Humoral and cell-mediated immune responses in fully allogeneic bone marrow chimera in mice

AKR mice were protected from lethal irradiation and established as long-lived chimeras by transplanting allogeneic C57BL/6 (B6) bone marrow that had been treated in vitro with anti-Thy-1 antiserum without complement. In these chimeras, which were designated [B6 {arrow} AKR], virtually all the thymus and spleen cells were shown to be derived from the B6 donor; several immune functions studied in these chimeras were as follows: (a) The chimeric mice were tolerant of histocompatibility antigens of both donor and recipient strain and nearly fully reactive to antigens of third party, as revealed by Simonsen's splenomegaly assay. The tolerance of these chimeras could not be attributed to suppressor cells but was compatible with clonal depletion. (b) Proliferative responses to concanavalin A, phytohemagglutinin, and lipopolysaccharide as well as natural killer and antibody-dependent cell- mediated cytotoxicity activity of the chimeric mice was normal. (c) Plaque- forming cell (PFC) assays of antibody responses to sheep erythrocytes (SRBC) showed gross deficiency in the primary response of the [B6 {arrow} AKR] and [AKR {arrow} B6] chimeras. By contrast, [B6-H-2(k)(E(k)) {arrow} AKR] H-2-compatible chimeras and [AKR {arrow} AKR] syngeneic marrow transplanted mice had normal primary PFC responses. PFC responses after secondary stimulation with SRBC, however, revealed vigorous direct plaque formation and substantial but somewhat smaller indirect plaque formation in the [B6 {arrow} AKR] chimeras. This observation favors operationally the concept of adaptive differentiation proposed by Katz et al. (44). (d) Analysis of ability of the chimeras to develop and express delayed-type hypersensitivity responses to contact sensitizer (2,4-dinitro-l-fluorobenzene [DNFB]) showed no apparent immunodeficiency of either chimeras to this form of immunization. Development of immunologic tolerance to DNFB, however, was grossly deficient in [B6 {arrow} AKR] chimeras but normal in [AKR {arrow} AKR], [B6 {arrow} B6], and [E(k) {arrow} AKR] chimeras. These findings indicate that full chimeras across major histocompatibility complex have considerable immunologic vigor even though primary immune responses that require histocompatibility between interacting cell types are initially defective.

Studies in acute leukemia. I. Antibody-dependent and spontaneous cellular cytotoxicity by leukemic blasts from patients with acute nonlymphoid leukemia

Leukemic blasts from patients with acute nonlymphoid leukemia were examined for the presence of Ig, receptors for IgGFc, and for their capacity to mediate antibody-dependent cellular cytotoxicity (ADCC) against chicken red blood cells (RBC) coated with IgG and spontaneous cell-mediated cytotoxicity (SCMC) against cells of K562 cell line. Leukemic blasts from acute myeloblastic leukemia (AML) patients lacked both Fc receptors and Ig on their surface, had no SCMC activity and majority, but not all of them, lacked ADCC activity. Leukemic blasts from patients with acute monocytic leukemia (AMOL) had Fc receptors, and 50% had IgG on their surface. IgG was cytophilic and appeared not to be directed against cell-surface antigens. This antibody did not interfere with the ADCC activity of leukemic cells. Leukemic blasts from majority of patients with AMOL mediated ADCC, but had no SCMC activity. An association between ADCC and presence of Fc receptor was observed.

Circadian Rhythm in Activity of Lympholytic Natural Killer Cells from Spleens of Fischer Rats

Three and one-half-week-old male inbred Fischer rats housed individually at 24 ± 1°C with Purina Chow and water ad libitum were randomly assigned to six different rhythmometry chambers, each lighted daily for 12 hr and darkened the following 12 hr. The timing of these regimens differed from one chamber to the next by 4 hr (i.e., one chamber was illuminated from 0600 to 1800, the next from 1000 to 2200, etc.). Thus, completely light-dark synchronized animals sampled from the six chambers at any given clock time were intended to represent, in relation to the onset of the daily light span, six different circadian stages, differing from each other by 4 hr. After 2-week standardization in the chambers, rectal temperature was measured and the animal killed, its spleen collected aseptically in RPMI 1640 medium containing 10% fetal calf serum, and the activity of natural killer (N.K.) cells determined in a direct 51Cr release assay. Spleen cells of 6-week-old rats were effector cells and RL♀1 mouse lymphoma cells in tissue culture were target cells. Two experiments carried out, each on 3 successive days in November 1977 and February 1978, using subtotals of 24 rats at each lighting stage; i.e., a total of 144 rats for six intended circadian stages, revealed by cosinor analysis a circadian rhythm in N.K. cell activity and rectal temperature. The circadian recetal temperature acrophase may be a marker with similar timing of high murine N.K. cell activity. In the context of a budding chronoimmunology, these findings extend the scope of a spectrum of bioperiodic neuroendocrine influences on lymphoid activity and body resistance.

