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At least 1,621 records · Page 90Linked to original sources
PubMed1992

Neuroendocrine-immune interactions associated with loss and restoration of immune system function in spinal cord injury and stroke patients.

Both natural and adaptive immune responses were shown to be strikingly decreased in initial blood samples from 34 spinal cord injury and stroke patients. NK-cell function decreased to 24.8% (mean) 2 weeks after spinal cord injury in previously healthy young adults whose control group revealed a mean NK-cell function of 48.7%. This was accompanied at 2 weeks by increased plasma ACTH (mean of 17.0 pg/ml from 17 patients compared to a mean of 11.2 pg/ml from 12 controls) and urine free cortisol levels (mean of 152.1 micrograms/24 h from 9 patients compared to 53.6 micrograms/24 h from 15 controls). T-cell function and/or activation decreased to below normal values within 3 months after injury as revealed by lymphocyte transformation that was 32.8% of normal at 3 months. T-cell activation diminished as shown by a mean IL-2 receptor level of 179.3 units/ml in patients compared to 328.2 units/ml in controls. Serial monitoring of NK- and T-cell function revealed that specific physical rehabilitation therapy over a period of 6 months after injury restored NK- and T-cell function to near normal levels in most patients. This improvement was accompanied by a parallel rise in the patient's functional independence measurement scores. Results suggest critical neuroendocrine-immune system interactions in the restoration of immune function. Cortisol levels reverted to normal after 6 months of rehabilitation. Limited data suggest that natural immune system depression, NK-cell function, persists in spinal cord injury patients not receiving rehabilitation therapy (mean NK-cell lysis of 10.3%; p < 0.01).

Adrenocorticotropic Hormone↗
PubMed2004

Elevation of immune activation in kenyan women is associated with alterations in immune function: implications for vaccine development.

The infectious burden leading to immune activation can vary between different populations and lead to various immune dysfunctions. We compared the effect of immune activation on apoptosis and T cell function in HIV uninfected individuals from Nairobi, Kenya (n=34), and Winnipeg, Canada (n=10). Women from Nairobi had a significantly greater number of CD8+ T cells expressing the activation markers CD38 and HLA DR. Kenyan women also had significantly higher levels of CTLA-4+ CD4 and CD8+ T cells, and reduced levels of CD28+ CD8+ cells. Levels of CD95+ CD4+ T cells were higher in Kenyan women and, correspondingly, showed higher levels of spontaneous apoptosis. Kenyan women also demonstrated hyper-responsiveness to T cell activation as assessed by interferon gamma production. This study demonstrates that in a population of Kenyan women with high levels of T cell activation, there were also elevated levels of T cell apoptotic death and hyper-responsiveness. These differences may influence the efficacy of immune responses to pathogens and must be considered when testing candidate vaccines.

Apoptosis↗
PubMed2006

Nasal immunization with anthrax protective antigen protein adjuvanted with polyriboinosinic-polyribocytidylic acid induced strong mucosal and systemic immunities.

PURPOSE: The current anthrax vaccine adsorbed (AVA) was originally licensed for the prevention of cutaneous anthrax infection. It has many drawbacks, including the requirement for multiple injections and subsequent annual boosters. Thus, an easily administrable and efficacious anthrax vaccine is needed to prevent the most lethal form of anthrax infection, inhalation anthrax. We propose to develop a nasal anthrax vaccine using anthrax protective antigen (PA) protein as the antigen and synthetic double-stranded RNA in the form of polyriboinosinic-polyribocytidylic acid (pI:C) as an adjuvant. METHODS: Mice were nasally immunized with recombinant PA admixed with pI:C. The resulting PA-specific antibody responses and the lethal toxin neutralization activity were measured. Moreover, the effect of pI:C on dendritic cells (DCs) was evaluated both in vivo and in vitro. RESULTS: Mice nasally immunized with rPA adjuvanted with pI:C developed strong systemic and mucosal anti-PA responses with lethal toxin neutralization activity. These immune responses compared favorably to that induced by nasal immunization with rPA adjuvanted with cholera toxin. Poly(I:C) enhanced the proportion of DCs in local draining lymph nodes and stimulated DC maturation. CONCLUSIONS: This pI:C-adjuvanted rPA vaccine has the potential to be developed into an efficacious nasal anthrax vaccine.

Adjuvants, Immunologic↗
PubMed1983

Identification of carcinogens by measurement of cell-mediated immunity. IV. Antitumor immunity following perinatal exposure to 1,2-dimethylhydrazine.

