BACKGROUND: Recently chitosan nanoparticles have been applied as an immunostimulant and adjuvant in biomedical fields. OBJECTIVES: In this study the adjuvant effects of nanochitosan, derived from shrimp shell's chithin, on immunogenicity of Aeromonas hydrophila vaccine in common carp were evaluated. METHODS: Totally 300 juvenile common carp (51±5.6 g, Mean ±SD) were randomly divided into four groups each contained three subgroups with 25 fishes. Groups 1, 2 and 3 were immunized intraperitoneally with A. hydrophila vaccine. No adjuvant used in group 1, but nanochitosan and freund adjuvant were used with vaccine in groups 2 and 3 respectively. Group 4 (Control) injected with normal saline instead of vaccine. Fish were immunised at days zero and 14 and fishes were reared in the same situation for 6 weeks. Serum samples were taken every other weeks and immunological parameters including WBC, serum lysozyme and bactericidal activity, serum complement activity, NBT reduction activity, total protein and globulin levels and anti A.hydrophila antibody titer were compared among the groups. At the end of experiment all groups were challenged with LD50 concentration of A. hydrophila and mortality recorded for ten days. RESULTS: WBC, serum lysozyme and complement activity, NBT activity, globulin level and anti A.hydrophila antibody titer were increased in nanochitosan and freund groups compare to control group (P<0.05). Serum bactericidal activity and serum albumin level showed no significant change among the groups (P>0.05). Challenge mortality decreased in immunised groups compare to control. CONCLUSIONS: Nonochitosan posses proper adjuvant effects which is comparable with freund adjuvant and can be a good candidate as an alternative to current adjuvant in fish vaccines.

Riemerella anatipestifer (RA) infections can lead to high mortality in ducklings. Inactivated vaccines against RA are commercially available, but they fail to provide cross-protection against various serotypes. We have previously demonstrated that a subunit vaccine containing recombinant outer membrane protein A (rOmpA) antigen of serotype 2 formulated with CpG oligodeoxynucleotides (ODN) as the adjuvant was able to stimulate both humoral and cellular immunities.

Riemerella anatipestifer (RA) infections can lead to high mortality in ducklings. Inactivated vaccines against RA are commercially available, but they fail to provide cross-protection against various serotypes. We have previously demonstrated that a subunit vaccine containing recombinant outer membrane protein A (rOmpA) antigen of serotype 2 formulated with CpG oligodeoxynucleotides (ODN) as the adjuvant was able to stimulate both humoral and cellular immunities. In the present study, thirty healthy 7-day-old Pekin ducks were randomly assigned to three equal treatment groups: rOmpA-vaccinated, rOmpA + CpG-vaccinated, and control. Vaccine was injected intramuscularly and a booster dose of the same vaccine was given two weeks after primary immunisation. The long-term antibody response and cross-serotype reaction of this vaccine were evaluated in ducks. Compared to ducks immunised with rOmpA alone, ducks immunised with rOmpA + CpG ODN had significantly (p < 0.05) increased serum antibody titre from two weeks until nine months after primary immunisation. In addition, expression of cytokines including interferon (IFN)-α, IFN-γ, interleukin (IL)-6, and IL-12 was significantly (p < 0.05) enhanced in PBMC of ducks immunised with rOmpA + CpG ODN two weeks after primary immunisation. Antibodies from ducks immunised with the rOmpA + CpG ODN vaccine could also detect RA serotypes 1 and 6 in Western blot analysis. Combination of rOmpA and CpG ODN could be a feasible strategy for developing a subunit RA vaccine with long term and broader-ranging protection.

The bursa of Fabricius (BF) is a central humoral immune organ unique to birds. Four bursal peptides (BP-I, BP-II, BP-III, and BP-IV) have been isolated and identified from the BF. In this study, the immunoadjuvant activities of BPs I to IV were examined in mice immunized with H9N2 avian influenza virus (AIV) vaccine. The results suggested that BP-I effectively enhanced cell-mediated immune responses, increased the secretion of Th1 (interferon gamma)- and Th2 (interleukin-4)-type cytokines, and induced an improved cytotoxic T-lymphocyte (CTL) response to the H9N2 virus. BP-II mainly elevated specific antibody production, especially neutralizing antibodies, and increased Th1- and Th2-type cytokine secretion. BP-III had no significant effect on antibody production or cell-mediated immune responses compared to those in the control group. A strong immune response at both the humoral and cellular levels was induced by BP-IV. Furthermore, a virus challenge experiment followed by H and E staining revealed that BP-I and BP-II promoted removal of the virus and conferred protection in mouse lungs. BP-IV significantly reduced viral titers and histopathological changes and contributed to protection against H9N2 AIV challenge in mouse lungs. This study further elucidated the immunoadjuvant activities of BPs I to IV, providing a novel insight into immunoadjuvants for use in vaccine design.

In order to search the availability of the lectin extracted from Korean mistletoe (Viscum album coloratum) as an adjuvant for the avian vaccines, attempts were made to determine toxicity of the lectin in chicks and its immunostimulating activity on the inactivated vaccines against Newcastle disease virus (NDV). For the determination of toxicity, the lectin was injected into the thigh muscle of SPF chicks (Charles River) of 1-week-old and observed hematologically and pathologically.

