[Correction of cytostatic-induced immunosupression with staphylococcal vaccine in mice]

Studies aimed on evaluation of possibility for correction of cyclophosphan-induced immunosuppression in BALB/c mice by using acellular staphylococcal vaccine "Staphylovac" (SV). Cyclophosphan (CP) administered to mice four times with 24 hours intervals decreased levels of T-, B-, T-regulatory (T-reg CD4/CD25/Foxp3) lymphocytes, increased quantity of cells expressing early activation marker CD25 (assessment after 4 hours). Administration of SV along side with cytostatic does not influenced significantly on characteristics of CP-induced immunosuppression at the moment of its assessment. Twenty four hours after administration of CP or SV with CP level of cells expressing CD3 and MHC I continued to decrease as compared with control. Compared with administration of CP only or with control group, SV administered along side with CP increased expression of MHC II on 38- and 1.8-fold respectively. Levels of CD4, CD25, CD8, and CD19 cells in these groups were already closer to control values that points to the beginning of restoration of some disturbances in mechanisms of immunoregulation. Five days after administration of CP or CP+SV levels of CD3, MHC I, and CD8 lymphocytes significantly increased, although were lower than in the control group in 3.3- and 2.3-fold (CD3), 12- and 4-fold (MHC I), and in 2.8- and 1.8-fold (CD8) respectively. Levels of NK, NKT were higher as compared to control. CP continued to decrease levels of CD4 and CD19 cells and simultaneously increased level of T-regulatory cells, which play key role in suppression of immune response. Administration of SV during CP course corrected levels of cells expressing these markers. It was established that under the influence of SV, cytotoxic potential of NK cells and proliferative activity of lymphocytes were restored.

[Experimental, clinical and immunologic assessment of acellular staphylococcal vaccine "Staphylovac"]

Results of experimental, clinical and immunological effects of acellular dry staphylococcal vaccine "Staphylovac" developed in Mechnikov Research Institute of Vaccines and Sera are presented. Original mildly virulent strains of Staphylococcus aureus having high immunogenicity, and intra- and interspecies protective activity against different representatives of opportunistic microflora were used for construction of the preparation. Low-toxicity and weak anapylactogenicity of the vaccine were established. In experiments on mice, guinea pigs and rabbits significant protective, antigenic and immunomodulate activity of the preparation was revealed with low sensitization of animals. Clinical trials performed in different centers showed that inclusion of vaccinotherapy in complex treatment of chronic staphylococcal infections (chronic pyodermia, lung abscess etc.) resulted in prolonged pathologic locus, decrease of number and severity of exacerbations, prolongation of remission, and complete recovery in significant number of patients. Activation of innate and adaptive immunity was revealed in the same patients. It was shown on the large group of athletes that administration of the vaccine by aerosol route prevents disruption of immunologic adaptation occurring due to excess physical activity and stress situations during competitions.

Experimental trial in heifers vaccinated with Staphylococcus aureus avirulent mutant against bovine mastitis

Staphylococcus aureus, is the most frequently isolated pathogen from cases of bovine mastitis. Vaccination against S. aureus seems to be a rational approach for the control of staphylococcal mastitis. In the present work we evaluate the response of heifers vaccinated with a S. aureus avirulent mutant to the intramammary challenge with a S. aureus virulent strain. Clinical signs, production of milk, shedding of S. aureus cells, somatic cell count (SCC) and antigen-specific IgG in blood and milk, were determined. Two subcutaneous doses of a culture of the mutant, used as vaccine, was administered to four pregnant heifers 30 and 10 days before calving. The vaccinated heifers and four non-vaccinated were challenged 10 days after calving with the homologous virulent S. aureus strain, which was inoculated by intramammary route into two quarters of each animal. No local tissue damage was observed due to the administration of the vaccine. A significantly increase of specific IgG to S. aureus RC122 was detected in blood and milk of vaccinate heifers as well as a slight increase in daily milk yield during the trial. No significant difference on shedding of bacteria in milk and SCC were found among groups. In conclusion, vaccination of heifers before calving by an avirulent mutant vaccine of S. aureus, induced specific and significant antibody responses and provide better post-challenge conditions in vaccinated heifers.

