Formulation and immunogenicity studies of type III secretion system needle antigens as vaccine candidates

Bacterial infections caused by Shigella flexneri, Salmonella typhimurium, and Burkholderia pseudomallei are currently difficult to prevent due to the lack of a licensed vaccine. Here we present formulation and immunogenicity studies for the three type III secretion system (TTSS) needle proteins MxiH(Δ5), PrgI(Δ5), and BsaL(Δ5) (each truncated by five residues at its C terminus) as potential candidates for vaccine development. These antigens are found to be thermally stabilized by the presence of carbohydrates and polyols. Additionally, all adsorb readily to aluminum hydroxide apparently through a combination of hydrogen bonds and/or Van der Waals forces. The interaction of these proteins with the aluminum-based adjuvant changes with time resulting in varying degrees of irreversible binding. Peptide maps of desorbed protein, however, suggest that chemical changes are not responsible for this irreversible association. The ability of MxiH(Δ5) and PrgI(Δ5) to elicit strong humoral immune responses was tested in a murine model. When administered intramuscularly as monomers, the needle components exhibited dose dependent immunogenic behavior. The polymerized version of MxiH was exceptionally immunogenic even at low doses. The responses of both monomeric and polymerized forms were boosted by adsorption to an aluminum salt adjuvant.

[Immunotherapy and long-term chemoprophylaxis in prevention of recurrent urinary infections in women]

In clinical practice, management of urinary infections is a frequent task. Long-term prophylactic administration of small-dose chemotherapy had been shown to prevent recurrent urinary infections. Recently, an interest increases in applying immunotherapy in this indication. The authors compare immunomodulators Urovaxom and Luivac as part ofa combined immunotherapy and chemoprophylaxis regimens with small doses of fluorochinolones over 12 months in women with recurrent urinary infections. This treatment statistically significantly decreases occurrence of relapses and has been relatively well-tolerated. Unlike previous studies, we managed to isolate resistant strains producing the so-called extended-spectrum beta-lactamases (ESBL) and this may provide a signal for revision of some therapeutic approaches. In line with international recommendations, we prefer immunotherapy as comparably effective but safer treatment modality than the long-term chemoprophylaxis with fluorochinolones.

Inhibition of tumor angiogenesis by the matrix metalloproteinase-activated anthrax lethal toxin in an orthotopic model of anaplastic thyroid carcinoma

Patients with anaplastic thyroid carcinoma (ATC) typically succumb to their disease months after diagnosis despite aggressive therapy. A large percentage of ATCs have been shown to harbor the V600E B-Raf point mutation, leading to the constitutive activation of the mitogen-activated protein kinase pathway. ATC invasion, metastasis, and angiogenesis are in part dependent on the gelatinase class of matrix metalloproteinases (MMP). The explicit targeting of these two tumor markers may provide a novel therapeutic strategy for the treatment of ATC. The MMP-activated anthrax lethal toxin (LeTx), a novel recombinant protein toxin combination, shows potent mitogen-activated protein kinase pathway inhibition in gelatinase-expressing V600E B-Raf tumor cells in vitro. However, preliminary in vivo studies showed that the MMP-activated LeTx also exhibited dramatic antitumor activity against xenografts that did not show significant antiproliferative responses to the LeTx in vitro. Here, we show that the MMP-activated LeTx inhibits orthotopic ATC xenograft progression in both toxin-sensitive and toxin-resistant ATC cells via reduced endothelial cell recruitment and subsequent tumor vascularization. This in turn translates to an improved long-term survival that is comparable with that produced by the multikinase inhibitor sorafenib. Our results also indicate that therapy with the MMP-activated LeTx is extremely effective against advanced tumors with well-established vascular networks. Taken together, these results suggest that the MMP-activated LeTx-mediated endothelial cell targeting is the primary in vivo antitumor mechanism of this novel toxin. Therefore, the MMP-activated LeTx could be used not only in the clinical management of V600E B-Raf ATC but potentially in any solid tumor.

[Experience in immunomodulators application for comprehensive dental caries prevention in children and teenagers]

Prophylaxis and treatment procedures in children with different dental status was done during 9 years. Children and teenagers of 6-12 and 15-years were given teeth treatment and professional hygiene. One group of patients was additionally treated by immunomodulators imudon. It was demonstrated that improving of oral cavity hygiene and local immunity factor balance was achieved. Positive result was better in the group with imudon.

