Characterization of bovine cellular and serum antibody responses during infection by Cryptosporidium parvum.

Cellular and serum antibody responses of calves were monitored for 23 days after oral inoculation of the calves with oocysts of Cryptosporidium parvum. In vitro blastogenic responses of peripheral blood lymphocytes were assessed after stimulation with a C. parvum preparation. Specific lymphocyte blastogenic responses to the parasite were detected 2 days after inoculation. Parasite-specific antibody titers were demonstrable 7 days after inoculation with oocysts and achieved peak levels 9 days after inoculation, coinciding with oocyst shedding at 5 to 10 days after inoculation. Both lymphocyte and antibody responses remained elevated until the termination of the experiment. Immunoblotting the C. parvum preparation with serum from an infected calf revealed six major parasite antigens. Five of these antigens reacted on immunoblots from 7 to 14 days after inoculation with oocysts. A parasite antigen of approximately 11,000 molecular weight demonstrated intense reactivity on immunoblots from 7 to 23 days after inoculation. The 11,000-molecular-weight antigen also reacted on immunoblots with parenterally raised antioocyst and antisporozoite rabbit sera. These results indicate that cell-mediated as well as humoral immune responses are initiated by cryptosporidial infection in calves and that the 11,000-molecular-weight parasite antigen is immunodominant.     

Cellular and Humoral Hypersensitivity to Adrenal Antigen in Experimental Adrenalitis

A role for specific cellular, as well as humoral immunity has been suggested in experimental adrenalitis. This study was performed to seek a correlation between cellular and humoral immunity in experimental adrenalitis of the guinea pig.

34 guinea pigs (GP) were arranged into 4 experimental groups. One group (11 GP) was immunized with a single injection of 250 mg homologous adrenal antigen (HAA) in complete Freund's adjuvant (CFA). A second group (6 GP) was similarly immunized at 1 and 14 days. A third group (9 GP) received 3 such injections at 1, 14, and 21 days. The fourth group (8 control GP) received RPMI-1640 in CFA. The following were performed on all groups 10 days after the last injection: lymphocyte response to PHA and HAA; HAA-specific macrophage migration inhibition (MIF); antibody titers to HAA by hemagglutination; and histopathology of adrenal, thyroid and testis.

Antibody titers reached a mean level of 500 in each of the 3 HAA-immunized groups. In the single injection group, MIF activity and response to PHA were significantly increased when compared to the other immunized groups and to controls. Histopathologic changes were seen in adrenal glands of all immunized groups, but were most remarkable in the single injection group. Progressively fewer changes were observed in double and triple immunized groups. Antibody titers and histological changes were not found in controls.

Histopathology correlated better with cell-mediated immune parameters than with specific antibody titers; this suggests that cell-mediated mechanisms may be the more important factor in pathologic lesions of experimental adrenalitis.     

Cell-mediated immune response following intracutaneous immunisation with human diploid cell rabies vaccine

Specific cell-mediated immune response (CMIR) against rabies antigens was studied in recipients of two regimens of human diploid cell rabies vaccine (HDCV) using the antigen-stimulated lymphocyte transformation test (LTT) as a measure of CMIR. Reconstituted HDCV could be conveniently used as the in vitro stimulating antigen and the response was antigen-dependent. Conventional intramuscular immunization with full-dose HDCV resulted in positive LTT as early as 14 days after starting immunisation, and peaked on day 28. Intracutaneous immunisation with 0.1 ml of HDCV at four sites on days 0, 3 and 7 was a more efficient means of inducing specific lymphocyte response. Specific CMIR was evident as early as seven days and became maximal on day 14. In addition to the more rapid induction of specific CMIR, our intracutaneous regimen also resulted in a brisker and higher antibody response than the intramuscular regimen. The peak antibody level of the intracutaneous regimen was reached on day 14 whereas that of the intramuscular regimen was reached on day 28 and the geometric mean antibody titre on day 14 of the intracutaneous route was significantly higher than that of the intramuscular regimen. We therefore conclude that our closely spaced intracutaneous immunisation with HDCV was effective both in the induction of specific antibodies and the cell-mediated immune response.     

