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A dose-dependent increase of parameters of non-specific defence of the organism and depression of primary humoral immune response following a single subcutaneous administration of armin in doses of 0.04-0.16 mg/kg were found during experiments on mice and rats.
The authors carried out a complex study of natural humoral immunity factors in rabbits experimentally infected with various doses of diphtheria bacillus (500, 200, 100, 50 and 1 million, 10 000 and 1000 microorganisms). Natural protection factors--the complement, properdin, and lysozyme proved to undergo similar dynamic changes with each infection dose. The extent and direction of the changes depended on the infection dose. No significant natural immunity changes were caused by a low dose. A dose of 10 000 microbes caused stimulation of properdin and lysozyme activity. Dose of 1, 5, and 50 million suppressed the activity of all the components, the most pronounced with the later dose. Changes occurring with the doses of 200 and 100 million microbes were phasic in character.
Development of a broad based cellular and humoral immune response to hepatitis C virus (HCV) structural proteins may be important for irradication of infection. DNA-based immunization is a promising approach to generate HCV-specific immune responses. Previous studies of DNA-based immunizations in mice using an HCV core DNA expression plasmid (pHCV2-2) demonstrated an efficient CTL response against HCV core epitopes; however, the humoral and Th cell proliferative responses were found to be weak. To enhance the immunogenicity of this nonsecreted viral structural protein at the B and T cell level, we coimmunized mice with pHCV2-2 and DNA expression constructs encoding for mouse IL-2, IL-4, and granulocyte-macrophage CSF proteins. Under these experimental conditions, a seroconversion frequency to anti-HCV core increased from 40 to 80% in immunized mice. The CD4+ inflammatory T cell proliferative responses as well as CD8+ CTL activity to HCV core protein were enhanced substantially after coimmunization with the IL-2 and granulocyte-macrophage CSF DNA expression constructs. In contrast, coimmunization with an IL-4-producing construct induced differentiation of Th cells toward a Th0 subtype and suppressed HCV core-specific CTL activity. Taken together, these studies emphasize that generation of antiviral immune responses using DNA-based immunization may be modified by local cytokine production at the site of Ag presentation.
Shigella flexneri vaccine strain (SFL124) given orally, evokes humoral immune response in human volunteers. Such a strain, expressing antigenic epitope of B subunit of Shiga toxin, would also provide immunity to the toxin produced by some species of Shigella. A synthetic oligonucleotide, specifying an epitope [13-26 amino acids (aa)] of the B subunit of Shiga toxin, was inserted into the lamB gene of Escherichia coli and expressed in the S. flexneri vaccine strain. The chimeric LamB protein functioned normally and the epitope was expressed at the surface of the bacteria. The animals immunized with the live bacteria, expressing the epitope or sonicated lysates, showed a humoral response that was specific to the peptide (13-26 aa) and to the whole B subunit molecule. The elicited antisera neutralized the toxin activity on HeLa cells up to 40%, while the purified IgG fractions from the sera gave 90% neutralization.
OBJECTIVE: A humoral autoimmune response to glutamic acid decarboxylase (GAD65) is common both in patients with type 1 diabetes and in those with the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome, while overt type 1 diabetes is relatively rarely diagnosed in APECED patients. The aim of this study was to assess whether this difference in the incidence of type 1 diabetes is associated with variability in the humoral immune response to GAD65, one of the major autoantigens in type 1 diabetes. METHODS: Epitope- and isotype-specific GAD65 autoantibodies were analysed in 20 patients with APECED and 20 patients with newly diagnosed type 1 diabetes alone by radiobinding assays. RESULTS: GAD65 autoantibodies targeted the middle and carboxy-terminal regions of GAD65 and occasionally the amino-terminal region in the APECED patients and comprised mainly the IgG1 subclass and less frequently the IgG2 and IgG4 subclasses. The profile of epitope- and isotype-specific GAD65 autoantibodies was similar in type 1 diabetes and APECED, except that IgG2 subclass antibodies were observed more often and at higher levels in the patients with type 1 diabetes alone (P < 0.05). None of the measured parameters separated APECED patients with type 1 diabetes from those without type 1 diabetes. CONCLUSION: APECED-associated humoral autoimmunity to GAD65 does not differ markedly from that observed in type 1 diabetes; only IgG2-GAD65 antibodies may be more closely associated with the latter entity.
A number of factors can influence immune function affecting the magnitude and duration of specific immune responses. One factor which has been noted to affect immune responses is age of animal. In mammals, juveniles have a lower immune response when compared to adults. In fish, fry have a lower immune response than adults; however, few studies have investigated the immune response in juveniles, the age when most fish are reared in aquaculture settings. The humoral immune responses of hybrid striped bass (Morone saxatilis x Morone chrysops) at five different ages were compared to determine any maturational changes. Fifty fish were bath immunized with a commercial Vibrio vaccine at 4, 6, 9, 15, and 19 months of age. The antibody response in these fish was monitored by an enzyme-linked immunosorbent assay (ELISA) for 106 days post-vaccination. The magnitude, duration, and time to peak level were compared to controls and between the different ages using analysis of variance (ANOVA). Younger fish exhibited significantly lower antibody levels indicating that juvenile fish may not be able to mount as effective an immune response as young adult fish.
