Preventive properties of the blood sera from persons vaccinated with a Proteus vaccine made from soluble antigen complexes

In experiments of the passive protection of mice the protective properties of sera obtained from humans before and after their immunization with Proteus vaccine used as a monopreparation or in combination with staphylococcal toxoid and/or pyoimmunogen were studied. When introduced in a single subcutaneous injection, Proteus vaccine prepared from soluble antigenic complexes ensured an increase in the protective properties of sera. The second injection of the vaccine essentially enhanced the protective potency of the sera of the immunized donors. The therapeutic injection of Proteus vaccine ensured the essential increase of the protective properties of the sera. This increase could be experimentally detected within at least 25-30 days from the beginning of immunization. The immunization of volunteers with Proteus vaccine in combination with pyoimmunogen and adsorbed staphylococcal toxoid ensured the maximum increase of the protective properties of their sera.     

The mutagenicity of a new multicomponent vaccine made from the antigens of Klebsiella pneumoniae, Staphylococcus aureus, Proteus vulgaris and Escherichia coli

Inactivated bacterial vaccine, containing K. pneumoniae, S. aureus, P. vulgaris and E. coli antigenic complexes were tested for mutagenicity in the test described by Ames et al. and in vivo, in experiments on mice. In Salmonella typhimurium cells, strain TA-98 and TA-100, the preparation (5-75 mg/ml) did not increase the frequency of reversions and histidine-independence either in direct experiments or after metabolic activation with rat liver homogenate. In experiments on mice the vaccine (3.3 mg/kg and 33 mg/kg) did not induce chromosomal anomalies in spermatogonia. In all experiments the mutagens used for positive control produced a mutagenic effect.     

The specific activity of a multicomponent vaccine made from the antigens of opportunistic microorganisms

Multicomponent vaccine prepared from the antigens of 4 representatives of opportunistic microflora possesses high specific activity. The passive hemagglutination (PHA) test with the use of associated diagnosticum showed that antibody titers in the sera of immunized rabbits increased 10- to 10(4)-fold in comparison with the titers observed prior to immunization. The PHA test with the use of the antigens contained in the vaccine revealed the accumulation of antibodies to each of the 4 components of the preparation in the blood sera of immunized rabbits. When stored at 4 degrees C, the vaccine was shown to retain its specific activity for 5 years (the term of observation).     

Postvaccinal reactions to the administration of a dried staphylococcal vaccine made from water-soluble antigens

An unequivocal regularity in local and systemic reactions to multiple (in 5 injections) administration of lyophilized staphylococcal vaccine prepared from water-soluble antigens has been established in patients and in healthy adults: the number and intensity of reaction decreased after each subsequent injection. A similar tendency has been observed in the vaccinees who were examined for their IgE levels. These data are indicative of the desensitizing action of the vaccine.     

Immunogenicity of soluble extracts from a UV light-induced mouse sarcoma

Summary Soluble tumor extracts were isolated from a UV light-induced mouse sarcoma by 3 M KCl extraction followed by 2 M (NH₄)₂SO₄ precipitation. The precipitates dissolved in phosphate buffered saline (PBS) produced transplantation resistance against syngeneic cell inocula of the tumor at a restricted dose range. While 1.0–1.2 mg of protein per mouse were effective, double this dose was not. An extract prepared from ascitic fluid of tumor-bearing mice showed effects similar to one prepared from tumor cells.     

Mucosal vaccine delivery of antigens tightly bound to an adjuvant particle made from food-grade bacteria

Mucosal immunization with subunit vaccines requires new types of antigen delivery vehicles and adjuvants for optimal immune responses. We have developed a non-living and non-genetically modified gram-positive bacterial delivery particle (GEM) that has built-in adjuvant activity and a high loading capacity for externally added heterologous antigens that are fused to a high affinity binding domain. This binding domain, the protein anchor (PA), is derived from the Lactococcus lactis AcmA cell-wall hydrolase, and contains three repeats of a LysM-type cell-wall binding motif. Antigens are produced as antigen-PA fusions by recombinant expression systems that secrete the hybrid proteins into the culture growth medium. GEM particles are then used as affinity beads to isolate the antigen-PA fusions from the complex growth media in a one step procedure after removal of the recombinant producer cells. This procedure is also highly suitable for making multivalent vaccines. The resulting vaccines are stable at room temperature, lack recombinant DNA, and mimic pathogens by their bacterial size, surface display of antigens and adjuvant activity of the bacterial components in the GEM particles. The GEM-based vaccines do not require additional adjuvant for eliciting high levels of specific antibodies in mucosal and systemic compartments.     

