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Results for “Immunization, Passive”

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PubMed1976

Increase in basal and thyrotropin-releasing hormone (TRH)-stimulated secretion of thyrotropin (TSH) by passive immunization with antiserum to somatostatin in rats.

Passive immunization of rats with an antiserum to synthetic somatostatin caused a 250% elevation of basal serum TSH levels and a nearly 200% increase in TSH-response to TRH. These findings strongly support the concept that pituitary thyrotrophs are regulated by endogenous somatostatin as well as by TRH and thyroid hormones. Serum GH levels in the antiserum-treated rats were considerably higher than those in rats which received normal serum. No clearcut influence on prolactin secretion was observed.

Animals↗

PubMed1998

Active and passive immunization against HIV type 1 infection in chimpanzees.

Several vaccine strategies have been developed to prevent primary infection with human immunodeficiency virus (HIV), and some of the candidate vaccines have been tested in chimpanzees to determine their safety, efficacy, and to delineate immune correlates of protection. To date, more than 25 vaccines representing active and passive immunization strategies have been evaluated in the chimpanzee model. Efficacy of a given vaccine was based on protection against primary infection with HIV after intravenous or mucosal challenge with cell-free or cell-associated virus. Based on the results from a majority of the studies, neutralizing antibodies appear to play a major role in preventing primary infection with HIV.

Animals↗

PubMed1993

Passive immunization for prevention of rotavirus illness in healthy infants.

Infant formula supplemented with bovine antibody (BCIg) to human rotavirus has been reported to prevent or modify rotavirus infection and illness. The purpose of this field trial was to determine the safety and feasibility of passive immunization with bovine antibody for the prevention of rotavirus infection and illness in healthy infants. Sixty-four infants, 31 of whom received BCIg and 33 placebo, participated in the study. Rotavirus infection was detected in 11 (35%) and 14 (42%) infants in the 2 groups, respectively. Symptomatic rotavirus infection was documented in 1 (3%) of the infants receiving BCIg and in 6 (18%) of the infants who received the placebo (P > 0.05). The number of days with diarrhea/1000 days of observation was significantly less in the BCIg group, 4.2, than in the placebo group, 16.8 (P < 0.01). Similarly the number of days with rotavirus-associated diarrhea/1000 days was less in the BCIg group, 1.0, than in the placebo group, 13 (P < 0.01). This study establishes the feasibility of providing passive immunity for the prevention of rotavirus illness in healthy infants.

Antibodies, Viral↗

PubMed1987

Passive immunization of mice with monoclonal antibodies raised against tick-borne encephalitis virus. Brief report.

Adult Balb/c mice were passively immunized with monoclonal antibodies (100 micrograms/mouse) raised against tick-borne encephalitis (TBE) virus then challenged 24 hours later s.c. with 10 LD50 of TBE virus (Nëudorfl isolate). None of the mice showed evidence of premature death although all except one of the monoclonal antibodies tested are capable of enhancing the infectivity of TBE virus in the Fc receptor-bearing mouse macrophage-like cell line P 388 D 1. The ability of monoclonal antibodies to neutralize TBE virus in vitro, and to fix complement was examined, and of these properties only a single monoclonal antibody, which was able to neutralize virus, was also able to protect mice against virus challenge.

Animals↗

PubMed2005

Targeting amyloid-beta peptide (Abeta) oligomers by passive immunization with a conformation-selective monoclonal antibody improves learning and memory in Abeta precursor protein (APP) transgenic mice.

Passive immunization of murine models of Alzheimer disease amyloidosis reduces amyloid-beta peptide (Abeta) levels and improves cognitive function. To specifically address the role of Abeta oligomers in learning and memory, we generated a novel monoclonal antibody, NAB61, that preferentially recognizes a conformational epitope present in dimeric, small oligomeric, and higher order Abeta structures but not full-length amyloid-beta precursor protein or C-terminal amyloid-beta precursor protein fragments. NAB61 also recognized a subset of brain Abeta deposits, preferentially mature senile plaques, and amyloid angiopathy. Using NAB61 as immunotherapy, we showed that aged Tg2576 transgenic mice treated with NAB61 displayed significant improvements in spatial learning and memory relative to control mice. These data implicated Abeta oligomers as a pathologic substrate for cognitive decline in Alzheimer disease.

Alzheimer Disease↗

PubMed1999

Passive immunization of piglets against enterotoxigenic colibacillosis by vaccinating dams with K88ac pili bearing bacterins.

