The inhibitory co-receptor programmed death 1 （PD-1, encoded by pdcdl） and its two ligands PD-L1 and PD-L2 comprise an important immune inhibitory signaling pathway for defense against microbes and for self-toleranc...The inhibitory co-receptor programmed death 1 （PD-1, encoded by pdcdl） and its two ligands PD-L1 and PD-L2 comprise an important immune inhibitory signaling pathway for defense against microbes and for self-tolerance. Unlike other members of the B7-CD28 family, expression of PD-L1 and PD-L2 is not limited to the immune system. In this study, we determined that a polyclonal antibody （pAb） （R＆D Systems） against extracellular domains of mouse PD-L2 （mPD-L2） could recognize anti- gen（s） in diverse mouse tissues, including the anterior and intermediate pituitary gland, olfactory bulbs and olfactory epitheli- um, tongue epithelium, keratinized epithelial ceils and skin and whisker hair follicles. These findings differed from previous reports of mPD-L2 localization. Reverse transcription PCR and Western blot analyses, however, were unable to detect any mPD-L2 transcripts or proteins of the 25-kD predicted molecular weight in RNA and protein extracts, respectively, from the above tissues, suggesting that the anti-mPD-L2 pAb cross-reacts with certain novel antigen（s）. Developmental studies revealed that the earliest expression of mPD-L2-1ike antigen was in the olfactory epithelium at embryonic day 12.5 （E12.5）. At E14.5, mPD-L2-1ike antigen was present in the skin, tongue and follicles of the skin and whiskers. The distribution patterns of mPD-L2-1ike antigen remained similar from E18.5 to adulthood. The results of bioinformatic analysis and other experiments suggested neural cell adhesion molecule and hemicentin-1 as candidate proteins with cross-reactivity to the anti-mPD-L2 pAb. These results demonstrate that care is required in interpreting staining patterns generated when anti-PD-L2 pAb is used to lo-cate PD-L2-expressing cells in the central nervous system and epithelial tissues, such as the olfactory epithelium. In addition, this anti-PD-L2 pAb may be used as an alternative antibody for labeling the olfactory epithelium during embryonic develop-ment in mice.展开更多
基金supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China (Grant No. HG3102)National Natural Science Foundation of China (Grant No. 81100899)
文摘The inhibitory co-receptor programmed death 1 （PD-1, encoded by pdcdl） and its two ligands PD-L1 and PD-L2 comprise an important immune inhibitory signaling pathway for defense against microbes and for self-tolerance. Unlike other members of the B7-CD28 family, expression of PD-L1 and PD-L2 is not limited to the immune system. In this study, we determined that a polyclonal antibody （pAb） （R＆D Systems） against extracellular domains of mouse PD-L2 （mPD-L2） could recognize anti- gen（s） in diverse mouse tissues, including the anterior and intermediate pituitary gland, olfactory bulbs and olfactory epitheli- um, tongue epithelium, keratinized epithelial ceils and skin and whisker hair follicles. These findings differed from previous reports of mPD-L2 localization. Reverse transcription PCR and Western blot analyses, however, were unable to detect any mPD-L2 transcripts or proteins of the 25-kD predicted molecular weight in RNA and protein extracts, respectively, from the above tissues, suggesting that the anti-mPD-L2 pAb cross-reacts with certain novel antigen（s）. Developmental studies revealed that the earliest expression of mPD-L2-1ike antigen was in the olfactory epithelium at embryonic day 12.5 （E12.5）. At E14.5, mPD-L2-1ike antigen was present in the skin, tongue and follicles of the skin and whiskers. The distribution patterns of mPD-L2-1ike antigen remained similar from E18.5 to adulthood. The results of bioinformatic analysis and other experiments suggested neural cell adhesion molecule and hemicentin-1 as candidate proteins with cross-reactivity to the anti-mPD-L2 pAb. These results demonstrate that care is required in interpreting staining patterns generated when anti-PD-L2 pAb is used to lo-cate PD-L2-expressing cells in the central nervous system and epithelial tissues, such as the olfactory epithelium. In addition, this anti-PD-L2 pAb may be used as an alternative antibody for labeling the olfactory epithelium during embryonic develop-ment in mice.
