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The role of CXCR4 in maintaining peripheral B cell compartments and humoral immunity.

The chemokine receptor CXCR4 is expressed in B cells at multiple stages of their development. CXCR4 function in humoral immunity has not been fully investigated. We have generated gene-targeted mice in which CXCR4 can be selectively inactivated in B cells and have shown that it is required for retention of B cell precursors in the bone marrow. CXCR4-deficient B cell precursors that migrated prematurely became localized in splenic follicles despite their unresponsiveness to CXCL13. Concomitantly, mature B cell populations were reduced in the splenic marginal zone and primary follicles, and in the peritoneal cavity in the mutant animals, as were T-independent antibody responses. In addition, aberrant B cell follicles formed ectopically in intestinal lamina propria around Peyer's patches. These findings establish an important role for CXCR4 in regulating homeostasis of B cell compartmentalization and humoral immunity.

Animals↗

[Hypothalamo-pituitary system controls the development of humoral immune response during prenatal ontogenesis in rats].

We studied the influence of the neuroendocrine system on the development of humoral immune response to sheep erythrocytes in rat fetuses. The removal of brain in utero by decapitation of 18-day fetuses induced a fourfold increase in the number of antibody-forming cells in the liver, as compared to the unoperated fetuses. After the removal of the forebrain, including hypothalamus (encephalectomy), the number of antibody-forming cells was comparable to that in unoperated fetuses. The observed increase in the number of antibody-forming cells in the liver was not due to a disturbed migration of precursors of B-lymphocytes in the spleen, since their content in the spleen was also four times that in the encephalectomized and unoperated fetuses. The increased number of antibody-forming cells in decapitated fetuses could be due to an enhanced proliferative activity of the lymphocytes in the liver of these fetuses. It has been proposed that humoral immunity is controlled by the hypothalamo-pituitary-adrenal system already during prenatal development; the adrenocorticotropic hormone and glucocorticoids appear to be involved in this regulation.

Animals↗

Non-specific humoral immunity in rabbits immunised with Chlamydia psittaci-Gocaltovo strain.

In this study we monitored parameters of non-specific humoral immunity in rabbits immunised with Ch. psittaci-Gocaltovo strain and looked for specific anti-Chlamydia antibodies. The results obtained indicated that the parameters evaluated, including activity of myeloperoxidase and the level and activity of lysozyme, manifested alterations earlier than positive titers of specific antibodies developed. This may indicate that alterations in parameters of non-specific humoral immunity can be used as accessory tests in the diagnosis of chlamydioses.

Animals↗

[Cellular and humoral immunity in asymptomatic carriers of the hepatitis B virus].

Eighty-eight asymptomatic HBsAg carriers were examined for cellular and humoral immunity and markers of virus B hepatitis in liver tissue and blood serum. The following results were obtained: HBsAg and HBcAg in liver tissue were found in 10 and 19 out of the 24 examinees, respectively, HBeAg and anti-Hbe in blood serum in 2 and 20 out of the 25 examinees, respectively. No alterations were recorded on the part of humoral immunity. Changes in cellular immunity manifested themselves by reduction in the number of T lymphocytes, and decreased response to PHA. Sensitization to HBsAg led to the purification of hepatitis B virus whereas the presence of simultaneous sensitization to liver-specific lipoprotein contributed to development of graver patterns of liver injury. The role of the immune system and hepatitis B virus itself in the pathogenesis of liver injury in asymptomatic HBsAg carriers is discussed.

Adolescent↗

Humoral immune response of carp (Cyprinus carpio) induced by oral immunization with liposome-entrapped antigen.

To study the value of liposomes as carriers of antigens for oral vaccination in fish, humoral immune responses were analyzed after immunizing carp (Cyprinus carpio) with liposome-entrapped bovine serum albumin (BSA) as a model antigen. Oral immunization of BSA (100 microg)-containing liposomes that were stable in carp bile induced significant antibody responses against BSA in serum as well as in intestinal mucus and bile. By contrast, no serum antibody responses were observed when fish were orally immunized with the same dose of BSA-containing unstable liposomes or BSA alone. BSA-specific antibody-secreting lymphocytes were detected in the spleen and head kidney of immunized fish. Furthermore, when we applied Vibrio cholerae toxin B subunit (CT-B)-conjugated liposomes containing BSA for oral immunization we found significant increases of anti-BSA antibodies in serum. Our results suggest that delivery systems using liposomes or liposomes with CT-B to the intestinal tract are essential for inducing effective humoral immune responses following oral vaccination.

Administration, Oral↗

Humoral immune response in mice over-expressing or deficient in growth hormone.