Antistaphylococcal vaccines and immunoglobulins: current status and future prospects

Staphylococci are among the most frequently encountered pathogens in both the inpatient and the outpatient setting. Management of infections caused by these organisms is complicated by the increasingly common resistance of staphylococcal pathogens to commonly used antibacterials. As a consequence, novel approaches to prevention and treatment are urgently required. Such approaches include the development of vaccines and immunoglobulin preparations targeted at virulence factors expressed in vivo by staphylococci. This article reviews the biopharmaceutical progress made to date in this field and suggests approaches to further progress.

Intranasal vaccination with a double mutant of staphylococcal enterotoxin C provides protection against Staphylococcus aureus infection

Staphylococcus aureus expresses a repertoire of factors including staphylococcal exotoxins (SEs), exoenzymes, and numerous cell-associated components that contribute to the pathogenesis of disease. We constructed and expressed a nontoxic double mutant SEC (dmSEC), devoid of superantigenic activity, and investigated the ability of intranasal vaccination with dmSEC plus cholera toxin (CT) adjuvant to protect mice against S. aureus infection. Mice were vaccinated with dmSEC and inoculated with a viable S. aureus clinical isolate strain. The survival rate in the immunized mice was higher, and bacterial counts in the organs were significantly lower than those in the control group. Intranasal vaccination with dmSEC induced the production of SEC-specific antibodies such as IgG1, IgG2b and IgA. dmSEC-vaccinated mice elicited significantly higher titers of interleukin-4 (IL-4) and IL-10, and lower levels of interferon-gamma (IFN-gamma) after challenge with S. aureus compared with the control group. Furthermore, the sera from dmSEC-immunized mice significantly inhibited IFN-gamma and tumor necrosis factor-alpha production in vitro. These results indicate that intranasal vaccination with dmSEC devoid of superantigenic properties induces systemic immune responses and provides protection against S. aureus infection.

Evaluation of the humoral immune response in BALB/c mice immunized with a naked DNA vaccine anti-methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is the major pathogen involved in nosocomial infections, leading to high rates of morbidity and mortality in hospitals worldwide. The methicillin resistance occurs due to the presence of an additional penicillin-binding protein, PBP2a, which has low affinity for beta-lactam antibiotics. In the past few years, vancomycin has been the only antibiotic option for treatment of infections caused by multiresistant MRSA; however, reports of vancomycin-resistant strains have generated great concerns regarding the treatment to overcome these infections. In the present study, we report preliminary results regarding the humoral immune response generated in BALB/c mice by two different doses of naked DNA vaccine containing an internal region, comprising the serine-protease domain, of the PBP2a of MRSA. The immunization procedure consisted of four immunizations given intramuscularly within 15-day intervals. Blood was collect weekly and anti-PBP2a-specific antibodies were screened by ELISA. BALB/c mice immunized with DNA vaccine anti-PBP2a have shown higher antibody titers mainly after the fourth immunization, and intriguingly, no correlation between the humoral immune response and DNA dose was observed. Our results suggest that the DNA vaccine anti-PBP2a induced an immune response by production of specific antibodies anti-MRSA in a non-dose-dependent manner, and it could represent a new and valuable approach to produce specific antibodies for passive immunization to overcome MRSA infections.