The effects of short-term acute nutritional deprivation and refeeding on immune function was investigated in rats. Animals previously sensitized to keyhole-limpet hemocyanin were starved for 72 hours and refed for 7 days. Recall skin testing with keyhole-limpet hemocyanin and immunization with tetanus toxoid (TT) were used to assess delayed-type hypersensitivity (DTH) and humoral immune responses. DTH was maximally depressed late, after refeeding had begun. Anti-TT responses were depressed early during starvation. Neither DTH nor anti-TT responses had returned to normal after a period of refeeding sufficient to restore weight. The data indicate that short-term acute nutritional deprivation may contribute to acquired immunodeficiency in patients undergoing surgery.
Dendritic cells (DC) are extremely efficient at generating both prophylactic and therapeutic anti-tumour immunity. We aimed to analyse the respective roles of humoral and cellular immune responses generated in mice vaccinated with bone marrow (BM)-derived DC in terms of in vivo anti-leukaemia effect. We used the murine L1210 B lymphocytic leukaemia genetically modified to express on the cell surface of human CD4 (hCD4) (L1210/hCD4) as a model tumour-associated antigen (TAA). DC cultures were loaded with either purified soluble hCD4 (shCD4) protein or unfractionated L1210/hCD4 extracts and injected as vaccine into mice. The efficacy of these vaccinations was compared with that of vaccination with shCD4 protein emulsified in Freund's adjuvant (FA). We evaluated the immune responses generated after these vaccinal protocols and the survival rate of vaccinated mice subsequently challenged with a lethal injection of L1210/hCD4 cells. Our results demonstrated that vaccination with shCD4 protein or tumour extract-loaded DC mainly generated an hCD4 antigen-specific cell-mediated cytotoxic immune response that was associated with a specific protection against leukaemia. In contrast, vaccination with the protein emulsified in FA only generated potent humoral immune responses that were not protective against leukaemia. Altogether, our results indicate that the unique property of loaded DC to trigger an anti-leukaemia protective effect is mainly associated with cellular immune responses.
The objective of this experiment was to examine the relationship between levels of circulating T3, T4, and humoral immunity in immature male chickens. Three week old Single Comb White Leghorn male chicks were used as the experimental animals. In order to produce a wide range of circulating thyroid hormone concentrations, birds were divided into groups and received one of nine treatments including surgical thyroidectomy; 0.1% propylthiouracil (PTU) in the feed; 1 ppm T3 and 10 ppm T4 in the feed. Antibody production against sheep red blood cells (SRBC) (thymus-dependent antigen) and Brucella abortus (BA) (thymus-independent antigen) was tested at 6 weeks of age. Concentrations of T3 and T4 were measured in birds from each treatment group at 7 and 11 weeks of age. At 11 weeks of age, birds were weighed, sacrificed and lymphoid organs removed and weighed. There were positive correlations between circulating thyroid hormones and weights of bursa of Fabricius and spleens. There were no significant correlations between circulating thyroid hormones and antibody production. It was concluded that physiological levels of thyroid hormones are needed to maintain normal weights of bursa and spleen. Furthermore, we conclude that lower than physiological levels might be sufficient for normal antibody production. Finally, stimulation of antibody production using thyroid hormones may require different doses than what were utilized in this study.
We have correlated the virus-specific humoral immune response of sheep newly infected with bovine leukemia virus (BLV) with the appearance in their blood of cells that transcribe BLV RNA or produce virus in culture. Neutralizing antibodies and antibodies binding to the viral capsid protein were present in most animals early after infection, often before BLV-expressing cells were first detected in blood. Neutralizing antibodies increased rapidly during the period when the number of cells that expressed BLV was also increasing. However, the titers developed by individual animals were independent of the maximum number of BLV-expressing cells. Antibodies that bound to the viral surface glycoprotein on immunoblots became evident at the same time as large peaks in the numbers of BLV-expressing cells. Despite ensuing sharp drops in BLV-expressing cells, neutralizing titers remained relatively constant through the rest of the first 8 months after infection. Two early phases of BLV replication were thus defined: initial, low-level replication that induced neutralizing and capsid-specific antibodies followed by a second period of intense replication that induced sharp increases in antiviral antibodies and preceded the release of many infected cells into the blood.