Oral treatment of chickens with lactobacilli influences elicitation of immune responses

Commensal microbes in the intestine are in constant interaction with host cells and play a role in shaping the immune system. Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus salivarius are members of the chicken intestinal microbiota and have been shown to induce different cytokine profiles in mononuclear cells in vitro. The objective of the present study was to examine the effects of these bacteria individually or in combination on the induction of antibody- and cell-mediated immune responses in vivo. The birds received lactobacilli weekly via oral gavage starting on day of hatch and subsequently, at 14 and 21 days, were immunized with sheep red blood cells (SRBC), keyhole limpet hemocyanin (KLH), Newcastle disease virus vaccine, and infectious bursal disease virus vaccine. Antibody responses in serum were measured weekly for 4 weeks beginning on the day of primary immunization. The cell-mediated immune response was evaluated at 21 days postimmunization by measurement of gamma interferon (IFN-γ) production in splenocytes stimulated with inactivated vaccine antigens. L. salivarius-treated birds had significantly more serum antibody to SRBC and KLH than birds that were not treated with probiotics. L. salivarius-treated birds also had decreased cell-mediated immune responses to recall antigen stimulation. L. reuteri treatment did not significantly affect the systemic immune response, while L. acidophilus treatment increased the antibody response to KLH. These results indicate that systemic antibody- and cell-mediated immune responses can be modulated by oral treatment with lactobacilli but that these bacteria may vary in their ability to modulate the immune response.     

Local and systemic antibody response to oral administration of glucosyltransferase antigen complex

The salivary and serum immune responses to orally administered glucosyltransferase antigen complex from Streptococcus mutants strain 6715 were investigated in hamsters. All enzyme-linked immunosorbent assay was used to measure the antibody quantity and isotype, and a [14C]glucosyl-labeled sucrose incorporation assay was used to measure functional inhibition of the enzyme. A total of 21 to 27 daily doses of antigen administered in hamster oral cavities elicited salivary immunoglobulin C and immunoglobulin A antibody responses and functional inhibitory activity. The salivary response increased throughout the immunization procedure, and the amount of salivary antibody was dependent upon the dose of antigen given. The salivary response to a second oral administration of antigen for 4 days showed some features of anamnesis. The response after a second antigen administration was detected sooner than the primary response, and somewhat higher levels of antibody and inhibitory activity were observed. Serum antibody (immunoglobulin G and immunoglobulin M) and functional inhibitory responses were also elicited by oral administration of the soluble enzyme antigen. These responses were lower than responses induced by local injections of antigen in complete Freund adjuvant. The ability to evoke a salivary immune response to the glucosyltransferase antigen complex may increase the potential of using this antigen in an effective caries vaccine.     

Modulation of delayed-type hypersensitivity during the time course of immune response to a protein antigen

Delayed-type hypersensitivity reactions elicited in the footpad of ovalbumin-sensitized mice after challenge with aggregated ovalbumin on day 4 or 8 of immunization are distinct. The former was characterized by a dense mononuclear infiltrate and, macroscopically, the reaction peaked at 48 hr after antigen challenge; the latter was preceded by immediate-type reactions, reached the maximum at 24 hr and faded drastically later. Histologically, oedema and a mixed granulocytic-lymphocytic infiltrate was found at this time-point. Immunoglobulin G1 (IgG1), IgG2a and IgE antibodies were detected only in plasma obtained after 8 days of immunization. Regarding the cytokines produced by draining lymph node cells after in vitro restimulation, interleukin-4 (IL-4) and IL-10 were predominant after 4 days and interferon-gamma and IL-2 after 8 days of immunization. These two types of delayed-type hypersensitivity (DTH) were used to study the influence of antibody-mediated responses on the inductive and effector phases of cell-mediated immunity. The effector phase of DTH was not affected by immediate-type reactions, as abrogation of these reactions by mediators' antagonists on day 8 or induction of passive reactions by transfer of immune serum on day 4 did not change the extent or kinetics of either type of DTH. Only transfer, before immunization, of whole or T-cell-enriched spleen cells, but not sera, from hyperimmunized donors (high antibody producers) abolished the induction of pure DTH in 4-day immunized recipient mice and changed their cytokine profile to a T helper 2 type. These results indicate that in a non-polarized immune response to a protein antigen there is initially a bias towards cell-mediated immunity, which is gradually dampened by the development of antibody-mediated immunity.     

