Characterization of Chlamydia pneumoniae Antigens Using Human T Cell Clones

Abstract

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.

Association of HLA-DRB3*0202 and serum IgG antibodies to Chlamydia pneumoniae with essential hypertension in a highly homogeneous population from Majorca (Balearic Islands, Spain)

“…Since the interaction in the risk for EH of one allele of the HLA system (a key element of the immune response) and an infectious agent (C. pneumoniae) has been described in our study, the probability that immune and inflammatory mechanisms are important factors in the pathogenesis of EH (as has been well documented in atherosclerosis at the cellular 21 and biochemical level 22 ) is clearly higher than that previously suspected. On the basis of several experimental findings, [23][24][25][26][27][28] it has been hypothesized that chronic C. pneumoniae infection of the vessels may induce a chronic immune response orchestrated by cytokines and mediated by reactive oxygen intermediates. This may result in increased vascular resistance and lead to increased blood pressure.…”

The Prevalence of Chlamydophila pneumoniae in the Blood Samples of Patients with Primary Cutaneous Lymphomas

“…The pathophysiology of this immunodeficiency is probably multifactorial. Data from experimental studies suggest that the T-cell repertoire in CTCL patients is significantly contracted [27] Immunological abnormalities in CTCL are typically associated with depressed ability of peripheral blood cells to produce the Th 1 cytokines, interferon gamma and IL-2 as a result of Th 2 skewing. [28][29][30][31][32][33][34][35][36][37] During CTCL progression, reduced T-cell-mediated cellular immune responses and diminished natural killer cell activity also develop [38,39] Wysocka et al have demonstrated a direct relationship between the extend of the pool of circulating malignant T-cells and an impaired immune response [40].…”

Heat Shock Protein 60 Specific T‐Cell Response in Chlamydial Infections

“…Although chlamydial elementary body (EB) contains dozens of proteins that are able to elicit lymphocyte proliferation [47], as many as 30% of the C. trachomatis-specific T-cell clones recognized chlamydial HSP60, suggesting that it is a relatively important antigen for the induction of cellular responses in the salpingeal tissue of TFI patients [Kinnunen and coauthors, unpublished observations].…”