Inhibition of growth of Chlamydia trachomatis by human gamma interferon

Shemer, Yonat; Sarov, Israel

doi:10.1128/iai.48.2.592-596.1985

Cited by 123 publications

(55 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cytokine analysis of the C. pneumoniae-reactive TLC showed that five out of nine of the clones expressed IFN-g mRNA but no IL-4 mRNA. 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].…”

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

“…However, circumstantial evidence suggests that the induction of abnormal forms could occur in vivo by local release of interferon gamma and subsequent degradation of tryptophan on activation of host cell indole dioxygenase [36][37][38]. It has been demonstrated in vitro that tryptophan is degraded after exposure of infected epithelial and macrophage cultures to interferon gamma [37][38][39][40] and tumor necrosis factor alpha [41, 42], and that aberrant forms are produced [41, 43,44]. Both cytokines have a role in protective immunity in chlamydial infection [45][46][47][48][49] and analysis of other infection systems in vivo has provided evidence of indole dioxygenase activation via excretion of tryptophan degradation products [36,50].…”

Section: Discussionmentioning

confidence: 99%

Low-nutrient induction of abnormal chlamydial development: A novel component of chlamydial pathogenesis?

Coles

Reynolds

Harper

et al. 1993

FEMS Microbiology Letters

105

View full text Add to dashboard Cite

The intracellular development of chlamydiae in McCoy cells incubated in Eagle's minimal essential medium lacking all 13 amino acids was examined both by fluorescence and electron microscopy and by infectivity titration. Aberrant development occurred in almost all inclusions of strains of Chlamydia trachomatis and C. psittaci with the production of abnormal forms which differed in size, shape and internal structure from normal reticulate and elementary body forms. Detailed analysis of the response of C. trachomatis L2 strain 434 to graded reductions in amino acid level showed that infectivity was reduced and morphological abnormality increased as amino acid concentrations were lowered from 33 to 0% of amino acids present in minimal essential medium. Reversion of inclusions to normal and reappearance of infectious forms occurred on restoration of amino acids and further incubation. It is suggested that aberrant development may account for the presence in vivo of non-cultivable chlamydiae and that such development can arise via tryptophan deprivation mediated by local release of interferon gamma.

show abstract

Inhibition of growth of Chlamydia trachomatis by human gamma interferon

Cited by 123 publications

References 15 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

Low-nutrient induction of abnormal chlamydial development: A novel component of chlamydial pathogenesis?

Contact Info

Product

Resources

About