Day-old-piglets were passively immunized by vaccinating the pregnant sows with K88ac enterotoxigenic Escherichia coli (ETEC) vaccine. High level of ETEC specific antibodies was excreted in colostrum (3733.33 +/- 1152.13) and maintained a detectable level (100.00 +/- 0.00) up to 21 day post partum (DPP). The IgG was the predominant immunoglobulin followed by IgA and IgM. Piglets born of vaccinated dam (group A) and unvaccinated dam (group B) were challenged in 7 day of age. Clinical and faecal scores were significantly (P < 0.01) low in group A than that of group B. Piglets of group A developed mild diarrhoea (33.33%), while all the control piglets developed profuse diarrhoea and 3 of these died before 14 day of challenge infection.

Animals↗

PubMed1985

Passive immune protection by herpes simplex virus-specific monoclonal antibodies and monoclonal antibody-resistant mutants altered in pathogenicity.

Virus-neutralizing monoclonal antibodies specific for 13 different genetically defined epitopes of glycoproteins gC, gB, and gD of herpes simplex virus type 1, strain KOS-321, were compared for their ability to provide passive immunity to DBA-2 mice challenged intracranially. Protection was highly specific, since individual monoclonal antibodies failed to protect against infection with monoclonal antibody-resistant (mar) mutants altered in the single epitope recognized by the injected antibody. The dose-response kinetics of passive immunity paralleled the in vitro neutralization titers for each antibody. No correlation was observed between immune protection and antibody isotype or complement-dependent in vitro neutralization titers. This suggests that virus neutralization was not the protective mechanism. In general, antibodies reactive with epitopes of gC were protective at the lowest antibody doses, antibodies specific for gB were less efficient in providing immunity, and antibodies against gD were the least effective. mar mutants with single epitope changes in gC and multiple epitope changes in gB showed highly reduced pathogenicity, requiring up to 5 X 10(6) PFU to kill 50% of infected animals. These findings indicated that antigenic variation affects virus growth and spread in the central nervous system. Thus, mutations which affect antigenic structure also can alter virus pathogenicity. The alteration of these epitopes does not, however, appreciably reduce the development of resistance to infection. Infection of mice with these mutants or inoculation of mice with UV-inactivated, mutant-infected cells before challenge rendered the animals resistant to infection with wild-type herpes simplex virus type 1.

Animals↗

PubMed1987

Passive immunization with antibodies against iron-regulated outer membrane proteins protects turkeys from Escherichia coli septicemia.

Escherichia coli septicemia is a common disease of young poultry and several species of mammals. Rabbit antiserum was prepared against iron-regulated outer membrane proteins of E. coli. Eighteen-day-old turkeys were passively immunized with antiserum and challenged by air sac inoculation of 1 X 10(6) to 2 X 10(6) CFU of E. coli O78:K80:H9. Turkeys injected with normal rabbit serum or saline solution before challenge served as controls. Fatalities (8 of 51 turkeys inoculated) occurred only in groups given saline solution or normal rabbit serum. The remaining turkeys were necropsied 96 h after challenge. Passive immunization with antiserum significantly (P less than 0.05) reduced the frequency of bacteremia at 96 h after challenge, the frequency of recovery of E. coli from air sacs, and the severity of gross lesions in inoculated birds as compared with birds given normal rabbit serum or saline solution.

Animals↗

PubMed2000

Characterization and formulation of multiple epitope-specific neutralizing monoclonal antibodies for passive immunization against cryptosporidiosis.

