Limits...
Hyperreactive onchocerciasis is characterized by a combination of Th17-Th2 immune responses and reduced regulatory T cells.

Katawa G, Layland LE, Debrah AY, von Horn C, Batsa L, Kwarteng A, Arriens S, W Taylor D, Specht S, Hoerauf A, Adjobimey T - PLoS Negl Trop Dis (2015)

Bottom Line: Since disease pathogenesis is associated with host inflammatory reactions, we investigated whether Th17 responses could be related to aggravated pathology in HO.Flow cytometry data was further confirmed using a PCR array since Th17-related genes (IL-17 family members, IL-6, IL-1β and IL-22) and Th2-related (IL-4, IL-13, STAT6) genes were all significantly up-regulated in HO individuals.In addition, stronger Onchocerca volvulus-specific Th2 responses, especially IL-13, were observed in vitro in hyperreactive individuals when compared to GEO or EN groups.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany; Advanced School of Medical Biology and Food Technology (ESTBA), University of Lomé, Lomé, Togo.

ABSTRACT
Clinical manifestations in onchocerciasis range from generalized onchocerciasis (GEO) to the rare but severe hyperreactive (HO)/sowda form. Since disease pathogenesis is associated with host inflammatory reactions, we investigated whether Th17 responses could be related to aggravated pathology in HO. Using flow cytometry, filarial-specific cytokine responses and PCR arrays, we compared the immune cell profiles, including Th subsets, in individuals presenting the two polar forms of infection and endemic normals (EN). In addition to elevated frequencies of memory CD4+ T cells, individuals with HO showed accentuated Th17 and Th2 profiles but decreased CD4+CD25hiFoxp3+ regulatory T cells. These profiles included increased IL-17A+, IL-4+, RORC2+ and GATA3+CD4+ T cell populations. Flow cytometry data was further confirmed using a PCR array since Th17-related genes (IL-17 family members, IL-6, IL-1β and IL-22) and Th2-related (IL-4, IL-13, STAT6) genes were all significantly up-regulated in HO individuals. In addition, stronger Onchocerca volvulus-specific Th2 responses, especially IL-13, were observed in vitro in hyperreactive individuals when compared to GEO or EN groups. This study provides initial evidence that elevated frequencies of Th17 and Th2 cells form part of the immune network instigating the development of severe onchocerciasis.

No MeSH data available.


Related in: MedlinePlus

PBMCs from hyperreactive onchocerciasis individuals exhibit strong IL-6 responses following filarial specific activation in vitro.Isolated PBMCs (1×105/well) from EN (n = 16) and O. volvulus-infected GEO (n = 16) or HO (n = 6) individuals were left either unstimulated (Cont.) or activated with either O. volvulus antigen extract (OvAg, 20 µg/ml) or αCD3/αCD28 (40,000 beads/ml) for 7 days. Thereafter, levels of IL-17A (A, B), IL-6 (C, D), IL-22 (E,F) and IL-1β (G,H) were measured in the culture supernatants using a FlowCytomix™ Multiplex kit via flow cytometry. Graphs show data as box whiskers(tukey) with median, interquartile ranges and outliers. Asterisks show statistical differences (Kruskal-Wallis and Mann Whitney test) between the groups indicated by the brackets (*p<0.05, **p<0.01, ***p<0.001).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4288720&req=5

pntd-0003414-g006: PBMCs from hyperreactive onchocerciasis individuals exhibit strong IL-6 responses following filarial specific activation in vitro.Isolated PBMCs (1×105/well) from EN (n = 16) and O. volvulus-infected GEO (n = 16) or HO (n = 6) individuals were left either unstimulated (Cont.) or activated with either O. volvulus antigen extract (OvAg, 20 µg/ml) or αCD3/αCD28 (40,000 beads/ml) for 7 days. Thereafter, levels of IL-17A (A, B), IL-6 (C, D), IL-22 (E,F) and IL-1β (G,H) were measured in the culture supernatants using a FlowCytomix™ Multiplex kit via flow cytometry. Graphs show data as box whiskers(tukey) with median, interquartile ranges and outliers. Asterisks show statistical differences (Kruskal-Wallis and Mann Whitney test) between the groups indicated by the brackets (*p<0.05, **p<0.01, ***p<0.001).

