Aspects of intradermal immunization with different adjuvants: The role of dendritic cells and Th1/Th2 response.

Intradermal (i.d.) application of vaccine is promising way how to induce specific immune response against particular pathogens. Adjuvants, substances added into vaccination dose with the aim to increase immunogenicity, play important role in activation of dendritic cells with subsequent activation of lymphocytes. They can, however, induce unwanted local reactions. The aim of the study was to determine the effect of i.d. administration of model antigen keyhole limped hemocyanine alone or with different adjuvants-aluminium hydroxide and oil-based adjuvants-on local histopathological reaction as well as dendritic cell activation at the site of administration and local cytokine and chemokine response. This was assessed at 4 and 24 hours after application. Selection of the adjuvants was based on the fact, that they differently enhance antibody or cell-mediated immunity. The results showed activation of dendritic cells and both Th1 and Th2 response stimulated by oil-based adjuvants. It was associated with higher expression of set of genes, incl. chemokine receptor CCR7 or Th1-associated chemokine CXCL10 and cytokine IFNγ. Application of the antigen with aluminium hydroxide induced higher expression of Th2-associated IL4 or IL13. On the other hand, both complete and incomplete Freund´s adjuvants provoked strong local reaction associated with influx of neutrophils. This was accompanied with high expression of proinflammatory IL1 or neutrophil chemoattractant CXCL8. Surprisingly, similarly strong local reaction was detected also after application of aluminium hydroxide-based adjuvant. The best balanced local reaction with sufficient activation of immune cells was detected after application of oil-based adjuvants Montanide and Emulsigen.

The emergence of Clostridium difficile PCR ribotype 078 in piglets in the Czech Republic clusters with Clostridium difficile PCR ribotype 078 isolates from Germany, Japan and Taiwan.

Clostridium difficile is a major nosocomial pathogen in humans with an increasing incidence in the community. The "one-health" approach of research is needed to investigate possible reservoirs of C. difficile and route of its transmission. The objective of this study is to investigate the occurrence of C. difficile in pigs in the Czech Republic with characterisation of the isolates to determine their genetic relatedness to C. difficile isolates from European and Asian pigs. A total of 198 pig faeces samples from 23 farms were investigated and of those 57 samples (55 piglets, 2 sows) from 11 farms were confirmed as C. difficile positive. The majority of C. difficile isolates belonged to the sequence type 11 and clade 5. The predominant ribotypes were 078 (n = 23), 078-variant (n = 5), 033 (n = 10) followed by RTs 150 (n = 7), 011 (n = 5), 045 (n = 4), 126, 014, 002 (n = 1, each). All isolates were susceptible to metronidazole, vancomycin and tetracycline. Isolates of RTs 150 and 078-variant were moxifloxacin resistant (MIC≥32 mg/L) and carried the amino acid substitution Thr82Ile in the GyrA. A multi-locus variable number tandem-repeats analysis (MLVA) revealed a clonal relatedness of isolates within individual farms and in C. difficile RT078 isolates between two Czech farms. Czech C. difficile RT078 isolates clustered with German C. difficile RT078 isolates and Czech C. difficile 078-variant isolates clustered with C. difficile RT078 isolates from Japan and Taiwan. This study found an emergence of C. difficile RT078 in Czech piglets that was related genetically to C. difficile RT078 isolates from Germany, Japan and Taiwan.

Oil-based adjuvants delivered intradermally induce high primary IgG2 immune response in swine.

The effects of intradermal application of antigen with or without different adjuvants and activation of immune response are presented in this study. Six groups of six piglets each were immunized with keyhole limpet haemocyanin (KLH) antigen in combination with aluminium hydroxide or oil-based adjuvants (complete and incomplete Freund's adjuvants, Montanide ISA 206 and Emulsigen). IgG1 and IgG2 levels in sera were measured by KLH-specific ELISA. Interestingly, oil-based adjuvants induced high primary IgG2 response, suggesting the Th1 lymphocyte polarization. Also, considering the similarities between human and porcine organism, we suggest that intradermal application could be considered as an effective vaccine delivery route in both veterinary and human medicine.

