Changes in lymphocyte populations in protein--calorie-deficient mice

Effects of soybean peptide on immune function, brain function, and neurochemistry in healthy volunteers

OBJECTIVE

Soybeans, an excellent source of dietary peptides, have beneficial effects on health. We investigated the effect of the soybean peptide on immune function, brain function, and neurochemistry in healthy volunteers.

METHODS

Near-infrared spectroscopy (NIRS) was used to analyze brain cerebral blood flow. The A and DA levels in the serum were analyzed by ELISA kit. The total number of leukocytes was recorded with a standard counter. Flow cytometry was used to assess lymphocyte subset levels.

RESULTS

Cell numbers were upregulated in the group that had fewer leukocytes but downregulated in the group with more leukocytes. For the lymphocyte-rich type, lymphocyte counts tended to decrease, accompanied by an increase in granulocyte numbers. For the granulocyte-rich type, granulocyte counts tended to increase, but lymphocyte counts also increased. The numbers of CD11b(+) cells and CD56(+) cells increased significantly. Soybean peptide decreased the adrenalin level in plasma but increased the level of dopamine. Near-infrared spectroscopy showed significant increases in the amplitudes of θ, α-2, and β-L frequency bands after the ingestion of peptides.

CONCLUSION

Soybean peptides can modulate cellular immune systems, regulate neurotransmitters, and boost brain function.

Acute starvation and subsequent refeeding affect lymphocyte subsets and proliferation in cats

Although the early identification of patients with suboptimal nutritional status can allow the implementation of nutritional intervention to enhance the ability of the body to fight infection and disease, currently no definitive test of nutritional status exists. Therefore, this study was conducted to identify possible functional indicators of acute nutritional deprivation. The effects of total nutritional deprivation and subsequent refeeding on lymphocyte functions and subpopulations were examined in 23 healthy cats. Peripheral blood samples were analyzed at various times during food deprivation and refeeding periods. During the food deprivation period, decreases were observed in leukocyte number (P: < 0.05), lymphocyte number (P: < 0.05), percentage of CD4(+) cells [before stimulation with concanavalin-A (Con-A); P: < 0.05] and the CD4/CD8 ratio (before stimulation with Con-A; P: < 0.01) compared with d 0. Increases were observed in the percentage of CD8(+) cells [before (P: < 0.05) and after (P: < 0.01) stimulation with Con-A] and in intracellular calcium (P: < 0.01) during acute starvation. During the refeeding period, increases were observed in the percentage of CD4(+) cells (before and after stimulation with Con-A; P: < 0.01), the percentage of CD8(+) cells (before stimulation with Con-A; P: < 0.05) and lymphocyte number (P: < 0.05) compared with d 7. Lymphocyte proliferative capacity tended to decrease (P: = 0.07) during starvation and increased (P: < 0.01) during the refeeding period. These findings suggest that a 7-d starvation period had immunosuppressive effects on cats and that these effects were not completely normalized during 7 d of refeeding. CD4(+)/CD8(+) subset alterations and CD4/CD8 ratio in conjunction with lymphocyte proliferation may be useful as indices of nutritional status.

Humoral and cell mediated immune response to cadmium in mice

The effect of 30, 100 and 300 ppm of cadmium chloride (CdCl2) exposure for 35 days on humoral and cell mediated immune response was examined in Swiss Albino mice. Body burden of cadmium in kidney, spleen and liver was determined and histopathology of these organs was also done. Cadmium chloride in doses of 100 and 300 ppm when fed in drinking water caused significant decrease in IgM and IgG titre against sheep red blood cells (SRBC) and a significant decrease in IgG titre against bovine serum albumin (BSA). The delayed type hypersensitivity response to SRBC and splenic T cell proliferation to BSA was also significantly decreased following 100 amd 300 ppm cadmium exposure. Cadmium accumulation in the spleen, liver and kidney was associated with degeneration and inflammatory changes. It is concluded that cadmium causes significant suppression of humoral and cell mediated immune response in mice which could be due to its cytotoxic action on liver, kidney and immune cells.