Immunogenicity of a chromatographically concentrated influenza vaccine

The immunogenicity of the Czechoslovak-made commercial vaccine Adinvira as well as that of the chromatographically concentrated vaccine Leningrad of Soviet origin was evaluated in an immunization project. The both vaccines were well tolerated after administration, the Soviet-made Leningrad brand featuring greater efficiency in eliciting an antibody response against influenza virus haemagglutinin.     

Identification of protective pneumococcal t(h)17 antigens from the soluble fraction of a killed whole cell vaccine

Mucosal or parenteral immunization with a killed unencapsulated pneumococcal whole cell antigen (WCA) with an adjuvant protects mice from colonization by a T(H)17 CD4+ cell-mediated mechanism. Using preparative SDS gels, we separated the soluble proteins that compose the WCA in order to identify fractions that were immunogenic and protective. We screened these fractions for their ability to stimulate IL-17A secretion from splenocytes obtained from mice immunized with WCA and adjuvant. We identified 12 proteins within the stimulatory fractions by mass spectrometry; these proteins were then cloned, recombinantly expressed and purified using an Escherichia coli expression system. The ability of these proteins to induce IL-17A secretion was then evaluated by stimulation of mouse splenocytes. Of the four most stimulatory proteins, three were protective in a mouse pneumococcal serotype 6B colonization model. This work thus describes a method for identifying immunogenic proteins from the soluble fraction of pneumococcus and shows that several of the proteins identified protect mice from colonization when used as mucosal vaccines. We propose that, by providing protection against pneumococcal colonization, one or more of these proteins may serve as components of a multivalent pneumococcal vaccine.     

Immunogenicity of a chemical typhus vaccine and of a corpuscular radioantigen obtained from Rickettsia prowazekii

The protective activity of chemical typhus vaccine and R. prowazekii corpuscular radioantigen (CRA) was studied. Guinea pigs were immunized with doses of 32 and 48 antigenic units. Antibody production was assayed in the complement fixation test. On days 7, 15, 21, 30 and 60 after immunization the animals were challenged with R. prowazekii introduced in an amount of 10(5) minimum embryonal infective doses (MEID). On day 30 some of the animals were challenged with 10(3) MEID of R. typhi. The results demonstrated that both preparations were highly immunogenic and capable of protecting most of the animals from 10(5) MEID of R. prowazekii. Immunity developed earlier after immunization with CRA. The guinea pigs immunized with CRA, purified in percoll density gradient, and challenged with 10(3) MEID of R. typhi on day 30 showed a high level of cross immunity. In all control animals high fever and periorchitis were observed.     

Immunogenicity is unrelated to protective immunity when induced by soluble and particulate antigens from Nocardia brasiliensis in BALB/c mice

Cell-mediated immunity plays a major role in protection against intracellular microbes. Nocardia brasiliensis is a facultative intracellular pathogen that causes chronic actinomycetoma. In this work, we injected BALB/c mice with soluble P24 and particulate antigens from N. brasiliensis. A higher antibody titer and lymphocyte proliferation was induced by the particulate antigen than by the soluble antigen. However, five months after antigen injection, antibody concentration and lymphocyte proliferation were similar. An increase in CD45R and CD4 T cells was unrelated to protective immunity. Active immunization with soluble or particulate antigens induced complete protection during the primary immune response. This protective response was IgM mediated. The higher immunogenicity was not related to protective immunity since the particulate antigen induced protection similar to the soluble antigen. Using particulate antigens for vaccination guarantees a stronger immune response, local and systemic side effects, but not necessarily protection.     

