scholarly journals Heterogeneity of Wild Leishmania major Isolates in Experimental Murine Pathogenicity and Specific Immune Response

2001 ◽  
Vol 69 (8) ◽  
pp. 4906-4915 ◽  
Author(s):  
C. Kébaı̈er ◽  
H. Louzir ◽  
M. Chenik ◽  
A. Ben Salah ◽  
K. Dellagi

ABSTRACT Virulence variability was investigated by analyzing the experimental pathogenicity of 19 Leishmania major strains in susceptible BALB/c mice. Twelve strains were isolated from Tunisian patients with zoonotic cutaneous leishmaniasis; seven strains were isolated in Syria (n = 1), Saudi Arabia (n = 2), Jordan (n = 2), or Israel (n = 2). BALB/c mice were injected in the hind footpad with 2 × 106 amastigotes of the various isolates, and lesion progression was recorded weekly for 9 weeks. Interleukin-4 (IL-4) and gamma interferon (IFN-γ) production of lymph node mononuclear cells activated in vitro with parasite antigens were evaluated 5 weeks after infection. We show that disease progression induced by different L. major isolates was largely heterogeneous although reproducible results were obtained when using the same isolate. Interestingly, isolates from the Middle East induced a more severe disease than did the majority of Tunisian isolates. Strains with the highest virulence tend to generate more IL-4 and less IFN-γ in vitro at week 5 postinfection as well as higher levels of early IL-4 mRNA in the lymph node draining the inoculation site at 16 h postinfection. These results suggest that L. major isolates from the field may differ in virulence, which influences the course of the disease induced in mice and the type of immune response elicited by the infected host.

2014 ◽  
Vol 22 (3) ◽  
pp. 274-281 ◽  
Author(s):  
Cora N. Pollak ◽  
María Magdalena Wanke ◽  
Silvia M. Estein ◽  
M. Victoria Delpino ◽  
Norma E. Monachesi ◽  
...  

ABSTRACTVirB proteins fromBrucellaspp. constitute the type IV secretion system, a key virulence factor mediating the intracellular survival of these bacteria. Here, we assessed whether a Th1-type immune response against VirB proteins may protect mice fromBrucellainfection and whether this response can be induced in the dog, a natural host forBrucella. Splenocytes from mice immunized with VirB7 or VirB9 responded to their respective antigens with significant and specific production of gamma interferon (IFN-γ), whereas interleukin-4 (IL-4) was not detected. Thirty days after an intraperitoneal challenge with liveBrucella abortus, the spleen load of bacteria was almost 1 log lower in mice immunized with VirB proteins than in unvaccinated animals. As colonization reduction seemed to correlate with a Th1-type immune response against VirB proteins, we decided to assess whether such a response could be elicited in the dog. Peripheral blood mononuclear cells (PBMCs) from dogs immunized with VirB proteins (three subcutaneous doses in QuilA adjuvant) produced significantly higher levels of IFN-γ than cells from control animals uponin vitrostimulation with VirB proteins. A skin test to assess specific delayed-type hypersensitivity was positive in 4 out of 5 dogs immunized with either VirB7 or VirB9. As both proteins are predicted to locate in the outer membrane ofBrucellaorganisms, the ability of anti-VirB antibodies to mediate complement-dependent bacteriolysis ofB. caniswas assessedin vitro. Sera from dogs immunized with either VirB7 or VirB9, but not from those receiving phosphate-buffered saline (PBS), produced significant bacteriolysis. These results suggest that VirB-specific responses that reduce organ colonization byBrucellain mice can be also elicited in dogs.


Author(s):  
Akram Miramin-Mohammadi ◽  
Amir Javadi ◽  
Seyyed Ebrahim Eskandari ◽  
Mahmood Nateghi-Rostami ◽  
Ali Khamesipour

