Cellular responses and cytokine profiles in Ascaris lumbricoides and Trichuris trichiura infected patients

Abstract

The impact of intestinal helminth infection, i.e. Ascaris lumbricoides and Trichuris trichiura, on cellular responsiveness and cytokine production was investigated in young adults. Ascaris-specific cellular responsiveness was higher in parasite-free endemic controls than in patients infected with T. trichiura, or A. lumbricoides, or patients co-infected with both parasites. Also, mitogen-induced tumour necrosis factor (TNF)-alpha, interleukin (IL)-12 and interferon (IFN)-gamma secretion by peripheral blood mononuclear cells (PBMC) was higher in negative endemic controls than in infected individuals. Ascaris antigen-specific production of TNF-alpha, IL-12 and IFN-gamma was low in singly Ascaris as well as in co-infected patients, whereas secretion of IL-10 and IL-13 was elevated and similarly high in all patient groups. The detection of Trichuris-specific and Ascaris-specific IgG4 revealed significantly higher serum antibody levels in Trichuris or Ascaris patients when compared to endemic controls (P < 0.05), whereas parasite-specific IgE antibody levels were similarly high in infected individuals and in endemic controls. In summary, chronically infected Ascaris and Trichuris patients with a high parasite load presented reduced cellular reactivity and lower type 1 TNF-alpha, IFN-gamma and IL-12 responses when compared with endemic controls, whereas type 2 IL-10 and IL-13 productions were similar in all groups from the endemic area. The former may support parasite persistence, whereas substantial type 2 cytokine release may promote protective immunity, suggesting an adaptation of the host to control the parasite burden while minimizing immune-mediated host self-damage.

Intestinal Helminthiasis in Colombian Children Promotes a Th2 Response to Helicobacter pylori: Possible Implications for Gastric Carcinogenesis

“…Children are also commonly infected with intestinal helminths when climate and poor sanitation favor the life cycle and transmission of parasites. These observations suggest that Th2-polarizing helminthic infections in childhood could promote the Th2 response to H. pylori and is supported by studies indicating helminth infections inhibit Th1-promoted responses to unrelated antigens (23)(24)(25).…”

“…Serum IgE is a polyclonal response that has been associated with antigen-specific and nonspecific immune stimulation (36). In developed countries, elevated IgE is most commonly associated with allergies (37), and in developing tropical areas, such as Tumaco, elevated IgE is most commonly associated with parasitism (23). In addition to promoting IgE levels in serum and tissues, a variety of helminth infections have been shown to induce Th2-polarized cytokine responses (23,38), which may afford protection from reinfection (33).…”

“…In developed countries, elevated IgE is most commonly associated with allergies (37), and in developing tropical areas, such as Tumaco, elevated IgE is most commonly associated with parasitism (23). In addition to promoting IgE levels in serum and tissues, a variety of helminth infections have been shown to induce Th2-polarized cytokine responses (23,38), which may afford protection from reinfection (33). The variety of intestinal parasites found in the Colombian children confirms that helminth infection is common and coinfection with multiple species occurs.…”

Evaluation of memory immune response to mycobacterium extract among household contact of tuberculosis cases

“…This decision was taken because differences in TNF-a and IFN-g production by mitogen-stimulated PBMCs harvested from patients infected with intestinal parasites, as well as from endemic and nonendemic controls, have been reported (19,20).…”

Investigating the underlying mechanism of resistance to Ascaris infection

“…Geiger et al [12] recorded that both total IgG and the subclass IgG4 were significantly elevated in response to A. lumbricoides in infected patient groups. In contrast to this, a minimal IgG4 response was detected in infected hosts in a Nigerian population [13], while Cooper et al [11] also showed that levels of Ascaris-specific IgG, IgG1 and IgG2 antibodies are positively correlated with parasite burdens.…”