T Helper Cell Type 1 (Th1)- and Th2-like Responses Are Present in Mice with Gastric Candidiasis but Protective Immunity Is Associated with Th1 Development

Abstract

The relative contributions of local T helper cell type 1 (Th1)- and Th2-like responses to the course of primary and secondary gastrointestinal (GI) candidiasis were examined in adult immunocompetent BALB/c mice. Both Th1 cytokines, such as interferon-gamma (IFN-gamma), and the Th2 cytokines, interleukin (IL)-4 and IL-5, were produced by CD4+ cells from Peyer's patches (PP) and mesenteric lymph nodes at a time when the fungus was cleared from the stomach and intestine. Augmentation of antigen-specific Th2-like responses by treatment with cholera toxin did not modify the course of disease. In contrast, treatment with soluble IL-4 receptor, which increased Th1 cells, was associated with enhanced yeast clearance. In addition, IFN-gamma but not IL-4 mRNA was present in PP and spleen CD4+ cells in mice resistant to subsequent GI inoculation. Activation of Th1- but not Th2-like responses may be responsible locally for controlling GI candidiasis and generating protective immunity.

Depletion of CD8+ T Cells Exacerbates CD4+ Th Cell-Associated Inflammatory Lesions During Murine Mycoplasma Respiratory Disease

“…Despite past studies demonstrating that T cells are pivotal in the progression of mycoplasma respiratory disease (11), little is known about the T cell responses and their association with pathogenesis of any mycoplasma disease. In particular, the activation of Th1 and Th2 cell subsets has not been examined in any mycoplasma disease, despite their impact in the progression and pathology of other diseases (27)(28)(29)(30)(31)(32)(33)(34)(35). Because of the critical role that T cell responses have in modulating immunity, it is important to ascertain which T cell populations are responding to the mycoplasma infection and their contribution to disease pathogenesis.…”

“…In contrast, Th2 cells control Ab responses through their secretion of characteristic cytokines (e.g., IL-4). Studies have shown that Th cell subset activation is important in the control of other infectious diseases (27)(28)(29)(30)(31)(32)(33)(34)(35), but their impact on mycoplasma respiratory disease is unknown. In addition, CD8 ϩ T cells are also known to impact on the progression of inflammatory diseases, as they can regulate these responses (36,37) or cause lung injury through CD8 ϩ T cell-mediated apoptosis (38 -40).…”

B7/CD28-Dependent CD4+CD25+ Regulatory T Cells Are Essential Components of the Memory-Protective Immunity to Candida albicans

“…Early studies implicated the balance of protective Th1 and pathogenic Th2 responses as major regulators of immunity to the fungus (1, 2). Indeed, both Th2 and Th1 cell responses were concomitantly detected in mice with gastrointestinal candidiasis (5). However, the detection of Th2 responses, such as high level production of IL-4, IL-10, and IgE may or may not be observed in conditions of susceptibility to C. albicans infection (1).…”

Autoimmune Regulator (AIRE) Gene Is Expressed in Human Activated CD4+ T‐Cells and Regulated by Mitogen‐Activated Protein Kinase Pathway

“…There is a strong correlation between the incidence of oropharyngeal candidiasis and reduced blood CD4 ϩ T-cell numbers (9,28). Experimental studies have also revealed the importance of CD4 ϩ T-cells for protection against candida infections (3,24). Specifically, it has been shown that Th1-type response, characterized by antigen-stimulated lymphocyte production of IL-2, IFN-γ and delayed-type hypersensitivity reactions, are associated with protection against candida (25,26).…”