Number Of Antibody-forming Cells Research Articles

T and B lymphocyte function in response to a protein-free diet.

Groups of female adult rats were fed either isocaloric protein-free or 18% protein diets for various intervals. Four days before sacrifice, the animals were immunized either with sheep erythrocytes or with a trinitrophenyl-lipopolysaccharide (TNP-LPS) conjugate. Spleen lymphoid cell populations, spleen plaque-forming cells, and serum hemolysins were measured. A persistent diminution, proportional to the duration of protein deprivation, was observed in all parameters studied after immunization with the T-dependent antigen, sheep erythrocytes. The immune dysfunction was more pronounced for hemolysin titers, which became undetectable after 15 days of protein-free diet. The response of the protein-free group to the T-independent antigen (TNP-LPS) after 15 days of diet was only 34% of the control. When a T-cell lymphokine, macrophage migration inhibitory factor, was measured, a normal response was observed in the protein-free group. Feeding a normal diet rapidly restored the spleen plaque-forming cell populations to 60% of normal after 4 days and to 100% after 6 days. Protein starvation influenced the production of antibodies more than it did the number of antibody-forming cells. The nutritional impairment of immunoglobulin synthesis appears to be reversible.

Changes in plasma levels of calcium and in bone marrow mitosis after antigenic challenge in rats and mice.

When rats or mice were immunized with sheep red blood cells, bacterial lipopolysaccharides or bovine serum albumin, a proliferative response could be detected in the bone marrow and spleen. This response was associated with a hypercalcaemic phase. Parathyroidectomy, which resulted in a protracted hypocalcaemia, prevented the development of an increase in levels of plasma calcium. This operation also prevented the rise in bone marrow proliferations following antigenic challenge, but did not ablate the normal proliferative response to antigen by cells in the spleen. Antibody production and numbers of antibody-forming cells were not significantly reduced by parathyroidectomy. These results suggest that there is a pool of antigen-insensitive cells in the bone marrow which are stimulated after antigenic challenge. It is postulated that these events were mediated by the development of a parathyroid-dependent hypercalcaemia which stimulates the cells non-specifically. These events may form part of a cellular homeostasis, replacing cells in peripheral lymphoid tissues.

Serum thymic hormone activity in genetically-obese mice.

1. Serum thymic hormone was assayed in genetically-obese (C57B1/6J ob/ob) mice and lean controls (+/+, +/-) of the same strain. 2. The thymic hormone activity was higher in the majority of the obese animals compared with non-obese mice. 3. The number of antibody-forming cells in the spleen expressed as a proportion of the total mononuclear cells was increased in the obese mice. 4. It is suggested that obesity is associated with significant changes in the thymic hormone levels which may alter the relative proportion of lymphocyte subsets and cell-mediated immunity.

Immune responses after localized lung immunization in the dog.

The immune response in immunized and unimmunized bronchoalveolar spaces, as well as in the blood, was measured after localized deposition of antigen in the lung. Using a fiberoptic bronchoscope, groups of dogs were immunized with sheep red blood cells (SRBC) deposited into a single airway of the left apical or right apical lung lobes. Bronchoalveolar cells were obtained by lung lavage through the fiberoptic bronchoscope from the immunized lung lobe, as well as from lung lobes that did not receive antigen. Lavage cells and blood samples were collected at 3 to 21 days after immunization. The total number of lymphocytes, macrophages, and polymorphonuclear leukocytes, and the number of lymphoid cells producing anti-SRBC IgM and IgG antibodies were determined. Our results indicated that the highest number of antibody-forming cells (AFC) were found in the immunized lung lobes. An elevated, but significantly lower number of AFC were observed in the unimmunized lung lobes. The number of IgM and IgG AFC in the blood reached peak concentrations 3 to 7 days earlier than the AFC in the lung. We concluded from our data that the blood is an important source of the AFC found in the lung.

The suppressive effect of continuous infusion of bilirubin on the immune response in mice.

Mice (strains Balb/c and A/J) received an intravenous infusion of bilirubin for a 1 d period. The infusion was delivered at various phases of the primary reaction; the degree of the immune response was expressed as the number of antibody-forming cells against sheep erythrocytes. Bilirubin infusion during both the inductive and productive phase of the primary reaction decreased significantly the immune response. We assume that bilirubin influences the differentiation of immunocompetent cells immediately after their contact with the antigen; in addition it acts in the period of the quantitative increase of the number of antibody-producing cells.

