PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Humoral immune response”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2003

CpG immuno-stimulatory motifs enhance humoral immune responses against hepatitis C virus core protein after DNA-based immunization.

Chronic HCV infection is associated with a high morbidity and mortality rate, and currently a prophylactic or therapeutic vaccine is not available. DNA-based immunization is a powerful method to generate cellular and humoral immune responses. However, DNA immunization against HCV core results only in a weak humoral immune response demonstrated in several studies. Therefore, co-immunization with a novel adjuvant may enhance such potentially important immune responses. We examined whether unmethylated CpG motifs in the form of oligodeoxynucleotides (ODN) or E. coli DNA can act as adjuvants for a DNA vaccination approach, since CpG motifs have been shown to stimulate the innate immune system as well as B and T cell immune reactivity. The present study demonstrates that CpG motifs enhance in vivo antibody levels after DNA immunization against HCV core. However, despite some in vitro activity of CpG motifs, no enhancement of T cell responses in vivo was observed after immunization with HCV plasmid DNA and CpG motifs in mice. Our results suggest that co-immunization with CpG-ODN may strengthen humoral immune responses but show no potential effect as an adjuvant to induce cellular immunity against HCV core.

Adjuvants, Immunologic↗
PubMed1981

In vivo effects of antibodies to immune response gene products. I. Haplotype-specific suppression of humoral immune responses with a monoclonal anti-I-A.

Immune response (Ir) gene products control immunologic function at several critical sites. We administered in vivo a monoclonal antibody reactive with I-Ak to F1 mice with the genotype H-2k/b. These treated mnice made a markedly reduced antibody response to antigen (H,G)-A--L, under the control of I-Ak, but not to antigen (T,G)-A--L, under the control of I-Ab. This relative specificity was lost if the antigen was given in complete Freund's adjuvant rather than aqueous solution. The monoclonal antibody reduced the antibody titer in an ongoing, secondary response as well. Several potential mechanisms can be postulated for this effect. This haplotypic specificity might ultimately be relevant to human disease.

Animals↗
PubMed2004

Effects of copper and zinc source on performance and humoral immune response of newly received, lightweight beef heifers.

Two experiments were conducted to evaluate the effects of Cu and Zn source on performance, morbidity, and humoral immune response in lightweight, newly received beef heifers. A 2 x 2 factorial arrangement of treatments was used in both experiments, with either a sulfate or a polysaccharide mineral complex (SQM) source of both Cu and Zn as the factors. Supplemental Cu and Zn were included in the receiving diet at concentrations designed to provide 10 mg of Cu/kg and 75 mg of Zn/kg (DM basis). In Exp. 1, 219 newly received beef heifers (British x Continental, average initial BW = 208 kg) were given ad libitum access to a 65% concentrate diet for 35 d to determine treatment effects on DMI, ADG, G:F, and bovine respiratory disease (BRD) morbidity. In Exp. 2, 24 heifers (average initial BW = 272 kg) were fed a diet with no supplemental Cu or Zn for 35 d, followed by fasting-refeeding-fasting stress, after which the same treatment diets used in Exp. 1 were fed for 21 d to examine the effects on humoral immune response (plasma IgG titer determined by ELISA on d 7, 14, and 21) to an ovalbumin (OVA) vaccine given on d 0 and 14. Copper source x Zn source interactions were not detected in either experiment. In Exp. 1, neither Cu nor Zn source affected (P > 0.10) DMI, ADG, G:F, or BRD morbidity. In Exp. 2, d 14 (P = 0.02) and 21 (P = 0.06) OVA titers were greater for heifers that received SQM Zn compared with heifers receiving ZnSO4, but heifers receiving CuSO4 had greater OVA titers than did heifers on the SQM Cu treatment on d 14 (P = 0.01) and 21 (P = 0.001). In summary, neither supplemental Cu nor Zn source affected performance or morbidity of lightweight, newly received heifers; however, source of both Cu or Zn affected the humoral immune response to OVA, although source effects were not consistent for the two minerals.

Animals↗
PubMed2006

Effects of dietary supplementation with clostridium butyricum on the growth performance and humoral immune response in Miichthys miiuy.