Immunization with Staphylococcus aureus clumping factor B, a major determinant in nasal carriage, reduces nasal colonization in a murine model

Staphylococcus aureus is responsible for a wide range of infections, including soft tissue infections and potentially fatal bacteremias. The primary niche for S. aureus in humans is the nares, and nasal carriage is a documented risk factor for staphylococcal infection. Previous studies with rodent models of nasal colonization have implicated capsule and teichoic acid as staphylococcal surface factors that promote colonization. In this study, a mouse model of nasal colonization was utilized to demonstrate that S. aureus mutants that lack clumping factor A, collagen binding protein, fibronectin binding proteins A and B, polysaccharide intercellular adhesin, or the accessory gene regulator colonized as well as wild-type strains colonized. In contrast, mutants deficient in sortase A or clumping factor B (ClfB) showed reduced nasal colonization. Mice immunized intranasally with killed S. aureus cells showed reduced nasal colonization compared with control animals. Likewise, mice that were immunized systemically or intranasally with a recombinant vaccine composed of domain A of ClfB exhibited lower levels of colonization than control animals exhibited. A ClfB monoclonal antibody (MAb) inhibited S. aureus binding to mouse cytokeratin 10. Passive immunization of mice with this MAb resulted in reduced nasal colonization compared with the colonization observed after immunization with an isotype-matched control antibody. The mouse immunization studies demonstrate that ClfB is an attractive component for inclusion in a vaccine to reduce S. aureus nasal colonization in humans, which in turn may diminish the risk of staphylococcal infection. As targets for vaccine development and antimicrobial intervention are assessed, rodent nasal colonization models may be invaluable.

A novel Staphylococcus aureus vaccine: iron surface determinant B induces rapid antibody responses in rhesus macaques and specific increased survival in a murine S. aureus sepsis model

Staphylococcus aureus is a major cause of nosocomial infections worldwide, and the rate of resistance to clinically relevant antibiotics, such as methicillin, is increasing; furthermore, there has been an increase in the number of methicillin-resistant S. aureus community-acquired infections. Effective treatment and prevention strategies are urgently needed. We investigated the potential of the S. aureus surface protein iron surface determinant B (IsdB) as a prophylactic vaccine against S. aureus infection. IsdB is an iron-sequestering protein that is conserved in diverse S. aureus clinical isolates, both methicillin resistant and methicillin sensitive, and it is expressed on the surface of all isolates tested. The vaccine was highly immunogenic in mice when it was formulated with amorphous aluminum hydroxyphosphate sulfate adjuvant, and the resulting antibody responses were associated with reproducible and significant protection in animal models of infection. The specificity of the protective immune responses in mice was demonstrated by using an S. aureus strain deficient for IsdB and HarA, a protein with a high level of identity to IsdB. We also demonstrated that IsdB is highly immunogenic in rhesus macaques, inducing a more-than-fivefold increase in antibody titers after a single immunization. Based on the data presented here, IsdB has excellent prospects for use as a vaccine against S. aureus disease in humans.

DNA immunization of dairy cows with the clumping factor A of Staphylococcus aureus

Blocking the primary stages of Staphylococcus aureus infection, specifically the bacterial adhesion to cell and the colonization of the mucosal surface, may be the most effective strategy for preventing infections. Clumping factor A (ClfA) is considered to be one of the most important adhesions factors of S. aureus to host cells. The present study describes the immune response of dairy cattle to a DNA vaccine against ClfA and evaluates the ability of specific genetic adjuvants, targeting sequences (granulocyte macrophage colony-stimulating factor and cytotoxic T lymphocyte antigen-4) and transporter molecules (chitosan and copolymer) to modify the immune response of cows. The results show that vaccination of cows with fibrinogen-binding region A induced a strong and specific antibody response to ClfA in comparison with a control group injected with the pCI vector alone. Although the co-expression of both genetic adjuvants and the addition copolymer transporter did not augment the overall antibody response, these approaches decreased the number of non-responsive cows. Chitosan was the only factor that did not enhance the immune response. Three months after the last DNA immunization, three cows from each of the pGM-CSF, internal ribosomal entry site (IRES), pCTLA and pCI groups were injected with 200 microg of recombinant ClfA protein in incomplete Freund's adjuvant. A strong humoral response was observed in all groups following this protein boost, with the response occurring slightly earlier in DNA-primed protein boost cows. Sera and milk samples taken from cows after the second DNA injection or after the protein boost (sera only) were analyzed for their ability to block adherence and increase phagocytosis. Pre-incubation of S. aureus with sera or milk from vaccinated cows significantly reduced the pathogen's ability to adhere to MAC-T cells relative to the sera and milk samples from the pCI-injected control cows. Similarly, pools of sera and milk from vaccinated cows increased phagocytosis of S. aureus by neutrophils. After the protein boost, sera were more efficient promoters of phagocytosis, reflecting the higher anti-ClfA antibody level of these sera. DNA-prime/protein boost regimes combined with molecular adjuvants appeared to be effective in generating a strong immune response to S. aureus antigens in cattle.

