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Background: Malaria has high morbidity and mortality rates in some parts of tropical and subtropical countries. Besides respiratory and metabolic function, lung plays a role in immune system. γδT cells have multiple functions in producing cytokines and chemokines, regulating the immune response by interacting with other cells. It remains unclear about the role of γδT cells in the lung of mice infected by malaria parasites., Methods: Flow cytometry (FCM) was used to evaluate the frequency of γδT cells and the effects of γδT cells on the phenotype and function of B and T cells in Plasmodium yoelii-infected wild-type (WT) or γδTCR knockout (γδT KO) mice. Haematoxylin-eosin (HE) staining was used to observe the pathological changes in the lungs., Results: The percentage and absolute number of γδT cells in the lung increased after Plasmodium infection (p < 0.01). More γδT cells were expressing CD80, CD11b, or PD-1 post-infection (p < 0.05), while less γδT cells were expressing CD34, CD62L, and CD127 post-infection (p < 0.05). The percentages of IL-4 + , IL-5 + , IL-6 + , IL-21 + , IL-1α + , and IL-17 + γδT cells were increased (p < 0.05), but the percentage of IFN-γ-expressing γδT cells decreased (p < 0.05) post-infection. The pathological changes in the lungs of the infected γδT KO mice were not obvious compared with the infected WT mice. The proportion of CD3 + cells and absolute numbers of CD3 + cells, CD3 + CD4 + cells, CD3 + CD8 + cells decreased in γδT KO infected mice (p < 0.05). γδT KO infected mice exhibited no significant difference in the surface molecular expression of T cells compared with the WT infected mice (p > 0.05). While, the percentage of IFN-γ-expressing CD3 + and CD3 + CD8 + cells increased in γδT KO infected mice (p < 0.05). There was no significant difference in the absolute numbers of the total, CD69 + , ICOS + , and CD80 + B cells between the WT infected and γδT KO infected mice (p > 0.05)., Conclusions: The content, phenotype, and function of γδT cells in the lung of C57BL/6 mice were changed after Plasmodium infection. γδT cells contribute to T cell immune response in the progress of Plasmodium infection.

Many kinds of lymphocytes are involved in Schistosoma japonicum ( S. japonicum ) infection-induced disease. γδ T cells comprise a small number of innate lymphocytes that quickly respond to foreign materials. In this study, the role of γδ T cells in the lung of S. japonicum -infected C56BL/6 mice was investigated. The results demonstrated that S. japonicum infection induces γδ T cell accumulation in the lung, expressing higher levels of CD25, MHCII, CD80, and PDL1, and lower levels of CD127 and CD62L ( P < 0.05). The intracellular cytokines staining results illustrated higher percentages of IL-4-, IL-10-, IL-21-, and IL-6-producing γδ T cells and lower percentages of IFN-γ-expressing γδ T cells in the lung of infected mice ( P < 0.05). Moreover, the granuloma size in lung tissue was significantly increased in Vδ -/- mice ( P < 0.05). In the lung of S. japonicum -infected Vδ -/- mice, both type 1 and type 2 immune responses were decreased significantly ( P < 0.05). In addition, the expression of CD80 and CD69 on B cells was decreased significantly ( P < 0.05), and the SEA-specific antibody was markedly decreased ( P < 0.05) in the blood of infected Vδ -/- mice. In conclusion, this study indicates that γδ T cells could adjust the Th2 dominant immune response in the lung of S. japonicum -infected mice., (Copyright © 2020 Cha, Xie, Jin, Feng, Xie, Xie, Yang, Qi, Qiu, Wu, Yin, Mu and Huang.)

Despite the paramount role of TLRs in the induction of innate immune and inflammatory responses, there is a paucity of studies on the role of TLRs in Schistosoma japonicum infection. Here, we observed obvious infiltration of inflammatory cells in S. japonicum-infected C57BL/6 mouse lungs. Expression and release of IFN-γ, IL-4, and IL-17 were significantly higher in pulmonary lymphocytes from infected mice compared with control mice in response to anti-CD3 plus anti-CD28 mAbs. Higher percentages of TLR2, TLR3, TLR4, and TLR7 were expressed on such lymphocytes, and the TLR agonists PGN, Poly I:C, LPS, and R848 induced a higher level of IFN-γ. However, a higher level of IL-4 was found in the supernatant of pulmonary lymphocytes from infected mice stimulated by these TLR agonists plus CD3 Ab. Only R848 plus anti-CD3 mAb could induce a higher level of IFN-γ in such lymphocytes. TLR expressions were then compared on different pulmonary lymphocytes after infection, including T cells, B cells, NK cells, NKT cells, and γδT cells. The expression levels of TLR3 on T cells, B cells, NK cells, and γδT cells were increased in the lungs after infection. NK cells also expressed higher levels of TLR4 after infection of control mice. Collectively, these findings highlight the potential role of TLR expression in the context of S. japonicum infection.

Background: Recent studies have shown that CD103 is an important marker for tissue-resident memory T cells (TRM) which plays an important role in anti-infection. However, the role of CD103+ TRM was not elucidated in the progress of S. japonicum infection induced disease.Methods: 6-8 weeks old C57BL/6 mice were infected by S. japonicum. Mice were sacrificed and the lungs were removed 5-6 weeks after infection. Immunofluorescent staining and Q-PCR were performed to identify the expression of CD103 molecule. Single cellular populations were made, percentages of CD103 on both CD4+ and CD8+ T lymphocytes were dynamical observed by flow cytometry (FCM). Moreover, the expression of memory T cells related molecules CD69 and CD62L, T cell function associated molecules CD107a, IFN-γ, IL-4, IL-9, and IL-10 were compared between CD103+ CD4+ and CD8+ T cells by FCM.Results: CD103+ cells were emerged in the lung of both naive and S. japonicum infected mice. Both the percentage and the absolute numbers of pulmonary CD4+ and CD8+ cells were increased after S. japonicum infection (P < 0.05). The percentage of CD103+ cells in CD8+ T cells decreased significantly at the early stage of S. japonicum infection (P < 0.05). Increased CD69, decreased CD62L and CD107a expressions were detected on both CD4+ and CD8+ CD103+ T cells in the lungs of infected mice (P < 0.05). Compared to CD8+ CD103+ T cells, CD4+ CD103+ T cells from infected mice expressed higher level of CD69 and lower level CD62L molecules (P < 0.05). Moreover, higher percentage of IL-4+, IL-9+ and IL-10+ cells on CD4+ CD103+ pulmonary T cells was found in infected mice (P < 0.05). Significantly increased IL-4 and IL-9, and decreased IFN-γ expressing cells were detected in CD8+CD103+ cells of infected mice (P < 0.05).Conclusions: CD103-expressing pulmonary CD4+ and CD8+ T cells play important roles in mediating S. japonicum infection induced granulomatous inflammation in the lung. [ABSTRACT FROM AUTHOR]