The effects of dietary supplementation with Clostridium butyricum on growth performance and humoral immune response in Miichthys miiuy were evaluated. One hundred and fifty Miichthys miiuy weighing approximately 200-260 g were divided into five groups and reared in 15 tanks with closed circuiting culture system. The animals were fed 5 diets: basal diet only (control) or supplemented of the basal diet with C. butyricum at doses of 10(3) (CB1), 10(5) (CB2), 10(7) (CB3) or 10(9) (CB4) CFU/g. Compared with the control, the serum phenoloxidase activity was significantly increased by the supplementation (P<0.05), acid phosphatases activity was increased significantly (P<0.05) at the doses of 10(9) CFU/g. Serum lysozyme activity peaked at dose of 10(7) CFU/g and in the skin mucus at dose of 10(9) CFU/g. Immunoglobulin M level in the serum and skin mucus was increased except at dose of 10(3) CFU/g (P<0.05). The growth at the dose of 10(9) CFU/g was higher than that of the control (P<0.05). It is concluded that supplementation of C. butyricum can mediate the humoral immune responses and improve the growth performance in Miichthys miiuy.

Animal Feed↗
PubMed2006

Bacterial adherence and humoral immune response in women with symptomatic and asymptomatic urinary tract infection.

PURPOSE: To determine the role of humoral immune response and bacterial adherence in the pathogenesis of symptomatic and asymptomatic urinary tract infection in women. METHODS: The study population consisted of 30 women with symptomatic UTI, 30 women with asymptomatic UTI and 30 healthy women as controls. Bacterial adherence to vaginal epithelial cells was studied and the concentration of serum and urine antibodies to mixed coliform antigen and clinical isolate was determined by ELISA. Surface hydrophobicity of the urine isolates was determined. Student's unpaired t test and Pearson's correlation coefficient test were used in the statistical analysis. RESULTS: Compared to asymptomatic UTI, significantly more number of bacteria adhered to the epithelial cells of women with symptomatic UTI (P< 0.001). All cases of UTI had significantly high concentration of urinary IgG antibody to mixed coliform antigens. Asymptomatic UTI cases had higher concentrations of urinary IgG, IgM and IgA antibodies to clinical isolate. Concentration of sIgA level was more in symptomatic UTI. Significant correlation was observed between urinary IgG and adherence of clinical isolate in case of asymptomatic UTI. CONCLUSIONS: The present study showed that greater receptivity of epithelial cells to bacteria may increase the susceptibility to UTI. Humoral immune response and local immunity may modify the pathogenesis of UTI.

Adolescent↗
PubMed1981

Cell-mediated and humoral immune responses to chlamydial antigens in guinea pigs infected ocularly with the agent of guinea pig inclusion conjunctivitis.

Cell-mediated immune response and humoral response to chlamydial antigens were investigated in guinea pigs infected with the agent of guinea pig inclusion conjunctivitis (GPIC). Pronounced cell-mediated immune response to the homologous antigen, as well as to two other chlamydial antigens, 6BC (Chlamydia psittaci) and LB-1 (C. trachomatis), occurred in all infected animals. Cell-mediated immune response to GPIC, and to a lesser extent to 6BC and LB-1 as well, was enhanced with time after infection even without the re-inoculation of the infectious agent. Extensive cross-reactions among the three chlamydial antigens during the cell-mediated immune response appeared to be due to shared species-specific and group-reactive antigens. Serum antibody response was pronounced and uniform to GPIC; it was less marked to 6BC and LB-1, with fewer cross-reactions than seen in tests for cell-mediated immunity.

Animals↗
PubMed1992

Humoral immune response to the antigen administered as an immune complex.

Antigen (HSA) bound in immune complexes at equivalence with syngeneic anti-HSA antibodies elicit much stronger humoral immune response then soluble HSA. On the other hand, administration of immune complexes formed with xenogeneic (rabbit) anti-HSA antibodies suppressed humoral immune response against HSA, but not against rabbit IgG in mice. We suggest that immunization with antigen bound in immune complex might represent a powerful tool in enhancing humoral immune responses.

