the following examples set forth preferred materials and procedures in accordance with the present invention . it is to be understood , however , that these examples are provided by way of illustration only , and nothing therein should be deemed a limitation upon the overall scope of the invention . this example describes the isolation and sequencing of the protein of the present invention . in order to separate proteins from lawsonia intracellularis (“ lawsonia ”), lawsonia was first grown under standard conditions in a container having 1 l volume using mccoy cells . the extracellular lawsonia cells were harvested by first filtering the culture through a 5 micron filter in order to remove the mccoy cells and other cell debris . this was then followed by centrifugation sufficient to pellet the bacteria . the supernatant was discarded and the pellet was then washed with in pbs to remove residual media components . after washing , the pellet primarily contained lawsonia cells . this final preparation of cells was then dissolved in 2 ml solution of 50 mm tris buffer ( ph 8 . 0 ), 5 mm 2 - mercaptoethanol (“ 2 - me ”), and 8m urea buffer . after extraction for approximately 30 minutes , the mixture was centrifuged for 10 minutes at 20 , 000 × g in order to remove urea - insoluble material . the resulting urea - soluble material was then loaded onto a 1 ml q sepharose anion exchange column , where the proteins were separated over a gradient of 0 - 0 . 6 m nacl over 20 column volumes . one milliliter fractions were then collected , and peak fractions were separated in a second dimension following standard sds - page procedure ( 4 - 12 % bis / tris in mops buffer ). the resulting gel may be viewed as fig1 . following the sds - page , the proteins were then transferred to a pvdf membrane and blotted using swine anti - lawsonia convalescent serum . the serum was diluted to 1 : 100 in a ttbs buffer containing a 2 % blocking reagent ( dry milk ). the membrane was maintained at a constant 30v for over an hour using a novex blot module ( invitrogen , carlsbad , calif .). next , a second blot was done with vpm53 mab , which was diluted to 1 : 50 . next , the membrane was washed three times with ttbs . each wash lasted two minutes . the membrane was then incubated for at least one hour with a secondary antibody . this secondary antibody was goat anti - swine - hrp ( kpl , gaithersburg , md . ), which was diluted to 1 : 1000 in ttbs + 2 % dry milk . the membrane was then washed twice for two minutes with ttbs , then washed once for two minutes with pbs . detection of the protein was accomplished with a opti - 4cn substrate ( bio - rad , hercules , calif . ), which was developed for about 30 minutes , then rinsed with water to stop . the results of the blots may be seen in fig2 and fig3 . the resulting protein shown is a ˜ 52 kda protein that was detected by the convalescent serum . the fractions containing the above - mentioned protein were then concentrated by tca / acetone precipitation and then suspended in a 1 × sds - page buffer containing 10 mm 2 - me . the proteins were then separated using standard sds - page procedure ( 4 - 12 % bis / tris in mops buffer ). the proteins were then transferred from the gel to a pvdf membrane . the membrane was maintained at a constant 30 v for at least one hour using the novex blot module before being dried completely and stained with an aqueous coomassie blue stain ( invitrogen , carlsbad , calif .). the approximately 52 kda protein corresponding to that which was detected by western blot was then excised from the blot using a sterile razor blade . the excised protein was then sent to the protein facility at iowa state university for n - terminal sequencing . the resulting sequence , idfkakgvwdfnfe , is designated seq id no . 1 . the n - terminal sequence was utilized to search various databases for homologous sequences . the top hit protein was from desulfovibrio spp ., a closely related organism to lawsonia . it is likely that this protein has a signal sequence and characteristics of an outer membrane protein , thereby rendering this protein an excellent candidate for incorporation into an immunogenic composition or vaccine operable for eliciting an immune response in swine . such an immune response will provide a degree of protective immunity against lawsonia infection . this example describes the isolation and sequencing of a three other proteins of the present invention . extracellular lawsonia cells were prepared by filtering the culture through a five μm filter and centrifuging under conditions sufficient to pellet the bacteria . the resulting pellet was suspended in buffer a , which comprised 2 . 