Selected immune responses of adult cotton rats (Sigmodon hispidus) to dietary restriction

1. We examined the influence of moderate to severe dietary restriction on immune system function in adult cotton rats. Animals (N = 80) were fed ad lib. (controls) or restricted [moderate = 80% ad lib. for 1 or 2 weeks; severe = 80% ad lib. for 1 or 2 weeks followed by 40% ad lib. for one (week 3) or two (week 4) additional weeks] amounts of food for 1-4 weeks. 2. Average body weight loss for severely restricted animals in week 4 was 17%; dietary treatments had no measurable effect on hematological parameters (hematocrit, white blood cell count), lymphoid organ weights (thymus gland, spleen, popliteal lymph nodes), and mononuclear cell yields from lymphoid organs. 3. Cell-mediated immune function was assessed in vitro by a lymphoproliferative response assay and in vivo by a delayed-type hypersensitivity response assay. 4. Proliferative responses of spleen cell cultures stimulated with concanavalin A (Con A, Canavalia ensiformis) and pokeweed (PWM, Phytolacca americana) were normal or significantly greater among moderately restricted than control cotton rats during week 1 and week 2. 5. Lymphoproliferative responses of severely restricted animals were normal or reduced during week 3 and week 4. 6. Delayed-type hypersensitivity responses to the contact antigen oxazolone were significantly depressed among severely restricted animals in week 4 compared to controls. 7. In comparison with laboratory rodent strains, our initial results indicate that immune system function in adult cotton rats is not as sensitive to short term (1-4 weeks) periods of dietary restriction. 8. Immune system function was related to changes in body weight as a result of feed restriction.

Immunity to Pasteurella multocida in protein-deficient chickens

Studies were conducted to determine the effects of dietary protein restriction on the humoral immunity (HI) and cell-mediated immunity (CMI) of chickens. New Hampshire chickens were separated into two dietary treatment groups: basal, containing 3,200 kcal/kg and 21% protein; or protein restricted (PR), containing 3,200 kcal/kg and 7% protein. In studies involving HI, half of the birds in each dietary treatment were vaccinated against fowl cholera at 4 and 8 wk of age. Blood samples were collected weekly beginning at 4 wk of age. Overall, unvaccinated birds had lower titers than vaccinated birds and PR groups generally showed lower titers than basal groups. All birds were challenged by palatine cleft inoculation of live, virulent Strain X-73 of Pasteurella multocida. The vaccinated PR group survived live challenge as well as the vaccinated basal group, but all unvaccinated birds died as a result of the challenge, regardless of antibody titer. In studies involving CMI, half of the birds in each dietary treatment were vaccinated at 5 wk of age. At 2 to 3 wk postvaccination, representative birds from each treatment were bled for total and differential blood counts. Also, birds were sacrificed and spleen cells collected. Cells were cultured in Roswell Park Memorial Institute (RPMI) medium with phytohemagglutinin-M (PHA-M), sonicated P. multocida (X-73), or RPMI only.(ABSTRACT TRUNCATED AT 250 WORDS)

Calorie restriction modifies the delayed-type hypersensitivity response to the hapten trinitrobenzenesulfonic acid and to hapten-modified syngeneic spleen cells

We have studied the influence of different degrees of calorie restriction on the induction and the regulation of the delayed type hypersensitivity (DTH) response to trinitrobenzenesulfonic acid (TNBS) and TNBS-modified spleen cells (TNBS-SC), injected by the sc or the iv route. Immediately after weaning, BALB/c mice were placed on restricted diets for either 2 or 4 weeks and then the DTH response was induced. The results showed that a 37.5% restriction in the food supply significantly depressed the level of the DTH response induced by the sc injection of TNBS-SC. In contrast, a 25% restriction in the food supply was insufficient to depress the response. Calorie restriction did not modify the inhibitory influence of an iv injection of TNBS-SC on the DTH response. However, iv presensitization with free hapten or the simultaneous injection of TNBS-SC by the iv and the sc routes did not significantly depress the DTH response in calorie-restricted mice, indicating a defect in the inhibitory regulation of the DTH response in these dietary groups.