Immune responses to a DNA/protein vaccination strategy against Staphylococcus aureus induced mastitis in dairy cows

The fibronectin binding protein (FnBP) and clumping factor A (ClfA) of Staphylococcus aureus are important proteins involved in the pathogenesis of staphylococcal bovine mastitis. These antigens were the targets of a DNA and protein vaccination strategy against S. aureus induced mastitis in dairy cows. The DNA vaccine comprised the bicistronic plasmid (pCI-D(1)D(3)-IRES-ClfA) that encoded the fusion of two sequences, (D1(21-34); D3(20-33)) from the fibronectin-binding motifs of FnBP and a fragment from ClfA (aa 221-550) of S. aureus 8325-4 separated by an Internal Ribosomal Entry Site (IRES) sequence. In addition, the vaccine contained the plasmid encoding the bovine granulocyte-macrophage-colony stimulatory factor gene (pCI-bGM-CSF). Four, 7-month pregnant heifers were immunized twice with the DNA vaccine and boosted once with recombinant D(1)D(3) and ClfA proteins while four others were not immunized. The immunization induced lymphoproliferative responses and functional antibodies against D(1)D(3) and ClfA antigens. Three weeks after calving, three mammary quarters of each vaccinated and non-vaccinated cow were challenged with 900 CFU/each of S. aureus Newbould 305. The fourth quarter received saline only. Serum haptoglobin levels, cardiac rhythm and the body temperature of vaccinated cows during the 24-72 h post-challenge were lower than in non-vaccinated animals. At 21 days post-challenge, bacteria were present in 5 of the vaccinated and 11 of the control challenged quarters. The bacteria averaged 1.4 and 3.3 log(10) CFU/ml of milk from vaccinated and control cows respectively. In summary, DNA-protein vaccination against FnBP and ClfA of S. aureus caused both lymphoproliferative and humoral immune responses that provided partial protection of mammary gland from staphylococcal mastitis and better post-challenge conditions in vaccinated cows.

Microbiological and immunological study of staphylococcus vaccine effects in periodontitis

The aim of this study was to evaluate the immunomodulatory effect of the staphylococcal vaccine inoculated subcutaneously in 15 patients with chronic periodontitis. Bacteriological investigation of samples collected from the periodontal pocket for aerobic and anaerobic microorganisms was performed by classic bacteriological procedures before and after vaccination. The following immune system parameters were evaluated: C reactive protein (CRP), serum level of C3 complement fraction, IgG, IgA, and IgM by immunodiffusion, PMN granulocytes ROS release after in vitro stimulation with opsonized zymosan (OZ) and Concanavalin A (ConA) by chemiluminescence assay and lymphocytes sets and subsets by flow-cytometry immunophenotyping. The microbiological investigations revealed high frequency of Staphylococcus spp isolation and the presence of the most common anaerobe agents incriminated in human periodontitis like Fusobacterium, Porphyromonas, Peptostreptococcus, Veillonella spp and the reduction of this flora in the periodontal pocket after therapy. The immunological parameters quantification showed the absence of CRP, normal values of C3, IgG, IgA, IgM in the majority of cases. All patients presented normal values of lymphocytes sets and subsets. Significant increase of PMN respiratory burst after ConA stimulation was observed before vaccination which turned to normal values after therapy and a low ROS level both before and after therapy suggesting PMN Fc receptors dysfunction in this group of patients. The data presented in our study suggest an immunomodulatory effect of staphylococcal vaccine therapy in periodontitis and high frequency of Staphylococcus spp recovering from the periodontal pocket of investigated subjects.

