Helicobacter pylori: bacterial factors and the role of cytokines in the immune response.
Helicobacter pylori is a gram-negative micro-aerophilic bacterium that is widely distributed geographically and causes chronic gastritis, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. Bacterial virulence factors play an important role, since the virulent strains are more aggressive and increase the risk of developing severe clinical manifestations; in addition, other determinant factors are the nutritional state and the immune response of the host. Studies on humans, non-human primates, and rodents have reported that regulating proteins of the Th1 phenotype predominate in the immune response to the bacterial infection. The cytokines produced by this phenotype, are not very effective in eradicating the microorganism and furthermore, contribute to gastro-duodenal pathogenesis. Gastric inflammation in patients infected with H. pylori has been characterized by increased production of IL-1, IL-6, IL-12, IL-18, TNF-alpha, and IFN-gamma. Many prophylactic and therapeutic strategies have been researched using experimental animals. The utilization and effectiveness of vaccination on humans requires more study.
Graduate Studies in Immunology, Faculty of Medicine, University of Zulia, Maracaibo, Venezuela. betrizromero@cantv.net
Tania Beatriz
TB
Romero-Adrián
Jorymar
J
Leal-Montiel
Francisca
F
Monsalve-Castillo
Edgardo
E
Mengual-Moreno
Ernesto García
EG
McGregor
Lenis
L
Perini
Ana
A
Antúnez
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D016207:Cytokines / Q000235:genetics / Q000276:immunology*; D015870:Gene Expression; D016481:Helicobacter Infections / Q000276:immunology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology*
D001426:Bacterial Proteins; D016207:Cytokines; D037521:Virulence Factors