Current concepts in immune derangement due to undernutrition

Protein-calorie malnutrition (PCM) adversely affects more or less all immune competent cells. Nonspecific immunity is impaired, particularly adherence and chemotaxis of phagocytes, although the responsiveness of circulating cells may not be the same as that of noncirculating cells. PCM results in numerical and functional impairment in lymphocytes. PCM markedly affects IgG class antibodies which have the highest affinity when directed against T-dependent antigens. These impairments are interrelated, since cooperation between T-helper cell and B-cells is depressed, and the antigen presentation to T-helper cells by macrophages is deficient.

Appraisal of the methodology and applications for measurement of the zinc content of blood components as indicators of zinc status

Methods for the measurement of the zinc content of blood components (plasma, erythrocytes, platelets, mononuclear leukocytes, and polymorphonuclear neutrophils) as indicators of the zinc status of animals have been reviewed and evaluated. The values of plasma or serum zinc concentrations as indicators of zinc status in experimental animals or humans is questionable. Consequently, the zinc content of blood cellular components has been suggested as better indicators of zinc status. Methodological problems, such as incomplete cellular separation or zinc contamination, occur in some of the procedures applied to the quantitation of blood cellular component zinc. Specialized microprobe procedures involving, for example, proton-induced X-ray fluorescence, scanning ion technology, mass spectrometery, or laser microprobe mass analysis might be used to measure the absolute zinc level in individual cells subjected to minimal handling. Then, more conventional methods can be tested against the true standard. Nevertheless, there appears to be species differences in regard to the response of blood cellular zinc concentrations to dietary zinc deficiency. Blood cellular component zinc is conserved during severe zinc deficiency in the rat. In contrast, the zinc content of blood cellular components in humans may reflect the whole body zinc status.

Influence of protein restriction on lymphoid cell populations characterized by the binding of peanut agglutinin

Cells binding peanut agglutinin (PNA) were studied in the thymus, spleen, and mesenteric lymph nodes from mice placed in the post weaning period on protein-restricted diets containing 8% (R8%) and 4% (R4%) casein. The proportion of PNA+ thymocytes and the absolute number of total and PNA+ cells in the thymus were significantly diminished in R8% and R4% mice. Larger proportion of PNA+ thymocytes showed weaker fluorescence in R8% and R4% than in normally fed (N) animals. Recovery of PNA+ thymocytes was observed in R8% but not in R4% mice at 8 weeks. The number of total and PNA+ cells was significantly diminished although the proportion of PNA+ cells was not modified in the peripheral lymphoid organs of R8% and R4% mice. Results indicate that protein restriction preferentially affected the immature cortical PNA+ cells in the thymus whereas cell depletion in the peripheral lymphoid organs occurred at the expense of both the PNA+ and PNA- subpopulations.

Affinity and distribution of subpopulations of antibody-producing cells in protein-restricted C57BL/6 mice

To study the effect of protein restriction on the affinity of antibodies produced by plaque-forming cells (PFC), C57BL/6 mice were fed diets containing 4% (R4%), 8% (R8%), or 27% (N) casein for 2 (short-term) or 12 (long-term) weeks and immunized with dinitrophenyl (DNP) bovine gamma-globulin in complete Freund's adjuvant. Affinity was assessed by inhibition of plaque formation in the presence of free hapten. Anti-DNP PFC per 10(7) spleen cells were not diminished in short- and long-term R8% mice, and were increased in the former group at certain times after immunization. Affinity of indirect PFC was increased at Days 14 and 21 after immunization in short-term R8% mice and at Day 7 in R4% mice, and was similar in long-term R8% and N animals. No limitation in the heterogeneity of PFC affinities was observed in the restricted groups. Short-term restricted mice showed a rise of the high-affinity PFC subpopulation. The number of mice with hapten-augmentable PFC was diminished in the short-term R8% group at 7 days after immunization and in long-term restricted mice at 14 days, suggesting depressed levels of auto-anti-idiotypic antibodies in protein restriction.