The coccidian parasite Cryptosporidium parvum causes diarrhea in humans, calves, and other mammals. Neither immunization nor parasite-specific pharmaceuticals that are consistently effective against this organism are available. While polyclonal antibodies against whole C. parvum reduce infection, their efficacy and predictability are suboptimal. We hypothesized that passive immunization against cryptosporidiosis could be improved by using neutralizing monoclonal antibodies (MAbs) targeting functionally defined antigens on the infective stages. We previously reported that the apical complex and surface-exposed zoite antigens CSL, GP25-200, and P23 are critical in the infection process and are therefore rational targets. In the present study, a panel of 126 MAbs generated against affinity-purified CSL, GP25-200, and P23 was characterized to identify the most efficacious neutralizing MAb formulation targeting each antigen. To identify neutralizing MAbs, sporozoite infectivity following exposure to individual MAbs was assessed by enzyme-linked immunosorbent assay. Of 126 MAbs evaluated, 47 had neutralizing activity. These were then evaluated individually in oocyst-challenged neonatal mice, and 14 MAbs having highly significant efficacy were identified for further testing in formulations. Epitope specificity assays were performed to determine if candidate MAbs recognized the same or different epitopes. Formulations of two or three neutralizing MAbs, each recognizing distinct epitopes, were then evaluated. A formulation of MAbs 3E2 (anti-CSL [alphaCSL]), 3H2 (alphaGP25-200), and 1E10 (alphaP23) provided highly significant additive efficacy over that of either individual MAbs or combinations of two MAbs and reduced intestinal infection by 86 to 93%. These findings indicate that polyvalent neutralizing MAb formulations targeting epitopes on defined antigens may provide optimal passive immunization against cryptosporidiosis.

Animals↗

PubMed1989

Passive immunization of pregnant mice against early pregnancy factor causes loss of embryonic viability.

Early pregnancy factor (EPF) is a monitor of the incidence of fertilization and the progress of the early embryo. To determine whether, as well as being a marker of embryonic viability, EPF is also necessary for embryonic survival, passive immunization studies with monoclonal and polyclonal antibodies to EPF were carried out on pregnant mice. In the preparation of monoclonal antibodies, it was noted that most anti-EPF producing hybridomas failed to grow in vitro, while those that did grow produced only low yields of specific IgM antibodies. Two stable hybridoma cell lines were established both producing low affinity anti-EPF IgM; polyclonal anti-EPF IgG was prepared in rabbits. Mice were passively immunized with 500 micrograms monoclonal anti-EPF IgM at 32 and 56 h post coitum (total dose 1 mg) or with 500 micrograms polyclonal anti-EPF IgG at 8, 16, 32 and 40 h post coitum (total dose 2 mg). At 10 days, only 6/18 and 3/6 mice receiving monoclonal antibodies and 2/7 and 1/6 mice receiving polyclonal antibodies had maintained their pregnancies. In contrast, all mice receiving control IgM (N = 14) or control IgG (N = 4) and 22/23 receiving saline were still pregnant at Day 10.

Animals↗

PubMed1980

Value of passive immune hemolysis for detection of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli.

The method of passive immune hemolysis of Evans and Evans (Infect. Immun. 16:604-609, 1977) for detection of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli was modified. A total of 373 strains of E. coli were tested by this method using materials obtained by treating the cells with polymyxin B and rabbit antiserum against cholera enterotoxin, purified by affinity gel column coupled with purified cholera enterotoxin, in N-hydroxyethylpiperazine-N'-2-ethanesulfonic acid buffer (pH 6.7). The results correlated very well with those obtained in an assay with Chinese hamster ovary cells. It is concluded that passive immune hemolysis is useful as a routine clinical method for identifying E. coli strains that produce heat-labile enterotoxin.

Animals↗

PubMed1987

Passive immunization of pregnant goats against ovine LH.

Groups of three goats at 50, 90 and 130 days of gestation were passively immunized against ovine LH (oLH) by i.v. infusion of 8 ml serum equivalent of the immunoglobulin fraction of rabbit anti-oLH serum (LHAS). Goats at the same stages of gestation as above served as controls and received 8 ml serum equivalent of the immunoglobulin fraction of normal rabbit serum (NRS). Plasma concentrations of progesterone were determined by specific radioimmunoassay of blood collected at 20-min intervals from 6 h before infusion of LHAS or NRS to 12 h after infusion. Less frequent sampling was performed from 2 days before to 6 days after infusion. Plasma from all LHAS-immunized goats exhibited binding of oLH. Twelve hours after immunization, titres ranged from 1:135 to 1:215. All LHAS-treated goats had titres of less than 1:10 by 5 days after immunization, but a low level of oLH binding was still detectable. Treatment with LHAS or NRS did not shorten the length of gestation, with all goats delivering live offspring between 142 and 147 days after conception. Plasma concentrations of LH ranged from less than 0.15 micrograms/l to 4.8 micrograms/l and were greater than 0.15 micrograms/l in 181 of 255 samples (71%) for both the NRS-treated group, throughout the experiment, and the LHAS-treated groups before infusion of antiserum. Luteinizing hormone was not detectable in plasma samples obtained after LHAS infusion in goats at 50 or 130 days of pregnancy. Plasma concentrations of LH exceeded 0.15 micrograms/l in only five of 51 (10%) samples in 90-day-pregnant goats treated with LHAS, the maximum value reached being 0.80 micrograms/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1981

[Study on passive immunization for biological action of oxytocin (author's transl)].