Mentions: To measure filarial-specific responses from cyro-preserved PBMCs, cells were cultured with OvAg for 7 days: the optimal time-point for cytokine production (S1A-D Fig.). When compared to EN or GEO groups, PBMCs from HO individuals secreted significantly more IL-5 and IL-13 when activated with either OvAg or αCD3/αCD28 (Fig. 5A-D). Cultures from all groups produced little IL-10 in response to OvAg (Fig. 5E), although infected individuals did produce more IL-10 than control cultures upon activation with αCD3/αCD28 (Fig. 5F). Cultures from EN secreted significantly more IFN-γ upon activation with OvAg (Fig. 5G) which correlates with their CD4+ T cell cytokine profile shown in Fig. 2A. The dampened IFN-γ responses from cells of HO individuals was not reflected upon αCD3/αCD28 activation indicating that failure to produce IFN-γ was not a deficit of Th1 cells but dampened filarial-specific IFN-γ-producing cells (Fig. 5H). The induction of Th17 cells requires IL-6, IL-1β, TGF-β and IL-23 [19]. In contrast to the high amounts of IL-17A secreting CD4+ T cells observed by flow cytometry (Fig. 2C), upon culturing with OvAg, only low levels of IL-17A were detected in the culture supernatants in the HO group. Nevertheless, the basal levels of IL-17A were significantly higher than the basal levels in culture supernatants from the GEO group (Fig. 6A). Upon activation with αCD3/αCD28 however, cells from HO individuals presented significantly higher levels of IL-17A when compared to both EN and GEO group (Fig. 6B), reflecting again the findings via flow cytometry (Fig. 2C). IL-6 levels from cultures of PBMCs from HO individuals were significantly higher than the other groups (Fig. 6C and D). As with IL-17A, no significant differences in the levels of IL-22 or IL-1β following stimulation with OvAg were observed (Fig. 6E and G respectively). However, after activation with αCD3/αCD28, PBMCs cultures from HO individuals secreted elevated amounts of IL-22 and IL-1β when compared to EN and GEO groups (Fig. 6F and H respectively). Thus, although the overall filarial-specific Th17-related responses were not highly significant in hyperreactive individuals, these cytokines were enhanced upon αCD3/αCD28 activation indicating a biased Th17 inflammatory profile.


Hyperreactive onchocerciasis is characterized by a combination of Th17-Th2 immune responses and reduced regulatory T cells.

Katawa G, Layland LE, Debrah AY, von Horn C, Batsa L, Kwarteng A, Arriens S, W Taylor D, Specht S, Hoerauf A, Adjobimey T - PLoS Negl Trop Dis (2015)

PBMCs from hyperreactive onchocerciasis individuals exhibit strong IL-6 responses following filarial specific activation in vitro.Isolated PBMCs (1×105/well) from EN (n = 16) and O. volvulus-infected GEO (n = 16) or HO (n = 6) individuals were left either unstimulated (Cont.) or activated with either O. volvulus antigen extract (OvAg, 20 µg/ml) or αCD3/αCD28 (40,000 beads/ml) for 7 days. Thereafter, levels of IL-17A (A, B), IL-6 (C, D), IL-22 (E,F) and IL-1β (G,H) were measured in the culture supernatants using a FlowCytomix™ Multiplex kit via flow cytometry. Graphs show data as box whiskers(tukey) with median, interquartile ranges and outliers. Asterisks show statistical differences (Kruskal-Wallis and Mann Whitney test) between the groups indicated by the brackets (*p<0.05, **p<0.01, ***p<0.001).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4288720&req=5