Comparison of cell-mediated and humoral immunity in the dog lung after localized lung immunization

This study evaluated cell-mediated immunity (CMI) and antibody production serially in control and immunized lung lobes of beagle dogs. A fiberoptic bronchoscope was used to immunize selected airways in the left cardiac lung lobe with 10(10) sheep red blood cells (SRBC); the right cardiac lobe received saline as control. The immune responses produced by this localized lung immunization were evaluated in cells and fluids obtained from blood and serial bronchial washings of the immunized and control lung lobes from 5 to 21 days after immunization. The antigen-specific production of procoagulant activity (LPCA) and inhibition of migration of alveolar macrophages by SRBC antigen were used to measure CMI in lavage cells from immunized and control lung lobes. The level of specific IgM and IgG antibody in lavage fluid from the control and immunized lung lobes was evaluated with the enzyme-linked immunosorbent assay (ELISA). The results of this study showed a significantly greater percentage of neutrophils and lymphocytes in the lavage fluid from the immunized lung lobes than from the control lung lobes. The increased number of lymphocytes in the immunized lung lobes showed a positive correlation with increased antibody concentrations. In contrast to the antibody response, CMI as measured by LPCA and MIF assays was positive, with nearly equal responses in control and immunized lung lobes. Even though there were only a few lymphocytes in the control lung lobes, there were apparently enough specific immune lymphocytes present that produced mediators after antigen stimulation to result in positive CMI responses.     

Antivirus antibody-dependent cell-mediated cytotoxicity during murine cytomegalovirus infection.

BALB/c mice infected with murine cytomegalovirus were studied to determine whether antibody-dependent cell-mediated cytotoxicity contributes to the immune control of this infection. Antibody-dependent killer cells from uninfected mice were used as effector cells to assay for antibody in sera of infected mice. Secondary immune sera were found to contain both cytomegalovirus-specific and autoreactive antibodies. After primary infection only cytomegalovirus-specific antibodies were found. These were detected by antibody-dependent cell-mediated cytotoxicity within 8 to 10 days after onset of infection, but usually not until day 21, by a neutralizing antibody assay. Antibody titers were about 10-fold higher by antibody-dependent cell-mediated cytotoxicity than by neutralization. The results indicate that cellular immunity to cytomegalovirus infection includes an antibody-dependent cell-mediated cytotoxicity response which is likely to be highly efficient and may contribute significantly to control of both acute and later stages of infection.     

Bronchial Reactivity in Relation to Immune Responses in Rats after Subcutaneous Sensitization without Adjuvant

Rats of BN×Wi/Fu strain were immunized by daily subcutaneous (S.C.) injections of antigen without the use of adjuvant for two 2-week periods with a 4-week interval. The bronchial responses to airway and intravenous (i.v.) antigen challenge were measured during and after the immunization period. These responses were compared with both the humoral and the cell-mediated immune response of the animals. Immunization induced bronchial reactivity of the animals to antigen after airway and i.v. challenge. This reactivity persisted for 7 weeks following the second immunization period. Specific IgE antibodies were detected in serum, bronchial fluid and in supernatants from cultured peripheral lymph node cells. The immunization also resulted in an IgG antibody response. Neither the amount of IgE. IgG2a, nor of any other isotype, correlated with the bronchial reactivity in the animals. Antigen simulation of lymph node cells mixed with syngeneic spleen cells induced proliferation. This procedure also resulted in a maturation of mast cells in 3-week cultures. The immunization also resulted in some increase in the number of mast cells around vessels in the lung. There was no correlation between these parameters of cell-mediated immunity and either antibody responses or bronchial reactivity.     

