زمينه و هدف: گونههاي لاكتوباسيلوس بهدليل داشتن توانايي تعديل پاسخهاي ايمني در انسان و اثرات درماني در اختلالات التهابي، بهعنوان باكتريهاي پروبيوتيك در نظر گرفته شدهاند. هدف از اين مطالعه بررسي اثرات استرينهاي پروبيوتيكي لاكتوباسيلوس بر روي بيان ژنهاي TLR2, TLR4 در ردهي سلولهاي سرطان كولون (HT-29) عفوني شده با سالمونلا انتريتيديس بود.
روش بررسي: اين مطالعه تجربي از فروردين تا اسفند 1395 در مركز تحقيقات ميكروبيولوژي مواد غذايي دانشگاه علوم پزشكي تهران اﻧﺠﺎم ﺷﺪ. در اين مطالعه از دو سويه لاكتوباسيلوس اسيدوفيلوس PTCC1643 و لاكتوباسيلوس كازيي PTCC 1608 استفاده شد. سلولهاي HT29 كشت داده شدند و سپس اين سلولها پيش و پس از چالش با پاتوژن، توسط سويههاي پروبيوتيكي لاكتوباسيلوس تيمار شدند. پس از استخراج RNA تام از سلولها و سنتز cDNA، توانايي لاكتوباسيلوسها در تعديل بيان ژنهاي TLR-2 و TLR-4 توسط روش Real-time PCR مورد بررسي قرار گرفت.
يافتهها: يافتههﺎي ﻣﺎ نشان داد ﮐﻪ پس از تيمار ﺳﻠﻮلهﺎي ﺳﺎﻟﻢ و غيرعفوني HT29، ﺑﺎ هﺮ يﮏ از دو ﺑﺎﮐﺘﺮي ﭘﺮوﺑﯿﻮﺗﯿﮏ، ﺑﯿﺎن ژنهﺎي TLR2-4 ﺑﻪﻃﻮر چشمگيري اﻓﺰايﺶ داشت. ﺑﺮﺧﻼف آن، ﻣﯿﺰان ﺑﯿﺎن ايﻦ دو ژن در ﺳﻠﻮلهﺎي آﻟﻮده ﺑﻪ ﺳﺎﻟﻤﻮﻧﻼ اﻧﺘﺮيﺘﯿﺪيﺲ، پيش و پس از درﻣﺎن ﺑﺎ هﺮ يﮏ از ﺑﺎﮐﺘﺮيهﺎي ﭘﺮوﺑﯿﻮﺗﯿﮏ ﻻﮐﺘﻮﺑﺎﺳﯿﻠﻮس اﺳﯿﺪوﻓﯿﻠﻮس و ﻻﮐﺘﻮﺑﺎﺳﯿﻠﻮس ﮐﺎزيي ﺑﻪصورت معناداري ﮐﺎهﺶ يﺎﻓﺖ (0/05
چكيده لاتين :
Background: Probiotics are living organisms that are beneficial for human health.
Lactobacillus species has been considered as probiotic bacteria due to their adjustment
of human immune responses and therapeutic effects in inflammatory disorders. The aim
of the present study was to evaluate the effects of Lactobacillus probiotic strains on
toll-like receptors (TLR2 and TLR4) expression in HT29 cell line (a human colon cancer
cell line) infected with S. enteritidis.
Methods: This experimental study was done in Food Microbiology Research Center of
Tehran University of Medical Sciences, Iran, from March 2016 to February 2017. In
this study, two strains of Lactobacillus acidophilus PTCC 1643 and Lactobacillus casei
PTCC 1608 were used. HT29 cells were cultured in RPMI medium containing fetal
bovine serum and antibiotics. Then, the cells were treated with the Lactobacillus
strains, after or before challenge with S. enteritidis. After total RNA extraction and
cDNA synthesis, the capacity of probiotic lactobacilli to modulate TLR2 and TLR4
expression on treated and un-treated HT29 cells were assessed quantitatively using Real-
time polymerase chain reaction technique with specific primers.
Results: Our findings indicated that after treatment of non-infected HT29 cells, with
both the probiotics, the expression of TLR2 and TLR4 genes significantly increased. In
contrast, the expression of these two genes in HT29 cells which were infected with S.
Enteritidis was significantly reduced before and after treatment with each one of the
probiotic bacteria. The anti-inflammatory effect of probiotic lactobacilli on S. enteritidis
were confirmed in tests. This study showed that L. acidophilus and L. casei play a major
role in boosting the innate immune responses, the TLR2 and TLR4 expression levels
also decreased, pre and post-infection with S. enteritidis.
Conclusion: According to the results, both Lactobacillus strains have remarkable antiinflammatory
effect in pathogenicity of S. enteritidis, but L. acidophilus display greater antiinflammatory
activity than L. casei in this work. Additional in vivo and in vitro studies are
required to further elucidate the mechanisms underlying this anti-inflammatory effect.