This study was initiated to investigate the possible perinatal carcinogenic effects of the colon carcinogen 1,2-dimethylhydrazine (DMH) in Fischer F344 inbred rats. Pregnant female animals during their 16-18th day of gestation were administered the chemical by intraperitoneal injections, and beginning at 4 months postparturition, the antitumor cell-mediated immunity (CMI) was delineated in the dams and pups as an indirect measure of carcinogenesis. The CMI status was established by the ability of peripheral blood lymphoid cells obtained from the rats to injure and kill target tumor cells derived from an X-ray-induced rat small bowel adenocarcinoma cell line with the degree of damage being reflected in the quantity of loss of radioiodinated peripheral and integral membrane proteins from the target cells. A significant antitumor CMI was observed in the exposed offsprings although there was no apparent difference between the immunoresponsiveness observed in either the males or the female siblings. Unexpectedly, the mothers exhibited little such antitumor cellular immunity following the carcinogenic insult; even though all previous investigations of adult animals always demonstrated such an immunological response following exposure to the quantities of DMH that were administered (0.1 to 20 mg per kg body wt). As a consequence, these findings tentatively implied that the state of pregnancy alters a female's response to chemical carcinogenic insults and may actually serve as a device for protection from environmentally caused cancer. The threshold detection level for DMH exposure utilizing immune measurements was found to be approximately 10 times smaller for the perinatal susceptibility to the chemical insult intimating that such tests might usefully be incorporated in those bioassays utilized for determining the cancer-causing potential of weak carcinogens. Our findings now suggest that DMH may indeed be a perinatal carcinogen and that immune responsiveness may be readily employed for identifying such substances. However, the definitive studies of actually identifying cancer following such in utero exposures remain to be accomplished.

1,2-Dimethylhydrazine↗
PubMed1992

Studies of stage-specific immunity against Trichostrongylus colubriformis in sheep: immunization by normal and truncated infections.

Sheep immunized with multiple normal infections of 30,000 Trichostrongylus colubriformis larvae (T.c. L3) suppressed the fecundity, establishment and survival of adoptively transferred adult worms, showing that these parasites were susceptible to the effects of host immunity. When sheep were immunized by four 'truncated' larval infections of 4, 7 or 10 days' (d) duration with 10(5) T.c. L3, animals given 4 x 4d infections were susceptible to challenge, whereas sheep given 4 x 7d and 4 x 10d infections were significantly protected. A serial analysis of the rejection of T. colubriformis from nine sheep given 5 x 7d infections revealed that the challenge larval infection given intraduodenally was expelled within 3 days after challenge (DAC). However, another five of these sheep only rejected around 50% of transferred adult worms by 21 DAC when compared with control animals. The results indicate that stage-specific antigens produced by early L3 and L4 stages of T. colubriformis effectively immunize sheep against a larval challenge but appear less reliably protective against adult worms.

Animals↗
PubMed1983

Local immunity and Ostertagia circumcincta: changes in the gastric lymph of immune sheep after a challenge infection.

Immunity to Ostertagia circumcincta was demonstrated in 5 previously infected sheep which were killed 10 days after challenge with 50 000 larvae. This immunity was expressed as a reduction in the number as well as the degree of development of the surviving parasites compared with those found in 6 control sheep. Gastric lymph was sampled from the immune group from 2 days before till 10 days after challenge and a secondary local immune response was detected. The main features of this response were a large increase in cell output in the lymph, especially in lymphoblasts and IgA-containing cells, which reached a peak on day 4 or 5, followed by a ten-fold increase in IgA immunoglobulin and IgA anti-worm antibody which reached a peak 7 or 8 days after challenge. The timing of these events suggested that the cellular, but not the IgA, response could have been involved in a putative mechanism which caused arrested development, although both components could have been implicated in mechanisms which may have caused expulsion of developing larvae.

Animals↗
PubMed1989

Intravenous immune globulin in patients with acquired immune deficiency syndrome.