Background: Recovery from cutaneous leishmaniasis (CL) leads to protection against further lesion development. In contrast, vaccination using killed parasites does not induce enough protection; the reason(s) is not currently known but might be related to different immune response induced against live versus killed parasites. In this study, Th1/Th2 cyto-kine profiles of CL patients were evaluated against live versus killed Leishmania major. Methods: In this study peripheral blood mononuclear cells (PBMC) of the volunteers with active CL lesion (CL), history of CL (HCL) and healthy volunteers were cultured and stimulated with live or killed Leishmania major, the superna-tants were collected and levels of IFN-γ, IL-5 and IL-10 were titrated using ELISA method. Results: The results showed that IFN-γ levels in CL patients (p< 0.001) and HCL volunteers (p< 0.005) are signifi-cantly higher when stimulated with live than stimulated with killed L. major. IFN-γ production in PBMC volunteers with CL and HCL stimulated with live or heat-killed L. major was significantly (p< 0.001) higher than in unstimulated ones. The level of IL-5 in CL patients (p< 0.005) and HCL volunteers (p< 0.001) are significantly lower when stimulated with live than killed L. major. There was no significant difference between the levels of IL-10 in PBMC stimulated with either live or killed L. major. Conclusion: It is concluded that using live Leishmania induces a stronger Th1 type of immune response which justify using leishmanization as a control measure against CL.


Parasitology ◽  
2009 ◽  
Vol 136 (11) ◽  
pp. 1243-1250 ◽  
Author(s):  
HAMID DANESHVAR ◽  
RICHARD BURCHMORE ◽  
PAUL HAGAN ◽  
R. STEPHEN PHILLIPS

SUMMARYAn attenuated line of Leishmania major (L. major H-line) has been established by culturing promastigotes in vitro under gentamicin pressure. A modification of the previously described method for the generation of attenuated L. major is described, giving rise to attenuated parasites after 8 rather than 12 subpassages. No lesions developed in BALB/c mice infected with L. major H-line, whereas L. major wild-type (WT) induced a Th2 like response with progressive lesions. Analysis of splenocyte IFN-γ and IL-4 production following stimulation with promastigotes shows that the L. major H-line preferentially induces Th1-like responses and possibly down-regulates Th2 responses in BALB/c mice. L. major H-line parasites remained localized in the skin and draining lymph node, whereas L. major WT parasites disseminated into the visceral organs of BALB/c mice. Mice infected with L. major H-line acquired some resistance against L. major WT. These results show that the attenuated cell line of L. major is not only avirulent but that it may also modulate the host immune response.


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.


2007 ◽  
Vol 14 (4) ◽  
pp. 369-374 ◽  
Author(s):  
Stephanie Jacks ◽  
Steeve Giguère ◽  
John F. Prescott

ABSTRACT Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in foals but does not induce disease in adult horses. Virulence of R. equi depends on the presence of a large plasmid, which encodes a family of seven virulence-associated proteins (VapA and VapC to VapH). Eradication of R. equi from the lungs depends on gamma interferon (IFN-γ) production by T lymphocytes. The objectives of the present study were to determine the relative in vivo expression of the vap genes of R. equi in the lungs of infected foals, to determine the recall response of bronchial lymph node (BLN) lymphocytes from foals and adult horses to each of the Vap proteins, and to compare the cytokine profiles of proliferating lymphocytes between foals and adult horses. vapA, vapD, and vapG were preferentially expressed in the lungs of infected foals, and expression of these genes in the lungs was significantly (P < 0.05) higher than that achieved during in vitro growth. VapA and VapC induced the strongest lymphoproliferative responses for foals and adult horses. There was no significant difference in recall lymphoproliferative responses or IFN-γ mRNA expression by bronchial lymph node lymphocytes between foals and adults. In contrast, interleukin 4 (IL-4) expression was significantly higher for adults than for foals for each of the Vap proteins. The ratio of IFN-γ to IL-4 was significantly higher for foals than for adult horses for most Vap proteins. Therefore, foals are immunocompetent and are capable of mounting lymphoproliferative responses of the same magnitude and cytokine phenotype as those of adult horses.