Staphylococcus aureus vaccine conjugate--Nabi: Nabi-StaphVAX, StaphVAX

Staphylococcus aureus is a major cause of hospital-acquired infections and infections in kidney dialysis patients. Over 90% of these infections are due to types 5 and 8. Nabi, under a CRADA agreement with the US National Institutes of Health, is developing a bivalent vaccine against S. aureus types 5 and 8 [Nabi-StaphVAX, StaphVAX]. The vaccine contains type 5 and type 8 S. aureus capsular polysaccharides conjugated to a protein carrier (recombinant exoprotein A, a genetically detoxified form of Pseudomonas aeruginosa exotoxin A). Nabi changed its name to Nabi Biopharmaceuticals on 5 March 2002. StaphVAX is available for licensing (http://www.nabi.com). Nabi's preference is for a licensee that can provide non-US marketing and regulatory capabilities in addition to financial resources to accelerate the vaccine's development. Nabi intends to develop a second-generation version of StaphVAX that will include antigen from Staphylococcus type 336. This would increase the vaccine's coverage of staphylococcal infection. Nabi also intends to develop two combination vaccines. The first, StaphVAX+ will contain both StaphVAX and EpiVAX trade mark in a single vial and the second, CombiVAX, will contain components of StaphVAX, EpiVAX trade mark and EnteroVAX trade mark. The vaccine has completed phase II clinical trials in chronic, ambulatory, peritoneal dialysis patients. Nabi-StaphVAX completed a multicentre, phase III trial in the US involving 1800 end-stage renal disease patients on haemodialysis. In September 2000, Nabi announced preliminary results from the phase III trial; these indicated that although Nabi-StaphVAX elicited a significant decrease in S. aureus bacteraemias in the first 10 months after vaccination, statistical significance was not reached in the primary endpoint of the study, a decrease after 1-year follow up. As a result, the US FDA indicated that US registration would require a second phase III trial in which the primary endpoint is reached. Following discussions with the US FDA, Nabi stated that the initiation of a second phase III trial in collaboration with a corporate partner was likely. Nabi intends to request either an accelerated- or fast-track review by the FDA, on the basis that the vaccine prevents a fatal disease for which no other prophylactics are available. In the meantime, Nabi initiated a boosting study of Nabi-StaphVAX in July 2001. This trial is administering a second dose of Nabi-StaphVAX to 100 patients enrolled in the phase III trial. Nabi plans to begin the confirmatory phase III study of the vaccine, as requested by the US FDA, in 3000 end-stage kidney patients in Q4 2003. The primary endpoint will be a statistically significant reduction of S. aureus bacteraemia caused by type 5 and 8 S. aureus through 8 months post-vaccination, the peak efficacy point in the first phase III trial. This trial will include a booster vaccination at 8 months and vaccinees will be followed up for up to 6 months after the booster to evaluate the vaccine's ability to generate antibodies, efficacy and safety. Results from this study will be used to support eventual product registration, now planned for 2005. In July 2003, Nabi reported that proceeds totalling 32.9 million US dollars from the private placement of its common stock to selected investors will enable the planned confirmatory phase III trial to proceed. In June 2003, Nabi Biopharmaceuticals announced the start of a clinical trial (a bridging study) to evaluate the safety and immunogenicity of a newly manufactured lot of StaphVAX produced by the contract manufacturer, Dow Biopharmaceutical Contract Manufacturing, intended for use in a planned confirmatory phase III trial later in 2003. The study demonstrated that the new batch of vaccine generated antibody levels that were equivalent to the levels generated by the vaccine produced at Nabi's R&D pilot plant and used in previous phase III studies.