Increase of NK cells and proinflammatory monocytes are associated with the clinical improvement of diffuse cutaneous leishmaniasis after immunochemotherapy with BCG/Leishmania antigens

Diffuse cutaneous leishmaniasis (DCL) is characterized by disseminated lesions and the absence of a specific cellular immune response. Here, the immunochemotherapy outcome of a patient with DCL from Amazonian Brazil infected with Leishmania (Leishmania) amazonensis is presented. After several unsuccessful chemotherapy treatment regimens and many relapses, a monthly immunotherapy scheme of L. amazonensis PH8 plus L. (Viannia) braziliensis M2903 monovalent vaccines associated with Bacillus Calmette-Guerin (BCG) was established, one round of which also included an M2903 vaccine associated with intermittent antimonial treatment. Temporary healing of all lesions was achieved, although Leishmania skin tests were negative and interferon gamma was not detected in mononuclear cell cultures stimulated with Leishmania antigens. The frequencies of CD16 (+)CD56(+) NK cells (approximately 2x) and CD14 (+)CD16(+) proinflammatory monocytes (approximately 8x) increased in peripheral blood, and CD56 (+) lymphocytes were found infiltrating the lesions. An association between the increase of the frequency of innate immune system cells and the healing of lesions is shown, suggesting that this protocol of immunotherapy reduced the parasite load and activated NK cells and monocytes.

[Preparation of two antigens--Ag85b and HspX of Mycobacterium tuberculosis H37Rv and the effects of their co-administration with adjuvants in mice]

OBJECTIVE

To synthesize two antigens-Ag85b and HspX of Mycobacterium tuberculosis H37Rv with molecular biological methods and to observe their biologic activity after co-administration of adjuvants (aluminum and/or CpG) in mice.

METHODS

Recombinant expression plasmids pET30a-Ag85b and pET30a-HspX were constructed. The objective DNA fragments was characterized with restriction enzyme. Then the recombinant plasmids were transformed into E. coli BL-21, and two proteins were expressed by induction of isopropyl beta-D-1-thiogalactopyranoside. After purification with anion exchange column Source30, QHP, and hydrophobic chromatography column, two proteins were identified by amino acid sequencing. After the successful preparation of these two antigens, they were co-administered in mice with adjuvants of aluminum and/or CpG (Ag85b, Ag85b + Al, Ag85b + CpG, Ag85b + Al + CpG; HspX, HspX + Al, HspX + CpG, HspX + Al + CpG); one group received normal saline and served as the control. Splenic lymphocytes were isolated for enzyme-linked immunosorbent spot assay to detect the secreted specific interferon-gamma (IFN-gamma); in addition, lymphocytes proliferation test was performed to observe lymphocytes proliferation after in vitro stimulated with two antigens.

RESULTS

The purity of two proteins reached 95% after purification. The N-terminal amino acid sequence (15 aa) of the purified proteins was same as the target sequence. For Ag85b, the secreted specific IFN-gamma from isolated splenic lymphocytes after having been stimulated in vitro with Ag85b (80 microg/ml) remarkably increased in Ag85b + CpG group, Ag85b + Al group, and Ag85b + CpG + Al group; the changes were significantly different between these three groups and control group (P < 0.05). For HspX, the changes were significantly different between HspX + Al + CpG group and normal sodium group, although remarked increase of IFN-gamma was also observed in HspX group, HspX + Al group, and HspX + CpG group.

CONCLUSIONS

Ag85b and HspX were successfully expressed and purified. A cell-mediated immunity may be induced when the antigens are co-administered with adjuvants of aluminum and/or CpG in mice, indicating that the recombinant proteins are bioactive.

Bacterial extract (OM-89) specific and non specific immunomodulation in rheumatoid arthritis patients

The Escherichia Coli bacterial extract (OM-89) is used in the treatment of rheumatoid arthritis (RA). We evaluated the immunological changes induced by oral administration of OM-89 in 12 RA patients (polyclonal T cell reactivity to PHA, T cell precursor frequencies specific for OM-89 and Tetanus toxoid (TT), a control antigen and the release of Th1 (IFN-gamma, TNF-alpha), Th2 (IL-4) and T regulatory 1 cell (Tr1) (IL-10) cytokines in the supernatants of PBMC cultures. Stimulation index in response to PHA decreased at month 3 as well as T cell precursor frequencies specific for TT with similar trends for OM-89-specific T cell precursor frequencies. OM-89 induced a strong production of IL-10, a significant decrease in IL-4 production while TNF-alpha and IFN-gamma production tended to decrease during the study. Our results suggest that OM-89 has immunomodulatory properties by inducing changes in PBMC cytokines release suggestive of an induced Tr1 response to OM-89.

