Open AccessCathepsin L promotes secretory IgA response by participating in antigen presentation pathways during Mycoplasma Hyopneumoniae infection
Author(s) -
Ning Zhang,
Peng Gao,
Bao Yin,
Jiahe Li,
Tong Lei Wu,
Yu Kuang,
Wenxue Wu,
Jinxiang Li
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0215408
Subject(s) - cathepsin l , immune system , mycoplasma hyopneumoniae , biology , microbiology and biotechnology , antigen , antigen presentation , secretion , mycoplasma , immunology , acquired immune system , cathepsin , t cell , biochemistry , enzyme
Cathepsin L (CTSL) has been proved to help contain leishmaniasis and mycoplasma infection in mice by supporting cellular immune responses, but the regulatory functions of CTSL on mucosal immune responses haven’t been tested and remain undefined. Here, we investigated the effects of CTSL on SIgA responses and invariant chain (Ii) degradations in the co-cultured swine dendritic cells (DCs) and B cells system in vitro . When the cells system were transfected with vector CTSL-GFP or incubated with recombinant CTSL (rCTSL) before they were infected with Mycoplasma hyopneumoniae ( M . hp ), SIgA significantly increased and Ii chain was degraded into smaller intermediates, while SIgA decreased when CTSL was knockdown or inhibited with E64. To confirm the SIgA responses promoted by CTSL contribute to the resistance to mycoplasma pneumonia, pigs injected with rCTSL before they were challenged with M . hp , showed milder clinical symptoms and histopathological damage of lungs, less mycoplasma burden together with higher secretion of SIgA, percentages of CD4 + T cells and level of MHC II molecules comparing with the group without rCTSL. Collectively, these results suggested that rCTSL could provide effective protection for piglets against mycoplasma pneumonia by enhancing M . hp -specific mucosal immune responses through its role in antigen presentation by processing the invariant chain.