MSCRAMM--targeted vaccines and immunotherapy for staphylococcal infection

Hospital-acquired infections are associated with prolonged hospitalization and an increase in both healthcare costs and resources. Advances in sophisticated medical procedures, an increase in the number of immunocompromised patients, and the continued emergence of resistance to conventional antibiotic therapy has created a need for alternative strategies to prevent and treat infectious bacterial diseases. Immunoprevention and immunotherapy targeting microbial surface components recognizing adhesive matrix molecule (MSCRAMM) proteins are viable approaches to potentially impede bacterial adherence, eliminate colonization, and minimize hematogenous dissemination, thereby halting the inception and progression of infection. This review summarizes several investigative efforts where staphylococcal MSCRAMM proteins are being utilized in the design of subunit vaccines and in the development of innovative therapeutic strategies that could be implemented following the onset of infection to manage severe and life-threatening disease.

Assessment of the Opsonic Activity of Purified Bovine sIgA Following Intramammary Immunization of Cows with Staphylococcus aureus

The phagocytosis of Staphylococcus aureus by bovine polymorphonuclear neutrophils (PMN) requires the presence of antibodies. Among the major isotypes of bovine antibodies, IgG2 and IgM are considered opsonic for bovine PMN. However, the role of purified bovine secretory IgA (sIgA) as an opsonin has not been assessed. In the present study, IgG2 were obtained from serum and sIgA, IgG1, and IgM were purified from the colostrums of three cows intramammarily immunized with heat-killed Staphylococcus aureus. The Ig preparations were assayed for specific antibodies, and the opsonic capacity of every isotype was investigated. Despite the presence of antibodies, we observed no distinct chemiluminescence response of PMN stimulated with sIgA- or IgG1-opsonized S. aureus, whereas IgM or IgG2 bound to bacteria induced a marked chemiluminescence response. Moreover, the counting of internalized bacteria per PMN after phagocytosis revealed a low uptake of S. aureus opsonized with sIgA or IgG1, in contrast to IgM or IgG2, which triggered efficient ingestion of bacteria. Priming of neutrophils by TNF-alpha, IFN-gamma, or C5adesArg did not promote an oxidative burst or uptake of sIgA-opsonized S. aureus to a greater extent than with IgG1-opsonized bacteria. Furthermore, analysis of uningested bacteria by flow cytometry after incubation with PMN showed a preferential uptake of IgM-opsonized S. aureus by PMN and only few sIgA-positive stained bacteria were PMN-associated. These experiments indicate that sIgA, like IgG1 and unlike IgM or IgG2, could not be considered as a major opsonin for phagocytosis of S. aureus by bovine blood PMN.

Correlation of body temperature with protection against staphylococcal enterotoxin B exposure and use in determining vaccine dose-schedule

The immunoprotective potential of a recombinant vaccine against the incapacitating effect of aerosolized staphylococcal enterotoxin B (SEB) in nonhuman primates is reported. SEB belongs to a family of structurally related superantigens responsible for serious, life threatening pathologies. Injecting the recombinant SEB vaccine did not induce temperature elevation in rhesus monkeys, a classical symptom of toxic-shock syndrome. No temperature elevation was noted following injection with control tetanus toxoid. In addition to 100% survival, we observed a clear correlation between vaccine dose and mitigation of temperature elevation after a lethal SEB aerosol challenge. We conclude that the recombinant SEB vaccine is non-pyrogenic and that monitoring changes in body temperature is an important biomarker of toxic shock in a primate animal model.

Development of a Staphylococcus aureus vaccine against mastitis in dairy cows. I. Challenge trials

A vaccine composed of three field isolates of Staphylococcus aureus (S. aureus) derived from cases of mastitis in cows was developed. The vaccine was administered to nine uninfected cows while 10 other cows were used as controls. All cows were challenged with a highly virulent S. aureus strain administered into two quarters of each cow. Quarters were tested for clinical signs, secretion of S. aureus, and somatic cell count (SCC). No systemic effects were observed in any of the cows, vaccinated or control. Vaccinated cows had 70% protection from infection compared with fewer than 10% in the controls. Moreover, all quarters challenged in the vaccinated cows, regardless of whether they were successfully infected or not with S. aureus, exhibited very mild inflammatory reactions, identified by their low SCCs (<100,000).