[Preclinical tests of Staphylococcus aureus somatic antigen as the basis for drugs for treatment of staphylococcal skin infections]

AIM

To analyze results of conducted preclinical animal tests of ointment and gel preparations based on the somatic antigen ("Somatin") of Staphylococcus aureus.

MATERIALS AND METHODS

Contents of ointment and gel as well as method of "Somatin" extraction from cytosomatin ointment are presented. Standard serum was obtained by immunization of rabbits by "Somatin". Tests for acute and chronic toxicity and sensitizing effect of cytosomatin ointment were performed. 1% gentamycin ointment was used for comparison with cytosomatin ointment and gel for treatment of pyodermia. Preparations were patented.

RESULTS

Authenticity and specific activity of ointment and gel preparations were demonstrated. Animal tests for acute and chronic toxicity of cytosomatin ointment did not reveal inflammatory reaction of skin and sclera as well as influence on biochemical parameters of the blood or abnormalities of visceral morphological structure. Assessment of sensitizing effect of cytosomatin ointment did not reveal promotion of allergy. Advantages in treatment of staphylococcal skin infections and wounds with cytosomatin ointment and gel as compared with gentamycin ointment were established.

CONCLUSION

The main immunogenic mechanism of "Somatin" substance was activation of complete phagocytosis. The character of immune response was specific. Selected optimal ratios of therapeutic doses for ointment and gel bases promote active permeation of the drug into skin that enhances its therapeutic effect. Duration of treatment with cytosomatin ointment was shortened on 5 days as compared with gentamycin ointment. Duration of treatment with cytosomatin gel was shortened on 8 days as compared with prototype.

Dendritic cell targeting of Bacillus anthracis protective antigen expressed by Lactobacillus acidophilus protects mice from lethal challenge

Efficient vaccines potentiate antibody avidity and increase T cell longevity, which confer protection against microbial lethal challenge. A vaccine strategy was established by using Lactobacillus acidophilus to deliver Bacillus anthracis protective antigen (PA) via specific dendritic cell-targeting peptides to dendritic cells (DCs), which reside in the periphery and mucosal surfaces, thus directing and regulating acquired immunity. The efficiency of oral delivery of L. acidophilus expressing a PA-DCpep fusion was evaluated in mice challenged with lethal B. anthracis Sterne. Vaccination with L. acidophilus expressing PA-DCpep induced robust protective immunity against B. anthracis Sterne compared with mice vaccinated with L. acidophilus expressing PA-control peptide or an empty vector. Additionally, serum anti-PA titers, neutralizing PA antibodies, and the levels of IgA-expressing cells were all comparable with the historical recombinant PA plus aluminum hydroxide vaccine administered s.c. Collectively, development of this strategy for oral delivery of DC-targeted antigens provides a safe and protective vaccine via a bacterial adjuvant that may potentiate mucosal immune responses against deadly pathogens.

The systemic administration of lethal toxin achieves a growth delay of human melanoma and neuroblastoma xenografts: assessment of receptor contribution