Infection with the human immunodeficiency virus results in a progressive immune deficiency involving many components of the immune system. The major target cells for infection are CD4 antigen-bearing cells, which include predominantly, but not exclusively, the helper T cell subset and the monocyte-macrophage cell system. Hypergammaglobulinemia is a common and early feature of human immunodeficiency viral infection but is often associated with an inability to mount specific antibody responses to neoantigens and decreased in vitro B cell differentiation responses. On the basis of our data and reports of others, a major component of B cell hyperactivity is related to the direct activity of the human immunodeficiency virus and its proteins. We and others have documented that B cells of these patients lose the capacity to respond to both T cell-dependent and T cell-independent stimuli in vitro. Thus the human immunodeficiency virus can profoundly influence B cells, causing both "stimulation" (vis-à-vis hypergammaglobulinemia) and "suppression" (poor specific antibody responses). However, the memory cells are probably not suppressed, and their dysfunction may be directly related to the extent of helper cell dysfunction. This explanation lends itself well to the clinical observation that children (who have not developed memory to recall antigens) with human immunodeficiency viral infection have more profound defects in specific antibody responses than do adults (who have an existing pool of memory cells). Thus the main rationale for intravenous immune globulin in acquired immune deficiency syndrome is to provide antibody replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1986

Immunization of carp (Cyprinus carpio) with a Vibrio anguillarum bacterin: indications for a common mucosal immune system.

Uptake and transport of formalin-killed Vibrio anguillarum bacteria were studied in the second gut segment of carp and the resulting reaction of the immune system was investigated. Within a few hours after anal administration antigenic determinants of bacteria were present in intraepithelial macrophages of the second gut segment. In gut and skin mucus and bile, immunoglobulins (Ig's) were detected, but the amount was much lower than found in serum. In mucus of the second gut segment, 4 times more Ig (per mg protein) was found than in the first segment. Upon oral or anal immunization, slightly enhanced antigen-specific Ig titers could be detected in skin mucus and bile, but only after a booster along the same route. The existence of a common mucosal immune system is discussed, with special reference to the significance of the second gut segment. After anal intubation an increase of antigen-specific Ig could also be observed in serum. Following a booster, an enhanced cal memory. After anal boosting equal levels of serum antibody were reached compared with two consecutive intramuscular injections. However, no significant antibody increase occurred in serum after oral immunization, not even when bacteria were administered daily with the food.

Administration, Oral↗
PubMed1987

Immunization with immune complexes: characterization of monoclonal antibodies against a TSH-antibody complex.

Monoclonal antibodies (MAb) to human thyrotropin (hTSH) were prepared by immunization of mice and rats according to different procedures. We have previously demonstrated that a specific antigenic region on the surface of the hTSH molecule was highly immunogenic; in order to produce specific MAb to weakly immunogenic regions of hTSH, we immunized mice and rats with a complex composed of hTSH and an anti-beta hTSH MAb 27 directed against the highly immunogenic region. Monoclonal antibodies elicited by this immunization procedure were highly specific and a high percentage was found complementary to the MAb 27 used in the immunogen. We did not search for anti-MAb 27 antibodies, however one hybridoma produced antibody that preferentially reacted with the immune complex. This antibody, called 515, is an IgG1 that binds the complex with 100-fold greater affinity than it does to the anti-beta hTSH MAb 27 alone. This enhancement was also observed with the Fab fragment of the MAb suggesting that the epitope recognized by this anti-complex MAb is displayed in a very different way when hTSH is bound to the first MAb.

Animals↗
PubMed1991

Immune response after immunization with an experimental Toxoplasma gondii ISCOM vaccine.

Mice were immunized with ISCOM preparations of tachyzoites from two different strains of Toxoplasma gondii. The antibody response and the cellular response, as measured in vitro, were comparable with those found in chronically infected mice. When challenged with virulent T. gondii tachyzoites, all the immunized mice died, whereas all the chronically infected mice survived. However, the immunized mice generally survived longer than non-immunized animals.

Animals↗
PubMed1992

Induction of anti-viral immune responses by immunization with recombinant-DNA encoded avian coronavirus nucleocapsid protein.

Immune responses to the infectious bronchitis virus (IBV) nucleocapsid protein were studied using a recombinant-DNA expression product. In mice, a lymphocyte proliferative response and a delayed-type hypersensitivity reaction to IBV were induced upon immunization with this nucleocapsid protein. Next, we studied the role of the expressed nucleocapsid protein in induction of a protective immune response to IBV in chickens. Chickens were primed with nucleocapsid protein and subsequently boosted with inactivated IBV, strain M41. Proliferative responses of blood mononuclear cells corresponded with increased mean haemagglutination inhibition and virus neutralization titres. Finally, an increased tracheal protection against challenge with live IBV was observed. These results indicate that infectious bronchitis virus nucleocapsid protein is a relevant target for immune recognition in both the mouse and the chicken.

