scholarly journals Leishmania pifanoi Amastigote Antigen P-4: Epitopes Involved in T-Cell Responsiveness in Human Cutaneous Leishmaniasis

1998 ◽  
Vol 66 (7) ◽  
pp. 3100-3105 ◽  
Author(s):  
Jessica E. Haberer ◽  
Alda Maria Da-Cruz ◽  
Lynn Soong ◽  
Manoel P. Oliveira-Neto ◽  
Luis Rivas ◽  
...  

ABSTRACT In experimental murine cutaneous leishmaniasis, the purifiedLeishmania pifanoi amastigote protein P-4 has been shown to induce significant protection against infection. Further, recent studies examining the response of peripheral blood mononuclear cells (PBMC) from Leishmania braziliensis-infected human patients have demonstrated that the P-4 protein selectively elicits a significant TH1-like response. Because a TH1-like response is associated with cure, epitope studies were conducted to further evaluate the human response to P-4. PBMC from confirmed cutaneous leishmaniasis patients infected withL. braziliensis in Rio de Janeiro, Brazil, an area where the disease is endemic, were examined for T-cell proliferation and/or cytokine production in response to whole-parasite homogenate, isolated P-4 protein, and/or P-4 peptides. Twenty of the 22 patients (91%) examined responded to the native P-4 protein by proliferation and/or gamma interferon (IFN-γ) production. According to the proliferation data, PBMC from 14 patients (64%) were found to respond to the intact P-4 protein (stimulation index of ≥2.5). Fifty-seven percent of the P-4-responsive patients studied responded to at least one of the P-4 peptides; 11 individual peptides were found to elicit a proliferative response. Of 17 patients examined for cytokine production, no PBMC produced detectable interleukin-4 in response to P-4 protein or peptides. However, PBMC from 14 patients (82%) produced significant levels of IFN-γ (≥20 pg/ml) in response to native P-4 protein. Nineteen of the 23 peptides were found to elicit an IFN-γ response from at least two patients. These data indicate that multiple epitopes spanning the entire P-4 molecule are responsible for the TH1-like immune response observed, indicating that the intact P-4 amastigote molecule, rather than selected peptides, may prove to be the most useful for leishmaniasis vaccine development.

Gut ◽  
1998 ◽  
Vol 42 (5) ◽  
pp. 643-649 ◽  
Author(s):  
M Carol ◽  
A Lambrechts ◽  
A Van Gossum ◽  
M Libin ◽  
M Goldman ◽  
...  

Background—Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses.Aims—To quantify interferon γ (IFN-γ) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation.Patients—Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa.Methods—Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-γ and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT).Results—The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-γ (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-γ SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-γ and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-γ in the basal state, and 0.1% secreted IL-4.Conclusions—Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-γ and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.


Author(s):  
M E Jacobs ◽  
J N Pouw ◽  
M A Olde Nordkamp ◽  
T R D J Radstake ◽  
E F A Leijten ◽  
...  

Abstract Background Signals at the contact site of antigen-presenting cells (APCs) and T cells help orchestrate the adaptive immune response. CD155 on APCs can interact with the stimulatory receptor DNAM1 or inhibitory receptor TIGIT on T cells. The CD155/DNAM1/TIGIT axis is under extensive investigation as immunotherapy target in inflammatory diseases including cancer, chronic infection and autoimmune diseases. We investigated a possible role for CD155/DNAM1/TIGIT signaling in psoriatic disease. Methods By flow cytometry we analyzed peripheral blood mononuclear cells of patients with psoriasis (n=20) or psoriatic arthritis (n=21), and healthy individuals (n=7). We measured CD155, TIGIT and DNAM1 expression on leukocyte subsets and compared activation-induced cytokine production between CD155-positive and -negative APCs. We assessed the effects of TIGIT and DNAM1 blockade on T cell activation, and related the expression of CD155/DNAM1/TIGIT axis molecules to measures of disease activity. Results High CD155 expression associates with TNF production in myeloid and plasmacytoid dendritic cells (DC). In CD1c+ myeloid DC, activation-induced CD155 expression associates with increased HLA-DR expression. CD8 T cells - but not CD4 T cells - express high levels of TIGIT. DNAM1 blockade decreases T cell pro-inflammatory cytokine production, while TIGIT blockade increased T cell proliferation. Finally, T cell TIGIT expression shows an inverse correlation with inflammation biomarkers in psoriatic disease. Conclusion CD155 is increased on pro-inflammatory APCs, while the receptors DNAM1 and TIGIT expressed on T cells balance the inflammatory response by T cells. In psoriatic disease, low TIGIT expression on T cells is associated with systemic inflammation.


