scholarly journals Host Susceptibility toBrucella abortusInfection Is More Pronounced in IFN-γknockout than IL-12/β2-Microglobulin Double-Deficient Mice

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ana Paula M. S. Brandão ◽  
Fernanda S. Oliveira ◽  
Natalia B. Carvalho ◽  
Leda Q. Vieira ◽  
Vasco Azevedo ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cd8 T Cells ◽  
Bacterial Load ◽  
Bacterial Pathogen ◽  
Domestic Animals ◽  
Host Susceptibility ◽  
Mouse Splenocytes ◽  
Host Immune Responses ◽  
Deficient Mice

Brucella abortusis a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. IFN-γ, IL-12, and CD8+ T lymphocytes are important components of host immune responses againstB. abortus. Herein, IFN-γand IL-12/β2-microglobulin (β2-m) knockout mice were used to determine whether CD8+ T cells and IL-12-dependent IFN-γdeficiency would be more critical to controlB. abortusinfection compared to the lack of endogenous IFN-γ. At 1 week after infection, IFN-γKO and IL-12/β2-m KO mice showed increased numbers of bacterial load in spleens; however, at 3 weeks postinfection (p.i.), only IFN-γKO succumbed toBrucella. All IFN-γKO had died at 16 days p.i. whereas death within the IL-12/β2-m KO group was delayed and occurred at 32 days until 47 days postinfection. Susceptibility of IL-12/β2-m KO animals toBrucellawas associated to undetectable levels of IFN-γin mouse splenocytes and inability of these cells to lyseBrucella-infected macrophages. However, the lack of endogenous IFN-γwas found to be more important to control brucellosis than CD8+ T cells and IL-12-dependent IFN-γdeficiencies.

scholarly journals CD8 Knockout Mice Are Protected from Challenge by Vaccination with WR201, a Live Attenuated Mutant ofBrucella melitensis

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Samuel L. Yingst ◽  
Mina Izadjoo ◽  
David L. Hoover
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cd8 T Cells ◽  
Knockout Mice ◽  
Present Report ◽  
Serum Antibody ◽  
Cytotoxic Cells ◽  
Knockout Animals ◽  
Deficient Mice

CD8+ T cells have been reported to play an important role in defense againstB. abortusinfection in mouse models. In the present report, we use CD8 knockout mice to further elucidate the role of these cells in protection fromB. melitensisinfection. Mice were immunized orally by administration ofB. melitensisWR201, a purine auxotrophic attenuated vaccine strain, then challenged intranasally withB. melitensis16M. In some experiments, persistence of WR201 in the spleens of CD8 knockout mice was slightly longer than that in the spleens of normal mice. However, development of anti-LPS serum antibody, antigen-induced production ofγ-interferon (IFN-γ) by immune splenic lymphocytes, protection against intranasal challenge, and recovery of nonimmunized animals from intranasal challenge were similar between normal and knockout animals. Further, primaryBrucellainfection was not exacerbated in perforin knockout and Fas-deficient mice and these animals’ anti-Brucellaimmune responses were indistinguishable from those of normal mice. These results indicate that CD8+ T cells do not play an essential role as either cytotoxic cells or IFN-γproducers, yet they do participate in a specific immune response to immunization and challenge in this murine model ofB. melitensisinfection.

Defective lung CD8+ T cells lacking NFATc2 induced lung metastasis in NFATc2 deficient mice in a bronchoalveolar adenocarcinoma murine model

Pneumologie ◽  
2007 ◽  
Vol 61 (01) ◽  
Author(s):  
JH Maxeiner ◽  
R Karwot ◽  
K Sauer ◽  
P Scholtes ◽  
R Wiewrodt ◽  
...  
Keyword(s):  
T Cells ◽  
Lung Metastasis ◽  
Cd8 T Cells ◽  
Murine Model ◽  
Deficient Mice

CCR5 deficiency decreases susceptibility to experimental cerebral malaria

Blood ◽  
2003 ◽  
Vol 101 (11) ◽  
pp. 4253-4259 ◽  
Author(s):  
Elodie Belnoue ◽  
Michèle Kayibanda ◽  
Jean-Christophe Deschemin ◽  
Mireille Viguier ◽  
Matthias Mack ◽  
...  
Keyword(s):  
T Cells ◽  
Cerebral Malaria ◽  
Cd8 T Cells ◽  
Cytokine Production ◽  
Wild Type ◽  
Experimental Cerebral Malaria ◽  
Pathologic Features ◽  
Th1 Cytokine ◽  
The Brain ◽  
Deficient Mice