Two of the three components of anthrax toxin, protective antigen (PA) and lethal factor (LF), together known as lethal toxin (LeTx), reportedly show anti-tumor activity in melanoma in vitro and in vivo. The growth inhibitory activity of LeTx in culture was determined in nine human cancer cell lines, including melanoma, neuroblastoma and adenocarcinoma cells, as well as in human umbilical vein endothelial cells (HUVEC). The contribution of the two known PA receptor proteins, ANTXR1/TEM8 and ANTXR2/CMG2, to the sensitivity of the cells was assessed. The efficacy of LeTx was evaluated in vivo in the SK-N-AS neuroblastoma and SK-MEL-28 melanoma tumor xenograft models. Sensitivity to LeTx in vitro was observed in the neuroblastoma and colorectal adenocarcinoma cells and HUVEC, as well as melanoma cells. ANTXR1/TEM8 and ANTXR2/CMG2 protein expression studies suggested that a certain threshold of the PA receptor protein level must be met for sensitivity to LeTx to be observed. However, although the SK-N-AS neuroblastoma cells expressed the highest levels of receptor proteins and achieved the lowest IC50 in vitro (0.1 ng/ml), we observed no correlation between either the ANTXR1/TEM8 or ANTXR2/CMG2 protein levels and sensitivity to LeTx in vitro. In vivo, LeTx was an active anti-tumor agent when administered intravenously to mice bearing the human SK-N-AS or SK-MEL-28 tumor xenografts. The tumor growth delays were 6-8 days with a lower dose regimen and 14-16 days with a higher dose regimen for the two tumor models. These in vitro data suggest that LeTx may have broad therapeutic indications in cancer and the in vivo studies demonstrate that LeTx has systemic efficacy in neuroblastoma as well as melanoma. The therapeutic potential of LeTx needs to be further investigated in non-melanoma tumor models expressing the ANTXR1/TEM8 and/or ANTXR2/CMG2 protein.

Prevention and treatment of colitis with Lactococcus lactis secreting the immunomodulatory Yersinia LcrV protein

BACKGROUND & AIMS

The low calcium response V (LcrV) protein synthesized by gram-negative, pathogenic yersiniae participates in bacterial evasion of the host's innate immune response by stimulating synthesis of the anti-inflammatory interleukin (IL)-10 and preventing the activation of proinflammatory cytokines.

METHODS

We genetically engineered the food-grade bacterium Lactococcus lactis to secrete the LcrV protein from the enteropathogenic species Yersinia pseudotuberculosis. The protective and therapeutic potential of orally administered LcrV-secreting L lactis was evaluated in 2 models of acute experimental colitis (induced by trinitrobenzene sulfonic acid [TNBS] and dextran sodium sulfate [DSS], respectively) in wild-type and knockout mice.

RESULTS

Oral administration of LcrV-secreting L lactis led to active delivery of LcrV and induction of IL-10 (via a Toll-like receptor 2-dependent pathway) in the colon and prevented TNBS-induced colitis, in contrast to the L lactis control not producing LcrV. Down-regulation of tissue inflammatory markers correlated well with the reduction in damage to the colonic mucosa. In contrast, TNBS-induced colitis was not prevented in IL-10(-/-) mice pretreated with LcrV-secreting L lactis, thus showing that IL-10 is required for LcrV protection. Administration of LcrV-secreting L lactis also proved to be very effective in preventing and treating acute DSS-induced colitis.

CONCLUSIONS

LcrV-secreting L lactis decreased experimentally induced intestinal inflammation in 2 murine models of colitis. This novel approach highlights the potential of using pathogen-derived immunomodulating molecules in vivo as novel therapeutics for inflammatory bowel diseases.

[Genotypic study on the Helicobacter pylori vacA, cagA and iceA genes in the infected children in Guangzhou area]

OBJECTIVE

To investigative vacA, cagA and iceA genes dominant genotypes of Helicobacter pylori (Hp) isolated from children suffering from gastric and duodenal diseases in Guangzhou area.

METHODS

Totally 105 children who underwent gastroscopy in Guangzhou Children's Hospital were enrolled into this study. From each patient, 3 biopsy specimens from the gastric antrum were taken, one was used for rapid urease test, one for histological examination, and one for polymerase chain reaction (PCR) for detecting ureA, vacA, cagA, and iceA genes. DNA was prepared directly from the biopsy specimens from the gastric antrum using a QIAamp DNA mini kit (Qiagen, Germany) according to the manufacturer's instructions. Then 11 primers were used for detecting the genotypes including ureas, (s1, s1a, s1b, s1c, s2) and m (m1, m1T, m2) region of vacA, cagA and iceA (iceA1 and iceA2) genotypes in the 105 children. The distribution of the genotypes of Hp was analyzed.