Respiratory Tract Cell-Mediated Immunity: Comparison of Primary and Secondary Response

A secondary local and splenic cell-mediated immune response was observed and compared to the primary response. Previous studies have demonstrated cell-mediated immunity (CMI) by lymphocytes from bronchopulmonary washings and have shown that its appearance is to a large extent inedpendent of splenic CMI. This study evaluated the secondary as compared to the primary response, with respect to both cellular and humoral immune responses. Guinea pigs were immunized with influenza virus vaccine either nasally or parenterally, booster immunizations were given by the same route, and animals were killed at various times after immunization or booster. The inhibition of macrophage migration was used to assess CMI. As in previous studies, local application of antigen led to mainly local appearance of CMI, whereas parenteral immunization led to mainly systemic CMI. Both pulmonary and splenic lymphocytes showed an inhibition of macrophage migration that appeared 2 to 3 days sooner after the booster, as compared to the primary immunization. There was no evidence, however, for the earlier production or increased amount of antibody in the bronchial secretions in the boosted animals. The results suggest that pulmonary as well as splenic T lymphocytes exhibit memory, but that pulmonary B lymphocytes do not.     

Humoral and cellular immune responses of seronegative children vaccinated with a cold-adapted influenza A/HK/123/77 (H1N1) recombinant virus.

Humoral and cell-mediated immune responses of young, seronegative children were assessed after intranasal vaccination with a cold-adapted influenza. A/HK/77 (H1N1) CR 35 recombinant virus. Vaccines shedding influenza virus experienced a rise in hemagglutinin-inhibition antibody 15 to 30 days after vaccination. Vaccinees showed low but significant lymphocyte transformation to A/USSR (H1N1) by day 8 after vaccination, which decreased to prevaccination levels at 30 to 34 days. The lymphocyte transformation response occurred before serum antibody rises were detected by hemagglutinin-inhibition assay. No change in lymphocyte responsiveness was observed after vaccination as measured by phytohemagglutinin stimulation. Lymphocytes responded to in vitro incubation with inactivated influenza (H1N1) virus by producing interferon. The interferon produced was of type I and was observed in vaccinees and nonvaccinees both before and after vaccination.     

A long-lasting interferon-gamma response is induced to a single inoculation of antigen-pulsed dendritic cells.

Vaccines against infectious organisms must produce not only long-lasting immunity but also the appropriate immune response to clear the infection. Obligate intracellular parasites, such as mycobacteria, require a predominantly cell-mediated immune response rather than antibody. Presentation of antigen by dendritic cells (DC) has been associated with the development of strong cell-mediated responses generating the production of interferon-gamma (IFN-gamma). This cytokine has an essential role in the elimination of mycobacteria. Therefore, we investigated both the duration and the nature of the immune response after priming with DC pulsed with mycobacterial antigen and compared this with priming using a conventional adjuvant. We used two strains of mice: C57BL/6, which inherently produces a T-helper 1 (Th1)-type response to mycobacterial antigen, and BALB/c, which does not. DC-enriched cell suspensions, purified DC or cultured bone marrow cells resembling DC (BMAPC) were prepared, pulsed overnight with PPD and injected intravenously (i.v.) into naive mice. Six and 12 weeks later, splenic T lymphocytes from these mice were challenged in vitro with antigen and their proliferative response and cytokine production was determined. Significant antigen-specific proliferation was observed in all assays on rechallenge with antigen in vitro 6 and 12 weeks after the initial priming with DC. IFN-gamma was detected in both strains but was only antigen specific in the C57BL/6 strain. Purified protein derivative (PPD)-pulsed BMAPC generated similar responses 6 weeks after priming. Thus, long-term T-lymphocyte responses and the production of IFN-gamma can be generated using a single inoculation of PPD-pulsed DC.     

Immune response to hepatitis B surface antigen.

A total of 69 persons were investigated for assessment of cell-mediated and humoral immunity to hepatitis B surface antigen (HBsAg). Three groups, each consisting of 20 normal persons, 20HBsAg carriers, and 20 convalescent hepatitis B patients, were studied for HBsAg, anti-HBs, and leukocyte migration inhibition with purified HBsAg. Sequential sampling if an additional group of nine acute hepatitis B patients defined the cellular and humoral immune response to HBsAg. The antigen was eliminated rapidly by mounting of cell-mediated immune response detectable for a limited period, followed by antibody response in relatively few patients moore than 3 months after clearance of circulating HBsAg.     

