells in diseased kidneys without alpha chain may support an hypothesis for an independent role for secretory component in renal disease, apart from its function in the transport and stabilization of secretory IgA.

Adolescent↗

PubMed1979

Septate-like junctions between cells of the immune system in vivo.

Septate-like junctions between lymphocytes, lymphocytes and macrophages, and macrophages were observed in cellular capsules surrounding larvae of the tapeworm Taenia crassiceps after intraperitoneal inoculation into immunized mice. The morphology of the junctions found in vivo is similar to that reported for septate-like junctions between cells of the immune system in vitro. These findings support the possibility that septate-like junctions may be involved in functional interactions between cells of the immune system both in vivo and in vitro.

Animals↗

PubMed1977

Effector mechanisms in allograft rejection. III. Kinetics of killer cell activity inside the graft and in the immune system during primary and secondary allograft immune responses.

The cells recovered from sponge matrix allografts and from various lymphoid organs of recipient mice were tested for their ability to perform relevant target cell lysis in vitro. In the primary response, the peak cytotoxic activity was detected 8 days after transplantation, inside the graft, in regional lymph nodes, and in the spleen. In the secondary response, the peak cytotoxic activity in the regional lymph nodes and in the spleen took place promptly, 4 days after transplantation. The peak activity inside the graft was recorded on day 7. In the primary response, the activity inside the graft had declined. In the secondary response, the cytotoxic activity in the blood was low, and significant cytotoxic activity appeared only after the activity in the blood was high and demonstrated a biphasic profile, with one peak on day 3--4 and another activity peak on day 14. Killer cells were detected inside the graft for a far longer time in the primary (4 weeks) than in the secondary (2 weeks) response. I conclude that cellular kinetics in the secondary anti-allograft response is qualitatively but possibly not quantitatively different from the primary response.

Animals↗

PubMed1976

Influenza immunization in chronic bronchitis: local and systemic immune response.

Explore the source record for details and available documents.

Adult↗

PubMed2025

The ecology and evolution of microbial immune systems: a look on the wild vibrio side.

Natural populations of vibrio beyond the well-studied pandemic strains of Vibrio cholerae, provide a powerful model for investigating the eco-evolutionary dynamics of microbial immune systems. Their genetic diversity, ecological versatility, ease of culturability and the availability of time-series data enable detailed studies of phage-host interactions in natural contexts. This review synthesizes recent advances in vibriophage research, highlighting key findings and emerging tools. High-throughput assays and genomic tools have offered new perspectives on phage specificity, host range and the evolutionary pressures shaping these interactions. Theoretical frameworks, such as arms race and fluctuating selection dynamics, are informed by empirical data from vibrio-phage systems, with time-series sampling providing crucial insights into their temporal and spatial dynamics. A major finding is the role of mobile genetic elements (MGEs) in encoding bacterial defence systems, which shape phage-host coevolution. Discoveries like the phage satellite PICMI illustrate how MGEs facilitate the transfer of antiviral systems, influencing ecological and evolutionary dynamics. The paradox of generalist vibriophages, rare despite their broad host ranges, is also explored. By integrating experimental approaches with field observations, vibriophage research advances microbial ecology and informs sustainable applications in aquaculture and phage therapy, reinforcing vibrios as a versatile model system.This article is part of the discussion meeting issue 'The ecology and evolution of bacterial immune systems'.

Bacteriophages↗

PubMed1979

Age-related changes in the immune system of mice of eight medium and long-lived strains and hybrids. II. Short- and long-term effects of natural infection with parainfluenza type 1 virus (Sendai).

Studies on the effects of natural infection with parainfluenza type 1 virus (Sendai) on the immune system of 8 strains and hybrids of aging mice revealed that (a) 55 of 63 indices tested were abnormal as late as 8 months after the disappearance of clinical systoms, (b) thymus weight and cell indices and lymph node T cell activity still exhibited a statistically significant negative correlation with age following infection, and (c) immunologically immature young and immunodeficient old mice suffered more severe sequelae following viral infection than did adult or middle-aged mice as determined by accelerated decline of thymus indices, mortality, IgM Coombs' titer, and in the case of old mice, anemia. These findings suggest that chronic viral infection can accelerate immunologic aging and that viral infection in utero can suppress or retard the development of the T cell component of the immune system. In support of our previous study, they also suggest that the thymus regulates immunologic aging and that genetic factors regulating immunologic aging are not easily influenced by environmental factors.

Aging↗

PubMed1979

Effects of 2,3,7,8-tetrachlorodibenzofuran (TCDF) on the immune system in guinea pigs.

The effects of TCDF exposure on the immune system were investigated in Hartley guinea pigs. TCDF was administered by gavage at doses of 0.05, 0.17, 0.5 or 1.0 microgram/kg body weight once weekly for six weeks. Thymus/body weight ratios were suppressed in the higher dosage groups. Parameters of cell-mediated and humoral immune function were investigated. TCDF modestly suppressed cell-mediated immune function and had slight effects on humoral-mediated functions. TCDF immunosuppression appears similar to that induced following exposure to TCDD.

Animals↗

PubMed1979

Organ and isotype distribution of plasma cells producing specific antibody after oral immunization: evidence for a generalized secretory immune system.