RESULT

Among the 105 children, only 52 children were positive by the three methods, among these 52 children, 26 were boys and 26 girls. Hp vacA s1as1c/m2 was detected in 43 out of 52 children (82.7%), s1as1c/m1T in 9.6% (5/52), m region that could not betyped was 7.7% (4/52). No strains presented genotypes vacA s1b, s2, m1. The comparison of the positive ratio of vacA s1as1 c/m2 detected in the children infected with Hp and that of the other combination of signal region and middle region was statistically significantly different (P < 0.01). With regard to cagA gene, cagA(+) gene and cagA(-) gene were found in 90.4% (47/52) and 9.6% (5/52) of the children, respectively. The cagA(+) gene was more frequent in the children infected with Hp. Single iceA1 was detected in 78.8% (41/52) children, and single iceA2 was detected to be 1.9% (1/52), multiple strains infection of iceA1 and iceA2 were detected in 3.8% (2/52) children, iceA1 and iceA2 were not detected in 15.4% (8/52), the comparison of the positive ratio of iceA1 detected in the children infected with Hp and that of the other genotypes was statistically significantly different (P < 0.01).

CONCLUSION

The s1as1c/m2, cagA and iceA1 were the dominant genotypes of Hp in the children in Guangzhou area and s1as1c/m2, cagA and iceA1 were the dominant genotypes combination of Hp in the children in this area.

Development of protective immunity in a murine model of melioidosis is influenced by the source of Burkholderia pseudomallei antigens

Melioidosis is a potentially fatal disease caused by the bacterium, Burkholderia pseudomallei. The current study was carried out to determine the mechanisms involved in the development of protective immunity in a murine model of melioidosis. Following intravenous infection with B. pseudomallei, both C57BL/6 and BALB/c mice demonstrated delayed-type hypersensitivity responses and lymphocyte proliferation towards B. pseudomallei antigens, indicating the generation of B. pseudomallei-specific lymphocytes. Adoptive transfer of these lymphocytes to naïve C57BL/6 mice was demonstrated by a delayed-type hypersensitivity response. Mice were not protected from a subsequent lethal challenge with a highly virulent strain of B. pseudomallei, suggesting that a single intravenous dose of the bacterium is insufficient to induce a protective adaptive immune response. Attempts to induce resistance in susceptible BALB/c mice used repetitive low-dose exposure to live B. pseudomallei. Immune responses and resistance following subcutaneous immunization with live B. pseudomallei were compared with exposure to heat-killed, culture filtrate and sonicated B. pseudomallei antigens. Compared to heat-killed B. pseudomallei, significant protection was generated in BALB/c mice following immunization with live bacteria. Our studies also demonstrate that the type of immune response generated in vivo is influenced by the antigenic preparation of B. pseudomallei used for immunization.

Vaccine potential of influenza vectors expressing Mycobacterium tuberculosis ESAT-6 protein

We generated several attenuated recombinant influenza A vectors expressing the Mycobacterium tuberculosis early secretory antigenic target (ESAT-6) protein. The ESAT-6 protein was recently identified as one of the most promising protective antigens for cell-mediated immunity. The obtained vectors appeared to be capable of inducing ESAT-6 specific Th1 immune response in mice after intranasal immunization. We found that double immunization with two influenza vectors of different subtypes provided a significant level of protection in mice, when applied as prophylactic vaccine, as well as substantial therapeutic effect in mice with pre-established tuberculosis infection. Moreover, we found a strong synergistic effect when vaccination with Flu/ESAT-6 vectors was combined with isoniazid treatment, resulting in a dramatic reduction of bacterial load in the lungs of infected mice.

Novel bacterial delivery system with attenuated Salmonella typhimurium carrying plasmid encoding Mtb antigen 85A for mucosal immunization: establishment of proof of principle in TB mouse model

Tuberculosis (TB), the leading killer of young adults worldwide, newly affects one person every second and kills one in every 15 seconds. The recent increase of TB in developing countries has been exacerbated by many causes including pandemic HIV, war and political instability, drug resistance, and increasing poverty. Genetic immunization has emerged with tremendous potential in vaccination against TB with success in animal models with naked DNA encoding different genes such as Ag85A, Pst3, and hsp65. However, there are shortcomings in translating this success into reality in human clinical trials due to limitations at the level of delivery, quality, and quantity of DNA to be administered, which can be circumvented by using an attenuated bacteria delivery system for transgene vaccination for mucosal immunization targeting the inductive sites of the immune system. We compare this novel delivery system using an attenuated Salmonella delta aroA strain through a mucosal route with classic intramuscular DNA delivery using a potential protective antigen, Ag85A, of Mycobacterium tuberculosis in a mouse infection virulent challenge model. We show an immune response and superior protection in the mice at the level of the lungs as well as the spleen against a virulent challenge after intranasal immunization by recombinant Salmonella typhimurium carrying a eukaryotic expression plasmid encoding Ag85A rather than the classic DNA immunization and at par with the protection conferred by BCG. This study establishes the proof of principle of this system for further exploitation of this platform for vaccine development, which is being pursued for postexposure vaccine development for TB.