In the present study toxicity and immunostimulating activity of the lectin (KML-C), which was extracted from Korean mistletoe (Viscum album coloratum) were investigated in swine. To determine the toxicity, lectin was injected into thigh or cervical muscles of 4-week-old piglets (Landrace) and observed clinically and pathologically. For determinatio of the immunostimulating activity, lectin (0.7 ㎍/kg of body weight)-adjuvanted vaccine of Aujeszky's disease virus (ADV) (NYJ1-87) which was inactivated by 0.2% formalin was injected into the cervical muscle of antibody-negative piglets in the same age group.

Mycobacterial cell-wall skeleton (CWS) is an immunoactive and biodegradable particulate adjuvant and has been tried to use for immunotherapy. The CWS of Mycobacterium bovis bacillus Calmette-Guerin (BCG-CWS) was studied as an universal vaccine vehicle for antigen conjugation, to develop potentially effective and safe vaccine. Although a variety of biological activities of BCG-CWS have been studied, the effects of BCG-CWS on spleen cells are not fully elucidated. Using MTT assay and trypan blue exclusion test, we found that BCG-CWS significantly enhanced the viability and proliferation of cells. Multiple clusters, indicating proliferation, were observed in BCG-CWS-treated spleen cells and surface marker staining assay revealed that BCG-CWS promoted the proliferation of CD19+ B lymphocyte rather than CD4+ or CD8+ T lymphocyte. In addition, BCG-CWS up-regulated the expression of anti-apoptotic molecules such as bcl-2, bcl-xL. BCG-CWS increased the surface expression of CD25 and CD69 as well as IL-2 production of spleen cells, suggesting increased activation. Furthermore, BCG-CWS enhanced the antigen-specific cell proliferation and interferon-gamma production of spleen cells. Taken together, these results demonstrate the immunostimulatory effects of BCG-CWS on spleen cells via multiple mechanisms, providing valuable information to broaden the use of BCG-CWS in clinical and research settings.

Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals that is primarily controlled by vaccination of susceptible animals and movement restrictions for animals and animal-derived products in South Africa. Vaccination using aluminium hydroxide gel-saponin (AS) adjuvanted vaccines containing the South African Territories (SAT) serotypes has been shown to be effective both in ensuring that disease does not spread from the endemic to the free zone and in controlling outbreaks in the free zone. Various vaccine formulations containing antigens derived from the SAT serotypes were tested in cattle that were challenged 1 year later. Both the AS and ISA 206B vaccines adjuvanted with saponin protected cattle against virulent virus challenge. The oil-based ISA 206B-adjuvanted vaccine with and without stimulators was evaluated in a field trial and both elicited antibody responses that lasted for 1 year. Furthermore, the ISA 206 adjuvanted FMD vaccine protected groups of cattle against homologous virus challenge at very low payloads, while pigs vaccinated with an emergency ISA 206B-based FMD vaccine containing the SAT 1 vaccine strains were protected against the heterologous SAT 1 outbreak strain.

Hemorrhagic shock was induced in nonsplenectomized dogs by removing 41% of their blood volume over a 15-minute period. Hemodynamic and metabolic variables were determined prior to and for 3 hours after completion of hemorrhage. One group of 5 dogs was not treated. After the 30-minute sample was collected, a second group of 5 dogs was given lactated Ringer solution (LRS) at 88 ml/kg of body weight, IV. A third group of 5 dogs was given LRS (88 ml/kg, IV) and prednisolone sodium succinate (11 mg/kg, IV) 30 minutes after hemorrhage. The IV administration of LRS was completed within 15 minutes. The glucocorticoid was administered as an IV bolus after 500 ml of LRS had been given. The large volume and administration of LRS significantly (P = 0.05) improved many of the hemodynamic and metabolic effects of acute hemorrhage and hemorrhagic shock. At one time or another during the 2.5-hour observation period after the initiation of treatment, mean arterial pressure, cardiac index, systemic vascular resistance, heart rate, respiratory rate, lactate, glucose, and arterial and venous blood gas values were significantly (P = 0.05) improved, compared with baseline values. The addition of prednisolone sodium succinate to the treatment regimen improved the effectiveness of LRS alone only in some dogs at random sampling times. Significant trends were not observed except, possibly, the improvement of venous pH and A-V pH and P(CO)2 differences.

The quick diagnosis of Newcastle disease requires known serum against the disease. In this study, an attempt was made to raise anti- Newcastle disease virus hyperimmune serum in rabbits. Three different inoculum were prepared to inoculate in the rabbits; (i) Fresh harvested allantoic fluid containing Newcastle disease virus (NDV) Mukteswar vaccine strain; (ii) Freshly harvested ND virus pelletted through centrifuging at 40,000 rpm for two hours and resuspended in normal saline and (iii) Pelletted virus (centrifuged and suspended as in ii) with addition of incomplete Freund's adjuvant. It was observed during the monitoring of haemagglutination inhibition (HI) titre that the serum collected after series of inoculation of 1st and 2nd inoculum provided maximum titre upto 1:256. However, the serum collected after series of injection of 3rd inoculum gave maximum HI titre 1:1024. This study suggested that antigen containing incomplete Freund's adjuvant provided better immune response against Newcastle disease virus in rabbits.