Molecular weight analysis of soluble antigens from Toxoplasma gondii

Ultrasonicated Toxoplasma gondii (RH strain) tachyzoites were fractionated into a water-soluble and a deoxycholate-soluble fraction. Polyclonal immune mouse serum was prepared by challenging chronically-infected mice with viable RH strain tachyzoites. The parasite fractions were labelled with 125I, and the radio-labelled antigens were precipitated by the immune mouse serum or a monoclonal anti-Toxoplasma antibody (FMC 20), that reacts only in the indirect hemagglutination antibody test. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of the immunoprecipitates showed that the water-soluble fraction contained 10 antigenic polypeptides, and the deoxycholate-soluble fraction contained seven antigenic peptides. The FMC 20 reacted against a 98,000-dalton antigen that was present in the water-soluble fraction only.     

Preparation and description of high-molecular-weight soluble surface antigens from a group A Streptococcus

High-molecular-weight proteins having M protein reactivity were isolated without acid or alkaline digestion. Treatment of a heat-killed group A Streptococcus with sonic vibration released antigens which reacted strongly and specifically with absorbed type-specific antiserum. This antigen preparation was released without diminishing the total yield of acid-extractable M protein of the original heat-killed cells. Fractionation of the sonic preparation on a sucrose gradient yielded four peaks of M reactivity. When these fractions were placed on Sephadex G-200 columns, the M reactive material of three fractions appeared in the void volumes, suggesting that the active material in each had a molecular weight greater than 300,000. The reactivity of the fourth fraction followed closely the void volume of Sephadex G-100. Chemical analysis revealed heterogeneity of the fractions. Spectral analysis showed virtual absence of nucleic acid in three of the fractions and a moderate amount in the fourth. Bactericidal inhibition tests showed activity of three of the four fractions. Analysis of the fractions by Ouchterlony double-diffusion technique revealed that each of the four fractions had several antigenic constituents. All four contained M antigen. T antigen and a third unnamed antigen were present in some of the fractions. Group reactivity was present in all fractions, but did not reside on the M molecule. The enhanced potential of sonically released antigens to induce high-titer specific precipitating antibodies to M protein is discussed.     

Surface antigens of Proteus mirabilis revealed by electroblotting from sodium dodecyl sulphate-polyacrylamide gels

Western Blotting of whole cell preparations of three strains of Proteus mirabilis after separation by electrophoresis on SDS-polyacrylamide gels revealed a complex pattern of antigens. Similar antigen profiles were obtained with isolated outer membranes indicating that the majority of cell surface antigens are located in the outer membrane. Major outer membrane proteins were strongly antigenic and cross-reactive. The highly immunogenic flagella were detected in whole cell preparations and visible in isolated outer membranes. Whereas the protein and flagellar antigens were cross-reactive, lipopolysaccharide (LPS) could only be detected as immunoreactive material using homologous antisera for each strain. The LPS appeared as two broad bands (high and low Mr, respectively) in immunoblots of whole cells, isolated outer membranes and purified LPS. However, isolated LPS could be resolved into multiple sharp bands when 4 M urea was included in the gel system. These discrete bands are assumed to represent differing O antigen chain lengths of the LPS as reported for other Gram-negative organisms.     

Immunogenicity of surface and capsular antigens of Burkholderia

Study showed that five (C3, C6, C9, C10, C11) out of ten chromatographic fractions of surface and capsular antigens of B. mallei significantly stimulated cell-mediated immunity that manifested in activation of delayed hypersensivity reactions (DHS) and phagocyteability of noncapsulated avirulent strain of B. mallei with added surface and capsular antigenic complexes. Other fractions did not stimulate cell-mediated immunity, furthermore, fraction C8, which contained capsular biopolymer with mass of 200 kD (Ar8), was characterized by immunosuppressive effect on DHS and phagocytosis. Observed stimulation of cell-mediated immunity by fractions referred above has been confirmed by assessment of their protective effects on the model of experimental melioidosis in white rats. Relationship between markers of humoral and cell-mediated immunity, including markers of specific response, was not observed.