Effects of adjuvants on the immune response of pigs after intradermal administration of antigen.

The ability of different adjuvants to enhance immune responses to intradermal (ID) immunisation with a model antigen was studied in pigs. Immune responses were evaluated with respect to the intensity of systemic and mucosal antibody formation, their isotype characterisation and rate of cell-mediated immunity. These findings were compared with the intensity of adverse local reactions. Six groups of piglets were immunised with keyhole limpet haemocyanin (KLH) antigen alone or in combination with aluminium hydroxide or selected oil-based adjuvants (complete and incomplete Freund's adjuvants, Montanide ISA 206 and Emulsigen). Systemic specific antibody responses were significantly increased following ID administration of antigen together with any of the adjuvants used. IgG antibody responses were most pronounced after the first administration of antigen, being stimulated with both Freund's and Montanide ISA 206 adjuvants. The oil adjuvants also enhanced the cell-mediated immune responses and the levels of local IgA antibodies in the respiratory mucosa. On the other hand, they elicited more pronounced adverse local reactions.

[Fifty years with MRSA. An attempt to evaluate methods used to control infections caused by methicillin-resistant Staphylococcus aureus (MRSA)]. / Pokus o zhodnoceni postupu pouzivanych k omezeni vyskytu infekci vyvolanych kmeny Staphylococcus aureus rezistentnimi k meticilinu (MRSA).

The authors summarize information on the basic aspects of MRSA infections. Special attention is concentrated on the epidemiology of these infections, risk factors facilitating their transmission and spread in hospitals. Furthermore, this paper attempts to evaluate methods used to reduce their occurrence and pays attention to the procedures aimed at identifying the sources of infection, including carriers and patients. This study also deals with organizational procedures used to control transmission of MSRA infections in hospitals. Lastly, procedures of infection control practices applied abroad are compared with those implemented in our hospitals.

A correlation of in vitro tests for the immune response detection: a bovine trichophytosis model.

The aim of our study was to extend knowledge about possibilities of replacing challenge tests by in vitro methods in cattle on the model of trichophytosis. We correlated results of three in vitro tests for the detection of immune response, i.e. a specific antigen-driven lymphocyte transformation test measured by (3)H-thymidine incorporation, specific antigen-induced production of interferon-gamma and detection of IgG1 and IgG2 isotypes of specific antibodies, in calves vaccinated against the disease or challenged with Trichophyton verrucosum as causative agent. The results obtained in the present study by different methods are correlated together. Lymphocyte transformation test correlated positively with interferon-gamma production. Ratio of IgG1 to IgG2 isotypes of antibody correlated negatively with both cell-mediated methods. Moreover the results show that any of the methods might in future replace the in vivo challenge tests that are still conventionally used for testing of newly developed vaccines.

Liposomal preparations of muramyl glycopeptides as immunomodulators and adjuvants.

The need for safe and structurally defined immunomodulators and adjuvants is increasing in connection with the recently observed marked increase in the prevalence of pathological conditions characterized by immunodeficiency. Important groups of such compounds are muramyl glycopeptides, analogs of muramyl dipeptide (MDP), glucosaminyl-muramyl dipeptide (GMDP), and desmuramylpeptides. We have designed and synthesized new types of analogs with changes in both the sugar and the peptide parts of the molecule that show a high immunostimulating and adjuvant activity and suppressed adverse side effects. The introduction of lipophilic residues has also improved their incorporation into liposomes, which represent a suitable drug carrier. The proliposome-liposome method is based on the conversion of the initial proliposome preparation into liposome dispersion by dilution with the aqueous phase. The description of a home-made stirred thermostated cell and its link-up with a liquid delivery system for a rapid and automated preparation of multilamellar liposomes at strictly controlled conditions (sterility, temperature, dilution rate and schedule) is presented. The cell has been designed for laboratory-scale preparation of liposomes (300-1000 mg of phospholipid per run) in a procedure taking less than 90 min. The method can be readily scaled up. Examples of adjuvant and immunostimulatory effect of liposomal preparation in mice model will be presented.