2001 ◽  
Vol 69 (11) ◽  
pp. 6981-6986 ◽  
Author(s):  
Mineo Watanabe ◽  
Masaaki Nagai

ABSTRACT The protective immunity induced by infection with Bordetella pertussis and with Bordetella parapertussis was examined in a murine model of respiratory infection. Convalescent mice that had been infected by aerosol with B. pertussis or with B. parapertussis exhibited a protective immune response against B. pertussis and also against B. parapertussis. Anti-filamentous hemagglutinin (anti-FHA) serum immunoglobulin G (IgG) and anti-FHA lung IgA antibodies were detected in both mice infected with B. pertussis and those infected with B. parapertussis. Antibodies against pertussis toxin (anti-PT) and against killed B. pertussis cells were detected in mice infected with B. pertussis. Pertactin-specific antibodies and antibodies against killed B. parapertussis cells were detected in mice infected with B. parapertussis. Spleen cells from mice infected with B. pertussis secreted interferon-γ (IFN-γ) in response to stimulation by FHA or PT. Spleen cells from mice infected with B. parapertussis also secreted IFN-γ in response to FHA. Interleukin-4 was not produced in response to any of the antigens tested. The profiles of cytokine secretion in vitro revealed induction of a Th1-biased immune response during convalescence from infection by B. pertussis and byB. parapertussis. It is possible that Th1 and Th2 responses against FHA might be related to the reciprocal protection achieved in our murine model.


2001 ◽  
Vol 69 (2) ◽  
pp. 906-911 ◽  
Author(s):  
Abhay R. Satoskar ◽  
Marcelo Bozza ◽  
Miriam Rodriguez Sosa ◽  
Guoshing Lin ◽  
John R. David

ABSTRACT To determine the role of endogenous migration-inhibitory factor (MIF) in the development of protective immunity against cutaneous leishmaniasis, we analyzed the course of cutaneous Leishmania major infection in MIF gene-deficient mice (MIF−/−) and wild-type (MIF+/+) mice. Following cutaneous L. major infection, MIF−/− mice were susceptible to disease and developed significantly larger lesions and greater parasite burdens than MIF+/+ mice. Interestingly, antigen-stimulated lymph node cells from MIF−/− mice produced more interleukin-4 (IL-4) and gamma interferon (IFN-γ) than those from MIF+/+ mice, although the differences were statistically not significant. IFN-γ-activated resting peritoneal macrophages from MIF−/− mice showed impaired macrophage leishmanicidal activity and produced significantly lower levels of nitric oxide and superoxide in vitro. The macrophages from MIF−/− mice, however, produced much more IL-6 than macrophages from wild-type mice. These findings demonstrate that endogenous MIF plays an important role in the development of protective immunity against L. majorin vivo. Furthermore, they indicate that the susceptibility of MIF−/− mice to L. major infection is due to impaired macrophage leishmanicidal activity rather than dysregulation of Th1 and Th2 responses.


2018 ◽  
Author(s):  
Franciele Carolina Silva ◽  
Vinicius Dantas Martins ◽  
Felipe Caixeta ◽  
Matheus Batista Carneiro ◽  
Graziele Ribeiro Goes ◽  
...  

AbstractAn association between increased susceptibility to infectious diseases and obesity has been described as a result of impaired immunity in obese individuals. It is not clear whether a similar linkage can be drawn between obesity and parasitic diseases. To evaluate the effect of obesity in the immune response to cutaneous L. major infection, we studied the ability of C57BL/6 mice submitted to a high fat and sugar diet to control leishmaniasis. Mice with diet-induced obesity presented thicker lesions with higher parasite burden and more inflammatory infiltrate in the infected ear when infected with L. major. We observe no difference in IFN-γ or IL-4 production by draining lymph node cells between control and obese mice, but obese mice presented higher production of IgG1 and IL-17. A higher percentage of in vitro-infected peritoneal macrophages was found when these cells were obtained from obese mice when compared to lean mice. In vitro stimulation of macrophages with IL-17 decreased the capacity of cells from control mice to kill the parasite. Moreover, macrophages from obese mice presented higher arginase activity. Together our results indicate that diet-induced obesity impairs resistance to L. major in C57BL/6 mice without affecting the development of Th1 response.Author SummaryThe obesity is a public health problem and it is reaching extraordinary numbers in the world and others diseases are being involved and aggravated as consequence of obesity. What we know is that some diseases are more severe in obese people than in normal people. We did not know how obesity changes the profile of immune response to infectious agents, leading to the more severe diseases. That‘s why we decided to investigate how obese mice lead with Leishmania major infection. Leishmaniasis is a protozoa parasite infection considered a neglected disease. To try our hypothesis we gave a hipercaloric diet to induce obesity in C57BL/6 mice. After that, we injected L. major in the mice ear and followed the lesion for 8 weeks. We observed a ticker lesion and the cells from draining lymph node from obese mice produced more IL-17 than cells from normal mice. We also infected in vitro, macrophages from obese mice and stimulated the cells with IL-17, and we observed that the macrophages from obese mice are more infected by the L. major and it is worst in the presence of IL-17. Our results suggest that diet induced obesity decrease the resistance to infection.


