Studies on difference in cellular immune-response between the human tonsil and blood lymphocytes

Tonsillectomy and poliomyelitis: Development of causality

OBJECTIVE

This paper serves to review the historical progression of clinical, epidemiological and immunological evidence on the relationship between tonsillectomy and poliomyelitis and its influence on clinical medicine.

METHODS

A literature review was conducted using terms relating to poliomyelitis, tonsillectomy, and immunology. Primary sources published between 1900 and 2000 were reviewed, analyzed and evaluated based on their historical, clinical, epidemiological, scientific and immunological pertinence towards the relationship between tonsillectomy, and poliomyelitis during epidemics.

RESULTS

The first study proposing a relationship between poliomyelitis and tonsillectomy was a case report published in 1910 by Phillip Sheppard. In response, other physicians began conducting clinical and epidemiological studies investigating the relationship between recent tonsillectomy and poliomyelitis in children. While the results of many of these studies demonstrated an increased morbidity and mortality rate associated with poliomyelitis in children who underwent recent tonsillectomy, other studies claimed there was no connection. Opposing study results and diverging physician views on this relationship left the medical community divided on whether to recommend against elective tonsillectomies during poliomyelitis outbreaks. The relationship between tonsillectomy and poliomyelitis was established after many years of clinical and epidemiological studies. Further scientific and immunological investigations revealed the causal nature of this relationship.

Influence of IL-6 on proliferation and differentiation of tonsillar lymphocytes and detection of IL-6 producing cells in tonsil

When tonsillar B cells were cultured in the presence of exogenous interleukin-6 (IL-6), a small portion of them differentiated into plasma cells which seemed to have IL-6 receptors on their surfaces. The number of plasma cells tended to be greater in the tonsils of children than in the tonsils of adults. When tonsillar cells collected by Ficoll-Conray's method were cultured in medium containing IL-6, T cells differentiated and the number of activated T cells increased. Of the four subsets of T cells, this effect of IL-6 was strongest on cytotoxic T cells. IL-6-mediated proliferation and activation of cytotoxic T cells tended to be greater in the tonsils of children than in those of adults. IL-6 is produced in some tonsillar macrophages. The number of macrophages producing IL-6 was very different in different subjects. However, the number of macrophages producing IL-6 in tonsils of children tended to be greater than the number in tonsils of adults.

T lymphocytes from tonsil and peripheral blood show different cytolytic and helper activities

T lymphocytes from tonsil (To) and peripheral blood (PB) of 4 tonsillectomized children were subjected to clonal expansion with PHA in order to analyze at single cell level their cytolytic activity and their ability to produce interleukins such as IL-2, IFN-gamma and IL-4. Analyzing all T-cell clones (CD4+ and CD8+) obtained from To in comparison with those from PB, a reduced proportion of cells with lectin-dependent cytolytic activity (LDCC) (25% vs. 42%, p less than 0.01) and natural killer (NK) activity (18% vs. 31%, p less than 0.02) was found. These differences were proportionally related to the lower number of CD8+ T-cells in To than in PB. The proportion of CD4+ clones able to produce IL-2 and/or IL-4 were higher in To (75% and 61%) than in PB (52% and 25%, p less than 0.001 and p less than 0.001, respectively). In contrast, the proportion of CD4+ clones able to produce IFN-gamma was similar (53% and 58%) in both series of clones. According to the patterns of lymphokine synthesis, tonsillar T-cells differed from PB T-cells as follows: 1) the number of Th1-like CD4+ clones producing IL-2 and/or IFN-gamma (but not IL-4) were 23% vs. 44% in PB (p less than 0.001); 2) there was no difference between To and PB in the proportion of CD4+ clones producing IL-4 alone (Th2 clones: 9% vs. 8%); 3) CD4+ clones synthesizing IL-2, IL-4 and IFN-gamma at the same time were more frequent in To than in PB (Th3 clones: 53% vs. 17%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Subsets of tonsillar lymphocytes and activated cells in each subset analysed by three-color flow cytometry

