Inhibition of Chlamydia pneumoniae growth in HEp-2 cells pretreated with gamma interferon and tumor necrosis factor alpha

Summersgill, James T.; Sahney, Narendra N.; Gaydos, Charlotte A.; Quinn, Thomas C.; Ramírez, Julio

doi:10.1128/iai.63.7.2801-2803.1995

Cited by 99 publications

(30 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In spite of the limited number of analysed TLC, the result is in accordance with the concept that successful host defence against Chlamydia is dependent on the presence of IFNg [29,30], a characteristic product of Th1-type cells [31]. The IFN-g inhibits the growth of chlamydial species [5,30,32], including C. pneumoniae [33]. Activity of Th1 has also been found to be dominant in C. trachomatis-responsive TLC derived from the synovial fluid of Chlamydia-reactive arthritis patients [34].…”

Section: Discussionsupporting

confidence: 82%

Characterization of Chlamydia pneumoniae Antigens Using Human T Cell Clones

1997

View full text Add to dashboard Cite

Halme S, Saikku P, Surcel H-M. Characterization of Chlamydia pneumoniae Antigens Using Human T Cell Clones. Scand J Immunol 1997;45:378-384 Chlamydia pneumoniae infection is followed by the development of antigen-specific cell-mediated immunity (CMI), which is detectable as a positive lymphocyte proliferation (LP) response to C. pneumoniae elementary body (EB) antigen, but the proteins inducing the T cell activation are not known. In the present work the authors used human T lymphocyte clones (TLC) raised against C. pneumoniae EB antigen to characterize C. pneumoniae proteins as T cell-stimulating antigens. A total of 55% of the TLC established recognized antigenic determinants only on C. pneumoniae species, while the rest of the TLC proliferated to both C. pneumoniae and C. trachomatis EB. The antigen specificity of the TLC was further analysed by stimulating with SDS-PAGE fractionated C. pneumoniae EB proteins. Chlamydia pneumoniae species-specific antigens were found in the molecular weight ranges 92-98, 51-55, 43-46 and 31.5-33 kDa and genus-specific antigens in the ranges 12, 26 and 65-70 kDa. The 46.5-49.5 and 55-61 kDa regions contained both speciesspecific and genus-specific antigens. Human leucocyte antigen (HLA) restriction analysis for the TLC isolated from an HLA DR4, 15(2) heterozygous person showed the majority (81.3%) to be restricted to the HLA DR4 molecule, the rest being DR15(2)-restricted. An interesting preliminary finding was that the expression of interferon-gamma (IFN-g) mRNA by the TLC was predominantly associated with antigen recognition in the context of the HLA DR4 molecule, while interleukin-4 (IL-4) production was linked to antigen recognition in the context of the HLA DR15(2) molecule.

show abstract

Section: Discussionsupporting

confidence: 82%

Characterization of Chlamydia pneumoniae Antigens Using Human T Cell Clones

1997

View full text Add to dashboard Cite

show abstract

“…and Toxoplasma gondii. [49][50][51][52][53] Although we should not exclude the possibility that IL-27-mediated induction of IDO may offer some protection for neonates in the control of intracellular growth of some bacteria and parasites, the immunomodulatory activity is likely to make the most significant impact. IDO has been associated with immunosuppressive activity of human macrophages in decidual tissue and at immune privileged sites.…”