Effects of growth hormone (GH) levels on the humoral immune response were investigated in metallothionein I (MT)-bovine (b) GH-transgenic (tg) and GH-deficient Ames dwarf (Prop1 df(-/-)) mice. Four-month-old mice were given primary and secondary injections of either normal saline or tetanus toxoid (TT) to induce specific antibody (Ab) production. MT-bGH-tg mice with high peripheral levels of bGH produced less TT-specific Ab than normal nontransgenic (Ntg) littermates, df, or nondwarf (Ndf) control mice. Titers reached maximum levels at 3-4 weeks post-primary immunization (PPI) and declined gradually through 24 weeks PPI in all groups of mice. Peripheral CD4(+) and CD8(+) T cell populations were significantly lower in tg than in Ntg, df, or Ndf mice. No significant differences were found in B cell numbers between tg, Ntg, or df mice. T helper 2 (Th2) cell populations were significantly greater in df mice compared to Ntg control mice. No significant differences were found in CD4(+):CD8(+) T cell ratios, interleukin (IL)-4 concentrations or interferon (IFN)-gamma levels between tg,Ntg, df, and Ndf mice. No patterns of significant sexual dimorphism were found for any of the immune parameters studied. Elevated levels of corticosterone were investigated as a possible immunosuppressant mechanism responsible for low Ab responses in the tg mice. Ab production was not enhanced by decreasing corticosterone in tg mice. Thus, high endogenous GH levels inhibit specific Ab production and peripheral T cell populations but not peripheral B cell numbers, Th2 cell populations, or IL-4 or IFN-gamma production. Elevated corticosterone levels do not appear to be responsible for suppressed humoral immune responses. Low levels of endogenous GH do not inhibit specific Ab production but may contribute to increased peripheral Th2 cell numbers.

Adrenalectomy↗

Adjuvant effects of various lipopeptides and interferon-gamma on the humoral immune response of chickens.

The adjuvant effects of various lipopeptides and recombinant chicken interferon gamma (IFN-gamma) on the humoral immune response of laying hens was investigated in four immunization studies. We used the lipopeptide Pam3Cys-Ser-(Lys)4 (PCSL), the conjugate P-Th1 consisting of the lipopeptide P3CS and the T-helper epitope Th1 (FISEAIIHVLHSRHPG), and the conjugate P-Th2 of the lipopeptide P3CSS and the T-helper epitope Th2, which corresponds to the peptide EWEFVNTPPLV, as adjuvants. Human serum albumin (HSA), recombinant bovine somatotropin (RBST), and human immunoglobulin G (IgG) served as antigens in the different experiments. All tested adjuvants enhanced the humoral immune response with various intensities. Chickens showed high antibody titers after the immunization with HSA even without adjuvant, but the adjuvant effects of PCSL and the combination of PCSL and recombinant chicken interferon-gamma (IFN-gamma) were much more pronounced using the antigens RBST and IgG. Especially after the third immunization, higher titers of antibodies were induced by the coadministration of P-Th1 and, to a greater extent, by the combination of PCSL and P-Th1 compared with the use of PCSL. Also, chickens that had received PCSL and P-Th2 showed the highest immune response, even after the second booster. The average concentrations of chicken immunoglobulin Y were significantly higher in 5-mo-old chickens (9.4 mg/mL serum and 10.1 mg/mL egg yolk) compared with 9-mo-old chickens (5.9 mg/mL serum and 5.1 mg/mL egg yolk). The specific serum antibody response was higher in the older chickens than in the younger chickens. Because chicken antibodies are likely to be used increasingly for diagnostic and therapy in the future, lipopeptides and recombinant chicken IFN-gamma may find many applications as adjuvants, thus contributing to the welfare of experimental animals.

Adjuvants, Immunologic↗

Effects of anti-B7 monoclonal antibodies on humoral immune responses.