Animals↗
PubMed1993

Circulating cellular immune response to oral immunization of humans with cholera toxin B-subunit.

Peripheral blood mononuclear cells were taken from subjects before and after oral immunization with cholera toxin B-subunit. Cells obtained from naive volunteers before immunization did not proliferate in vitro to B-subunit. Oral immunization induced a proliferative response in all volunteers with a peak stimulation index of 20, and was detected up to 1 year later. The proliferative response kinetics suggest the appearance in the blood of primed T cells from the gut coinciding with the disappearance of primed plasmablasts from the circulation, supporting the concept of a common mucosal immune system in man for T and B cells.

Administration, Oral↗
PubMed1994

Chronic pain and immunity: mononeuropathy alters immune responses in rats.

In order to investigate the possible relationship between chronic pain and the immune system, delayed-type hypersensitivity (DTH) and humoral immunity were assessed in Sprague-Dawley rats subjected to unilateral peripheral mononeuropathy induced by sciatic ligation. Paw withdrawal latency (PWL) time was measured twice during the experiment in animals subjected to sciatic nerve ligation or sham surgery. Sciatic nerve-ligated animals showed hyperalgesia in the leg subjected to neural ligation when compared to the contralateral leg. No differences in PWL times existed in sham-operated animals. In order to exclude possible alterations in immune response due to the surgical procedure or to the hyperalgesia testing, a group of control animals, not subjected to surgical procedures or hyperalgesia testing, was also included in the experiment. Three days post-sciatic ligation or sham surgery, both experimental and control animals were sensitized to keyhole limpet hemocyanin (KLH). A secondary sensitization followed 1 week after the initial immunization. Fourteen days after the initial sensitization, KLH was injected into the hind foot pad and vehicle into the contralateral foot pad in order to assess DTH. One group of rats subjected to sciatic nerve ligation was tested for DTH in the hind foot pad ipsilateral to the ligated nerve, while another group was tested in the contralateral foot pad. Twenty-four hours following foot pad injections, the thickness of both paws was measured and animals were bled to test for anti-KLH immunoglobulins. Animals in which mononeuropathy was induced, but not sham-operated or control animals, exhibited an enhanced DTH response to KLH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Combined effects of herbicides on biomarkers reflecting immune-endocrine interactions in goldfish. Immune and antioxidant effects.

Goldfish (Carassius auratus) were exposed to a mixture of herbicides, namely atrazine, simazine, diuron, and isoproturon (ASDI) at a cumulative concentration of 50microg/l for 12 weeks. Control fish and exposed fish were sampled at 4, 8 and 12 weeks of exposure to observe the combined impact of herbicides on non-specific and specific mechanisms of immunity and antioxidant defenses. The antioxidant defenses were evaluated in haemopoietic organs and liver. ASDI-induced stress was reflected as a significant induction of superoxide (O(2)(-)) production in phagocytic cells of head kidney and spleen. In addition, plasma lysozyme activity was consistently high in the treatment group. Specific immunity was assessed by antibody titre responses following immunization of the fish with sheep red blood cells (SRBCs). Antibody titre was reduced throughout the period of observation in ASDI-treated fish. This reduction was found to be significant at week 4 (p<0.05). Herbicide-exposed fish showed reduced resistance against pathogen invasion but remarkable enhancement in lysozyme activity. The ASDI-induced oxidative stress in spleen, kidney and liver was reflected as a change in the antioxidant enzyme activities in these vital organs of fish. Our data indicate that herbicides at concentrations present in water bodies in Europe cause immune suppression in goldfish.

Aeromonas hydrophila↗
PubMed2004

Forward genetic dissection of afferent immunity: the role of TIR adapter proteins in innate and adaptive immune responses.

The innate immune system senses pathogens largely through signals initiated by proteins known as 'Toll-like receptors' (TLRs), of which ten representatives are known to be encoded in the human genome. The understanding of the biochemical circuitry that maintains the innate capacity for immune recognition and response has loomed as a major hurdle in immunology. A total of five adapter proteins with cytoplasmic domain homology to the TLRs are known to exist in mammals. These proteins show preferential association with individual TLR family members, giving a particular character to the signals that distinct microorganisms initiate, and also initiate the adaptive immune response. The adaptive immune response is dependent upon upregulation of costimulatory molecules (UCM) such as CD80 and CD86. Forward genetic analysis has revealed that this upregulation depends upon an adapter encoded by a locus known as Lps2, and upon type I interferon receptor signaling.

