Comparison Of Antibody Titers Research Articles

Induction of protective immunity to monoclonal-antibody-defined Plasmodium falciparum antigens requires strong adjuvant in Aotus monkeys.

Monoclonal antibodies to the major Plasmodium falciparum merozoite surface coat and rhoptry antigens were produced. A combination of the affinity-purified polypeptides with Freund complete adjuvant which was given three times completely protected an Aotus lemurinus azure (karotype VI) monkey against homologous challenge; however, immunization with the same polypeptides with a muramyl dipeptide derivative [MDP-Lys(L18)] did not protect a second Aotus monkey, even though comparable high antibody titers were induced.

Influenza Vaccines in Children

We compared a new cetrimonium bromide (CTAB) subunit vaccine with a conventional polysorbate (Tween)-ether split-product vaccine in 63 children and young adults. The vaccines each contained influenza A/Bangkok/79, A/Brazil/78, B/Singapore/79; two doses were given one month apart. Among persons initially seronegative for A/Bangkok/79, the geometric mean antibody titer rose to more than 100 following one dose of vaccine, while those initially seropositive had titers of greater than 200 after one dose of either vaccine. Neither vaccine was able to induce comparable antibody titers to A/Brazil/78 or B/Singapore/79 after one dose in initially seronegative persons. After two doses the titers were greater than 100 for A/Brazil but not for B/Singapore. An A/Bangkok epidemic struck the New York City metropolitan area. The attack rate in the unvaccinated matched sibling control group was 35% (15/43). Only two of the 27 recipients of cetrimonium bromide vaccine and none of the 36 polysorbate-ether vaccines had a fourfold or greater increase in antibody titer during the epidemic.

Detection and characterization of circulating immune complexes by ultracentrifugation. Technical aspects

Most techniques for detection of immune complexes (IC) in biological fluids do not fulfil criteria essential for IC definition, i.e. identification of the antigen and antibody after dissociation and demonstration of their immunological binding. We have fractionated plasmas by sucrose density gradient ultracentrifugation at pH 7.4 and 2.8 and studied the effects of acid pH on isolated and plasma immunoglobulins, on antibody titers, on IC formed in vitro and on aggregated immunoglobulins. There was no effect on the distribution of isolated radiolabeled IgG, IgA or IgM or on IgG and IgA of fresh serum samples. Heavy IgG appeared at pH 2.8 in samples stored at −20°C in excess of 1 month and also at pH 7.4 when stored in excess of 6 months. Heavy IgA was present in samples frozen for 1 week or more at both pHs. Anti-BSA and anti-DNA antibody titers and distribution were identical at both pHs. BSA : anti-BSA and DNA : anti-DNA IC formed in vitro were almost completely dissociated with recovery of antigen and antibody. IC obtained by fractionation at pH 7.4 could be refractionated at pH 2.8 with recovery of antibody and antigen. The distribution of aggregated IgG and IgA was unchanged at acid pH. This technique allows differentiation of complexed and aggregated Ig, identification of specific IC by comparing antibody titers at physiologic and acid pH, isolation of IC and the recovery of antigen and antibody from IC formed in vitro.

DETECTION OF ACUTE SERUM ANTIBODIES TO A/NEW JERSEY/76 INFLUENZA VIRUS AFTER REMOVAL OF IgG WITH COWAN I STAPHYLOCOCCUS AUREUS

Cowan I strain of Staphylococcus aureus contains a cell wall substance, protein A, which can absorb most of the IgG from human serum; IgM, IgA, and IgD remain practically unaffected. In the present study, acute sera from children who received killed A/New Jersey/76 influenza virus vaccine were absorbed with S. aureus (Cowan I). An aliquot of the serum was also absorbed with S. aureus (Wood), a strain which does not contain protein A. A third aliquot was left unabsorbed. Hemagglutination-inhibiting (HAI) antibodies to A/New Jersey/76 antigen were determined on the three serum aliquots in tandem. The unabsorbed sera and sera which were absorbed with S. aureus (Wood) had comparable HAI antibody titers. The sera of 11 of 14 children had an eight-fold or less decline in HAI antibody titer after absorption with S. aureus (Cowan I); the sera of two other children decreased sixteen-fold. Only one child's serum had no detectable HAI antibodies after the absorption procedure with S. aureus (Cowan I). In contrast, the latter absorption completely removed HAI antibodies from the sera of a control group who had long-standing antibodies to A/New Jersey/76 (or an antigenically similar virus). The acute sera of the vaccinees which still contained HAI antibodies after S. aureus (Cowan I) absorption suggests the presence of specific IgM and/or IgA antibodies. This relatively simple absorption procedure performed on a single serum may be useful for the detection of an acute influenzal infection.