2003 ◽  
Vol 71 (11) ◽  
pp. 6116-6123 ◽  
Author(s):  
Limei Meng Okkels ◽  
Inger Brock ◽  
Frank Follmann ◽  
Else Marie Agger ◽  
Sandra M. Arend ◽  
...  

ABSTRACT Proteins encoded by DNA segment RD1 of Mycobacterium tuberculosis have recently been demonstrated to play important roles in bacterial virulence, vaccine development, and diagnostic reagent design. Previously, we characterized two immunodominant T-cell antigens, the early secreted antigen target (ESAT-6) and the 10-kDa culture filtrate protein (CFP10), which are encoded by the esx-lhp operon in this region. In the present study we characterized a third putative open reading frame in this region, rv3873, which encodes a PPE protein. We found that the rv3873 gene is expressed in M. tuberculosis H37Rv and that the native protein, Rv3873, is predominantly associated with the mycobacterial cell or wall. When tested as a His-tagged recombinant protein, Rv3873 stimulated high levels of gamma interferon secretion in peripheral blood mononuclear cells isolated from tuberculosis (TB) patients, as well as from healthy tuberculin purified protein derivative-positive donors. In contrast to other RD1-encoded antigens, Rv3873 was also found to be recognized by a significant proportion of Mycobacterium bovis BCG-vaccinated donors. Epitope mapping performed with overlapping peptides revealed a broad pattern of T-cell recognition comprising both TB-specific epitopes and epitopes also recognized by BCG-vaccinated donors. The immunodominant epitope (residues 118 to 135) for both TB patients and BCG-vaccinated individuals was found to be highly conserved among a large number of PPE family members.


2007 ◽  
Vol 81 (11) ◽  
pp. 5460-5471 ◽  
Author(s):  
J. William Critchfield ◽  
Donna Lemongello ◽  
Digna H. Walker ◽  
Juan C. Garcia ◽  
David M. Asmuth ◽  
...  

ABSTRACT The intestinal tract is a lymphocyte-rich site that undergoes severe depletion of memory CD4+ T cells within days of simian immunodeficiency virus or human immunodeficiency virus type 1 (HIV-1) infection. An ensuing influx of virus-specific CD8+ T cells, which persist throughout the chronic phase of infection, has also been documented in the gastrointestinal tract. However, little is known of the functionality of these effector cells or their relationship to the disease course. In this study, we measured CD8+ T-cell responses to HIV-1 peptides in paired rectal and blood samples from chronically infected patients. In both blood and rectum, there was an immunodominant CD8+ T-cell response to HIV Gag compared to Pol and Env (P < 0.01). In contrast, cytomegalovirus pp65 peptides elicited gamma interferon (IFN-γ) secretion strongly in peripheral blood mononuclear cells (PBMC) but weakly in rectal CD8+ T cells (P = 0.015). Upon stimulation with HIV peptides, CD8+ T cells from both sites were capable of mounting complex responses including degranulation (CD107 expression) and IFN-γ and tumor necrosis factor alpha (TNF-α) production. In rectal tissue, CD107 release was frequently coupled with production of IFN-γ or TNF-α. In patients not on antiretroviral therapy, the magnitude of Gag-specific responses, as a percentage of CD8+ T cells, was greater in the rectal mucosa than in PBMC (P = 0.054); however, the breakdown of responding cells into specific functional categories was similar in both sites. These findings demonstrate that rectal CD8+ T cells are capable of robust and varied HIV-1-specific responses and therefore likely play an active role in eliminating infected cells during chronic infection.