Sequential changes in the humoral immune response of pigs to pseudorabies virus (PRV) after each of several exposures to the virus were evaluated by determining virus neutralization (VN) and radioimmunoprecipitation (RIP) activities of sera collected at selected intervals. Pigs were vaccinated intramuscularly with live attenuated virus (6 pigs), inactivated attenuated virus (6 pigs), or inactivated virulent virus (6 pigs). All pigs were challenged oronasally with virulent virus 3 weeks later and 12 (4 pigs of each vaccine group) were subsequently treated with dexamethasone in an attempt to reactivate latent virus. The relatively low serum titers of VN antibody that were raised by vaccination (titers ranged from 2 to 32) increased markedly (at least 16-fold) for all pigs after exposure to virulent virus. After dexamethasone treatment, the VN titers of 2 pigs increased 16-fold, whereas those of the other 10 dexamethasone-treated pigs and the 6 nontreated pigs either remained the same or increased only minimally (i.e., no more than 2-fold). The results of RIP using 35S-methionine-labeled viral proteins were initially similar to those of VN in that the low levels of serum RIP activity detected after vaccination increased markedly after subsequent exposure to virulent virus. In contrast to VN, however, most pigs (11 of 12) treated with dexamethasone had a clear increase in serum RIP activity. The increase was particularly striking for viral proteins of relatively low (less than 46K) molecular weight. Precipitating activity for 14C-glucosamine-labeled viral glycoproteins was not detected until after pigs were exposed to virulent virus. The increase in RIP activity detected after dexamethasone treatment was likely due to an additional antigenic stimulus associated with virus reactivation. However, virus was isolated from nasal swabs of only 4 of the 12 treated pigs. None of the results appeared to be affected appreciably by the type of vaccine used for initial immunization.
In vivo activation of complement components C3 and GBG as revealed by crossed immunoelectrophoresis reflects humoral immune system activity in disease. These methods have been applied to a material of 25 patients with ulcerative colitis (UC) and 29 patients with Crohn's disease (CD). Signs of activity in the complement sequence were observed in approximately half the patients of both categories. Fifty blood samples from 30 healthy controls were all negative. The presence of complement activation was correlated with disease activity in both groups, and in patients with CD this could also be shown in longitudinal studies in single patients. In UC complement activation was correlated with the extent of the disease process. The serum levels of factors C4, GBG, and C3 in the patient groups did not differ significantly from those found in the normals.
29 practically healthy persons and 97 herpetic ganglionitis patients were examined at different periods during 1986-1987. The seasonal changes of humoral immunity both in clinically healthy persons and in herpetic ganglionitis patients were established. The conclusion was made that clinical manifestations of herpetic ganglionitis are linked with a decrease in the level of IgG ensuring natural resistance to chickenpox virus.
Quil-A, a purified extract of saponin, was analyzed for its adjuvant properties in the porcine humoral immune response against lysozyme. The adjuvant properties of Quil-A are comparable to the oil adjuvant properties in the pig. The optimal dose was found to be 1 mg per pig. Quil-A enhanced also slightly the homocytotropic antibodies.
The changes in cellular-humoral immune reactivity were followed up in 13 patients with lupus nephritis and 10 patients with chronic glomerulonephritis, treated with corticosteroids or with corticosteroids and imuran. A tendency to correction of lymphocyte and T-lymphocyte deficiency, inhibition of FsG- and FsM-receptor lymphocytes and of T-gamma and T-mu lymphocyte subpopulations was established in the patients with lupus nephritis, treated only with corticosteroids. The treatment with corticosteroids and imuran inhibited more sharply T gamma- and T-mu lymphocytes than with corticosteroids alone. It was established, in the patients with chronic glomerulonephritis, treated with corticosteroids, that GsG- and FsM-receptor lymphocytes were with significantly lower values than the non-treated ones. No significant changes were established in B-cellular reactivity and serum level of immunoglobulins (IgG, IgM, IgA) with the treatment with corticosteroids and corticosteroids and imuran in both nosological entities. C3- fraction of the complement in the lupus patients treated was with lower values than in the non-treated. The authors conclude that the corticosteroids and corticosteroids and imuran, inhibiting the reactivity of T-lymphocytes, regulating the immune-biological balance, should be cautiously used and under the control of the cellular populations, exposed to their effect.
We studied the relationship between reticuloendothelial Fc receptor function and some parameters of the humoral immune response in vivo and in vitro in 18 SLE patients. Fc receptor-mediated immune clearance correlated remarkably well with (a) a decrease of antigen specific IgG after immunization with a primary test antigen (alpha-Helix pomatia haemocyanin) (P less than 0.01) and (b) the spontaneous IgG release in vitro of B cells obtained from peripheral blood (P less than 0.01). These two parameters were significantly interrelated. Reticuloendothelial Fc receptor function was not related to serum IgG levels. The study provides evidence for an association between polyclonal B cell activation and Fc receptor-mediated immune clearance in SLE patients. The possible nature of this association is discussed.
It has been shown that partial hepatectomy inhibits the induction of cells exerting a suppressant effect on the development of humoral immune response.
The humoral immune response to the retinal S-antigen was studied in premature babies with active and cicatricle stages of retinopathy of the premature (RP) and in the controls (102 serum test). The presence of antibodies to the S-antigen of classes IgG and IgM was established by the enzyme multiplied analysis and by an authors' developed test-system. A definite specific humoral response to the S-antigen correlated with the nature of the course and prognosis of the disease was found in 71% of cases. The first peak of IgM-antibodies was found in babies of the risk-group (preretinopathy), it correlated with a poor prognosis (progression of RP). The second peak was highly pronounced in babies with the terminal cicatricle stages of RP. The wave-like dynamics of IgG-antibodies suggests that specific circulating immune complexes shape up. The role of immune responses, induced by the retinal S-antigen, in the RP pathogenesis is discussed.