Mucosal and Systemic Immune Responses in Humans after Primary and Booster Immunizations with Orally Administered Invasive and Noninvasive Live Attenuated Bacteria

The mucosal and systemic immune responses after primary and booster immunizations with two attenuated live oral vaccine strains derived from a noninvasive (Vibrio cholerae) and an invasive (Salmonella typhi) enteric pathogen were comparatively evaluated. Vaccination with S. typhi Ty21a elicited antibody-secreting cell (ASC) responses specific for S. typhi O9, 12 lipopolysaccharide (LPS), as well as significant increases in levels of immunoglobulin G (IgG) and IgA antibodies to the same antigen in serum. A strong systemic CD4(+) T-helper type 1 cell-mediated immune (CMI) response was also induced. In contrast to results with Ty21a, no evidence of a CMI response was obtained after primary immunization with V. cholerae CVD 103-HgR in spite of the good immunogenicity of the vaccine. Volunteers who received a single dose of CVD 103-HgR primarily developed an IgM ASC response against whole vaccine cells and purified V. cholerae Inaba LPS, and seroconversion of serum vibriocidal antibodies occurred in four of five subjects. Serum IgG anti-cholera toxin antibody titers were of lower magnitude. For both live vaccines, the volunteers still presented significant local immunity 14 months after primary immunization, as revealed by the elevated baseline antibody titers at the time of the booster immunization and the lower ASC, serum IgG, and vibriocidal antibody responses after the booster immunization. These results suggest that local immunity may interfere with colonization of the gut by both vaccine strains at least up to 14 months after basis immunization. Interestingly, despite a low secondary ASC response, Ty21a was able to boost both humoral (anti-LPS systemic IgG and IgA) and CMI responses. Evidence of a CMI response was also observed for one of three volunteers given a cholera vaccine booster dose. The direct comparison of results with two attenuated live oral vaccine strains in human volunteers clearly showed that the capacity of the vaccine strain to colonize specific body compartments conditions the pattern of vaccine-induced immune responses.     

抗原致敏期缺损补体增强抗肿瘤免疫效应

目的 观察蛇毒因子(CVF)缺损补体对疫苗诱导的抗肿瘤免疫的影响.方法 用CVF分别在抗原的致敏期和免疫的效应期缺损补体,抗原OVA加完全弗氏佐剂(CFA)联合免疫C57BL/6小鼠,14 d后接种E.G7肿瘤细胞,评价补体缺损效果,观察肿瘤出现时间,记录小鼠肿瘤大小.结果 OVA CFA免疫的正常小鼠,在肿瘤接种14 d内能完全抑制肿瘤生长;抗原致敏期缺损补体,肿瘤接种21 d内能完全抑制肿瘤生长;免疫效应期缺损补体,肿瘤出现的时间与OVA CFA免疫的正常小鼠相似.结论 抗原致敏期补体缺损可能有利于抗肿瘤免疫.     

The safety and longevity of DNA vaccines for fish

A plasmid that contained the cytomegalovirus (CMV)-promoter-driven lacZ reporter gene (pCMV-lacZ) remained in the epaxial muscle of five of eight goldfish as covalently closed circles, the most functional form of plasmid, for at least 70 days at 22 degrees. It was not present in the gills or elsewhere by polymerase chain reaction and was not integrated. Its expressed protein, Escherichia coli beta-galactosidase (beta-gal), which was in the injected myofibres, was detected in all the fish at 4-21 days and in about half the fish from 28 days until the end of the experiment at 70 days. The numbers of cells that secreted antibody to beta-gal in the kidney peaked at 14 days. Serum antibody and proliferating kidney cells to beta-gal were in all fish from 14 days with a plateau of the responses from 21 days onwards. The plasmid did not induce autoimmune-like antibodies to itself or to single- or double-stranded salmon testis DNA. Plasmids can therefore induce long-term foreign protein expression whilst inducing humoral and cell-mediated immunity without autoimmunity or integration in goldfish.     