The generation of memory B-cell subpopulations capable of proliferation and expansion of the pool: Effect of time and antigen

The ability of antigen to induce proliferation of memory B lymphocytes, thus perpetuating and expanding the memory cell pool, has been examined using an antibody-forming cell (AFC) assay. This method provided confirmation of previous studies in which serum antibody titer was used as a relative measure of pool size and demonstrated directly that the number of antibody-forming cells is increased. Memory cell subpopulations were prepared by lg velocity sedimentation from recently immunized donors (2 weeks) and tested for their ability to proliferate, thus expanding the memory cell pool. Both large and small immature DNP-specific memory cells displayed antigen-dependent and antigen-independent proliferation while mature cells (8 weeks postpriming) were capable only of antigen-dependent proliferation. Chicken γ-globulin (CGG) specific memory cells were also evaluated in this system and were found to differ from DNP-specific cells in several ways. (A) DNP-specific AFC were found to be concentrated in the spleen while CGG-specific AFC were found predominantly in the bone marrow early after transfer and in the spleen upon delayed challenge. (B) The rate of maturation of CGG-specific memory cells capable of antigen-driven proliferation and pool expansion was delayed in comparison to DNP-specific memory cells. The relationship of these functionally defined subsets to previously described memory cell subpopulations is discussed.

Effect of experimental dengue virus infection on humoral and cell-mediated immune response to thymus-dependent antigen.

Mice injected with dengue virus showed a depressed primary and secondary humoral immune response to SRBC as measured by the number of antibody-forming cells, haemagglutinin and haemolysin titres. The time of administration of SRBC during the infection was found to be an important factor determining the response to SRBC. The cell-mediated immune response was also suppressed as measured by the delayed hypersensitivity reaction to SRBC in the footpad. While the immunosuppression of humoral immunity was only transient and the animals recovered within 30 days following infection, the cell-mediated immunity remained suppressed throughout this period. Immunofluorescent studies and LD50 determination of the infected brains demonstrated significant virus titres from 7 to 15 days postinfection. This period coincided with maximal immunosuppression.

Influence of dextran polymer particles (Sephadex G-200) on humoral immune responses.

Dextran polymer particles (Sephadex G-200) mixed with bovine serum albumin (BSA) or sheep red blood cells (SRBC) were injected intraperitoneally (i.p.) into mice and the number of antibody-forming cells in spleen and antibody titers in sera were determined. Antibody formation following the first and the booster immunization to BSA was enhanced to a similar degree by Sephadex G-200 and incomplete Freund's adjuvant. When SRBC were injected in a suboptimal dose of 5X10(6) cells, Sephadex G-200 enhanced the maximum of the primary immune response. In contrast, the polymer inhibited the primary and secondary immune response when 5X10(8) SRBC were given.

Antibody-forming capacity of mouse spleen cells after hypoxic hypoxia and injection of erythropoietin

The absolute and relative (per 106 spleen cells) number of antibody-forming cells (AFC) in the spleen of CBA mice was found to be reduced by half of the 1st, 4th, and 7th days after acute hypoxia (12 h, 6700 m) and on the 1st and 4th days after the end of exposure to chronic hypoxia (16 h daily for 16 days, 6700 m). By the 7th day after the end of exposure to chronic hypoxia the number of AFC in the spleen of the mice was back to normal. One of two injections of erythropoietin reduced the absolute and relative number of AFC in the spleen of the posthypoxic mice by 33–50% compared with control animals.

Role of distant interactions of lymphocytes in the development of antibody formationin vitro

To elucidate the nature of local intercellular interactions inhibiting the proliferation of antibody-forming cells (AFC) in culture, described previously, the possibility of realization of this effect at a distance was studied. A population containing many cells was shown to be capable of inhibiting, by its actionin vitro at a distance, an increase in the number of AFC in a cell population separated from it by Millipore membranes impermeable to cells. This effect is also transmitted through a polymethylmethacrylate film, 5–10 μ thick, which does not allow the passage of proteins with a molecular weight of 150,000 daltons ([125I]IgG antibodies) and certain ions (51CrO4), but is permeable to other low-molecular-weight substances.

Effect of combined injection of hydrocortisone and edta on the number of antibody-forming cells in the spleen of mice immunized with sheep's erythrocytes

Experiments on (CBA x C57BL)F1 mice showed that injection of hydrocortisone into the animals in a dose of 1 mg per mouse 24 h after immunization with sheep's erythrocytes, and against the background of repeated injections of EDTA, leads to a reduction in the relative number of plaque-forming cells by more than two-thirds in the spleen of the mice compared with the effect of the two agents separately, and by more than five-sixths compared with the control. It is suggested that this may be the result of the more intensive incorporation of hydrocortisone associated with the prolonged hypocalcemic action of the complexone, EDTA.

Immunologic reactivity and adrenocortical function in the early period of chemical carcinogenesis

A parallel study was made of the level of immunologic reactivity and the state of adrenocortical function in BALB/c mice 7 days after a single injection of various doses of methylcholanthrene. Definite correlation was found between the degree of immunodepression induced by different doses of methylcholanthrene and determined as the number of antibody-forming cells in the spleen of the experimental mice and the 11-hydroxycorticosteroid concentration (both free and bound) in the blood plasma of the mice 7 days after injection of the carcinogen. These results may indicate that adrenocortical hormones play an important role in the pathogenesis of immunodepression induced by a chemical carcinogen.

Cellular antibody synthesis in thiamin, riboflavin, biotin and folic acid-deficient rats.