The physiological roles of oxytocin in pregnant rats were studied by passive immunization. Oxytocin antibody (A/S OT) was produced to synthetic OT in rabbits by immunizing with OT conjugated to bovine serum albumin by glutaraldehyde method. Then the sera in the rabbits were tested for the potency of antibody to OT by double antibody radioimmunoassay. On the nineteenth day of pregnancy, each of ten rats was daily injected subcutaneously with 1 ml of A/S OT up to parturition. The mean gestation period in the treated rats was 23.1 +/- 0.31 days and in the control rats (normal rabbit serum: NRS treated), 23.2 +/- 0.13 days. The amount, 1 ml of antiserum, was inferred to be capable to sufficiently neutralize the endogenous oxytocin in pregnant rats. This antiserum was proved to inhibit the biological action of OT by Magnus equipment. These data suggest that, the hypothesis that OT may play a primary role of initiation of labor, is necessary to be reevaluated.

Animals↗

PubMed1992

A mechanism of passive immunization with monoclonal antibodies to a 185,000 M(r) streptococcal antigen.

The cell surface streptococcal antigen (SA) I/II of 185,000 M(r) is an immunodominant molecule that expresses one or more adhesion determinants. A series of 14 monoclonal antibodies (MAb) to defined parts of SA I/II were generated and some of these were used in passive immunization of macaques. Topical administration of selected MAb to the teeth of macaques prevented colonization of endogenous or implanted exogenous Streptococcus mutans for a period of 1 year. Significant reduction of both smooth surface and fissure caries was found in macaques who had MAb (Guy's 1) applied to their teeth, as compared with saline-treated animals. A series of in vivo passive immunization experiments was then carried out in 57 human subjects. Topical application of MAb to SA I/II prevented colonization of both artificially implanted exogenous strains of S. mutans, as well as natural recolonization by indigenous S. mutans. The properties of the protective MAb were then investigated and the epitope specificity within the SA I/II molecule was found to be essential but not the isotype specificity of the immunoglobulin (Ig). The requirement for complement activating and the phagocyte binding sites of the Fc fragment of MAb was not essential, as the F(ab')2 fragment of the MAb was as protective as the intact IgG, but the Fab fragment failed to prevent recolonization of S. mutans. Prevention of recolonization was specifically restricted to S. mutans, as the proportion of other organisms, such as S. sanguis, failed to show a significant change. The surprising feature of these experiments was that protection of re-colonization of S. mutans lasted up to 2 years, although MAb was applied for only 3 weeks and functional MAb was detected on the teeth only 3 days following application of the MAb. The long-term protection could therefore not be accounted for by a persistence of MAb on the teeth, but may be due to a shift in the microbial balance in which other bacteria occupy the ecological niche vacated by S. mutans, resulting in colonization resistance to S. mutans. Gene cloning and sequencing the SA from S. mutans, S. sobrinus and S. sanguis identified a conserved region (residues 955-1213) which on Southern hybridization and partial DNA sequence analysis was also found in 19 alpha-haemolytic oral streptococci. The results suggest that the SA molecule may constitute a family of adhesins in oral alpha haemolytic streptococci.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed2000

Passive immunization with antisperm monoclonal antibody ZAP-7 increases preimplantation embryo mortality in the mouse.

OBJECTIVE: To evaluate the effect of VIC-1 and ZAP-7 antihuman sperm monoclonal antibodies on in vivo fertility in the mouse. DESIGN: A randomized blinded study using a mouse model. SETTING: University-based laboratory. ANIMALS: B6CBAF1 mice (n = 6 per experimental group). INTERVENTION(S): Antisperm antibodies were administered intravaginally to female mice before mating. Control mice received no treatment, saline, or nonspecific antibodies. Number and viability of preimplantation embryos were determined by microscopic observation. Mouse sperm, oocytes, and normal preimplantation embryos were used in indirect immunofluorescence assays with antisperm antibodies. The effect of antibody treatment on sperm motility and vitality was evaluated. MAIN OUTCOME MEASURE(S): Antigen expression, sperm motility and vitality, number and viability of embryos. RESULT(S): ZAP-7 antibody recognizes a sperm antigen expressed in zygotes and early preimplantation embryos. Passive immunization with ZAP-7 increases embryo mortality significantly (more than 40% above controls). Passive immunization with VIC-1 has no deleterious effect. CONCLUSION(S): ZAP-7 monoclonal antibody disrupts fertilization and embryogenesis in the mouse.