2002 ◽  
Vol 70 (10) ◽  
pp. 5562-5567 ◽  
Author(s):  
Travis M. Gooding ◽  
Paul D. R. Johnson ◽  
May Smith ◽  
Andrew S. Kemp ◽  
Roy M. Robins-Browne

ABSTRACT Mycobacterium ulcerans, the cause of Buruli ulcer, is an environmental mycobacterium with a distinct geographic distribution. The reasons why only some individuals who are exposed to M. ulcerans develop ulcers are not known but are likely to reflect individual differences in the immune response to infections with this bacterium. In this study, we investigated cytokine profiles of peripheral blood mononuclear cells (PBMC) from 23 Buruli ulcer patients and 25 household contacts in a region of Australia where Buruli ulcer is endemic. The results showed that following stimulation with M. ulcerans or Mycobacterium bovis BCG, PBMC from Buruli ulcer patients mounted a Th2-type response, which was manifested by the production of mRNA for interleukin 4 (IL-4), IL-5, IL-6, and IL-10, whereas unaffected contacts responded mainly with the Th1 cytokines gamma interferon (IFN-γ) and IL-12. For example, mRNA for IL-4 was detected in 18 of 23 patients but in only 3 of 25 control subjects (P < 0.0001). By contrast, PBMC from 21 of 25 unaffected individuals produced IFN-γ compared with 3 of 23 patients (P < 0.0001). IFN-γ release following stimulation with mycobacteria was markedly reduced in affected subjects. Frequencies of antibodies to M. ulcerans in serum samples from affected and unaffected subjects were similar, indicating that many of the control subjects had been exposed to this bacterium. Together, these findings suggest that a Th1-type immune response to M. ulcerans may prevent the development of Buruli ulcer in people exposed to M. ulcerans, but a Th-2 response does not.


2004 ◽  
Vol 11 (3) ◽  
pp. 538-547 ◽  
Author(s):  
James A. DeVoti ◽  
Bettie M. Steinberg ◽  
David W. Rosenthal ◽  
Lynda Hatam ◽  
Andrea Vambutas ◽  
...  

ABSTRACT Recurrent respiratory papillomatosis (RRP) is a chronic, debilitating disease of the upper airway caused by human papillomavirus type 6 (HPV-6) or HPV-11. We describe responses of peripheral blood mononuclear cells (PBMC) and T cells from RRP patients and controls to the HPV-11 early proteins E6 and E7. PBMC were exposed in vitro to purified E6 or E7 proteins or transduced with fusion proteins containing the first 11 amino acids of the human immunodeficiency virus type 1 protein tat fused to E6 or E7 (tat-E6/tat-E7). TH1-like (interleukin-2 [IL-2], gamma interferon [IFN-γ], IL-12, and IL-18), and TH2-like (IL-4 and IL-10) cytokine mRNAs were identified by reverse transcription-PCR, and IFN-γ and IL-10 cytokine-producing cells were identified by enzyme-linked immunospot assay. These studies show that HPV-11 E6 skews IL-10-IFN-γ expression by patients with RRP toward greater expression of IL-10 than of IFN-γ. In addition, there is a general cytokine hyporesponsiveness to E6 that is more prominent for TH1-like cytokine expression by patients with severe disease. Patients showed persistent IL-10 cytokine expression by the nonadherent fraction of PBMC when challenged with E6 and tat-E6, and, in contrast to controls, both T cells and non-T cells from patients expressed IL-10. However, E7/tat-E7 cytokine responses in patients with RRP were similar to those of the controls. In contrast, E6 inhibited IL-2 and IL-18 mRNA expression that would further contribute to a cytokine microenvironment unfavorable to HPV-specific, T-cell responses that should control persistent HPV infection. In summary, E6 is the dominant inducer of cytokine expression in RRP, and it induces a skewed expression of IL-10 compared to the expression of IFN-γ.


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