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Host Defenses Against Prototypical Intracellular Protozoans, the Leishmania
Published in Peter D. Walzer, Robert M. Genta, Parasitic Infections in the Compromised Host, 2020
Richard D. Pearson, Mary E. Wilson
Circulating antibodies do not lead to resolution of infection. In general, the magnitude of the circulating antileishmanial antibody response is inversely proportional to the extent and progression of disease in both humans and animals (117,150,151). High antileishmanial antibody titers are found in patients with visceral leishmaniasis, while specific antibodies are absent or at low titer in patients with localized, self-healing cutaneous lesions. Passive transfer of serum has failed to protect animals against amastigote challenge (117,152,153). It is possible, however, that antibodies present during progressive leishmaniasis are not directed against protective parasite epitopes. Interestingly, immune sera from convalescent animals have been shown to augment the level of adoptive immunity expressed in recipient animals when administered concurrently with immune T cells (117).
Dermatophytosis
Published in Rebecca A. Cox, Immunology of the Fungal Diseases, 2020
Green and Balish136 have found that guinea pigs infected experimentally with T. mentagrophytes show suppression of blastogenic responses of lymph node lymphocytes to antigenic extracts of the organism as well as to nonspecific B- and T-cell mitogens. This form of suppression appears to be due to a serum factor, since the responses were higher if the medium contained fetal calf serum instead of autologous guinea pig serum. Interestingly, the animals could mount positive delayed skin test responses to the antigen even at times when the in vitro blastogenesis was suppressed. Calderon and Hay137 reported that in BALB/c mice the in vitro blastogenic responses of regional lymph node lymphocytes are suppressed to both B-cell and T-cell mitogens during experimental dermatophytosis. Suppression in this system was found to be mediated by T-lymphocytes and could be reversed by removing the suppressor T-cells using anti-Thy-1.2 or anti-LyT-2.2 antisera and complement. These authors also have found using sublethally irradiated BALB/c mice with chronic dermatophytosis that lymph node cells from these animals can confer adoptive immunity to irradiated recipients.138 However, this adoptive immunity could be blocked by serum from the chronically infected donors or by dermatophyte antigen. Using an ELISA system, dermatophyte antigen was found in the serum of both acutely and chronically infected animals, but the latter contained greater amounts. This finding suggests that circulating antigen could be responsible for suppression of cell-mediated immunity by serum in this system and perhaps in some human patients with extensive, chronic infections.
Precision medicine for colorectal cancer
Published in Debmalya Barh, Precision Medicine in Cancers and Non-Communicable Diseases, 2018
Candan Hızel, Şükrü Tüzmen, Arsalan Amirfallah, Gizem Çalıbaşı Koçal, Duygu Abbasoğlu, Haluk Onat, Yeşim Yıldırım, Yasemin Baskın
In the last few years years increasing proof from genetically engineered mice and clinical epidemiology have shown the significance of the immune barrier in formation and progression of tumors (Hanahan and Weinberg, 2011). The development of cancer in immunodeficient mice and the existence of antitumor immune responses in colon and ovarian cancers has been supported through clinical epidemiology studies (Pagès et al., 2010). During growth of cancer cells, the major histocompatibility complex (MHC) interacts with T-cell receptor (TCR) and expresses CD4+ or CD8+ lineage markers (Sukari et al., 2016). Both innate immunity (natural killer [NK] cells, unconventional T lymphocytes, and tumor infiltrating macrophages [TIM]) and adoptive immunity (intratumoural memory CD8T cells, and tumor-infiltrating CD45RO+ memory T lymphocytes [CD45RO+ T cells]) have an important role in the development as well as in prevention and recurrence of CRC tumors leading to better prognosis of colorectal cancers (Sandel et al., 2005; Galon et al., 2006; Sanchez-Castañón et al., 2016). Expression of tumor-associated antigens (TAAs), such as Wilms’ tumor gene 1 (WT1), carcinoembryonic antigen (CEA), mucin 1 (MUC1), and melanoma-associated antigen gene (MAGE) in human CRC cells make it an appropriate and potential target for immunological-based therapies (Kajihara et al., 2016). In CRC genetic and epigenetic aberrations due to CIN pathway, MSI phenotype, and CIMP could lead to manifold oncogenes mutations, resulting in immunogenic CRC (i.e., capable of inducing an immune response). Thus, since dendritic cell–based cancer immunotherapy induces TAAs (CEA, WT1, MAGE, and MUC1) in CRC cells, it is anticipated that a combination of immunotherapy with conventional chemotherapy and/or radiotherapy, surgery, and even with immune-checkpoint inhibitors could mediate a potent antitumor effect (Koido et al., 2012; Kajihara et al., 2016). Furthermore, since TILs interact most closely with the tumor cells and reflect tumor host interactions more accurately (Holmes, 1985), it is demonstrated that CRC patients with MSI tumors owing to high levels of TILs have better prognosis (Michael-Robinson et al., 2001; Phillips et al., 2004).