The costimulatory interaction between CD28 on T cells and B7-related molecules on antigen presenting cells plays an important role in a broad range of functions of the immune system, including protective immunity, tolerance induction, allograft rejection, and the development of autoimmune diseases. Monoclonal antibodies to B7-1 and B7-2 have been used in vivo to examine the mechanisms underlying these processes and to evaluate costimulation antagonism as an approach to treatment of chronic autoimmune diseases. To determine whether anti-B7 mAb might elicit, or inhibit, a host immune response that could influence the effects of these antibodies in vivo, we assessed the immune response to rat anti-B7-1 and anti-B7-2 mAb in healthy (BALB/c) mice and in lupus-prone NZB/NZW F1(B/W) mice. In BALB/c mice, low doses (1-10 microg) of mAb to B7-1 and mAb to B7-2 elicited brisk immune responses that occurred earlier and were significantly greater than the immune response to an isotype-matched control rat mAb to ovalbumin. In contrast, at higher doses (100-500 microg), both anti-B7 mAb, but not the control mAb, blocked the mouse anti-rat response. No such blockade occurred in B/W mice, who generated a significant mouse anti-rat response even at very high doses of anti-B7 mAb (1,000-4,000 microg). Blockade of the immune response to the anti-B7 mAb in BALB/c mice apparently did not reflect generalized immune suppression, because high doses of these mAb had little, if any effect on the humoral immune response to another antigen. These findings indicate that: (1) mAb to B7-1 and B7-2 can elicit either a potent immune response or no immune response at all depending upon the dose administered; (2) blockade of the immune response to anti-B7 mAb may be more difficult in the setting of autoimmunity; and (3) neither anti-B7-1 nor anti-B7-2 causes generalized suppression of humoral immunity.

Animals↗

Correlation between humoral immune responses and presence of virus in the CNS in dogs experimentally infected with canine distemper virus.

The role of the humoral immune response in clearance or prevention of canine distemper viral encephalitis of dogs infected with a virulent strain of canine distemper virus has been evaluated. Dogs that have demyelinating lesions, CDV proteins and infectious virus in their brains demonstrate an impaired humoral immune response. In dogs that recover from infection and contain no demyelinating lesions, viral proteins or infectious virus in the brain, antibodies to the internal proteins of CDV are observed early after infection. Later antibodies to primarily the H protein are detectable in sera of these dogs and the appearance of antibodies against the surface glycoprotein (H) correlates with the absence of lesions, CDV antigen and infectious virus in the brains of these dogs. Very late after infection immunoprecipitating antibody to all CDV antigens diminished rapidly so that at about ten weeks post infection antibodies that precipitate CDV antigens are barely detectable.

Animals↗

Effects of structural variations in synthetic glycolipids upon mitogenicity for spleen lymphocytes, adjuvancy for humoral immune response and on anti-tumour potential.

Synthetic glycolipids prepared by esterification of various sugars and sorbitol, and containing various numbers of saturated or unsaturated fatty acid residues as well as bacterial lipid A and lipopolysaccharide, were tested for mitogenicity of splenic cells of Fischer rats and Swiss mice and for the augmentation of humoral immune response against sheep red blood cells in these species. Subsequently a few of the humoral immune-response-enhancing glycolipids were compared with non-enhancers in their anti-tumour activity against 13762 rat mammary carcinoma in inbred Fischer 344 rats and Ehrlich tumour in Swiss mice. They were given systemically after tumour inoculation and intratumourally in squalene and Tween emulsion after intradermal MAC tumour development. It was observed that certain structural characteristics in glycolipids with respect to the type of sugar, the type and number of fatty-acid residues were needed for their adjuvant action of the humoral arm of the immune response. Although humoral immune-response enhancers were somewhat superior to non-enhancers in their anti-tumour activity, the correlation coefficient demonstrated a lack of significant concordance. It is concluded that glycolipids selected for their ability to augment humoral immune responses against standard antigens need not be suspect as tumour-enhancers on the grounds that they would elicit blocking antibodies in vivo against tumour-associated antigens.

Adenocarcinoma↗

Stress-induced alteration of T-lymphocyte subsets and humoral immunity in mice.

Effects of acute rotational stress on the tissue distribution of lymphocyte subpopulations, and the capacity to mount a humoral immune response were examined in normal and adrenalectomized mice. The splenic lymphocyte population showed a significant alteration in its content of T lymphocytes in normal, but not adrenalectomized animals subjected to rotational stress. Thus adrenal steroids may influence lymphocyte subpopulations in animals responding to stress. Humoral immune responsiveness of splenic lymphocytes was assessed by a direct lymphocyte plaque forming cell assay following immunization with sheep erythrocytes. The peak number of lymphocytes forming antibody to sheep erythrocytes found in spleens of animals subjected to stress begun 24 hours after antigen inoculation was 50% of the number observed in animals immunized and stressed simultaneously (p less than .001). No effect of adrenalectomy on the reduction in the numbers of antibody forming lymphocytes was observed. We conclude that stress can modify immune responsiveness by a number of mechanisms, some of which are independent of adrenal corticosteroid action.

Adrenalectomy↗

Limited contribution of humoral immunity to the clearance of measles viremia in rhesus monkeys.