Animals↗
PubMed1984

Role of autorosette forming cells in antibody synthesis in vitro: suppressive activity of ARFC in humoral immune response.

The role of autologous rosette forming cells (ARFC) in humoral immune responses was studied using an in vitro system. While depletion of ARFCs from PBL resulted in a significant increase of either total IgG or anti-TT IgG, addition of these cells to the system decreased the production of immunoglobulin to a level comparable to that of unfractionated PBL. The majority of the ARFCs reacted with anti-Leu2a and anti-Leu8. In contrast, the majority of non-ARFCs reacted with Leu3a and only 10% with Leu8 monoclonal antibodies. Stimulation of unfractionated PBL with concanavalin A (ConA) resulted in an increase of the ARFC population. ConA stimulation also increased the number of cells reactive with anti-Leu2 and/or anti-Leu8. The autorosette population had a higher purine nucleoside phosphorylase (PNP) content than the non-ARFC population. Although the ARFC suppressed synthesis of antibody by B cell in vitro when they were mixed with either autologous or allogeneic B cells, a marked proliferation of non-B cells was evident. We conclude that at least two different subpopulations of T cells are capable of forming rosettes with autologous red blood cells.

Antibodies, Monoclonal↗
PubMed1991

Humoral immune responses in human infection with the whipworm Trichuris trichiura.

The humoral immune response to infection with Trichuris trichirua was investigated by ELISA and immunoblotting using human sera from the Caribbean island of St Lucia. Immunoblot analysis of the degree of cross-reactivity with the related trichuroid Trichinella spiralis and with the other commonly co-existent nematodes, Ascaris lumbricoides and Toxocara canis, was carried out using selected sera. The IgM, IgA, IgE, and IgG subclass antibody levels were measured in ELISA using a detergent solubilized extract of adult T. trichiura. The IgG and IgE responses were highly Trichuris specific. Anti-T. trichiura IgM responses were totally cross-reactive with A. lumbricoides and were completely ablated by pre-incubation of sera with Ascaris antigen. The IgG response was predominantly of the IgG1 subclass with a minimal IgG3 response. Only 1 person out of 130 tested had a detectable IgG3 response. The IgG2 response appeared to be directed primarily against carbohydrate or polysaccharide antigens as pre-treatment of the ELISA plates with poly-L-lysine was necessary before a response could be detected. These data are the first demonstration of human isotypic responses to infection with T. trichiura.

Animals↗
PubMed1999

Antibiotics modulate vaccine-induced humoral immune response.

The effects of antibiotics on the antigen-specific humoral immune response are not known. Macrolides, tetracyclines, and beta-lactams are commonly prescribed antibiotics. The first two are known to have immunomodulatory activities. The effects of clarithromycin, doxycycline, and ampicillin on the primary and secondary antibody responses to tetanus toxoid, a pneumococcal polysaccharide vaccine, a hepatitis B virus surface antigen (HBsAg) vaccine, and live attenuated Salmonella typhi (Ty21a) were investigated using a mouse model. For the mice receiving the tetanus toxoid, the immunoglobulin M (IgM) level of the clarithromycin group at day 7 was significantly lower than the corresponding antibody level of the normal saline (NS) group. For the mice receiving the pneumococcal polysaccharide vaccine, the total antibody and IgM levels of the clarithromycin group and the IgM level of the doxycycline group at day 7 were significantly lower than the corresponding antibody levels of the ampicillin and NS groups. For the mice receiving the HBsAg vaccine, the IgM level of the doxycycline group at day 7 was significantly lower than the corresponding antibody levels of the clarithromycin and NS groups, while the IgM level of the clarithromycin group at day 28 was significantly lower than the corresponding antibody levels of the doxycycline, ampicillin, and NS groups. For the mice receiving all three vaccines, there were no statistically significant differences between any of the antibody levels of the ampicillin group and the corresponding antibody levels of the NS group. For the mice receiving Ty21a, the total antibody levels of the ampicillin group at days 7 and 21 were significantly higher than the corresponding antibody levels of the NS group. Moreover, the IgM levels of the clarithromycin, doxycycline, and ampicillin groups at days 7 and 21 were significantly higher than the corresponding antibody levels of the NS group. Furthermore, the total antibody level of the ampicillin group at day 21 was significantly higher than the corresponding antibody level of the doxycycline group. For all four vaccines, there were no statistically significant differences among the serum levels of interleukin-10 and gamma interferon for the mice treated with the various antibiotics. We conclude that clarithromycin and doxycycline, but not ampicillin, suppress the antibody responses of mice to T-cell-dependent and T-cell-independent antigens, whereas all three antibiotics enhance the antibody response to live attenuated mucosal bacterial vaccines.