Among the four subsets of tonsillar T cells, active cells were most abundant in the helper T subset, followed by the cytotoxic T, inducer T, and suppressor T subsets in order of decreasing cell count. The number of active cells was very small in the suppressor T subset. Plasma cells (PCA-1-positive cells) accounted for only about 3% of tonsillar cells. However, nearly half of the tonsillar B cells were activated (positive for Ba, being either Ba+/IgD+ or Ba+/IgD-). Ba-positive cells were hardly found in the population of peripheral-blood B cells. Ba+/IgD+ cells, which are ready to be transformed to cyclic cells or dormant cells depending upon the degree of stimulation, outnumbered cyclic cells. Many Ba+/IgD+ cells were present even in the small tonsils of adults, although these cells were very scarce in the peripheral blood. These findings show that the tonsil is prepared to perform immunologic functions in prompt response to external stimuli.

Subsets of tonsillar lymphocytes and activated cells in each subset analysed by two-color flow cytometry

We analysed subsets of tonsillar lymphocytes and activated cells in each subset by two-color flow cytometry. There were many helper T cells (CD 4+ leu 8-) and few inducer T cells (CD 4+ leu 8+) in the tonsil. The situation was the reverse in the peripheral blood. The tonsil had few suppressor T cells (CD 8+ CD 11+). The proportion of activated cells (HLA-DR+) was low in the peripheral blood and high in the tonsil. In the tonsil, the ratio of cells with transferrin receptors to total lymphocytes was higher in the B than in the T subset, and higher in the subset of CD 4+ than in that of CD 8+ cells. Activated and proliferating lymphocytes were more abundant in the tonsils of children than in those of adults and more abundant in patients with hyperplastic tonsillitis than in those with recurrent tonsillitis.

T cell subsets in the tonsil in relation to age analyzed with monoclonal antibodies (anti-leu antibodies) and fluorescence activated cell sorter (FACS)

The ratio of the cells reacting to anti-leu 1, 3a and 4 antibodies is as low as that of T cells in the tonsil to those in the peripheral blood. The number of the tonsillar cells reacting to anti-leu 2a and 7 antibodies is still smaller. Fluorescence intensity of tonsillar lymphocytes reacting to leu (1, 2a, 3a, and 4) antibodies is lower than that of peripheral blood lymphocytes. Adult tonsillar lymphocytes have higher ratios of the cells reacting to anti-leu 1, 2a, 3a, 4 and 7 antibodies than child tonsillar lymphocytes and fluorescence intensity of the cells reacting to these anti-leu antibodies tended to be higher in adult tonsillar lymphocytes. These findings suggest less cytotoxic/suppressor T and NK/K function cells in the tonsil than in the peripheral blood. From these, it is conceivable that the tonsillar lymphocyte constitution becomes closer to that of peripheral blood as the child grows up. Further, immature T cells are present in the tonsil, though in a small number. This tendency is stronger in children than in adults.

Studies on the cell-mediated immune response of tonsillar lymphocytes with regard to the clinical course and patient's age

There was no statistically significant difference in the intensity of the cell-mediated immune response of tonsillar T cells among different pathological conditions of the tonsils nor among different age groups. The tonsillar cell population of the adult was smaller than that of the child. Tonsillar cells were separated into 3 fractions with different specific gravities. In tonsillar cells from adults, fraction III consisting mainly of small lymphocytes with a high specific gravity occupied a larger portion than in those from children. Fraction I consisting of cells with a low specific gravity had a greater number of cells in the swollen tonsils of children than in the tonsils of adults. However, the absolute numbers of the cells in fraction III in adults and in children were nearly the same. The proportion of T cells in fraction III was higher than in fraction I. Hence, the proportion of T cells in adults' tonsils is higher than in children's tonsils. The cells composing fraction I include some cells that have undergone blastoid transformation in response to various stimuli and some lymphoid cells that are ontogenetically immature T cells, besides mature T cells. The cells composing fraction III include fully mature T cells and the total cell population of fraction III does not differ significantly with age. It seems likely that the child's tonsil contains a larger number of cells under antigenic stimulation or in preparation for immune response than does the adult's tonsil.

