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Results for “Immune function”

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At least 1,675 records · Page 93Linked to original sources
PubMed1981

Humoral and cell-mediated immune function in adult Japanese Quail following exposure to 2.45-GHz microwave radiation during embryogeny.

Japanese quail, Coturnix coturnix japonica, eggs were subjected to 2.45-GHz CW microwave radiation at 5 mW/cm2 (SAR = 4.03 mW/g) during the first 12 days of embryogeny. Following hatching the exposed embryos, as well as nonexposed controls, were reared to 22 weeks of age. Humoral immune potential, as indicated by comparable anti-CRBC antibody, IgM and IgG, levels at 0, 4, and 7 days postimmunization in both exposed and control quail was not affected significantly. However, cell-mediated immune potential, measured by the reaction to intradermal injection of phytohemagglutinin-P in the wing web, was reduced in the exposed females, but not in the exposed males. Additionally, total leukocyte numbers and absolute circulating numbers of lymphocytes, monocytes, and heterophils were increased significantly only in the exposed females. These data show that exposure of Japanese quail during embryogenesis reduced cell mediated immune potential and induced a general leukocytosis in females.

Animals↗
PubMed1997

Effects of purified bovine whey factors on cellular immune functions in ruminants.

The immunomodulatory properties of bovine milk and whey have long been documented. The recent advance of whey protein fractionation technology has now allowed us to study the immunobiological properties of some highly purified components of whey, with a view to exploiting their possible industrial and biomedical applications. The effects of fractionated bovine whey proteins on cellular immune responses were therefore examined using a panel of in vitro assays. Both lactoferrin (LF) and lactoperoxidase (LP) were found to inhibit proliferation and interferon-gamma (IFN-gamma) production of ovine blood lymphocytes in response to mitogenic stimulation. However, their effects in a combined fraction or in whey protein concentrate (WPC) were either diminished or eliminated. LF and LP had no effect on lipopolysaccharide (LPS)-induced ovine blood lymphocyte proliferation, production of interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF alpha) by ovine bronchoalveolar lavage (BAL) macrophages, major histocompatibility complex (MHC) Class II antigen expression by ovine BAL macrophages and bovine natural killer (NK) cell activity. However, alpha-lactalbumin (alpha LA) exhibited an enhancing effect on IL-1 beta production. It is noteworthy that as bovine whey fractions become progressively more purified, their modulatory effects on the immune response also become more clear-cut. The effects of LF, LP and alpha LA may be eliminated by their combination in whey or by other minor components of whey. Further investigation of industrial applications for whey proteins of high purity is warranted.

Adjuvants, Immunologic↗
PubMed2000

Abnormal immune function of hemopoietic cells from alymphoplasia (aly) mice, a natural strain with mutant NF-kappa B-inducing kinase.

Alymphoplasia (aly) mice, a natural strain with a mutant NF-kappa B-inducing kinase (NIK) gene, manifest a unique phenotype; they lack lymph nodes and Peyer's patches, have a disturbed spleen architecture, and exhibit defects in both Ab and cellular immune responses. Although a stromal defect caused by impaired lymphotoxin-beta receptor signaling accounts for their abnormal lymphoid organogenesis, the exact mechanisms underlying the development of immunodeficiency in aly mice are poorly understood. We therefore investigated the contribution of hemopoietic cells with the aly NIK mutation to the development of immunodeficiency. Transfer of aly/aly bone marrow cells into aly/+ mice resulted in poorly developed B cell follicles and lack of support for the development of germinal centers and isotype switching, indicating that the hemopoietic cells of aly mice contain an autonomous defect. However, follicular dendritic cell clusters were maintained in the spleens of these bone marrow chimeras, suggesting that the lack of follicular dendritic cell clusters in aly mice is probably due to the stromal defect. The aly mice lacked marginal zone B cells in their spleens, and aly/aly B cells showed an impaired proliferative response after in vitro stimulation. IL-2 production by activated T cells was also impaired. By contrast, the dendritic cells of aly mice exhibited grossly normal development and function. Supporting the concept of an autonomous cell defect, Rel protein expression was altered in aly/aly spleens. Thus, the aly NIK mutation affects hemopoietic cell function in an intrinsic fashion and, together with the stromal defect, may contribute to the development of immunodeficiency in aly mice.

Animals↗
PubMed1986

Influence of chronic low-level exposure to lead on plasma immunoglobulin concentration and cellular immune function in man.

The immunological status of individuals occupationally exposed to low levels of inorganic lead has been examined and compared with that of non-exposed, age and sex-matched controls. At the time of testing the exposed population had a mean (+/- SD) blood lead concentration of 38.4 +/- 5.6 micrograms X 100 ml-1 (n = 39) compared with a mean value of 11.8 +/- 2.2 micrograms X 100 ml-1 (n = 21) for the control group. No differences in the serum concentrations of IgG, IgA and IgM between the populations were observed and there existed no correlation between blood lead concentration and serum immunoglobulin levels. In addition assessment was made of the capacity of peripheral blood mononuclear cells to respond to the mitogen phytohaemagglutinin (PHA), a correlate of T cell function, and to spontaneously lyse cells of the erythroleukaemic cell line K562, a measure of NK cell function. In neither case was there a difference between exposed and control populations and no correlation between reactivity and blood lead concentration. Although previous studies in rodents have indicated that exposure to inorganic lead resulting in similar blood lead concentrations may compromise immune competence our data suggest that no similar effect occurs in man.