Abnormalities in clonable B lymphocytes and myeloid progenitors in autoimmune NZB mice

Cloning procedures were used to study B lymphocytes and progenitors of granulocytes and macrophages in NZB mice. Numbers of B cells that were detected in sheep erythrocyte-containing semisolid cultures were only slightly elevated in NZB tissues, and these were normally sensitive to inhibition by anti-mu or anti-delta antibodies or prostaglandin E. However, NZB mice rapidly developed large numbers of B cells that could be cloned in the presence of lipopolysaccharide, and these included unusual anti-mu resistant cells. Numbers of myeloid precursors in NZB bone marrow that were responsive to colony-stimulating activity in L-cell conditioned medium or endotoxin serum were at least normal, but at all ages granulocyte-macrophage precursors were poor responders in cultures stimulated by WEHI-3 cell conditioned medium. Almost no colonies were elicited in NZB cultures with a colony-stimulating activity moiety from WEHI-3 cells. Prostaglandin sensitivity of myeloid precursors from NZB and CBA mice was also different. Codominant genetic control of these abnormalities was suggested by their partial expression in F1 hybrid NZB X CBA and NZB X NZW mice. NZB mice expressed an unexpected IgD allotype allele.

Impairment of cell-mediated immunity functions by dietary zinc deficiency in mice

Several immunologic features were analyzed in mice on a zinc-deficient diet [Zn(-)], in mice pair-fed a diet containing zinc [Zn(+)], in mice fed a Zn(+) diet ad lib, and in mice fed laboratory chow ad lib. When placed on a Zn(-) diet, 6- to 8-week-old A/Jax, C57BL/Ks, and CBA/H mice showed loss of body weight, low lymphoid tissue weight, and profound involution of the thymus within 4-8 weeks after initiation of the regimen. Approximately 50% of the mice on the Zn(-) diet developed severe acrodermatitis enteropathica (lesions on tail and paws) and diarrhea. Pair-fed mice on the Zn(+) diet did not show any of these symptoms. Mice on the Zn(-) diet showed the following immune deficiencies: (i) depressed plaque-forming cells against sheep erythrocytes after in vivo immunization; (ii) depressed T killer cell activity against EL-4 tumor cells after in vivo immunization; and (iii) low natural killer cell activity. However, antibody-dependent cell-mediated cytotoxicity against chicken erythrocytes was normal in the mice on the Zn(-) diet. Deficiency of T killer cell activity was not observed when immunization with EL-4 allogeneic lymphoma cells was carried out in vitro. Progressive loss of relative and absolute number of Thy 1.2+ cells and a proportionate relative increase in cells bearing Fc receptors was seen in spleen and lymph nodes of Zn(-) animals. It appears that zinc is an essential element for maintenance of normal T cell and other immune functions in vivo.

Spontaneous and antibody-dependent cell-mediated cytotoxicity by human T cell subpopulations

Human peripheral blood non-T cells, T cells and their subpopulations (Tmu, Tgamma, Tphi, Tgamma-depleted cells, and Tmu-depleted cells) were assayed for their capacity to mediated spontaneous lymphocyte-mediated cytotoxicity (SLMC) or natural killer activity against K562 tumor cell line and antibody-dependent cellular cytotoxicity (ADCC) against chicken erythrocytes coated with antibody. Non-T cells, unseparated T cells, Tgamma cells, and Tmu-depleted (Tgamma-enriched) cells were found to have both SLMC (NK activity) and ADCC. Tmu, Tphi, and Tgamma-depleted cells had minimal or no SLMC and ADCC activity. This study demonstrates that SLMC and ADCC activity in T cells is mediated by Tgamma cell subpopulations. These two cytotoxic reactions were either mediated by two distinct subsets of Tgamma cells or by a single effector cell using two different mechanisms.

Dietary restrictions early and late: effects on the nephropathy of the NZB X NZW mouse

NZB X NZW F1 mice initiated on calorie restriction at weaning or at 4 to 5 months of age or initiated on moderate protein restriction at weaning, were afforded significant protection from the development of immune nephritis. Whereas animals on normal calorie intake demonstrated deposition of immune reactants in glomerular basement membrane-oriented pattern, those on either protein or calorie restriction exhibited mesangial confinement of immunoglobulins and complement. Associated with these divergent patterns of immune deposition, mice on normal calorie intake evidence extensive cellular proliferation and glomerular sclerosis while dietary restricted mice demonstrated virtually no hyalinization and only mild cellular proliferation. Autoantibody formation of calorie-restricted animals was significantly decreased compared to mice fed a normal diet. Thus, moderate dietary restriction may serve as either a prophylactic or effective therapeutic approach to ongoing autoimmune disease.