Altered immune response during cadmium administration in mice

C57BL/6 mice were administered 50 or 200 ppm of Cd as CdCl2 in the drinking water for either 3 to 4 (short term) or 9 to 11 (long term) weeks. In other experimental designs, mice were exposed orally to 300 ppm of Cd or injected with 2.5 mg/kg of Cd ip. The proliferative response to the T cell mitogens Con A and PHA was increased in cultures of spleen cells from orally treated mice in most of the experiments performed. After primary immunization with sheep red blood cells, the number of IgM antibody forming cells per 10(7) spleen cells was also moderately higher in mice exposed to 50 or 200 ppm of Cd for short or long term. In contrast, long-term exposure to 300 ppm of Cd depressed the antibody response to SRBC. Administration of ZnCl2 prevented the enhancement of the PFC response in mice orally administered 50 ppm of Cd. The capacity to suppress the antibody response of spleen cells preincubated with sodium periodate was decreased after short-term oral or ip. Cd administration but was completely or partially recovered after long-term exposure to either 50 or 200 ppm of Cd.

Polyclonal B-cell response to stimulation with Escherichia coli lipopolysaccharide in dietary protein restriction

The polyclonal B-cell response to Escherichia coli lipopolysaccharide was studied in C57BL/6 mice maintained after weaning on either a moderate protein-restricted diet with 8% casein or a normal diet. After in vitro or in vivo stimulation with the endotoxin, autoreactive and anti-hapten antibody-producing cells were quantitated by direct plaque assay, using bromelain-treated mouse erythrocytes and trinitrophenylated sheep erythrocytes as targets. Larger numbers of plaque-forming cells were generated in cultures of spleen cells from dietary-restricted than from normal mice stimulated with various doses of lipopolysaccharide. The number of background plaque-forming cells was also higher in nonstimulated spleen cell cultures from restricted animals. After injection of lipopolysaccharide in vivo, the number of cells producing antibodies to bromelain-treated mouse erythrocytes per 10(7) spleen cells was significantly increased in dietary-deficient mice. The results are discussed in relation to the different sensitivities of lymphocyte populations to protein deficiency and to the possible presence of high levels of endogenous polyclonal B-cell activators in the restricted mice.

Zinc, copper, and manganese in immune function and experimental oncogenesis

Dietary deficiency of trace metals among human populations, once thought to be exceedingly rare, has recently gained attention as a potential public health problem. The consumption of highly refined and heavily processed foods reduces the trace element content of the diet. The higher trace element requirements of pregnancy, lactation, growth, development, and chronic disease may further contribute to states of marginal trace metal nutriture. Experimental animal studies have demonstrated that even marginal trace element deprivation during critical periods of growth and development or, alternately, during prolonged deficiency in adults can significantly alter immunologic function. Furthermore, trace metal nutriture has been shown to affect initiation and progression of a large variety of neoplasia. Studies of the interaction of trace metal nutriture and cancer have, however, suffered from many methodological inconsistencies as well as failures to define and quantitate the trace element content of diets and the host alterations in response to neoplastic challenge. Similarly, there has been little information in the critical area of marginal and moderate trace metal deficiency, i.e., those experimentaL situations most analogous to deficiencies that may occur in human populations. In this review, an attempt is made first to place in perspective experimental data relevant to these issues, and second to emphasize the desirability of further investigation in this critical area of human nutrition.