Phagocytosis of Giardia lamblia trophozoites by human colostral leukocytes.
OBJECTIVE
To determine the phagocytic activity of the polymorphonuclear and mononuclear cells present in human colostrum, and to verify the influence of opsonins in the adherence, ingestion and killing of Giardia lamblia trophozoites.


METHODS
Polymorphonuclear and mononuclear phagocytes were incubated with G. lamblia trophozoites, in the presence as well as the absence of supernatant of human colostrum (the source of opsonins) for 30, 60 and 120 min. The trophozoites/phagocytes ratio was 1:1, and the percentage of phagocytosed trophozoites was determined by microscopic examination of acridine orange-stained cells.


RESULTS
The mononuclear phagocytes presented more functional activity than the polymorphonuclear. The highest indexes of adherence (77.6 +/- 5.1), ingestion (68.9 +/- 5.5) and killing (48.5 +/- 4.9) were obtained through the incubation of mononuclear cells in the presence of colostrum supernatant for 120 min.


CONCLUSIONS
The phagocytes of human colostrum were able to ingest G.lamblia trophozoites and presented microbicidal activity in vitro, suggesting that these phagocytes may act as an additional mechanism of protection against infant giardiasis through breastfeeding.
França-Botelho
Aline C
AC
Departamento de Ciências Biológicas, Instituto de Ciências da Saúde, Centro Universitário do Planalto de Araxá, Araxá, Minas Gerais, Brazil.
Honório-França
Adenilda C
AC
França
Eduardo L
EL
Gomes
Maria Aparecida
MA
Costa-Cruz
Julia M
JM
D000293:Adolescent; D000328:Adult; D000818:Animals; D018929:Cell Culture Techniques; D003126:Colostrum / Q000166:cytology*; D005260:Female; D016829:Giardia lamblia; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000502:physiology*; D050296:Microbial Viability; D009895:Opsonin Proteins / Q000502:physiology; D010586:Phagocytes / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology*; D011247:Pregnancy
D009895:Opsonin Proteins