Nutritional inhibition of genetically determined renal disease and autoimmunity with prolongation of life in kdkd mice

Striking inhibition of development of renal disease and prolongation of lifespan have been achieved in kdkd mice by restricting their daily food intake. Restricting protein intake alone did not prolong life nor did it inhibit development of kidney disease. The kdkd nephronophthisis, although very different histologically from the renal disease of B/W mice, may also have immunological components. Like the immunologically based renal disease of B/W mice, renal disease in kdkd mice is decreased or eliminated histologically by dietary restriction, which inhibits development of autoimmunity directed toward the erythrocytes of these mice. Further analysis will be needed to elucidate the cause of progressive renal disease in both the kdkd and B/W models and to permit understanding of the profound influence of restriction of food intake on development and progression of these very different renal diseases.

Influence of dietary restriction on immunologic function and renal disease in (NZB x NZW) F1 mice

In (NZB x NZW)F(1) (B/W) mice, moderate caloric intake [10 kcal (41.8 kJ) per day] from the time of weaning was associated with maintenance of lower body weight, greater capacity of spleen cells to be stimulated with T-cell mitogens, and better preserved capacity to generate cytotoxic cells in response to in vitro and in vivo stimulation with allogeneic tumor cells. Plaque-forming cell response to sheep erythrocytes was also well maintained in animals on the restricted diets when sensitization was accomplished either in vitro or in vivo. Spontaneous suppressor cell activity against plaque-forming cells that developed in controls did not appear in the mice on the restricted diet. Significantly less circulating antibody to native DNA was present in the blood of mice 10 months of age when their dietary intake had been restricted. Histological analysis revealed that the development of renal disease and the deposition of gamma globulin in the glomerular capillaries was markedly inhibited in the mice on restricted diets. Dietary restriction from the time of weaning thus appears to prolong significantly the life of autoimmunity-prone (NZB x NZW)F(1) male and female mice and to alter lymphoid cell immune function, thereby decreasing the autoimmune processes and immunological assault associated with progressive renal disease in these animals.

Immune response in the mutant diabetic C57BL/Ks-dt+ mouse. Discrepancies between in vitro and in vivo immunological assays

Cell-mediated and humoral immune responses of mutant diabetic db+/db+ mice were evaluated using in vivo and in vitro immunological assays. When compared to lean, nondiabetic db+/m+ or m+/m+ mice, db+/db+ mice demonstrated markedly altered in vivo immune responses characterized by a significantly diminished ability to reject allogeneic skin grafts, a markedly diminished capacity to generate cytotoxic cells after sensitization with allogeneic EL-4 lymphoma cells and a significantly enhanced plaque-forming cell response to sheep erythrocytes. In contrast, spleen cells from db+/db+ mice demonstrated only minimal alterations in in vitro responses to mitogens and allogeneic cells and no alteration in their capacity to generate an in vitro plaque-forming cell response. The spleens and thymuses of db+/db+ mice weighed significantly less than organs from db+/db+ mice. In addition, thymuses from db+/db+ mice demonstrated a marked deficiency in in vivo [125I]UdR uptake. These data suggest that the altered metabolic status of the diabetic host influences immune function in vivo possibly due to abnormal function of lymphocyte subpopulations.

Long survival and immunologic reconstitution following transplantation with syngeneic or allogeneic fetal liver and neonatal spleen cells

(1)Spleen cells from newborn syngeneic and allogeneic mice that lack fully differentiated T lymphocytes can be used as a hematopoietic source to reconstitute both hematopoietic and lymphoid systems of lethally irradiated mice without producing a GVHR. (2) Fetal liver cells from syngeneic and allogeneic mice that lack postthymic T lymphocytes can also be used for hematopoietic and immunologic reconstitution of lethally irradiated mice without producing GVHR. (3) Immunologic deficiency is observed in some experiments in mice given supralethal irradiation (1000 R) and fetal liver as reconstituting hematopoietic tissue. (4) The findings suggest that Tcells, at an early stage of differentiation, are more susceptible to tolerance induction than are T lymphocytes at later stages of differentiation and do not, in general, produce GVHR. (5) It is postulated that hematopoietic cells, free of postthymic lymphoid cells, can be used for hematopoietic or immunologic reconstituting and cellular engineering without producing GVHD.