Systemic anthrax lethal toxin therapy produces regressions of subcutaneous human melanoma tumors in athymic nude mice

PURPOSE

Anthrax Lethal Toxin (LeTx), composed of protective antigen and lethal factor, catalytically cleaves mitogen-activated protein kinase (MAPK) kinases and inhibits the MAPK signaling pathways. The majority of metastatic melanomas possess the V599E BRAF mutation, which constitutively activates MAPK1/2 signaling. LeTx is cytotoxic to BRAF mutant melanoma cell lines in vitro, whereas most normal cells are resistant to this toxin. In this study, we determine the in vivo potency and safety of systemically administered LeTx.

EXPERIMENTAL DESIGN

A s.c. xenograft melanoma model in athymic nude mice was treated with different i.p. doses of LeTx.

RESULTS

In this study, we show that in vivo systemic LeTx treatment of s.c. xenograft melanoma tumors in athymic nude mice yields partial and complete tumor regressions with minor toxicity to mice. When animal toxicity was observed, we did not find any histologic evidence of tissue damage.

CONCLUSIONS

LeTx is one of the rare targeted agents to produce complete remissions of human melanomas in an animal model and thus warrants further preclinical development.

CpG oligonucleotides improve the protective immune response induced by the licensed anthrax vaccine

Synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs act as immune adjuvants, improving the response elicited by a coadministered vaccine. Combining CpG ODN with anthrax vaccine adsorbed (AVA, the licensed human vaccine) increases the speed, magnitude, and avidity of the resultant antibody response. IgG Abs against anthrax protective antigen (PA) protect mice, guinuea pigs, and rhesus macaques from infection.

Ribosomal therapy in the prophylaxis of recurrent pharyngotonsillitis in children

OBJECTIVE

Although much has been written on how to manage recurrent pharyngotonsillitis, it remains a controversial topic. The composition of normal commensal oropharynx bacteria may be disrupted by frequently using antimicrobials, by inhibiting sensitive organisms and by allowing resistant organisms to overgrowth. This may cause the recurrence of acute episodes. The aim of this study was to evaluate the efficacy of ribosomal immunotherapy in the prophylaxis of recurrent pharyngotonsillitis.

METHODS

A total of 160 children aged between 5 and 14 years with recurrent pharyngotonsillitis were ramdomized to receive either ribosomal immunotherapy (group A one tablet a day, 8 days a month for 3 months) or a placebo (group B same dosage for the same period).

RESULTS

At the end of the study, each patient treated with Immucytal presented a subjective decrease of symptoms. Compared with group B, group A experienced a significant improvement of some clinical parameters.

CONCLUSIONS

The results show that ribosomal immunotherapy causes a significant improvement of both specific and non-specific immunity and may be effective in the prophylaxis of recurrent pharyngotonsillitis and in preventing recurrences without entailing side effects or bacterial resistance.

Immunotherapy for Orthotopic Murine Bladder Cancer Using Bacillus Calmette-Guerin Recombinant Protein Mpt-64

PURPOSE

We investigated the efficacy of the recombinant bacillus Calmette-Guerin subunit protein vaccine Mpt-64 for inducing cytokine production and suppressing orthotopic bladder tumor growth in mice.

MATERIALS AND METHODS

One mycobacteria candidate gene (Mpt-64) was cloned and ligated into eukaryotic expression vectors. The induction and efficiency of Mpt-64 protein expression were detected using Western blotting. Various doses of Mpt-64 proteins were instilled intravesically 6 times in 2 weeks after intravesical implantation of MBT-2 tumor cells in chemical injured urothelium. Systemic cytokine responses, tumor growth and cumulative survival rates were monitored.