Immunity to foot-and-mouth disease virus in guinea pigs: clinical and immune responses.

Clinical and immune responses were determined for guinea pigs infected with different doses of foot-and-mouth disease virus (FMDV) type A12, strain 119, administered by different routes. Vesicles developed on the tongue or heel pad 1 day after these areas were intradermally inoculated with FMDV. However, vesicles did not develop on the feet and tongue until 3 to 4 days after the intradermal inoculation of FMDV in the flank skin or after intracardiac or subcutaneous inoculation. Infected guinea pigs developed neutralizing antibody, immediate skin reactivity of the Arthus type (4 h), and delayed skin reactivity. In addition to a delayed skin response, the presence of a cell-mediated immune response to FMDV was shown by the specific production of macrophage migration inhibition factor by peritoneal exudate cells in response to FMDV. Kinetic studies showed that neutralizing antibodies were detected at 3 days postinfection, and Arthus and delayed skin reactivity were detected at 4 days postinfection. Some guinea pigs developed either mild or subclinical infections. Regardless of the dose of infectious virus, the route of inoculation, the severity of disease, or the time of clinical onset of disease, infected guinea pigs developed similar immune responses.     

Induction of antibody formation to goat erythrocytes in the developing chick embryo and effects of maternal antibody

The formation of antibody to goat erythrocytes has been studied in embryos and young chicks. Opsonizing antibody was measured by accelerated clearance of antigen and the sensitivity of this technique compared with haemagglutination tests. A wide range of immunizing doses of goat erythrocytes was used; all induced immunity. Small amounts of antibody were detected as early as the day of hatching but vigorous antibody production did not occur until 3 days later. An immune response could be induced in 12-day-old embryos and the most vigorous response was obtained by injection of 14-day-old embryos. Antibody production was relatively poor between the fifteenth day of embryonic life and 15 days after hatching. This was due to the presence of maternal antibody.     

Expermental glomerulonephritis in the rat induced by antibodies directed against tubular antigens. III. In vitro evaluation of cell-mediated immune responses against immune complexes influenced by immunosuppressive therapy.

In this paper, cell-mediated immunity (CMI) as evaluated by in vitro migration inhibition assays an in vivo delayed type skin reactions in experimental immune complex glomerulonephritis (ECGN) was studied as well as the effect of treatment with immunosuppressive drugs on these immune responses. In glomerulonephritic rats MIF production as well as delayed type skin reactions could be demonstrated directed against tubular brushborder antigen (Fx1A) containing immune complexes or to their constituents (FX1A or rabbit IgG). Treatment of the animals with immunosuppressive drugs during settled disease state (autologous phase) abolished these cellular immune reactions. However, neither the glomerular depositions of rat IgG associated with the autologous phase, nor the urinary excretion was influenced. When treatment of the animals was started simultaneously with the induction of the ECGN both cellular and humoral immune responses as well as proteinuria were affected. It was concluded that although in this glomerulonephritis model specific MIF response after specific stimulation in vitro as well as DTH reactions could be detected against immune complexes or their constituents, these immune reactions seem not to play important role in this ECGN in particular with respect to the proteinuria.     

Systemic cell-mediated and antibody responses in infants with respiratory syncytial virus infections

In order to investigate the possible role of immunity in lower respiratory tract disease of infants produced by respiratory syncytial (RS) virus, 18 hospitalized infants were tested for cell-mediated immune (CMI) responses in a whole blood culture assay utilizing a gamma emitting tracer, 5(¹²⁵ I) Iodo-2′-deoxyuridine [¹²⁵ IUdR] to quantitate cellular proliferative responses to virus antigen. Class-specific antiviral antibody titres were determined in an indirect membrane immunofluorescence test. One infant showed a CMI response in the acute phase of illness whereas 72% responded one month later. Of the 18 infants, 14 were tested for antibody responses and 71% showed significant rises of antiviral IgG. IgM was detectable in only one acute phase specimen. A tendency for higher CMI responses following severe infection with RS virus was noted but little difference in antibody responses was respect to severity was seen. These findings are discussed in relationship to the pathogenesis of RS virus.