Optimization of DNA-based vaccination in cows using green fluorescent protein and protein A as a prelude to immunization against staphylococcal mastitis

Staphylococcus aureus is a contagious pathogen that often results in chronic intramammary infections in dairy cows. Current vaccine formulations are ineffective in preventing this infection. The objective of this study was to stimulate an immune response in dairy cows through injection of plasmid DNA designed to express staphylococcal Protein A in transfected cells. Intramuscular and intradermal vaccination sites were evaluated using a plasmid containing the human cytomegalovirus (CMV) promoter/enhancer directing expression of green fluorescent protein (pcDNA3/GFP). DNA was delivered by needle and syringe, or by high-, intermediate-, or low-pressure jet injections (Ped-o-Jet and LectraJet). Five cows per treatment were injected with 0.5 mg of plasmid DNA at 6, 4, and 2 wk prepartum. Serum antibody levels determined by ELISA indicated that intradermal high-pressure jet injection elicited a greater immune response compared to needle and syringe injection. Differences in antibody production among low-pressure and needle and syringe treatment groups were not significant. An expression plasmid containing the CMV promoter/enhancer driving expression of the Fc-binding domain of S. aureus Protein A was coinjected into cows by vulvamucosal vaccination using the high-pressure Ped-o-Jet. Beginning 6 wk prepartum, groups of cows (n = 5) were injected three times at 2-wk intervals with DNA in saline, DNA in aluminum phosphate adjuvant, or served as noninjected controls. A cellular immune response to Protein A was detected in 4 of 10 animals, while cellular responses to GFP were not detected. Humoral responses to Protein A were observed in 6 of 10 animals and to GFP in 2 of 10 animals. Aluminum phosphate adjuvant appeared to enhance antibody production in response to Protein A. In experiment 3, a protein boost injection of Protein A was given to six animals approximately 5 mo postpartum. Three animals were nonvaccinated controls, and three were among those stimulated to produce antibody in response to the DNA-based vaccine. These results showed that Protein A specific antibodies remained elevated as compared to nonvaccinated controls and were stimulated in response to the protein boost. However, the magnitude of the response in animals previously vaccinated with DNA was not different than that observed in the nonvaccinated controls. We have shown that a humoral and cellular immune response to abbreviated Protein A can be raised in dairy cows using intravulvamucosal jet injection of a DNA-based vaccine.

Effect of vaccination therapy for acne, using a staphylococci antigenic complex in combination with clindamycin

A group of 46 patients with acne vulgaris were prescribed clindamycin in combination with a vaccination therapy using a staphylococci antigenic complex (Polystafana; Sevapharma, Czechia). Acne papulopustulosa was diagnosed in 36 patients and acne indurata in 10 patients. The clinical effect of clindamycin and Polystafana was determined on the basis of the regression of the inflammatory manifestation of acne: regression by 0-30% was considered unsuccessful, by 30-80% satisfactory, and above 80% excellent; the immunomodulation effect of the treatment was evaluated in parallel. The clinical effect was excellent in 21 patients with acne papulopustulosa and in 6 with acne indurata; it was accompanied by pronounced immunomodulation effect as both cellular and humoral immunity was also tended to return to normal values. A satisfactory clinical effect was observed in 15 patients with acne papulopustulosa, whose cellular immunity component was also stimulated. Only 4 patients with acne indurata failed to respond successfully. These were the patients who showed a pronounced deficit of the cellular immunity component persisting even after the treatment. The administration of clindamycin in combination with Polystafana vaccination can be recommended as an effective means for the treatment of acne vulgaris.