2006 ◽  
Vol 74 (2) ◽  
pp. 1215-1221 ◽  
Author(s):  
L. F. Alves Oliveira ◽  
E. C. Moreno ◽  
G. Gazzinelli ◽  
O. A. Martins-Filho ◽  
A. M. S. Silveira ◽  
...  

ABSTRACT Volunteers living in an area where schistosomiasis mansoni is endemic were subjected to ultrasound examination and classified into groups according to the levels of fibrosis diagnosed, namely, absence of indications of fibrosis (group 0), incipient fibrosis (group 1), and moderate/severe fibrosis (group 2). Peripheral blood mononuclear cells (PBMC) collected from the volunteers were stimulated with soluble antigens from adult schistosomes or from schistosome eggs, and the production of the cytokines gamma interferon, tumor necrosis factor alpha, transforming growth factor β (TGF-β), interleukin-4 (IL-4), IL-10, and IL-13 was determined. Potential associations of the level of fibrosis with age, sex, intensity of infection, and cytokine production were investigated between the three groups. Univariate analysis identified associations of age (>50), gender (male), and absence of eggs/g of feces with moderate/severe fibrosis and an association of intensity of infection (>100 eggs) with incipient fibrosis. When cytokine production in PBMC cultures stimulated by soluble egg antigens was categorized as low or high, significant differences in the distribution of IL-13 levels were established between groups 0 and 2. No significant differences were detected between the groups in the cytokines produced by PBMC cultures stimulated with soluble antigens from adult schistosomes. When all variables were tested in multivariate analyses, only IL-13 was strongly associated with fibrosis (odds ratio = 5.8; 95% confidence interval [CI] = 1.1 to 30.5). While high levels of TGF-β appeared to be associated with protection against fibrosis, the strength of the association was low.


2022 ◽  
Vol 24 (1) ◽  
Author(s):  
Spandana Maddukuri ◽  
Jay Patel ◽  
De Anna Diaz ◽  
Kristen L. Chen ◽  
Maria Wysocka ◽  
...  

Abstract Background Lenabasum is a cannabinoid type 2 receptor (CB2R) reverse agonist that demonstrates anti-inflammatory effects in vivo and in vitro in dermatomyositis (DM) and is currently being investigated for therapeutic potential. The purpose of our study is to investigate CB2R distribution as well as the effects of lenabasum in DM. Methods Immunohistochemistry staining (IHC) was utilized to examine immune cell and cytokine production changes in lesional DM skin biopsies from lenabasum and placebo-treated patients. CB2R expression in various immune cell populations within DM skin was investigated with image mass cytometry (IMC), whereas flow cytometry elucidated CB2R expression in DM peripheral blood mononuclear cells (PBMCs) as well as cytokine production by CB2R-expressing cell populations. Results After 12 weeks of lenabasum treatment, IHC staining showed that CD4+ T cells, CB2R, IL-31, IFN-γ, and IFN-β cytokines were downregulated. IFN-γ and IFN-β mRNA decreased in lesional DM skin but not in PBMCs. IMC findings revealed that CB2R was upregulated in DM lesional skin compared to HC skin and DM PBMCs (p<0.05). In DM skin, CB2R was upregulated on dendritic cells, B cells, T cells, and macrophages while dendritic cells had the greatest expression in both DM skin and PBMCs (p<0.05). These CB2R+ cells in the skin produce IL-31, IL-4, IFN-γ, and IFN-β. Conclusion Our findings of differential CB2R expression based on location and cell type suggest modes by which lenabasum may exert anti-inflammatory effects in DM and highlights dendritic cells as potential therapeutic targets.