Ampicillin↗
PubMed1985

Cellular and humoral immune responses of mice subclinically infected with Pneumocystis carinii.

Cellular and humoral immune responses to Pneumocystis carinii were investigated. ICR and DDD mice were intranasally infected with 10(4) mouse lung-derived P. carinii, and the delayed-type hypersensitivity (DTH) reaction and antibody titers to P. carinii were measured along with the number of P. carinii cysts in the lungs after infection. The number of P. carinii cysts in the lungs peaked at 2 weeks after infection and then decreased to barely detectable levels by 4 weeks. Serum antibody (immunoglobulin G) titers measured by indirect immunofluorescence increased up to 4 weeks. The DTH footpad reaction was most prominent at 2 weeks postinfection and declined thereafter. Thus, the decline in the number of P. carinii cysts in the lungs corresponded well with the time of the peak of the DTH reaction but not with the serum antibody response. Spleen T cells from infected mice mediated the DTH reaction when transferred intravenously into normal recipients and reduced the number of P. carinii cysts in the lungs when transferred intravenously into P. carinii-infected mice. The results indicated that cellular immunity is important for protection from subclinical P. carinii infections.

Animals↗
PubMed1991

[The dynamics of the humoral immune response to mycobacterial antigens in mice].

The main regularities of humoral immune response to mycobacterial antigens have been studied in experiments on BALB/c mice immunized with live and thermoinactivated Mycobacterium tuberculosis, var. bovis. As shown in this study, the maximum level of serum antibodies to mycobacterial antigen is achieved in two weeks after immunization irrespective of the dose and viability or mycobacteria, then follows a decrease in the antibody level. The absence of uniformity in the dependence of primary immune response and the formation of immunological memory on the dose and viability of mycobacteria has been demonstrated.

Animals↗
PubMed1981

Humoral immune response of cats to Paragonimus infection.

The time course of humoral immune response to Paragonimus siamensis was studied in 10 cats experimentally infected with either 30 or 60 matacercariae and the antibody produced was detected by enzyme linked immunosorbent assay (ELISA), complement fixation test (CFT), and immunoelectrophoresis (IEP) test. With ELISA and CFT, antibodies was detected as early as 2nd week after infection and the cats remained positive throughout the 12 week period of observation. In contrast, the IEP test was persistently negative. With respect to sensitivity, both ELISA and CFT are equally sensitive but the mean ELISA titer was consistently higher than that of CFT. THe magnitude of the antibody response appeared to be related to duration of the infection but not to the infective dose and the number of worms recovered. There was variability in titers among cats infected with equal numbers of metacercariae. The tests can not be used for differential diagnosis of infections by P. siamensis and P. heterotremus because of the cross-reaction. Such cross-reaction did not not occur against unrelated parasites including hookworm. Toxocara cati and Spirometra mansoni.

Animals↗
PubMed1978

Cellular and humoral immune response in pigs given vaccinal and chronic hog cholera viruses.

Humoral immune response (seroneutralization) and cellular immune response (lymphocyte-stimulation test) were analyzed in pigs inoculated with low virulent strains of hog cholera virus or vaccinated with a live-virus vaccine. Vaccinated animals exhibited an intense neutralizing antibody production, but cellular immune response was not detected. Neutralizing antibodies were not found in infected pigs, but a brief cellular immune response (18 days after inoculation) was observed.

Animals↗
PubMed1994

Cellular and humoral immune responses to recombinant 65-kD antigen of Mycobacterium leprae in leprosy patients and healthy controls.