Epitope mapping of neutralizing TSST-1 specific antibodies induced by immunization with toxin or toxoids

Toxic shock syndrome toxin-1 (TSST-1), a superantigen produced by Staphylococcus aureus, is a potent stimulator of the immune system. T-cells are activated by crosslinking of MHC class II molecules on antigen presenting cells with T-cell receptors (TCR). TSST-1 is associated with the majority of the cases of menstrual staphylococcal toxic shock, a severe and life-threatening multisystem disorder. Even though antibody mediated protection has been studied, information on antibody specificity directed to individual antigenic determinants of the protein is incomplete. To obtain immunogens with low toxicity, we generated a double-site mutant (dmTSST-1), modified at solvent-exposed residues predicted to be important for both MHC class II and TCR binding, and detoxified recombinantly expressed TSST-1 (rTSST-1) as well as native TSST-1 (nTSST-1) isolated from Staphylococcus aureus by treatment with formaldehyde. Rabbits were immunized with rTSST-1, nTSST-1, dmTSST-1, and formaldehyde inactivated toxoids. The sera obtained were used to map the antigen-reactive regions of the molecule and to identify specificities of antibodies induced by immunization with the different antigens. To detect linear antigenic epitopes of TSST-1 the reactivity of the sera with 11-meric peptides having an overhang of four residues, covering the entire molecule of TSST-1, have been studied. We found that sera of TSST-1 immunized rabbits predominantly reacted with N-terminal residues 1-15, while sera generated with formaldehyde inactivated toxoid recognized a total of 7 regions located at the N- and C-terminus and internal sites of TSST-1. Despite different specificities all sera were able to inhibit TSST-1 induced proliferation of human mononuclear cells.

[Homeostasis indexes of staphylococcal anatoxin immunized blood donors, previously immunized with tetanus toxoid]

On the 50 volunteers from 20 to 40 years old gomeostasis indexes of inoculating by staphylococci cleaning adsorbing anatoxini donors, before have been revactinated against tetanus, were studied. It was established, that attract of plasmaferes donors to consistent immunization by tetani and staphylococci anatoxini don't call negative alterations in their gomeostasis indexes. Results of study demonstrate, that it's possibly to attract for immunization by staphylococci anatoxini donors, before have been revactinated against tetanus.

Development of a time-resolved immunofluorometric assay for quantitation of mucosal and systemic antibody responses

We developed a solid phase immunoassay that measured mucosal and systemic antibody responses from mice inoculated with either a staphylococcal enterotoxin B vaccine (SEBv) or noninfectious virus-like particles (VLP) of lentiviral origin. The assay used time-resolved fluorescence (TRF) with affinity-purified goat anti-mouse IgA and IgG conjugated to samarium and europium chelates, respectively. By employing these fluorogenic conjugates with different spectral emissions, IgA and IgG specific for SEB or VLP were readily detected in serum and saliva from mice inoculated intranasally. The TRF assay detected antigen-specific IgA in saliva 10 min after the addition of enhancement solution, while a conventional alkaline phosphatase-based assay for salivary IgA required 18 h after substrate addition. The TRF assay also provided a significantly higher signal-to-noise ratio and exhibited greater sensitivity. TRF assays detected both IgA and IgG in the same well, thereby reducing sample and reagent requirements.

Extracellular-matrix-binding proteins as targets for the prevention of Staphylococcus aureus infections

Staphylococcal infections cause a number of serious diseases, ranging from acute septicaemia to chronic problems such as osteomyelitis and septic arthritis. Resistance to antibiotics is a growing problem and has re-ignited interest in vaccines and in passive immunization with antibodies. Natural infections and vaccines based on whole bacteria lead to poor antibody responses, but recent research using animal models of several staphylococcal diseases reveals that vaccines based on recombinant staphylococcal extracellular-matrix-binding proteins are much more protective. Passive immunization with antibodies against one of these proteins (collagen-binding protein) also shows promise in a mouse model of sepsis.