Studies On Preparation, Bioactivity Test And Application Of Transfer Factor(TF) In Pig's Spleen

The spleens of healthy pigs as raw materials were used in the research, and the spleen's transfer factor (TF) was made by PH adjust-Super filter law, which wais fully in line with biological agent standard in pharmacopoeia of the People's Republic of China, and the process was simple and low in costs, without special equipments and reagents. Results showed that PH of TF was 7.00. TF had a peak at a range of 250 to 260, A260/A280=2.25 when tested by ultraviolet spectra, the content of ribose was 33.51mL by the dihydroxytoluene method, the polypeptide's content was 313.82mL by the biuret method. Glu was the highest content in the relative percentage of free amino acids by high performance liquid chromatographic method, followed by Asp, Gly, Thr and Ala, and the contents of Cys, Arg, His, Met, Tyr and Lys were less relatively. The mice had no toxical reaction when they were injected with TF at a dosage of nearly 60 times of which used in human beings (6 times in concentration), which proved that TF was safe and avirulent. The temperature changes of rabbits were less than 0.6℃after they were injected with pig's spleen TF, and the pyrogenic test was negative. Peripheral blood films were tested under immersion objective after dyed with the improved esterase staining for classification and calculation of the ratio of T cells. The T cell's ratio was 48.9±4.2% before injection with the pig's spleen TF and was 61.5±2.8% after the injection in the tested group, which showed there was a significant difference (p<0.01) by injection of the pig spleen TF. The sterility test, sensitivity test and antigen test were all negative. The pig spleen TF had a very strong depressant effect on Staphylococcus aureus and bacillus coli and which was hyper-sensitive, the diameter of inhibition zone was 25±1.0mm and 40±1.0mm respectively. The depressant effect of the pig spleen TF on Pasteurella was strong and mid-range sensitive, the diameter of inhibition zone was 15±1.0mm. It had a weak depressant effect on chaincoccus which was low-sensitive, the diameter was 12±1.0 mm. It had a significant increase of the percentage and index of phagocytosis of Mφin mice abdominal cavity by pig spleen TF when compared with the control group (p<0.01). But the effect of TF on the weight of spleen was not significant.Hens were immunized with live vaccine of yellow hens and injected with the spleen TF simultaneously. Eggs were collected after the 5th immunization and highly immunized vitelline antibodies against swine pest were obtained and purified by the displacement of PEG 6000. Results showed that the antibody was stable and the titer was high (the vitelline antibody titer was 1:128 after the 5th immunization), without bacteria and adverse reactions. Results of clinical trials showed that the therapeutic efficacy of vitelline antibodies was better than attenuated vaccine of medium doses on swine pest at both early and middle stages, and there was a significant difference between them (P<0.01).Effect of TF on the vaccine of PRRS was observed in the experiment in which TF of pig's spleen was used as an immune adjuvant of PRRS vaccines. Results showed that the antibody emerged later when immunized with PRRS vaccine alone. At 28 day after immunization, the antibody was positive and the value of OD₆₅₀ was 0.51, S/P was 0.77, which had a protection to PRRSV. However, the antibody emerged early when immunized PRRS vaccine mixed with TF. It could gain an effective protection 14 day after immunization. The antibody titer and S/P value were significantly higher than the control group which was used PRRS vaccine alone. It showed that TFwas a kind of effective adjuvant to PRRS vaccine.