Nutritional deficiency, immunologic function, and disease

Several experiments conducted by our group over a period of 6 years have shown that nutritional stress, especially protein and/or calorie deprivation, leads to many, often dramatic, changes in the immune responses of mice, rats, and guinea pigs. Chronic protein deprivation (CPD) has been shown to create an enhancing effect on the cell-mediated immune responses of these animals. Humoral responses under CPD conditions were most often found to be depressed, but sometimes were unaffected, depending on the nature of the antigen employed. Chronic protein deprivation, consistent with the pattern just mentioned, improved tumor immunity by depressing production of B-cell blocking factors, and, in at least one instance, resistance to development of mammary adenocarcinoma in C3H mice was associated with evidence of increased numbers of T suppressor cells. Profound nutritional deficits (less than 5% protein per total daily food intake) depressed both cellular and humoral immunity. Early, though temporary, protein deprivation caused a long-term depression of both cellular and humoral immunity also, with the humoral component being the first to recover. Manipulation of protein and calories was found to have a profound effect on certain autoimmune conditions. Diets high in fat and low in protein favored reproduction but shortened the life of NZB mice, whereas diets high in protein and low in fat inhibited development of autoimmunity and prolonged life. Chronic moderate protein restriction permitted NZB mice to maintain their normally waning immunologic functions much longer than mice fed a normal protein intake. Further, the low-protein diet was associated with a delay in development of manifestations of autoimmunity. Decreasing dietary calories by a reduction of fats, carbohydrates, and proteins more than doubled the average life span of (NZB X NZW)F1 mice, a strain prone to early death from autoimmune disease. Histopathologic studies using immunofluorescent microscopy revealed that the development of the renal lesions caused by the deposition of antigen-antibody complexes, which is so characteristic of these mice, was markedly delayed.

Circadian rhythmic plaque-forming cell response of spleens from mice immunized with SRBC

Studies under controlled conditions of lighting and temperature revealed clear evidence of circadian periodicity with respect to the number of PFC present in the spleens of BALB/c mice 3 or 4 days after immunization with SRBC. Striking differences in proliferative responses of spleen lymphocytes to PHA or Con A were also observed at two different circadian times. Large proliferative responses occurred at the time when injection of antigen and/or sampling for PFC yielded a low PFC formation (early in the daily dark span) and small proliferative responses occurred at the time when antigen injection and sampling yielded high formation of PFC (early in the daily light span). These findings indicate that care should be taken to control the circadian timing of stimulation and sampling in studies of immune responses, and that rhythmically varying aspects constitute a new dimension of immunologic processes awaiting further analysis in both the circadian and weekly spectral regions.

Tumor immunology, autoimmunity and aging

Cell-mediated immune function declines with aging, and may be associated with autoimmunity and malignancy. Humoral immune responses also decline with aging. The chief age-related effect on the immune system is a decrease in T-cell function. The "thymus clock" and immunogenesis are discussed in relation to aging. In animals, attempts at immunologic rejuvenation by cellular or hormonal means have not been successful as the results attained by genetic manipulation.

Influence of diet on survival of mice

The longevity of mice of the (NZB X NZW)F1 (B/W) strain and the DBA/2f strain of mice is dramatically prolonged by dietary restriction. B/W mice are susceptible to, and die at an early age from, immunocomplex nephritis. Mice of the DBA/2f strain are also relatively short-lived. Restriction of caloric intake prolonged life of B/W mice more than did protein restriction. DBA/2f mice showed prolongation of life when the diet was restricted only with respect to protein. Caloric restriction alone prolonged life less in DBA/2f mice than in B/W mice. These observations show that dietary manipulations have profound effects on immunity functions, including inhibition of the development of life-shortening autoimmune disease.

Influence of protein restriction on immune functions in NZB mice

The influence of a low protein (6%) diet on the immunologic function of NZB mice was investigated. The low protein intake was associated with decreased weight gain in both male and female NZB mice. The mice fed the low protein diet did not develop splenomegaly, which generally occurs by 7 to 10 months of age in NZB mice fed a normal amount of protein. Further, 7- to 10-month-old NZB mice fed the low protein(6%) diet, maintained: 1) more vigorous antibody production to sheep red blood cells; 2) greater capacity to produce graft-vs-host reactions, and 3) more vigorous cell-mediated "killer" cell immunity after immunization against DBA/2 mastocytoma cells than did NZB mice on a normal (22%) protein diet. The decrease of PHA and Con A response which normally occurs with aging in NZB mice was abrogated to some degree by protein restriction. However, response to LPS, which also declines with age in NZB mice, did not appear to be influenced by diet.