5 ml of 50 mm sodium phosphate , 0 . 5 m nacl , and 5 mm 2 - me , at a ph of 7 . 4 ). the cells were disrupted through sonication before being subjected to three freeze / thaw three cycles , each comprising one minute pulses with 0 . 5 second duty cycles for a total often minutes . the sonication step was repeated once more for about five minutes and the resultant mixture ( the whole cell lysate ) was frozen and stored at − 85 ° c . until it was removed for use . to fractionate the proteins from the whole cell lysate , the lysate was thawed and then transferred to two eppe tubes that were centrifuged for five minutes at 20 , 000 × g at 4 ° c . this produced a first supernate and a first pellet . the first supernate was centrifuged at 100 , 000 × g at 4 ° c . for 1 . 5 hours to produce a second supernate and a second pellet . this second supernate is labeled as supe ( cytosol ) 1 in fig4 and the pellet is labeled as pellet 2 in fig4 . the first pellet from the initial centrifugation of the thawed whole cell lysate was extracted with buffer a plus 1 % octylglucoside . this was centrifuged for five minutes at 20 , 000 × g at 4 ° c . to produce a third pellet and supernate . the third supernate was then centrifuged the same as the first supernate in order to produce a fourth supernate product , which is labeled as supe ( octyl soluble ) 3 and a fourth pellet , labeled pellet 4 in fig4 . the third pellet was again extracted with butter a , this time with 1 % sarkosyl before centrifuging at 20 , 000 × g for five minutes at 4 ° c . this produced a fifth pellet and fifth supernate . the fifth pellet is labeled as pellet 5 in fig4 . the filth supernate was centrifuged in the same manner as the previous supernates in order to produce a sixth supernate , which is labeled in fig4 as supe ( sarkosyl soluble ) 6 , and a sixth pellet , which is labeled in fig4 as pellet 7 . each of the samples obtained in this example were then subjected to coomassie blue staining , the results of which are shown in fig5 . in that figure , lanes 3 - 9 correspond to fractionated proteins 1 - 7 , as shown in fig4 . fractionated proteins 3 , 5 , and 6 ( supe 3 , pellet 5 , and supe 6 ) were then subjected to western blot analysis using convalescent pig serum . the proteins labeled 3 , 5 , and 6 were transferred from gel to pvdf membrane , which was then subjected to a constant 30 v for at least one hour using a novex blot module . this was blocked for at least one hour in about 50 ml ttbs plus 2 % dry milk ( w / v ). the ttbs is made by adding 0 . 05 % of freshly prepared tween 20 to one liter of a 10 × tbs solution comprising a filter sterilized mixture of 200 ml of 1 m tris at a ph of 8 , and 292 . 2 grams nacl , that has been ph adjusted to 7 . 4 with hcl and qs to one liter . the membrane was then incubated with a primary antibody ( swine anti - lawsonia intracellularis ) 1 : 100 in ttbs plus 2 % dry milk for at least one hour . this was then washed three times for two minutes each time with ttbs . the membrane was then incubated with a secondary antibody ( goat anti - swine - hrp , kpl , lot # xd047 ) 1 : 1000 in ttbs plus 2 % dry milk for at least one hour . this was then washed twice for two minutes each time with ttbs before washing one time for two minutes with 10 × pbs . one liter of the 10 × pbs solution was made by adding 0 . 96 grams nah 2 po 4 ( monobasic ) anhydrous , 13 . 1 grams na 2 hpo 4 ( dibasic ) anhydrous 87 . 7 grams nacl , all of which are dissolved in water and adjusted to a ph of 7 . 