Expression of miR-425-5p in Pancreatic Carcinoma and Its Correlation with Tumor Immune Microenvironment
Published in Journal of Investigative Surgery, 2023
Shuo Jian, Dehua Kong, Jieli Tian
The interactions between immune cells, tumor cells, and cytokines present in the tumor immune microenvironment (TIME), which are classified into pro-tumor or anti-tumor, primarily determine the tendency of anti-tumor immunity, and despite the elimination of tumors by immune system via the cancer immune cycle, tumors seem to ultimately evade immune surveillance by forming an immunosuppressive microenvironment [15]. An existing study has uncovered that malignant progression, resistance to therapy, and poor prognosis of PC are strongly associated with the immunosuppressive property of tumor microenvironment (TME) [16]. Among the immune cells in the TME, T lymphocytes (especially CD4+ and CD8+) interact with tumor cells to maintain the suppressive TIME, further impacting the occurrence, development, and metastasis of tumors [17–19]. The CD8 T cell priming is essentially directed as a corroboration work between innate immune cells such as natural killer (NK) cells with the CD4+ T cells in adoptive immunity [20]. T regulatory lymphocytes (Tregs) can repress abnormal and excessive immune responses to nonself- or self-antigens to sustain immune homeostasis, which is also implicated in tumor development by inhibiting anti-tumor immunity [21]. Therefore, it is of paramount significance to investigate the TIME in PC and the composition and inhibitory characteristics of TIME to provide new ideas for immunotherapy of PC.
Cell therapy for cytomegalovirus infection
Published in Expert Opinion on Biological Therapy, 2021
The issues with resistance and drug-associated toxicity still lead to high levels of CMV-related morbidity post HSCT. Non-relapse mortality (NRM) rates for patients with chemorefractory CMV can be as high as 17.1% [44]. As the immune response to CMV requires T-cell reconstitution, which can take up to several months post allograft, several groups have looked at the adoptive transfer of CMV-specific T-cells to hasten this process. Bulk donor lymphocyte infusion (DLI) was one of the earliest attempts at providing adoptive immunity post-transplant, based on the principle that DLI should contain virus-specific memory T-cells [45]. However, because of the relatively low frequencies of CMV-specific T-cells within the DLI, and the presence of alloreactive T-cells within unselected DLI there were significant issues with Graft vs. Host Disease (GvHD) [46]. Despite these issues, this prompted interest into exploring the use of T-cells enriched for CMV reactivity.
The effects of cadmium exposure in the induction of inflammation
Published in Immunopharmacology and Immunotoxicology, 2020
Nikoo Hossein-Khannazer, Gholamreza Azizi, Solat Eslami, Hussaini Alhassan Mohammed, Farimah Fayyaz, Ramin Hosseinzadeh, Abubakar B. Usman, Ali N. Kamali, Hamed Mohammadi, Farhad Jadidi-Niaragh, Emad Dehghanifard, Mohammad Noorisepehr
They are various studies regarding the effects of cadmium on adaptive immune responses, the most relevant ones, is in a study by Wang et al. In this study the effects of CdCl2 and another environmental pollutant chlorpyrifos (CPF) on immune reactions were assessed. This investigation showed that both CdCl2 and CPF altered immune functions. Cd and CPF decreased splenoctyes proliferation and function. They also had a great impact on cytokine production by splenocytes. The results indicated that these elements decreased INF-γ production significantly. Cd and CPF had synergistic effect on inhibiting adoptive immunity was time and dose dependent [73]. In another study, it is demonstrated that Cd exposure had a significant impact on inducing oxidative stress and following immunosuppression in head kidney of common carp [74].