RESULTS

In vitro expression of recombinant Mpt-64 subunit protein was efficient in our system. Mice treated with 100 and 200 microg Mpt-64 subunit proteins significantly inhibited orthotopic MBT-2 tumor growth in C3H/HeN mice compared with that in control and 50 microg treatment groups in terms of the tumor taking rate, bladder tumor burden and mortality rate. Meanwhile, marked increased serum interferon-gamma with a limited but significant increase in serum interleukin-2 was observed in mice treated with 100 and 200 microg Mpt-64 proteins compared with control and 50 microg treated groups.

CONCLUSIONS

A highly immunopotent recombinant Mpt-64 subunit protein of bacillus Calmette-Guerin was produced and it elicited immune responses with a high serum interferon-gamma level, inhibited orthotopic tumor growth and prolonged survival in tumor bearing mice. Thus, intravesical immunogenic therapy using recombinant Mpt-64 protein may be an alternative bacillus Calmette-Guerin regimen for superficial bladder cancer.

Immunostimulants revisited: focus on the pharmacology of Ribomunyl

Ribomunyl is an immunostimulant that was developed and commercialized in the 1980s in France and has subsequently been made available in a large number of countries. The formulation is composed of proteoglycans from Klebsiella pneumoniae and of ribosomes from four of the most commonly encountered bacterial strains in recurrent respiratory tract infections. While it is obviously difficult to present a thorough summary of all historical data, here we revisit the mode of action of this immunostimulant and present a perspective in the context of the most recent data and hypotheses on the mechanisms of the antibacterial immune responses. We provide various examples of these mechanisms in innate immunity (phagocytosis, cell adhesion, dendritic cell maturation, Toll-like receptors, interferon production, proinflammatory cytokines, activation of natural killer cells), as well as in adaptative immunity (polyclonal activation of T and B cells, specific immunoglobulin A immune response in an integrated view of the mucosal immune system, and T helper type 1/type 2 [Th1/Th2] regulation and balance). The effect of this immunostimulant on anti-infectious responses can be explained, not only by a stimulation of the antibacterial defense directly assumed by innate immunity, but also by a stimulation of the specific (adaptative) immune response related to the activation of dendritic cells, of which the pivotal role in T-cell differentiation is already well known. This supports the potential of bacterial immunostimulants such as Ribomunyl in anti-infective therapy.

[Principles of the immune modulation therapy against papilloma virus infections]

The aim of the study was to investigate the effect of Immudone on local immune responses of cervical mucous in patients with papilloma virus cervicitis. 80 women of reproductive age with chronic cervicitis, 60 women with no signs of infection and 70 bioptates obtained from the base of vaginal section of the cervix. Colposcopic, bacterioscopic, patho-histological and immunohistochemical investigations have been performed. After using of Immudone healing of ectopia was observed in the most of cases. As a result of local application of Immudone in patients with PVI in the tissue of cervix the rate of CD4+ cells was increased, expression of receptors of interleukin-2 was increased, CD4/CD8 ratio also increased, quantity of macrophages and natural killers was increased. Local sIgA synthesis was restored.

Engineered chloroplasts as vaccine factories to combat bioterrorism

Bacillus anthracis is ideal for making biological weapons, but the licensed anthrax vaccine is unsuitable for widespread public administration. Recombinant subunit-vaccine candidates offer potential alternatives, and plant-based production systems facilitate the inexpensive bulking of target antigens. A recent report demonstrates expression of anthrax protective antigen in tobacco chloroplasts--this material is immunogenic and protective when injected into mice. Provided an economic purification scheme can be developed, this technology holds promise for an improved vaccine.

Phase II randomized, placebo-controlled trial of M. vaccae-derived protein (PVAC) for the treatment of psoriasis

The treatment effect against psoriasis of an antigen (delipidated, deglycolipidated form of M. vaccae-PVAC) was investigated. One hundred and sixty-five patients were enrolled in three arms (50 or 15 microg or placebo), each receiving a total of two intradermal injections (days 0 and 21). At week 12, a 75% decrease in psoriasis area and severity index was similar among the studied groups (13, 9 and 18%, p=0.429). The overall incidence of adverse events was significantly higher in the PVAC treated groups when compared to placebo (98.2, 87.3 and 70.9%; p<0.001) largely due to local reactions that were limited for the most part to grades 1 and 2 in severity and were self-limiting. Despite its overall safety, PVAC was not clearly indicated to be superior to placebo in the treatment of psoriasis in this study.