The invitro response of lymphocytes from adenoid vegetations and tonsils to PPD. Influence of autologous blood monocytes, T lymphocytes and unseparated lymphocytes

Thymidine incorporation in lymphocytes obtained from adenoids (AVL), tonsils (TL) and blood (PBL) and stimulated by PPD was compared in 19 BCG-vaccinated patients. Responses were approximately tenfold higher in vaccinated than in unvaccinated patients. The responses obtained for AVL/TL were lower than for PBL in BCG-vaccinated as well as in unvaccinated patients. In autologous mixtures of AVL/TL and PBL a linear increase in thymidine incorporation was obtained with increasing numbers of PBL. The monocyte concentration in cell suspensions obtained from adenoid and tonsil tissue was lower than in cells prepared from blood; addition of autologous monocytes purified from blood to cultures of AVL and TL was followed by a small increase in response to PPD, but not to the level of responsiveness of PBL. Addition of autologous T lymphocytes purified from blood to cultues of AVL and TL was followed by a small increase in thymidine incorporation, of similar proportions in cultures with and without PPD. It is concluded that the proportion of PPD-sensitized lymphocytes is smaller in AVL/TL than in PBL.

Biochemical characterization of the proliferation pool of lymphatic cells in the human tonsil and demonstration of the age-dependent pool size reduction

The DNA and RNA content and also the thymidine and uridine incorporation kinetics were determined in peripheral lymphocytes and lymphatic cells of the tonsil. The existence of a proliferation pool of lymphoid cells in the tonsil could be established by the comparison of all data. An age-conditioned reduction of the pool size was assumed from the uridine incorporation rate which takes place faster than the organo-specific cell decrease likewise conditioned by age in the tonsil. The abscess tonsil could be explained as a pathological state with considerable reduction of proliferation.

The effect of ozone and photochemical oxidants on the interferon production by tonsillar lymphocytes

In order to elucidate the biological effects of photochemical smog on the tonsil, lymphocytes from human tonsil were exposed to ozone and rabbits were exposed to ozone or photochemical oxidants. The tonsillar lymphocytes were studied for interferon production by Newcastle disease virus and blastoid transformation by PHA. Both interferon production by and blastoid transformation of the human tonsillar lymphocytes decreased markedly on exposure to ozone. Tonsillar lymphocytes from rabbits exposed to photochemical oxidants showed a significant decrease in interferon production. The decrease in interferon production in tonsillar lymphocytes from the rabbit exposed to photochemical oxidants was greater in magnitude than the decrease in interferon production in tonsillar lymphocytes exposed to ozone or non-irradiated automobile exhaust gas. The difference in blastoid transformation between the exposed groups and controls was not significnat. The results suggest that exposure to photochemical oxidants causes some functional changes in tonsillar lymphocytes.

Characterization of clinical tonsil stages by their T-cell count. Immunopathological description of tonsils after a peritonsillar abscess

The T-cell counts in five different clinical tonsil stages are compared. No particularities were observed, with the exception of the condition after a peritonsillar abscess. The differences existing between the individual groups are discussed as age-dependent. A considerable increase in T-cells is found in the abscess tonsil compared with other tonsils and the T-cell count in blood. Its pathomechanism is discussed.

Cell fractionation and cytological analysis of human lymphatic cells from tonsil and blood

No differences could be detected in the discontinuous density gradient when comparing the distribution pattern of tonsillar cells and peripheral lymphocytes. When the Kiel nomenclature is applied, the presence of centrocytes, centroblasts, lymphocytes and plasma cells in the tonsil is shown by a cytological analysis. The biological importance of these results is discussed from the point of cellular proliferation and tonsillar function.

Studies on the capacity of human tonsillar lymphocyte subpopulations to produce interferon

Tonsillar lymphocytes produced classical interferon (Type I) in response to NDV infection and produced immune interferon (Type II) in response to PHA, PPD or histo-incompatible antigens. Lymphocytes having higher specific gravity and having a greater proliferative response to mitogens or antigens produced more interferon than lymphocytes having lower specific gravity. There was no difference between heavy and light small tonsillar lymphocytes in regard to their sensitivity to the protective effects of interferon. As for the interferon produced in association with a cellular immune response, the peak of interferon production tended to appear earlier than the peak of 3H-TdR incorporation. It is suggested that tonsillar lymphocytes play an important role in human host defense against virus infections.