2001 ◽  
Vol 69 (5) ◽  
pp. 3232-3239 ◽  
Author(s):  
R. L. A. Bottrel ◽  
W. O. Dutra ◽  
F. A. Martins ◽  
B. Gontijo ◽  
E. Carvalho ◽  
...  

ABSTRACT Leishmaniasis, caused by infection with the protozoan parasiteLeishmania, affects millions of individuals worldwide, causing serious morbidity and mortality. This study directly determined the frequency of cells producing key immunoregulatory cytokines in response to the recombinant antigen Leishmania homolog of receptors for activated kinase C (LACK) and soluble leishmania antigen (SLA), and it determined relative contributions of these antigens to the overall cytokine profile in individuals infected for the first time with Leishmania braziliensis. All individuals presented with the cutaneous clinical form of leishmaniasis and were analyzed for proliferative responses to LACK antigen and SLA, frequency of lymphocyte subpopulations (analyzed ex vivo), and antigen-induced (LACK and SLA) cytokine production at the single-cell level (determined by flow cytometry). The following were determined. (i) The Th1-type response previously seen in patients with cutaneous leishmaniasis is due to gamma interferon (IFN-γ) production by several different sources, listed in order of contribution: CD4+ T lymphocytes, CD4−, CD8− lymphocytes, and CD8+ T lymphocytes. (ii) SLA induced a higher frequency of lymphocytes producing IFN-γ and tumor necrosis factor alpha (TNF-α) than did LACK. (iii) LACK induced an activation of monocyte populations as reflected by an increased percentage of CD14-positive cells. (iv) Neither SLA nor LACK induced detectable frequencies of cells producing interleukin-4 (IL-4) or IL-5. These data demonstrated a multifaceted immune response to SLA in human leishmaniasis involving Th1 CD4+ T lymphocytes (IFN-γ+ and IL-10−/IL-4−), Tc1 CD8+ T cells (IFN-γ+, and IL-10−/IL-4−), and a high frequency of TNF-α-producing lymphocytes. Moreover, it was determined that the recombinant antigen LACK acts as a weak inducer of Th1-type lymphocyte responses compared to SLA.


Author(s):  
Akram Miramin Mohammadi ◽  
Amir Javadi ◽  
Alireza Firooz ◽  
Ali Khamesipour

Background and Objectives: The surrogate marker (s) of cure and protection in intracellular pathogens is not yet well defined. The aim of this study was to compare the cytokine profile using whole blood cells (WBC) vs. peripheral blood mononuclear cells (PBMC) in healthy and cutaneous leishmaniasis (CL) volunteers. Materials and Methods: In this study, WBC and PBMC of the volunteers with history of CL (HCL), Active lesion (ACL) and healthy volunteers were collected. The WBC and PBMC were cultured and stimulated with either PHA or soluble Leish- mania antigens (SLA), after 72 hours, the supernatants were collected and the levels of IFN-γ, IL-5 and IL-10 were titrated using ELISA method. Results: The mean ± SD of cytokines using WBC and PBMC in cutaneous leishmaniasis volunteers stimulated with phy- tohemagglutin (PHA) or SLA are as follow, PHA, IFN-γ=2295±995 vs. 2339±1115, IL-10=853±309 vs. 1330±966, and IL-5=299±136 vs. 352+156, SLA, IFN-γ, 931±824 vs. 825±532, IL-10, 233±78 vs. 408±381, and IL-5, 185±59 vs. 217±76, respectively. There was no significant difference between the IFN-γ, IL-5 and IL-10 levels using WBC vs. PBMC. There was a strong correlation between the cytokine profiles using WBC and PBMC in cutaneous leishmaniasis volunteers. Conclusion: There was no significant difference between IFN-γ, IL-10, IL-5 levels in whole blood and PBMC of volunteers with active lesion or history of CL. Whole-blood culture which is easier, cheaper and more convenient could be used instead of PBMC to evaluate the cytokine profile in field conditions.


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