Measles virus antibodies in multiple sclerosis. Comparison of antibody titers in cerebrospinal fluid and serum.

Serum and cerebrospinal fluid (CSF) samples were collected from groups of 30 patients with multiple sclerosis (MS), no known somatic disease, or other neurological disorders and moderately increased total CSF protein content. Anti-body titers against different measles virus components were measured. As a reference, levels of adenovirus and poliovirus antibodies were also determined. Significantly reduced ratios of measles virus hemagglutination-inhibiting (HI) or nucleocapsid complement-fixing (CF) antibodies or both in serum: CSF were found in 12 of the 30 MS patients. Additional analysis of hemolyzing-inhibiting antibodies in samples from 19 patients demonstrated substantially reduced ratios in five more cases of MS. None of the 60 control patients displayed a significantly reduced ratio. Measles antibodies may be produced in the central nervous system by activated latent virus infections in some patients with MS.

Immunogenicity of toxic and detoxified endotoxin preparations.

SummarySeveral-times repeated injections of heat-killed cells, toxic endotoxins, or CH3OK detoxified derivative thereof (endo-toxid-2) result in a comparable antibody titer after 8-10 injections. The antibody titer produced by toxic preparations shows a rapid initial increase, while endotoxoid-2 produces a lower titer of circulating antibodies in the first 10 days. While toxic preparations produce both 2-Me resistant and sensitive antibodies from the beginning of the immunization, endotoxoid-2 produces almost exclusively 2-Me sensitive antibodies in the first 10 days. Simultaneous with the appearance of 2-Me resistant antibodies, the level of total antibodies rises rapidly. A single injection of toxic endotoxin produces a rapid antibody production which starts to decline after approximately 2 weeks. Booster injections bring this antibody level back to previous highs, but hardly any additional effect can be observed. A single injection of endotoxoid-2 gives a very slow output of antibodies, which seems to ...

A STUDY OF THE ANTIGENS INVOLVED IN ADENOVIRUS 12 TUMORIGENESIS BY IMMUNODIFFUSION TECHNIQUES.

The use of the agar gel diffusion technique has established the presence of three distinct antigenic reactions in the sera of Ad. 12 tumor-bearing hamsters. Only one of these antigens is directly demonstrable in the tumor. This "tumor" antigen is also formed during early stages of the infectious cycle in tissue culture cells. Other antigens present in the tumor, but only demonstrable indirectly with the use of antibody-containing serum of tumored hamsters, are the classical type-specific C antigen, and a new antigen, termed D. Of ninety-eight Ad. 12 tumored hamster sera, six reacted in gel diffusion with virus and tumor preparations, and thirty-one with tumor only. Sera which reacted in gel diffusion with viral antigen uniformly bad neutralizing antibody and high titers of CF antibody against viral and tumor antigens; however, many sera with comparable antibody titers did not react with the virus in gel diffusion. Sera which reacted in gel diffusion only with tumor antigen also had high CF antibody titers, but there was no correlation with neutralizing antibody.

Antigenic variants of influenza A virus, PR8 strain. I. Their development during serial passage in the lungs of partially immune mice.

Antigenically different strains of mouse-adapted PR8 influenza A virus have been produced by 17 serial passages of the virus in the lungs of mice immunized with the homologous agent. Comparative serological tests show that the variant strains share antigenic components with the parent strain but the dominant antigen is different. By means of antibody absorption it was shown that the "new" antigenic component of the variant was already present in minor amounts up to the eighth passage and thereafter gained prominence with continued passage in vaccinated mice. Groups of mice vaccinated with either the PR8-S or T(21) virus and having comparable antibody titers showed no growth of virus in the lungs following aid-borne challenge with homologous strains. On the other hand, following heterologous air-borne challenge no deaths occurred, but virus grew in the lungs of both groups of vaccinated mice. Almost unrestricted virus multiplication took place in the lungs of mice vaccinated with the parent strain and challenged with the PR8-T(21) virus which resulted in extensive consolidation. Less virus grew in the lungs of the mice vaccinated with the variant strains and challenged with the PR8-S virus. In these animals only microscopic evidence of changes due to virus growth in the lungs was observed. The successful serial passage of PR8 influenza A virus in immunized animals was dependent on the initial selection of mice with uniformly low H.I. antibody titers as determined on tail blood, and the intranasal instillation of sufficient virus to favor the survival of those virus particles least related to the antibodies present. The epidemiological implications of these observations are discussed briefly.