Abstract Infection of susceptible mouse strains with Plasmodium berghei ANKA (PbA) is a valuable experimental model of cerebral malaria (CM). Two major pathologic features of CM are the intravascular sequestration of infected erythrocytes and leukocytes inside brain microvessels. We have recently shown that only the CD8+ T-cell subset of these brain-sequestered leukocytes is critical for progression to CM. Chemokine receptor–5 (CCR5) is an important regulator of leukocyte trafficking in the brain in response to fungal and viral infection. Therefore, we investigated whether CCR5 plays a role in the pathogenesis of experimental CM. Approximately 70% to 85% of wild-type and CCR5+/- mice infected with PbA developed CM, whereas only about 20% of PbA-infected CCR5-deficient mice exhibited the characteristic neurologic signs of CM. The brains of wild-type mice with CM showed significant increases in CCR5+ leukocytes, particularly CCR5+ CD8+ T cells, as well as increases in T-helper 1 (Th1) cytokine production. The few PbA-infected CCR5-deficient mice that developed CM exhibited a similar increase in CD8+ T cells. Significant leukocyte accumulation in the brain and Th1 cytokine production did not occur in PbA-infected CCR5-deficient mice that did not develop CM. Moreover, experiments using bone marrow (BM)–chimeric mice showed that a reduced but significant proportion of deficient mice grafted with CCR5+ BM develop CM, indicating that CCR5 expression on a radiation-resistant brain cell population is necessary for CM to occur. Taken together, these results suggest that CCR5 is an important factor in the development of experimental CM.

scholarly journals Direct and Indirect endocrine-mediated suppression of human endometrial CD8+T cell cytotoxicity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Z. Shen ◽  
M. Rodriguez-Garcia ◽  
M. V. Patel ◽  
C. R. Wira
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Cytotoxic Activity ◽  
Cd8 T Cells ◽  
Immune Cells ◽  
Cd8 T Cell ◽  
Gynecological Cancers ◽  
Protective Strategies ◽  
T Cell Cytotoxicity

AbstractRegulation of endometrial (EM) CD8+T cells is essential for successful reproduction and protection against pathogens. Suppression of CD8+T cells is necessary for a tolerogenic environment that promotes implantation and pregnancy. However, the mechanisms regulating this process remain unclear. Sex hormones are known to control immune responses directly on immune cells and indirectly through the tissue environment. When the actions of estradiol (E2), progesterone (P) and TGFβ on EM CD8+T cells were evaluated, cytotoxic activity, perforin and granzymes were directly suppressed by E2 and TGFβ but not P. Moreover, incubation of polarized EM epithelial cells with P, but not E2, increased TGFβ secretion. These findings suggest that E2 acts directly on CD8+T cell to suppress cytotoxic activity while P acts indirectly through induction of TGFβ production. Understanding the mechanisms involved in regulating endometrial CD8+T cells is essential for optimizing reproductive success and developing protective strategies against genital infections and gynecological cancers.

MIP-1α and MIP-1β differentially mediate mucosal and systemic adaptive immunity

Blood ◽  
2003 ◽  
Vol 101 (3) ◽  
pp. 807-814 ◽  
Author(s):  
James W. Lillard ◽  
Udai P. Singh ◽  
Prosper N. Boyaka ◽  
Shailesh Singh ◽  
Dennis D. Taub ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Adaptive Immunity ◽  
Cd8 T Cells ◽  
Host Cells ◽  
Secretory Iga ◽  
Specific Cell ◽  
Cellular Immune Responses ◽  
Cc Chemokines ◽  
Cellular Immune

AbstractMacrophage inflammatory protein-1α (MIP-1α) and MIP-1β are distinct but highly homologous CC chemokines produced by a variety of host cells in response to various external stimuli and share affinity for CCR5. To better elucidate the role of these CC chemokines in adaptive immunity, we have characterized the affects of MIP-1α and MIP-1β on cellular and humoral immune responses. MIP-1α stimulated strong antigen (Ag)–specific serum immunoglobulin G (IgG) and IgM responses, while MIP-1β promoted lower IgG and IgM but higher serum IgA and IgE antibody (Ab) responses. MIP-1α elevated Ag-specific IgG1 and IgG2b followed by IgG2a and IgG3 subclass responses, while MIP-1β only stimulated IgG1 and IgG2b subclasses. Correspondingly, MIP-1β produced higher titers of Ag-specific mucosal secretory IgA Ab levels when compared with MIP-1α. Splenic T cells from MIP-1α– or MIP-1β–treated mice displayed higher Ag-specific Th1 (interferon-γ [IFN-γ]) as well as selective Th2 (interleukin-5 [IL-5] and IL-6) cytokine responses than did T cells from control groups. Interestingly, mucosally derived T cells from MIP-1β–treated mice displayed higher levels of IL-4 and IL-6 compared with MIP-1α–treated mice. However, MIP-1α effectively enhanced Ag-specific cell-mediated immune responses. In correlation with their selective effects on humoral and cellular immune responses, these chemokines also differentially attract CD4+ versus CD8+ T cells and modulate CD40, CD80, and CD86 expressed by B220+ cells as well as CD28, 4-1BB, and gp39 expression by CD4+ and CD8+ T cells in a dose-dependent fashion. Taken together, these studies suggest that these CC chemokines differentially enhance mucosal and serum humoral as well as cellular immune responses.

scholarly journals A role for CD9 molecules in T cell activation.

1996 ◽  
Vol 184 (2) ◽  
pp. 753-758 ◽  
Author(s):  
X G Tai ◽  
Y Yashiro ◽  
R Abe ◽  
K Toyooka ◽  
C R Wood ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Expression Cloning ◽  
Wild Type ◽  
Almost All ◽  
Antigen Presenting ◽  
Deficient Mice

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.

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