Progress 12/01/00 to 11/30/03
Outputs
We optimized the deleivery of protein antigens to macrophages and antigen presenting cells by chemical modification, followed by titration of antigen dosage. Broiler chickens were immunized with maleyl-proteins and found to have significantly greater signal in the tests for Th1 parameters over Th2 parameters as compared to the birds immunized with native protein with or without additional adjuvants such as alum. Alum in combination with maleylated proteins resulted in mixed Th1 and Th2 responses whereas maleylated proteins alone favored the Th1 responses. Thus depending on the optimal protection type [Th1 or a mixed response] one can choose the immunization scheme. We found that immunization of hatchlings was not as potent as immunization of adult birds. Immunization was demonstrable after day 7 after hatch in broiler birds with maleyl groups covalently conjugated to poly-l-lysine and then mixed with recombinate Eimeria protein on alum. Preferable in magnitude was the
direct conjugation of maleyl to recombinate Eimeria protein but both were superior to non-malylated poly-l-lysine or protein. Analysis was via wattle swelling and interferon-gamma production. RNA levels for interferon-gamma were both quantitative PCR using real-time methods. Protection against Eimeria infection been followed in one collaborative trial. Dr. Hyun Lillihoj provided oocysts and both Drs. David Chapman and Lillihoj gave us advice on how and when to do our initial study. We saw substantial reduction in pathology and oocyst counts. However the protocol is far from optimized.
Impacts
By delivering antigen to scavenger receptors by maleyl-poly-l-lysine, we have provided a basis to screen large numbers of recombinant proteins in a directly comparable fashion in disease situations where Th1 responses are needed for clearing an infectionl Such a tool will simplify and standardize trials for effective reconbinant vaccine candidate proteins and aid in generating protective immunity. As resistance to chemical and antibiotic treatments continues to rise amongst the Eimeria, having multiple effective vaccine strategies will be a plus. The directly maleylatived recombinate Eimeria protein was the best immunigen for protection against intestinal pathology and thus holds strong possibilities for the future.
Publications
- Vandaveer S, Erf G, Durdik J. 2001. Avian Th1/Th2 Immune Response Balance cn be Shifted Towards Inflammation by Antigen Delivery to Scavenger Receptors. Poultry Science 80: 172-181.
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Progress 01/01/02 to 12/31/02
Outputs
We are testing if proteins in general and a recombinant Eimeria protein, 31E, can induce a Th1 response when delivered to scavenger receptors in young broilers and egg-type birds. I. We have defined the earliest times that birds can be immunized. We have discovered that alum biases towards Th2 responses or mixed Th1/2 responses based on delayed type hypersensitivity, interferon gamma production compared with antibody production. II. We are testing the effectiveness of maleylated -poly-l-lysine mixed with unmodified protein and find that poly-l-lysine can act as a universal bridging protein to mix with recombinant or other protein sources to induce Th1 responses. III. In progress is our first trial for protection against Eimeria infection.
Impacts
By delivering antigen to scavenger receptors by maleyl-poly-l-lysine, we have provided a basis to screen large numbers of recombinant proteins in a directly comparable fashion in disease situations where Th1 responses are needed for clearing an infection. Such a tool will simplify and standardize trials for effective recombinant vaccine candidate proteins and aid in identifying vaccination schemes that result in protective immunity. As resistance to chemical/antibiotic treatments continues to rise amongst Eimeria, having multiple effective vaccine strategies will be a plus. This work with directly maleylated 31E and maleyl-poly-l-lysine: 31E will indicate whether this approach will be an option.
Publications
- Vandaveer S, Erf G, Durdik J. 2001. Avian Th1/Th2 immune response balance can be shifted towards inflammation by antigen delivery to scavenger receptors. Poultry Science 80: 172-181.
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Progress 01/01/01 to 12/31/01
Outputs
Optimization of the chemical modification of the immunogen dosage and refining of macrophage delivery of antigen has begun. I. Brioler chickens immunized with maleyl-proteins show a significantly greater signal in the tests for Th1 parameters over Th2 parameters, as compared to the chickens immunized with native protein with or without alum. Immunization with maleyl-proteins on alum as compared with saline augments immune responses. Alum in combination with maleyl-poly-l-lysine or directely maleylaed protein resulted in mixed Th1 and Th2 responses whereas maleyl in other oombinations resulted in Th1 dominated responses in adult birds. II. Immunization with protein antigens is not as potent in hatchlings as in adult birds. Current experiments are determining the earliest time when birds are competent and if adjuvant can overcome the early low responses. III. Immunization of broiler birds at day 7 after hatch with maley1 groups covalently conjugated to poly-l-lysine and
then mixed with recombinate Eimeria protein on alum gave greater wattle swelling and interferon-gamma production than the same protocol using non-malylated poly-l-lysine.
Impacts
We are defining if maleyl-poly-l-lysine can act as a universal bridging protein to mix with recombinant proteins to channel immunity to an inflammatory pathway. This provides a test system for screening large numbers of recombinant proteins in a directly comparable fashion. This eliminates having to directly modify each protein tested. Such a tool will simplify and standardize trails for effective recombinant vaccine candidate proteins and aid in identifying vaccination schemes that result in protective immunity.
Publications
- Vandaveer S, Erf G, Durdik J. 2001 Avain Th1/Th2 Immune Response Balance can be Shifted Towards Inflammation by Antigen Delivery to Scavenger Receptors. Poultry Science 80: 172-181.
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