pntd-0003414-g006: PBMCs from hyperreactive onchocerciasis individuals exhibit strong IL-6 responses following filarial specific activation in vitro.Isolated PBMCs (1×105/well) from EN (n = 16) and O. volvulus-infected GEO (n = 16) or HO (n = 6) individuals were left either unstimulated (Cont.) or activated with either O. volvulus antigen extract (OvAg, 20 µg/ml) or αCD3/αCD28 (40,000 beads/ml) for 7 days. Thereafter, levels of IL-17A (A, B), IL-6 (C, D), IL-22 (E,F) and IL-1β (G,H) were measured in the culture supernatants using a FlowCytomix™ Multiplex kit via flow cytometry. Graphs show data as box whiskers(tukey) with median, interquartile ranges and outliers. Asterisks show statistical differences (Kruskal-Wallis and Mann Whitney test) between the groups indicated by the brackets (*p<0.05, **p<0.01, ***p<0.001).
Mentions: To measure filarial-specific responses from cyro-preserved PBMCs, cells were cultured with OvAg for 7 days: the optimal time-point for cytokine production (S1A-D Fig.). When compared to EN or GEO groups, PBMCs from HO individuals secreted significantly more IL-5 and IL-13 when activated with either OvAg or αCD3/αCD28 (Fig. 5A-D). Cultures from all groups produced little IL-10 in response to OvAg (Fig. 5E), although infected individuals did produce more IL-10 than control cultures upon activation with αCD3/αCD28 (Fig. 5F). Cultures from EN secreted significantly more IFN-γ upon activation with OvAg (Fig. 5G) which correlates with their CD4+ T cell cytokine profile shown in Fig. 2A. The dampened IFN-γ responses from cells of HO individuals was not reflected upon αCD3/αCD28 activation indicating that failure to produce IFN-γ was not a deficit of Th1 cells but dampened filarial-specific IFN-γ-producing cells (Fig. 5H). The induction of Th17 cells requires IL-6, IL-1β, TGF-β and IL-23 [19]. In contrast to the high amounts of IL-17A secreting CD4+ T cells observed by flow cytometry (Fig. 2C), upon culturing with OvAg, only low levels of IL-17A were detected in the culture supernatants in the HO group. Nevertheless, the basal levels of IL-17A were significantly higher than the basal levels in culture supernatants from the GEO group (Fig. 6A). Upon activation with αCD3/αCD28 however, cells from HO individuals presented significantly higher levels of IL-17A when compared to both EN and GEO group (Fig. 6B), reflecting again the findings via flow cytometry (Fig. 2C). IL-6 levels from cultures of PBMCs from HO individuals were significantly higher than the other groups (Fig. 6C and D). As with IL-17A, no significant differences in the levels of IL-22 or IL-1β following stimulation with OvAg were observed (Fig. 6E and G respectively). However, after activation with αCD3/αCD28, PBMCs cultures from HO individuals secreted elevated amounts of IL-22 and IL-1β when compared to EN and GEO groups (Fig. 6F and H respectively). Thus, although the overall filarial-specific Th17-related responses were not highly significant in hyperreactive individuals, these cytokines were enhanced upon αCD3/αCD28 activation indicating a biased Th17 inflammatory profile.

Bottom Line: Since disease pathogenesis is associated with host inflammatory reactions, we investigated whether Th17 responses could be related to aggravated pathology in HO.Flow cytometry data was further confirmed using a PCR array since Th17-related genes (IL-17 family members, IL-6, IL-1β and IL-22) and Th2-related (IL-4, IL-13, STAT6) genes were all significantly up-regulated in HO individuals.In addition, stronger Onchocerca volvulus-specific Th2 responses, especially IL-13, were observed in vitro in hyperreactive individuals when compared to GEO or EN groups.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany; Advanced School of Medical Biology and Food Technology (ESTBA), University of Lomé, Lomé, Togo.

ABSTRACT
Clinical manifestations in onchocerciasis range from generalized onchocerciasis (GEO) to the rare but severe hyperreactive (HO)/sowda form. Since disease pathogenesis is associated with host inflammatory reactions, we investigated whether Th17 responses could be related to aggravated pathology in HO. Using flow cytometry, filarial-specific cytokine responses and PCR arrays, we compared the immune cell profiles, including Th subsets, in individuals presenting the two polar forms of infection and endemic normals (EN). In addition to elevated frequencies of memory CD4+ T cells, individuals with HO showed accentuated Th17 and Th2 profiles but decreased CD4+CD25hiFoxp3+ regulatory T cells. These profiles included increased IL-17A+, IL-4+, RORC2+ and GATA3+CD4+ T cell populations. Flow cytometry data was further confirmed using a PCR array since Th17-related genes (IL-17 family members, IL-6, IL-1β and IL-22) and Th2-related (IL-4, IL-13, STAT6) genes were all significantly up-regulated in HO individuals. In addition, stronger Onchocerca volvulus-specific Th2 responses, especially IL-13, were observed in vitro in hyperreactive individuals when compared to GEO or EN groups. This study provides initial evidence that elevated frequencies of Th17 and Th2 cells form part of the immune network instigating the development of severe onchocerciasis.

No MeSH data available.


Related in: MedlinePlus