Cellular and humoral immune responses to recombinant 65-kD antigen of Mycobacterium leprae (rML65) were studied in leprosy patients and healthy contacts from a leprosy-endemic population. Peripheral blood mononuclear cells from a considerable proportion of tuberculoid leprosy patients, healthy contacts and non-contacts showed proliferative response to rML65 in vitro. A strong positive correlation was observed between the responses to rML65 and bacille Calmette-Guérin (BCG) or leprosin A. Addition of recombinant IL-2 (rIL-2) enhanced the proportion of responders to rML65 considerably in all groups of leprosy patients, healthy contacts and non-contacts. Among lepromatous patients this enhancement was more pronounced in the bacterial index (BI)-negative group. These results indicate that the 65-kD antigen of Myco. leprae is a dominant T cell immunogen in our study population. Though lepromatous patients showed poor lymphoproliferative response to rML65, their IgG antibody levels to the same antigen were markedly high. Most of the BI-positive lepromatous patients with elevated anti-rML65 IgG levels did not show T cell reactivity even with the addition of rIL-2. On the other hand, tuberculoid leprosy patients, healthy contacts and non-contacts showed good T cell reactivity but low levels of IgG antibodies to rML65, thus indicating the presence of an inverse relationship between cell-mediated and humoral immune responses to a defined protein antigen of Myco. leprae in humans. A significant proportion of individuals among tuberculoid leprosy patients, healthy contacts and non-contacts showed neither T cell reactivity nor elevated levels of IgG antibody to rML65. However, in most of these subjects, a T cell response to rML65 was demonstrable with the addition of rIL-2. These results are discussed with reference to the immunoregulatory mechanisms occurring during Myco. leprae infection on the basis of differential activation of Th1 and Th2 subsets.

Antibodies, Bacterial↗
PubMed2001

Development and application of the serological assay for humoral immune response against duck hepatitis B virus.

OBJECTIVE: To develop a simple and specific assay for detection of humoral immune response in duck hepatitis B virus (DHBV) infected ducks. METHODS: Eighty serum samples were detected by ELISA for DHBsAg with prepared anti-preS 1H1 ascitic fluid and by PCR or dot blot hybridization for DHBV DNA. Thirty-two serum samples from experimentally infected 1-day-old ducks were assayed by ELISA for DHBcAb and DHBsAb. RESULTS: Of 66 PCR positive samples, 58 were positive for DHBsAg and 62 were positive for DHBV dot blot hybridization. Sensitivities of the two methods were 87.9% and 93.9%, respectively. Anti-DHBc was developed in 2/8 infected ducks at day 21 but negative after day 28. Anti-DHBs antibodies were negative throughout the infectious period. CONCLUSION: The application of DHBV infection and serological assay will be helpful to the study of kinetics of DHBV and humoral immune response of ducks against the virus.

Animals↗
PubMed2000

Regulation of humoral immune responses by CD21/CD35.

Before antigen-specific immunity arises, the complement system responds by activation through the classical and/or alternative pathways leading to the covalent deposition of complement fragments. Three models, not mutually exclusive, have been proposed to explain how these complement fragments interact with their receptors, CD21/CD35, to enhance humoral immune responses: i) CD21/CD35 retain and focus antigens for optimal presentation; ii) CD21/CD35 on B cells serve as enhancing co-receptors for B-cell antigen receptor (BCR) signaling; iii) CD21/CD35 regulate B-cell responses, by CD19 aggregation. The coreceptor model led us to predict that CD21/CD3 5 may lower the threshold of BCR affinity to diversify the repertoire of humoral immune responses, but surprisingly, CD21/CD3 5-deficient mice expressing a transgenic BCR with very low affinity (Kalpha approximately =1.2 x 10(5) M(-1)) for the (4-hydroxy-3-nitrophenyl)acetyl hapten generated significant antibody and germinal center responses to even low doses of antigens in alum. The magnitudes of these responses were much below those of normal controls but higher doses of antigens substantially rectified these deficits. Thus, while CD21/CD35 play important roles in humoral immunity, our observations provide little support to the hypothesis that CD21/CD35 promote clonal diversity in immune responses by helping recruit low-affinity B cells.

Animals↗