Animals↗
PubMed2004

Innate immunity in early chordates and the appearance of adaptive immunity.

In the urochordate Ciona intestinalis some membrane Immunoglobulin superfamily members with ancestral features of antigen receptors are homologs of vertebrate adhesion molecules acting as virus receptors. They include the following: the junction adhesion molecule (reovirus receptor) (JAM), the Cortical thymocyte marker of Xenopus (CTX family) (Coxsackie's virus receptor) and the poliovirus receptor (PVR). In humans these genes belong to the same linkage group, of which 4 paralogous groups exist. This situation is consistent with the notion that the Ciona set of genes would correspond to a preduplication state. In addition, the human region 3q13 and its paralogs, harbour genes remotely related to the nectin family that can be detected in Protostomes (human CRTAM and CD80-86 related to Drosophila Beat). In addition, this linkage group contains several CDs important for the immune system CD166, CD47 and many members of the tetraspanin family. The VC1-like core of the nectin is homologous to the VCI core of the MHC-linked tapasin and to the VC1 segments of, for example, specific antigen receptors of vertebrates, and could be related to a primitive antigen receptor gene. It is suggested that the virus binding property of the members of this family was exploited, and that they were recruited in the vertebrate immune system following the introduction of the somatic rearrangement machinery. In this way the adaptive immune system could have developed from a set of receptors involved in a primitive local innate immunity involving NF-kappaB-mediated apoptosis.

Amino Acid Sequence↗
PubMed2006

Recognition of pathogens and activation of immune responses in Drosophila and horseshoe crab innate immunity.

In innate immunity, pattern recognition receptors discriminate between self- and infectious non-self-matter. Mammalian homologs of the Drosophila Toll protein, which are collectively referred to as Toll-like receptors (TLRs), recognize pathogen-associated molecular patterns (PAMPs), including lipopolysaccharides (LPS) and lipoproteins, whereas the Drosophila Toll protein does not act as a PAMP receptor, but rather binds to Spätzle, an endogenous peptide. In Drosophila, innate immune surveillance is mediated by members of the peptidoglycan recognition protein (PGRP) family, which recognize diverse bacteria-derived peptidoglycans and initiate appropriate immune reactions including the release of antimicrobial peptides and the activation of the prophenoloxidase cascade, the latter effecting localized wound healing, melanization, and microbial phagocytosis. In the horseshoe crab, LPS induces hemocyte exocytotic degranulation, resulting in the secretion of various defense molecules, such as coagulation factors, antimicrobial peptides, and lectins. Recent studies have demonstrated that the zymogen form of the serine protease factor C, a major granular component of hemocyte, also exists on the hemocyte surface and functions as a biosensor for LPS. The proteolytic activity of activated factor C initiates hemocyte exocytosis via a G protein mediated signal transduction pathway. Furthermore, it has become clear that an endogenous mechanism for the feedback amplification of the innate immune response exists and is dependent upon a granular component of the horseshoe crab hemocyte.

Animals↗
PubMed2004

Immunostimulatory oligodeoxynucleotides are potent enhancers of protective immunity in mice immunized with recombinant ORFF leishmanial antigen.

Unmethylated CpG dinucleotides in bacterial DNA or synthetic oligonucleotides (ODN) have proved as promising adjuvants for promotion of T helper 1 (Th1) type immune response. The potent Th1 like immune activation by CpG-ODNs suggests a possible utility for vaccination against leishmaniasis. We therefore investigated the effect of ODN containing immunostimulatory CG motifs as adjuvant with recombinant ORFF (rORFF) leishmanial antigen. BALB/c mice were vaccinated with the rORFF with or without CpG-ODN as adjuvant and then challenged with Leishmania donovani metacyclic promastigotes. Administration of CpG-ODN alone resulted in partial protection against challenge with L. donovani in BALB/c mice. Combination of rORFF and CpG-ODN showed enhanced reduction in parasite load (84%) when compared to rORFF (56%) vaccinated mice. Immunization with rORFF alone did not induce the typical Th response whereas co-administration of rORFF with CpG-ODN resulted in enhanced production of immunoglobulin G2a and interferon gamma. Our results further demonstrate that CpG-ODN alone or in combination with rORFF resulted in a dose dependent increase of nitric oxide production in activated macrophages. These studies suggest that CpG-ODN are promising immune enhancers for vaccination against visceral leishmaniasis.

Adjuvants, Immunologic↗