Mice were induced to produce IgA antibodies against ferritin after oral immunization. Such antibodies were detected by immunofluorescence in plasma cells in the intestinal mucosa as well as in secretory sites located elsewhere, such as the lactating mammary gland, salivary gland, and respiratory tract. The observation suggested that cells immunized locally via the gut could home to distant secretory sites. To confirm this hypothesis, lymphocyte transfer studies were done with mesenteric node (MN) versus peripheral node (PN) cells from orally immunized donors into nonimmunized recipients. IgA anti-ferritin cells from MN homed to exocrine targets, whereas IgM and IgG anti-ferritin cells homed to PN. The findings overall support the concept of a generalized and interrelated secretory immune system.

Animals↗

PubMed1978

Interactions between age and the neuroendocrine and immune systems.

Three conclusions are suggested by some of the recent work on aging, immunology and the neuroendocrine system. 1) There appears to be sufficient data to implicate the neuroendocrine system in both the maturation and the senescence of at least some components of the immune system. 2) The thymus by its presence or its absence appears to influence certain functions of the pituitary; thus, there appears to be a possible reciprocal relationship between the pituitary and the thymus. 3) Changes in the levels of pituitary hormones or hormones that are controlled by the pituitary can restore in older rats and mice certain functions that are generally considered as part of the immune surveillance and defense system. Consequently, it can be hoped that further studies of neuroendocrine-immune relationships might lead to an understanding of some of the causes for the decline in immune competence with age in mammals.

Adrenocorticotropic Hormone↗

PubMed1976

Regulation of the immune system by synthetic polynucleotides. VI. Amplification of the immune response in young and aging mice.

Model systems for study of the action of adjuvants in immunodeficient states were developed in 10- to 14-day-old BALB/aj mice and aging BALB/aj mice (12 to 16 months). With sheep red blood cells as antigen polyadenylicpolyuridylic acid complexes (poly A:U) were found to be stimulatory in both the neonatal and aging mice. The effect of poly A:U was similar to that seen when 5 X 10(6) thymocytes from immunologically mature mice were given with antigen. Cell-free supernatant fluids induced by incubation of poly A:U with thymocytes likewise were capable of restoring the number of antibody-forming cells to normalcy in aging mice.

Adjuvants, Immunologic↗

PubMed2026

Admission whole-blood transcriptomic characterization of a neutrophil-predominant systemic immune response in patients with acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury (TBI) is accompanied by systemic immune responses, but their whole-blood transcriptomic features at hospital arrival remain incompletely characterized. We aimed to characterize these features in patients with acute TBI compared with healthy controls. METHODS: In this single-center prospective observational study, we performed whole-blood RNA sequencing on hospital-arrival samples from 42 patients with acute TBI and 21 healthy controls. Analyses included differential expression (limma-voom; FDR < 0.05, |log2FC| > 0.7), functional enrichment, Ingenuity Pathway Analysis, CIBERSORTx LM22 deconvolution, and per-sample neutrophil degranulation signature scoring. RESULTS: Differential expression analysis identified 996 upregulated and 863 downregulated genes, with marked upregulation of inflammation-, innate immunity-, and neutrophil-related genes including DUSP1, HMGB2, MMP9, and S100A8. Canonical pathways with positive IPA z-scores included Neutrophil degranulation, Neutrophil Extracellular Trap Signaling Pathway, and Toll-like Receptor Signaling; upstream regulators included TNF, IL1B, IFNG, and STAT3. Deconvolution identified 7 of 22 differing subsets (q < 0.05), with relatively higher myeloid and lower lymphoid fractions in TBI. The Neutrophil degranulation signature score correlated with Injury Severity Score within TBI (Spearman ρ = +0.55; q < 0.001). CONCLUSIONS: Admission whole-blood transcriptomics characterized a neutrophil-predominant systemic transcriptional response in patients with acute TBI. This response was also evident among patients without major extracranial injury and was associated with total ISS. However, because the study lacked an appropriately matched non-TBI trauma comparator, the findings should be interpreted as a descriptive characterization of a systemic injury response accompanying TBI and do not establish a TBI-specific molecular signature or mechanism.

gene expression↗

PubMed1979

Effects of cadmium on the immune system of mice.

Chronic oral exposure of mice to Cd++ inhibits cell-mediated immunity of delayed type hypersensitivity induced by sheep red blood cells (SRBC). No effect was detected on humoral immune response to SRBC. Spleen cells derived from mice exposed to Cd++ showed in vitro enhanced response to T and B cell mitogens. These results demonstrate that Cd++ exposure alters the immune system of mice.

Animals↗

PubMed1977

[Morphofunctional changes in the immune system during reparative regeneration of the liver].

A rise of the functional activity of the immune system was noted during reparative processes in the liver Resection of the liver was accompanied by sharp changes in the thymus and spleen structure. The thymus-dependent parts of the spleen were particularly reactive. Resection of the liver in rats was accompanied by an elevation in the bone marrow of the stem cell count (determined by the splenic colony method). The number of the colony-forming cells was significantly greater in the spleen of the recipients of lymphoid cells taken from the operated animals than in the spleen of the recipients of lymphoid cells from intact rats. In screening the limb the capacity to form endogenous colonies proved to be greater in partially hepatectomized rats as compared to the unoperated animals. In rabbits resection of the liver was accompanied by a significant increase of the immunological reactivity on the 1st-3rd postoperative days. Leukergia and leukocytolysis reaction displayed a marked intensification at this period.

Animals↗