The development of an improved vaccine for controlling measles virus (MV) infections in the developing world will require an understanding of the immune mechanisms responsible for the clearance of this virus. To evaluate the role of humoral immunity in the containment of MV, rhesus monkeys were treated at the time of MV challenge with either anti-CD20 monoclonal antibody (MAb) infusion, to deplete B lymphocytes, or both anti-CD20 and anti-CD8 MAb, to deplete both B lymphocytes and CD8+ effector T lymphocytes. Although the MV-specific antibody response in CD20+ lymphocyte-depleted monkeys was delayed by >1 week, the kinetics of MV clearance did not differ from those for monkeys that received control MAb. Furthermore, unusual clinical sequelae of MV infection were not observed in these monkeys. In contrast, MV-infected rhesus monkeys depleted of both CD20+ and CD8+ lymphocytes had a prolonged duration of viremia and developed a desquamating skin rash. These findings indicate that humoral immunity plays a limited role in the control of MV replication in an MV-naive individual and suggest that new measles vaccination strategies should focus on the elicitation of cell-mediated immune responses, in addition to neutralizing antibodies, to facilitate rapid elimination of locally replicating virus.

Animals↗

[Specific cellular and humoral immune responses induced by intramuscular injection of DNA vaccine containing HBV HBsAg gene in mice].

To know the influences on the function of cellular and humoral immunity in mice by DNA vaccine containing HBV HBsAg gene, the DNA vaccine, pcDNA3-HBsAg, in which the HBsAg gene sequences of HBV were inserted into downstream of CMV promoter in pcDNA3, were injected intramuscularly into Balb/C mice. The results were that the serum anti-HBsIgG was detected in all of the pcDNA3-HBsAg immunized mice, but none in control mice; serum levels of Th1 cytokines, interleukine 2, and interferon gamma, were significantly higher in pcDNA3-HBsAg immunized mice than these in controls. It is indicated that the good responses of cellular and humoral immunity can be induced by injection of pcDNA3-HBsAg in Balb/C mice.

Animals↗

Humoral immune response against minor collagens type IX and XI in patients with cartilage graft resorption after reconstructive surgery.

OBJECTIVES: The humoral immune response against a broad spectrum of cartilage antigens (cellular and matrix antigens) was studied in a group of patients who showed resorption and/or rejection of transplanted cartilage in nasal surgery. METHODS: Sera were obtained from patients with successful and unsuccessful cartilage grafting in the nose, from age and sex-matched healthy donors and from patients with rheumatoid arthritis. Antibodies to cartilage components were analysed by the following methods: (1) indirect immunofluorescence on cartilage sections, (2) ELISA using cultured human chondrocytes, isolated chondrocyte membranes and purified collagens type I, II, III, VI, IX and XI, and (3) immunoblotting with purified collagens and chondrocyte cell membranes. RESULTS: In the cartilage grafting group showing resorption problems, levels of anti-collagen antibodies were significantly higher against native collagen types IX (p < 0.002) and XI (p < 0.002) compared with the non-resorption group and the normal donors. Both transplantation groups revealed elevated reactivities against isolated chondrocytes in the ELISA. In contrast, no reactivity was detectable against collagens type II, III, and VI and chondrocyte cell membranes by both ELISA and immunoblotting. CONCLUSIONS: These data demonstrate for the first time the existence of a humoral immune response, primarily directed against the so called 'minor cartilage collagens', in patients showing cartilage resorption. Autoreactivities to collagen which are typical of inflammatory rheumatic diseases may also play an important role in the repeated failure of cartilage grafting.

Adult↗

Poliovirus-specific CD4+ Th1 clones with both cytotoxic and helper activity mediate protective humoral immunity against a lethal poliovirus infection in transgenic mice expressing the human poliovirus receptor.