4 and qs to one liter before filter sterilizing . finally , ten ml of opti - 4 cn lot # 99051 was added as the substrate and developed for up to 30 minutes before rinsing with water to stop . fig6 presents the results of the western blot of the respective lawsonia protein fractions , 3 , 5 , and 6 . each western blot is in 4 - 12 % bis - tris / mops gel . for the sample prep , 20 microliters of each fraction was mixed with five microliters of 4 × lds - page buffer . lanes 1 - 6 contained the strict negative control serum ( 1 : 100 ) followed by the conjugate ( 1 : 1000 ). lanes 7 - 11 contained the anti - lawsonia intracellularis serum ( 1 : 100 ) followed by the conjugate ( 1 : 1000 ). lane 1 contained the 10 kda marker ( 5 microliters ), lane 2 contained the prestained marker ( 5 microliters ), lane 3 contained protein fraction 6 ( supe 6 ), lane 4 contained protein fraction 5 ( pellet 5 ), lane 5 contained protein fraction 3 ( supe 3 ), lane 6 was empty , lane 7 contained the 10 kda marker ( 5 microliters ), lane 8 contained the prestained marker ( 5 microliters ), lane 9 contained protein fraction 6 ( supe 6 ), lane 10 contained protein fraction 5 ( pellet 5 ), and lane 11 contained protein fraction 3 ( supe 3 ). replicates of fractions 3 and 6 ( 20 μl each ) were run 10 times on 4 - 12 % nupage gels with mops buffer for transfer to pvdf membranes . these results are given in fig7 and 8 . in fig7 , anti - lawsonia intracellularis serum ( 1 : 50 ) was followed by the conjugate ( 1 : 1000 ) and lanes 3 - 9 correspond to fractions 1 - 7 of fig4 . coomassic stained protein fractions are provided in fig8 where lanes 3 - 9 correspond to fractions 1 - 7 from fig4 . the fractionation procedure resulted in fairly distinctive profiles for each protein fraction . in fig6 , li 1 and li 2 were from supe 6 . these protein fractions are octylglucoside insoluble and sarkosyl soluble and are likely from the cell wall fraction . li 3 and li 4 were from pellet 5 . these protein fractions are octyl and sarkosyl insoluble and appear to be membrane proteins . l15 was from supe 3 and is octyl soluble . this protein fraction is likely from the cell wall . of the fractionated proteins , li 1 and li 6 were excised from the membrane of fig6 and 7 , and their n - terminals were sequenced . the n - terminal sequence from li 6 , from supe 3 , is designated as seq id no . 3 and the n - terminal sequence from li , from supe 6 , is designated as seq id no . 7 . this example provides sub - sequences or seq id nos . 1 and 3 that are immunologically relevant and can be used to illicit an immune response against lawsonia intracellularis , thereby providing an animal susceptible to lawsonia intracellularis infection protective immunity , as well as a lessening of the clinical symptoms associated with infection from lawsonia intracellularis . seq id nos . 1 and 3 were analyzed for potential epitopes using a svm and ann - based ctl epitope prediction tool , as described in vaccine , 2004 aug . 13 ; 22 ( 23 - 24 ): 3195 - 204 , prediction of ctl epitopes using qm , svm , and ann techniques , bhasin m , and raghava g p , institute of microbial technology , sector 39a , chandigarh , india , the teachings and contents of which are incorporated by reference . seq id no . 1 contained 1 epitope , which had a score ( ann / svm ) of 0 . 82 /− 0 . 063950275 . this sequence is provided herein as seq id no . 2 . seq id no . 3 contained four epitopes , seq id no . 4 , which had a score of 0 . 91 / 0 . 68874217 , seq id no . 5 , which had a score or 0 . 73 / 0 . 55686949 , seq id no . 6 , which had a score of 0 . 83 / 0 . 17021055 , and seq id no . 2 . this example describes the formation of a vaccine . generally , any one of or a combination of seq id nos . 1 - 7 are provided for use as the antigenic portion of a vaccine . veterinary - acceptable carriers , such as adjuvants , dilulents , and the like will be added to the vaccine and the vaccine will be administered in any conventional manner .
the present invention provides nucleic acid and amino acid sequences useful as the immunogenic portion of vaccines or immunogenic compositions effective for lessening the severity of the clinical symptoms associated with lawsonia intracellularis infection or conferring protective immunity to an animal susceptible to such infection . preferred amino acid sequences include at least 9 contiguous amino acids from seq id nos 1 , 3 , or 7 . thus , the nucleic acid sequences encoding such proteins , or the proteins themselves are included in vaccine compositions , together with veterinary - acceptable carrier and administered to an animal in need thereof .