SummaryThe formation of splenic antibody-forming cells was determined by the Jerne agar-plaque technique in normal rats and in rats deficient in thiamin, riboflavin, biotin or folic acid immunized with sheep erythrocytes. The number of antibody-forming cells was reduced in all deficiency states with thiamin deficiency having the least effect. This decreased cellular immune response in biotin and folic acid deficiencies was partially restored to normal by administration of biotin or folic acid, respectively, shortly before immunization.

Dependence of antibody formation in lymphocyte cultures on incubation temperature

The increase in the number of antibody-forming cells (AFC) and in the incorporation of [3H]thymidine with a rise in the incubation temperature from 2 to 37°C was studied in cultures of spleen cells from immunized and nonimmunized C57BL/6 mice. An exponential increase in the number of AFC was found with an increase in temperature, and the existence of a “critical” temperature was demonstrated, above which the rate of increase in the number of AFC rises sharply. The curves showing increased incorporation of [3H]thymidine with an increase in temperature in some cases diverged from the curves of the increase in the number of AFC. Culture of immune cells at low temperatures leads to the accumulation of factors stimulating AFC formation in the medium.

Preparation of a mouse antiserum against isologous aggregated immunoglobulins and the study of its action on rosette-forming cells

A method of obtaining antiserum against isologous aggregated mouse immunoglobulins (MAAS) is described. This serum blocks the antigen-binding receptors of immune rosette-forming cells in vitro. MAAS was injected into mice immunized with sheep's red cells. By comparison with immunized mice receiving normal isologous serum, rosette-forming B cells were absent at the peak of the primary response in the spleen of the mice receiving MAAS. The number of antibody-forming cells was not reduced under the influence of MAAS.

High doses of subconjunctival corticosteroid and antibody-forming cells in the eye and draining lymph nodes.

After the intracorneal injection of rabbit eyes with bovine gamma-globulin, the subconjunctival administration of a corticosteroid in either the ipsilateral or contralateral eye resulted in essentially the same changes: a reduction in the number of antibody-forming cells in the draining lymph nodes and a reduction in the ocular inflammatory response.

T-dependent suppression of the primary antibody response to sheep erythrocytes in mice infected with Trichinella spiralis

Mice infected for 20 days with the parasitic mematode Trichinella spiralis had significantly reduced numbers of splenic antibody-forming cells (AFC) and decreased serum hemagglutinin titers following intraperitoneal immunization with sheep erythrocytes (SE). Similarly, when immunized in vitro to SE, cultures of splenocytes from infected mice developed fewer AFC than cultures of normal cells. Splenocytes from infected mice actively suppressed the in vitro response of normal cells to SE, and this in vitro suppression was abolished by lysis with anti-thy 1 antiserum and enhanced by lysis with anti-immunoglobulin antiserum. The addition of supernatant fluids from cultures of splenocytes from infected mice to cultures of normal cells on Day 0 of culture reduced by 70% the number of AFC produced by these cultures. These results indicate the presence of T-suppressor cells and suggest that antigen-induced suppression (antigenic competition) is one mechanism of Trichinella-induced suppression.

Genetic differences in reactivity of lymphoid tissue during regeneration of the liver in different strains of mice

Transplantation of lymphocytes from partially hepatectomized CBA and C57BL mice, together with sheep's red cells, into lethally irradiated syngeneic mice showed that the CBA mice acquired the ability to increase the number of antibody-forming cells much sooner after the operation (4 h) than C57BL mice (17 h). Transplantation of the lymphocytes in a semisyngeneic system led, as a result of the graft versus host reaction (GVHR), to a decrease in the number of antibody-forming cells during subsequent immunization of the recipients with sheep's red cells. The GVHR was less severe in the hepatectomized mice than in the controls. These changes also appeared sooner after the operation in CBA mice than in C57BL mice.

Role of the adenyl cyclase system in stimulation of immunogenesis by bacterial lipopolysaccharide and by endogenous serum pyrogen

Experiments on rabbits immunized intraperitoneally with corpuscular typhoid vaccine showed that after injection of the bacterial lipopolysaccharide pyrogenal (LPS) and endogenous serum pyrogen (ESP), together with theophylline, the number of antibody-forming cells in the spleen was increased. The results point to a role of the adenyl cyclase system in the mechanism of the stimulating action of LPS and ESP.

Age changes in immune response of rats to repeated injections of different doses of sheep's red cells

The number of antibody-forming cells and the serum antibody titers were determined in adult and old rats after tenfold immunization with “small” (4·108 cells) and “large” (4·1010 cells) doses of sheep's red cells. The antibody (hemolysin and hemagglutinin) titers in the animals of both age groups were found to be either similar in magnitude or higher in the younger adult rats (for hemolysins, in the case of injection of the “large” dose of antigen). The number of direct plaque-forming cells in the spleen of the old animals was greater than in the young adults at all times of immunization, but the number of indirect plaque-forming cells was greater only at the end of immunization. The results are evidence of differences in maturation of the immune response in animals of different ages.