The current understanding of the function of CD4+ T helper (Th) cells in immunity to infectious diseases is that Th1 cells, which secrete interleukin (IL)-2 and interferon-gamma, induce cellular immune responses, whereas Th2 cells, which secrete IL-4, IL-5, IL-6, and IL-10, provide helper function for humoral immunity. We have used a panel of poliovirus-specific murine CD4+ T cell clones and mice transgenic for the human poliovirus receptor to evaluate the role of Th cell subpopulations in protective immunity to poliovirus. The majority of T cell clones, as well as polyclonal T cells generated from mice infected or immunized with poliovirus, secreted IL-2 and interferon-gamma, but not IL-4, IL-5, or IL-10, a profile typical of Th1 cells. The Th1 clones displayed major histocompatibility complex class II-restricted cytotoxic T lymphocyte activity against specific poliovirus peptide-pulsed target cells, but also provided help for antipoliovirus neutralizing antibody production. To examine the mechanism of immunity in vivo, we have used poliovirus receptor-transgenic mice on a BALB/c (H-2d) background. These animals developed a poliomyelitis-like disease when challenged intravenously with a virulent wild-type strain of poliovirus, but not with an attenuated vaccine strain. Furthermore, mice immunized with the vaccine strain were protected against a subsequent challenge with wild-type virus. Using an adoptive transfer technique, we demonstrated that it was possible to confer protection with primed B cells in the presence of polyclonal poliovirus-specific T cells, but not when transgenic mice received either B cells or T cells alone. Furthermore, protection was observed when mice received primed B cells in the presence of a VP4-specific Th1 clone. The findings demonstrate that Th1 cells can mediate a protective immune response against poliovirus infection in vivo through helper activity for humoral immunity and that CD4+ T cells, specific for the internal poliovirus capsid protein, VP4, can provide effective help for a protective antibody response directed against surface capsid proteins.

Animals↗

Delayed development of humoral immunity in chickens following in ovo treatment with mibolerone.

In order to determine if mibolerone causes rapid development of the humoral immune system as previously hypothesized, 12-day-old chicken embryos were injected with 0.1, 1, or 10 micrograms mibolerone. Mibolerone caused bursal atrophy in a dose-dependent manner with severe atrophy at the 10 micrograms dose, substantial atrophy at the 1 microgram dose, and very little or no atrophy at the 0.1 microgram dose. Mibolerone-treated chicks were subsequently challenged with sheep red blood cells (SRBC) and Brucella abortus at 1, 7, 14, or 21 days of age. When serum samples were analysed for agglutinins to SRBC and B. abortus, the results indicated that treated chickens had lower agglutinin titers to both antigens at younger ages. These responses improved with age in groups treated with 0.1 microgram and 1 microgram and were comparable to controls at 5 weeks of age except for low primary and secondary (IgG specific) titers to B. abortus in birds treated with 1 microgram. Chickens treated with 10 micrograms mibolerone still had considerably lower primary responses to SRBC and lower primary as well as secondary responses to B. abortus at 4 and 5 weeks of age. These results indicate that mibolerone causes delayed rather than rapid development of the humoral immune system. In control as well as in treated chickens, agglutinin responses to SRBC appeared earlier than responses to B. abortus.

Age Factors↗

Humoral immune response against Borna disease virus (BDV) in experimentally and naturally infected cats.

In order to investigate the peripheral and intracerebral humoral immune response against Borna disease virus (BDV) in cats, serum and cerebrospinal fluid (CSF) samples from experimentally and naturally BDV-infected cats were analysed in two different test systems (indirect enzyme-linked immunosorbent assay and indirect immunofluorescent test). The experimentally infected cats developed high antibody titres against the major immunogenic BDV-proteins, p24 and p40. In contrast, the naturally infected cats showed a comparatively weak humoral immune response. The experimentally infected cats were inoculated with either BDV laboratory strain V or a feline BDV-isolate. Some differences existed between the two groups of cats. The former group developed a higher response against p40, whereas the latter group showed, beside the p40-response, a more pronounced p24-response, similar to the situation in the naturally infected cats.

Animals↗

Immune and inflammatory responses in TNF alpha-deficient mice: a critical requirement for TNF alpha in the formation of primary B cell follicles, follicular dendritic cell networks and germinal centers, and in the maturation of the humoral immune response.

To investigate the role of TNF alpha in the development of in vivo immune response we have generated TNF alpha-deficient mice by gene targeting. Homozygous mutant mice are viable and fertile, develop lymph nodes and Peyer's patches and show no apparent phenotypic abnormalities, indicating that TNF alpha is not required for normal mouse development. In the absence of TNF alpha mice readily succumb to L. monocytogenes infections and show reduced contact hypersensitivity responses. Furthermore, TNF alpha knockout mice are resistant to the systemic toxicity of LPS upon D-galactosamine sensitization, yet they remain sensitive to high doses of LPS alone. Most interestingly, TNF alpha knockout mice completely lack splenic primary B cell follicles and cannot form organized follicular dendritic cell (FDC) networks and germinal centers. However, despite the absence of B cell follicles, Ig class-switching can still occur, yet deregulated humoral immune responses against either thymus-dependent (TD) or thymus-independent (TI) antigens are observed. Complementation of TNF alpha functioning by the expression of either human or murine TNF alpha transgenes is sufficient to reconstitute these defects, establishing a physiological role for TNF alpha in regulating the development and organization of splenic follicular architecture and in the maturation of the humoral immune response.

Animals↗