Effects Of Lf And Lfcin With Treatments And Sources On The Proliferation Of Splenic Lymphocytes

Infant formula as a kind of breast milk substitutes,is the preferred food of non-breastfeeding babies.The development of infant formula powder aimed at from macroscopic to microcosmic are as close as possible to human milk.Formula powder has meet the requirements of the growth of infants on the nutrition currently,but is lack of active substances which can improve immunity of infants.Human lactoferrin(human lactoferrin,LFH)as an important immune active ingredients in breast milk,is one of the major protein in human milk,accounting for 10% of total protein content of normal milk,is key of enhance the immune system of infants,and is an important index of infant formula to mimic "human milk".Lactoferrin(LF)could release biological active site named lactoferricin(Lfcin)within the hydrolysis of pepsin.Researchs had showed that LF and Lfcin significant effects on against fungi,inflammation and bacteria infection,anticancer,the immunity system regulation of host and the ability to promote wound healing.At present,many countries,including China,LF has been allowed to added to infant formula,but dose has been not clear.The sources of LFH was limited,the price is high,which limited its addition.Bovine lactoferrin(LFB)has similar molecular weight with LFH's.Human lactoferrin shares as high as69% sequence identity with its bocine counterpart.LFB is more convenient to obtain and more cheaper.The peptide Lfcin B is cheapest.It is of great significance to reduce the cost of immune active ingredient in the infant formula powder with active material equivalent components.In this paper,bovine whey lactoferrin(LFW),bovine colostrum lactoferrin(LFC),LFH,Lfcin B and Lfcin H were used as raw material,The cell counting kit-8(CCK-8)assay was used to measure the effects of different LFs and Lfcins on the proliferation of mouse spleen lymphocytes for 24 h,48 h and 72 h,meanwhile,different LFs and Lfcins combined with the mitogen on the proliferation of mouse T and B lymphocytes were studied.ELISA was employed to determine the cell secreted cytokines IL-2,IL-4,IL-10 and TNF – ?.In order to explore the role of the dosage of the optimal dose and substituted proportional relationship.63 ? for 30 min,,72 ? for 15 min72 ? for 15 s,85 ? for 15 min,85 ? for 15 s and 95 ? for 10 min,and simulated LF digestion in vitro,all of the treatments to different Lfs were conducted aimed at study the influence of different processing conditions on the LF bioactivity,in order to provide scientific theory basis for wet processing of LF and the alternative LFH with LFB in infant formula.The results showed that:(1)The two kinds of unprocessed LFB could be used to alternative LFH in infant formula products in order to improve the infant immunity,and the recommended dosage is 0.50 mg/m L-2.00 mg/m L,Lfcin recommended dosage is 75?g/m L-125 ?g/m L(2)The different heating and digestion treatment can change the effects of LF.After processing three resource of LFs could promote the proliferation of lymphocytes either individually or stimulate by Con A and LPS at certain concentration range,and can effectively promote cell secreted cytokines IL-2,IL-4,IL-10 and TNF –?.(3)Heating at 95 ? for 10 min was the best processing for the most promoting among all of the processing conditions,and 85 ? for 30 min,63 ? for 10 min were relatively optimal.LFB heated were equivalent with the effects of LFH's.In summary,we studied the proliferation of lymphocytes and the secretion of cytokines induced by different LFs and Lfcins in vitro,confirmed that heat to LFB could promote both the proliferation of lymphocytes and the secretion of cytokines stimulated by LFB,LFW and LFC could reach the same effect of LFH,but differ in concentrations.This research provided the basis for the LFB instead of LFH,Lfcin replaced LF of infant formula,in order to improve the infant immunity,gave reasons for development of wet mixing LF,and provided support for substitution of LFH and LFcin H by LFB and LFcin B.