Section: Discussionmentioning

confidence: 99%

Elevated interleukin‐27 levels in human neonatal macrophages regulate indoleamine dioxygenase in a STAT‐1 and STAT‐3‐dependent manner

et al. 2016

View full text Add to dashboard Cite

SummaryMicrobial infections are a major cause of infant mortality as a result of limitations in immune defences. ) is a heterodimeric cytokine produced primarily by leucocytes and is immunosuppressive toward lymphocytes and leucocytes. Our laboratory demonstrated that human neonatal macrophages express IL-27 more abundantly than adult macrophages. Similarly in mice, IL-27 expression is elevated early in life and maintained through infancy. To determine IL-27-regulated mechanisms that may limit immunity, we evaluated the expression of a number of genes in response to this cytokine in primary human neonatal macrophages. Indoleamine 2,3-dioxygenase (IDO) gene expression was increased dose-responsively by IL-27. We have previously demonstrated inhibition of T-cell proliferation and cytokine production by neonatal macrophagegenerated IL-27, and IDO is often implicated in this negative regulation. An increase in IDO protein was demonstrated by immunofluorescence microscopy and was consistent with increased enzyme activity following treatment with IL-27. Inclusion of a soluble receptor to neutralize endogenous IL-27, decreased IDO expression and activity compared with untreated macrophages. In response to IL-27, neonatal macrophages phosphorylate signal transdcuer and activator of transcription 1 (STAT-1) and STAT-3. Both transcription factors are recruited to the IDO regulatory region. STAT-3 dominates during steady-state regulation by lower levels of endogenous IL-27 production. A shift to enhanced STAT-1 recruitment occurs during increased levels of exogenously supplied IL-27. These data suggest an interesting interplay of STAT-1 and STAT-3 to regulate IDO activity and immunosuppression in response to different levels of IL-27 in the microenvironment of the immune response that may further our understanding of this interesting cytokine.

show abstract

“…Puri¢ed EBs were suspended in sucrosep hosphate^glutamic acid bu¡er (0.2 M sucrose, 3.8 mM KH 2 PO 4 , 6.7 mM Na 2 HPO 4 , 5 mM L-glutamic acid, pH 7.4) and then stored at 370 ‡C until used. Inclusion forming units (IFUs) of prepared EBs were determined by counting chlamydial inclusions in HEp-2 cell monolayers [17,18]. UV-treated bacteria prepared by placing cultures under UV light was also used as a control.…”

Section: Bacteriamentioning

confidence: 99%

A Chlamydia pneumoniae infection model using established human lymphocyte cell lines

Yamaguchi

2002

FEMS Microbiology Letters

View full text Add to dashboard Cite

Since current studies indicate possible infection of human lymphocytes with Chlamydia (Chlamydophila) pneumoniae, establishment of an in vitro C. pneumoniae infection model using lymphocyte cell lines was demonstrated. Human lymphoid cell lines (Molt 4 [T-cell] and P3HR1 [B-cell]) were utilized for this purpose besides human monocyte cell line (THP-1) and human epithelial cell line (HEp-2), as a reference of monocyte/macrophage cells and a positive control for support of C. pneumoniae growth, respectively. Both lymphoid cells (Molt 4 and P3HR1) supported the growth of C. pneumoniae as demonstrated by Chlamydia inclusion formation, detection of increased infective progenies and increased bacterial antigen levels. Similar data were obtained using monocyte THP-1 cells. However, the bacterial growth in these cells was less than that in HEp-2 cells. The electron microscopic study showed typical inclusions with many Chlamydia elementary bodies in lymphoid cells tested, similar to that seen in HEp-2 cells. These results indicate that C. pneumoniae can infect cells with lymphocyte properties and this infection model with lymphoid cell line cells could be valuable to study details of lymphocyte^C. pneumoniae interaction.

show abstract

Inhibition of Chlamydia pneumoniae growth in HEp-2 cells pretreated with gamma interferon and tumor necrosis factor alpha

Cited by 99 publications

References 18 publications

Characterization of Chlamydia pneumoniae Antigens Using Human T Cell Clones

Characterization of Chlamydia pneumoniae Antigens Using Human T Cell Clones

Elevated interleukin‐27 levels in human neonatal macrophages regulate indoleamine dioxygenase in a STAT‐1 and STAT‐3‐dependent manner

A Chlamydia pneumoniae infection model using established human lymphocyte cell lines

Contact Info

Product

Resources

About