Toxoplasma gondii and the host cells

The protozoan Toxoplasma gondii, described by Nicolle and Manceaux in 1908, is a ubiquitous and cosmopolitan parasite that infects a wide range of mammal and bird species with high prevalence. The biological success of T. gondii is associated with the formation of a specific relationship between the parasite and host cells leading to the establishment of a latent, chronic infection. During primary infection, acquired mostly by the oral route, the quickly multiplying tachyzoites disseminate through the body crossing several structural-functional barriers as bloodbrain or blood-retina, then they transform into dormant bradyzoites which, enclosed in tissue cysts, occupy preferentially the brain, skeletal muscle and eye. Although T. gondii is able to infect all kinds of nucleated cells, it uses strictly defined host cells, dependent on the life-cycle phase and infection stage. The article discusses selected aspects of the parasite passing via the host body barriers as well as particular role of dendritic cells and skeletal muscle cells, used by the parasite as an very effective vehicle to disseminate throughout the host body or the site of long-term T. gondii persistence, respectively

Parasitic helminths as medicines

Many recent epidemiologic and experimental data showed immunomodulatory action of several helminths. Of particular interest have been the results demonstrating that helminths infections are able to inhibit the development of autoimmune processes and pathology in animal experimental models, and probably in humans. The article presents and discusses selected aspects of this novel therapeutic approach which seems particularly important for combat a dramatic rise in the incidence of allergy and autoimmune diseases in the West

Toxoplasma gondii - known and unknown parasite

The protozoan Toxoplasma gondii, described by Nicolle and Manceaux in 1908, is a ubiquitous and cosmopolitan parasite that infects a wide range of mammal and bird species. Although the parasite possesses a meiotic lifecycle phase it represents very unusual population structure comprising three archetypal clonal lines: I, II and III, which together account for over 95% of strains isolated in Europe and North America. The isolates from South America are more genetically diverse. Molecular phylogeny studies and phenotype analyses showed recently 11 successful parasite lineages (haplogroups) of different global distribution. Individual T. gondii strains vary strongly in their virulence which is very well defined in mice: there are extremely virulent strains (of RH type) with LD100=1 and low virulent strains (LD50≥1000), without any intermediate virulence strains. The article presents some recent data on the population structure and virulence of the parasite, mapping of virulence loci and new identified rhoptry antigens (ROP18 and ROP16) as major virulence components

Toxoplasma gondii - wewnatrzkomorkowy pasozyt

Toxoplasma gondii -intracellular parasite. Tue article presents selected data concerning invasion and intracellular life of obligate intracellular parasite Toxoplasma gondii in susceptible bosts

Personalized vaccination?

Several studies revealed a close relation between the sex and immunity including the immune responses to bacteria, viruses and parasites antigens. Dimorphic immune reactions in females versus males and an influence of sex factors on the efficacy and side effects of vaccines as well as a new approach in the construction of prophylactic vaccines dependent on the sex and genetic background of vaccinated individuals (personalized vaccinology) are presented in the article

Toxoplasma gondii and mast cells

Mast cells, discovered by Paul Burnet over one century ago, have been long recognized only as inductors of IgE-dependent allergic diseases (allergy of type I, Th2 lymphocytes dependent). However, numerous recent studies have indicated that they play an essential role in many other immunological and non-immunological processes. Infection with Toxoplasma gondii elicits the induction of a strong cell-mediated immunity characterized by a highly-polarized Th1 response, which can protect against allergy. Knowledge of the contribution of mast cells to Toxoplasma invasion is still limited, and the present article discusses aspects of the relationship between mast cells and T. gondii