Humans↗
PubMed1995

Cynomolgus monkeys (Macaca fascicularis) in preclinical immune function safety testing: development of a delayed-type hypersensitivity procedure.

A delayed-type hypersensitivity (DTH) test commonly used for humans was adapted for use with cynomolgus monkeys (Macaca fascicularis). Pilot experiments showed naive animals had poor response rates and inconsistent reactivity to the antigens. In an exploratory phase, it was determined that monkeys could be experimentally sensitized by immunization with commercially available antigens. Animals were then sensitized with various concentrations of diphtheria and tetanus toxoids, Candida, and Trichophyton in the dose-response phase. Antigens were injected intradermally (i.d.) 3 times over a 7-day period and monkeys were tested 14 days after the last injection. Responses were measured 24, 48, and 72 h post-challenge, with skin biopsies taken from two animals per group at the 24 h interval. Optimal concentrations were 1.2 Lf diphtheria, 6 Lf tetanus, 1000 PNU Candida, and 1000 PNU Trichophyton. These concentrations produced the best balance between DTH responses, homogeneity of dermal mononuclear cell infiltrate and lowest frequency of undesirable skin reactions. Positive responses were seen at 24 and 48 h post-challenge and were waning by 72 h. DTH responses were inhibited by topical corticosteroids. The final phase of these studies assessed whether sensitization of naive animals could be achieved using subcutaneous (s.c.) administration of the optimal antigen concentrations. Comparable responses to i.d. sensitization were obtained and skin sores did not develop at injection sites. These studies show that the DTH test adapted to monkeys was reproducible, minimally invasive, did not require sacrifice of the test animal, allowed repeated measurements and paralleled the reactions observed in humans.

Animals↗
PubMed1989

Alterations of immune functioning following exposure to stressor-related cues.

A critical period exists (approximately 72 h) following administration of sheep red blood cells (SRBC) during which inescapable footshock suppressed the peak splenic plaque forming cell (PFC) response and serum antibody titers in CD-1 mice. The immunosuppression was likewise provoked in mice that were exposed to the stressor 2 weeks prior to immunization and reexposed to stressor-related cues 72 h after inoculation. In contrast, when the stressor was initially applied immediately after immunization, reexposure to the stressor-related cues was found to provoke an immunoenhancement. Moreover, stressor exposure immediately following inoculation had the effect of counteracting the immunosuppression otherwise induced by a stressor applied at the 72-h interval. Evidently, environmental cues associated with a stressor provoke profound alterations of immunoresponsiveness, but the direction of the effect is dependent upon the time at which the stressor was initially applied.

Animals↗
PubMed2004

Administration of a polysaccharide from Grifola frondosa stimulates immune function of normal mice.

We have reported that D-Fraction, a polysaccharide extracted from the edible maitake mushroom (Grifola frondosa), activates immunocompetent cells, thereby eliciting antitumor activity. To extend the application of D-Fraction as a nutritional supplement for healthy people as well as treatment for those with cancer, we investigated the effects of D-Fraction on the immune system in normal C3H/HeJ mice. Splenocytes from mice administered D-Fraction intraperitoneally for 17 consecutive days were cultured, and the culture supernatants were analyzed for nitric oxide (NO) and interleukin (IL)-12 production by antigen-presenting cells (APCs), including macrophages and dendritic cells, and also for the T helper (Th)-1 cytokine interferon (IFN)-gamma and the Th-2 cytokines IL-4 and IL-10. The level of IL-10 as well as those of NO and IFN-gamma were increased by D-Fraction as compared with the control, in which the serum immunoglobulin E level was increased. The results suggest that D-Fraction induced a Th-2 dominant response through the activation of macrophages, resulting in the enhancement of humoral immunity rather than cell-mediated immunity. Furthermore, an increase in the percentage ratio of CD69 and CD89 expression on major histocompatibility complex II(+) cells revealed activation of APCs 4 h after D-Fraction administration. These results indicate that D-Fraction enhances both the innate and adaptive arms of the immune response in normal mice. Therefore, its administration may enhance host defense against foreign pathogens and protect healthy individuals from infectious diseases.

Agaricales↗
PubMed2006

Evidence for an immune function of lepidopteran silk proteins.

Hemolymph coagulation stops bleeding and protects against infection. Clotting factors include both proteins that are conserved during evolution as well as more divergent proteins in different species. Here we show that several silk proteins also appear in the clot of the greater wax moth Galleria mellonella. RT-PCR analysis reveals that silk proteins are expressed in immune tissues and induced upon wounding in both Galleria and Ephestia kuehniella, a second pyralid moth. Our results support the idea that silk proteins were co-opted for immunity and coagulation during evolution.

Animals↗