RESUMO

The aim of this study is to characterize intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL), as well as IgA B cells in the intestinal villi of the small intestine of rats which were fed a protein free diet (PF) and of those which were refed a 20% casein diet for 21 days (R21). Age matched control groups are also analyzed. T cell subsets and IgA-B cells were studied in tissue sections by the immunofluorescence technique. Lamina propria (LP) of the small intestine of the PF group were almost devoid of IgA-B cells; in the R21 group, the number of IgA-B cells was significantly diminished, when compared to the control group. The number of LPL in R21 group was not significantly different from the control group. W3/25+ (CD4) IEL diminished significantly in the intestinal villi of R21 group, while OX8+ (CD8) and OX22+ (CD45R) IEL were significantly increased when compared to the control group. These results indicate that: 1) Protein deficiency provokes an impairment of IgA-B cell terminal differentiation. 2) There is repopulation of LP by T cells in the R21 group. 3) The increased number of OX8+ (CD8) and OX22+ (CD45R) IEL might permit induction of intestinal delayed type hypersensitivity, thereby abrogating oral tolerance of systemic delayed type hypersensitivity.

Assuntos

Imunoglobulina A/análise , Intestino Delgado/imunologia , Linfócitos/imunologia , Deficiência de Proteína/imunologia , Envelhecimento , Animais , Linfócitos B/imunologia , Hospedeiro Imunocomprometido , Ratos , Ratos Endogâmicos , Subpopulações de Linfócitos T/imunologia , Desmame

RESUMO

A: Thymuses from protein deprived rats present: 1) a significant decrease in the absolute number of thymic cells bearing the CD5 phenotype (OX19+), as well as Thy 1.1 (OX7+). The predominant cell population was the one containing TdT (terminal deoxynucleotidyl transferase) as a sole marker: 2) in severely protein deprived rats followed by refeeding during 9 and 21 days, the existence of a small population of cells containing TdT as a sole marker. The TdT+W3/13+ cell population was restored but the CD4+ subpopulation (W3/25+) exists in lower numbers than in the age-matched controls. B: Severe protein deficiency at weaning, led to the presence in the Peyer's patches of very immature B-cells mostly c mu+OX7s mu-. Protein refeeding reinitiated the differentiation process as follows: 1) c mu+OX7+s mu- c mu-OX7-s mu+ as in the normal Peyer's patches; 2) however, switching of sIgM to sIgA-bearing cells was altered; 3) a low absolute number of W3/13+ and W3/25+ T-cells (CD4+) was found. C: Oral tolerance to dextrin evolved due to antigen specific CD8+ T-cells (found in Peyer's patches, mesenteric lymph nodes and spleen) and could be transferred to normal recipients.

Assuntos

Nódulos Linfáticos Agregados/patologia , Deficiência de Proteína/complicações , Timo/patologia , Animais , Antígenos CD4/análise , Imunidade Celular , Imunoglobulina A/análise , Ratos , Ratos Endogâmicos

RESUMO

A: Thymuses from protein deprived rats present: 1) a significant decrease in the absolute number of thymic cells bearing the CD5 phenotype (OX19+), as well as Thy 1.1 (OX7+). The predominant cell population was the one containing TdT (terminal deoxynucleotidyl transferase) as a sole marker: 2) in severely protein deprived rats followed by refeeding during 9 and 21 days, the existence of a small population of cells containing TdT as a sole marker. The TdT+W3/13+ cell population was restored but the CD4+ subpopulation (W3/25+) exists in lower numbers than in the age-matched controls. B: Severe protein deficiency at weaning, led to the presence in the Peyers patches of very immature B-cells mostly c mu+OX7s mu-. Protein refeeding reinitiated the differentiation process as follows: 1) c mu+OX7+s mu- c mu-OX7-s mu+ as in the normal Peyers patches; 2) however, switching of sIgM to sIgA-bearing cells was altered; 3) a low absolute number of W3/13+ and W3/25+ T-cells (CD4+) was found. C: Oral tolerance to dextrin evolved due to antigen specific CD8+ T-cells (found in Peyers patches, mesenteric lymph nodes and spleen) and could be transferred to normal recipients.