Animals↗

PubMed1988

Monoclonal antibodies specific for rat relaxin. II. Passive immunization with monoclonal antibodies throughout the second half of pregnancy disrupts birth in intact rats.

The purpose of this investigation was to use an approach targeted specifically on endogenous relaxin to determine the influence of relaxin on birth in the rat. To that end, a monoclonal antibody specific for rat relaxin, designated MCA1, was used to passively neutralize endogenous relaxin in intact pregnant rats. MCA1 was administered iv to intact rats daily from days 12-22 of pregnancy. Animals were observed for birth continuously from 2100 h on day 22 until 1200 h on day 24. MCA1-treated rats exhibited significantly prolonged durations of straining and litter delivery as well as reduced incidence of live pups compared with controls. Whereas approximately 20-25% of fetuses and placentae were retained in utero at 1200 h on day 24 in MCA1-treated rats, neither fetuses nor placentae were retained in control rats. Passive immunization with MCA1 throughout the second half of pregnancy had no apparent influence on normal ovarian function. The time of occurrence of the antepartum decline in serum progesterone levels (functional luteolysis) as well as the time interval between the attainment of basal progesterone levels and the onset of litter delivery in MCA1-treated and control rats that delivered on day 23 were in close agreement with previous reports. In conclusion, the prolonged durations of straining and litter delivery, reduced incidence of live pups, and increased incidence of retained fetuses and placentae after passive immunization with MCA1 establish the physiological need for endogenous relaxin to attain normal delivery of the young in the rat.

Animals↗

PubMed2006

Passive immunization of guinea pigs with llama single-domain antibody fragments against foot-and-mouth disease.

Foot-and-mouth disease (FMD) is a highly contagious disease that occasionally causes outbreaks in Europe. There is a need for therapies that provide rapid protection against FMD in outbreak situations. We aim to provide such rapid protection by passive immunization with llama single-domain antibody fragments (VHHs). Twenty-four VHHs binding serotype O FMDV in vitro were isolated from immunized llamas by phage display and expressed in bakers yeast for further characterization. They recognized four functionally independent antigenic sites. Six strongly FMDV neutralizing VHHs bound to a peptide representing the GH-loop of viral protein 1 known to be involved in binding to the cellular receptor of FMDV. Clone M8, recognizing this antigenic site, and clone M23, recognizing another antigenic site, showed synergistic in vitro virus neutralization. Three FMDV specific VHHs were PEGylated in order to decrease their rapid blood clearance and thus enable in vivo guinea pig protection experiments. Passive immunization with individual VHHs showed no protection, but a mixture of M8 and M23 showed partial transient protection. The protection afforded by these VHHs was however low as compared to the complete protection afforded by convalescent guinea pig serum. In contrast, these VHHs showed far more efficient in vitro FMDV neutralization than convalescent guinea pig serum. This lack of correlation between in vitro neutralization and in vivo protection lends further credence to the notion that opsonophagocytosis of FMDV is important for protection in vivo.

Amino Acid Sequence↗

PubMed1998

Passive immunization of newborn rhesus macaques prevents oral simian immunodeficiency virus infection.

To determine if passively acquired antiviral antibodies modulate virus transmission and disease progression in human pediatric AIDS, the potential of pre- and postexposure passive immunization with hyperimmune serum to prevent oral simian immunodeficiency virus (SIV) infection or disease progression in newborn rhesus macaques was tested. Untreated neonates became infected after oral SIV inoculation and had high viremia, and most animals developed fatal AIDS within 3 months. In contrast, SIV hyperimmune serum given subcutaneously prior to oral SIV inoculation protected 6 newborns against infection. When this SIV hyperimmune serum was given to 3 newborns 3 weeks after oral SIV inoculation, viremia was not reduced, and all 3 infants died within 3 months of age due to AIDS and immune-complex disease. These results suggest that passively acquired antihuman immunodeficiency virus (HIV) IgG may decrease perinatal HIV transmission. However, anti-HIV IgG may not impart therapeutic benefit to infants with established HIV infection.

Acquired Immunodeficiency Syndrome↗