Event Abstract

Changes of cell-mediated and humoral immune response, absolute cell number and their phagocytic activity in peritoneal cavity at experimental thyrotoxicosis in rats

  • 1 Acad. E.A. Wagner Perm State Medical University, immunology, Russia
  • 2 Institute of Ecology and Genetics of Microorganisms UB RAS, Russia

Among the elements of neuroendocrine regulation, one of the leading position is occupied by thyroid hormones, which are considered by many authors as the most important factors of immune system neuroendocrine regulation [1]. It is known that stimulation of murine macrophage phagocytosis may be mediated by thyroxine [2]. However, changes in functions of peritoneal mononuclear phagocytes, neutrophils and mast cells under experimental hyperthyroidism are not well explored. The purpose of this work is study of changes of cell-mediated and humoral immune response, absolute cell number and their phagocytic activity in peritoneal cavity at experimental thyrotoxicosis in rats. Materials and methods. The experiment was performed on 33 male white rats with initial average weight of 313±4 g. The animals of 1st and 2nd groups were administered daily subcutaneously for 14 days L-thyroxine for modeling experimental thyrotoxicosis. Daily dose of L-thyroxine for the 1st rat’s group was 0.04 mg/kg of body weight, and daily dose for the 2nd rat’s group was 4 mg/kg of body weight. Rats of the 3rd (control) group received a solvent of preparations. On the 10th day from the beginning of the experiment, all animals were sensitized by native sheep red blood cells (SRBC, 10⁸ cells subcutaneously into the right footpad). On the 4th day after sensitization, a resolution dose of antigen was injected (10⁹ erythrocytes into the right footpad). After 24 hours (the 15th day of the experiment), the following parameters were evaluated: the extent of local inflammation (index of delayed-type hypersensitivity reaction), the number of antibody-forming cells (AFC) in the regional (right popliteal) lymph node (evaluated by the method of local hemolysis in agarose gel) [3], the absolutely number of peritoneal cells and their phagocytic activity in test with formalinized sheep erythrocytes (fSRBC). Statistical analysis was performed by the methods of descriptive statistics and the post-hoc unpaired version of LSD-test. Results. It was found that thyroxin injection in 1st rat’s group leads to increase of inflammation extent under the delayed-type hypersensitivity (DTH) reaction to SRBC (p<0.05 when compared with the 3rd group), and thyroxin injection in the 2nd rat’s group leads to significant suppression of the DTH reaction (p<0.05 when compared with the 3rd group). Researching of the 1st group rats shows that the absolute number of AFC in the regional lymph node was statistically significant higher (p<0.05 to 3rd group), and researching of the 2nd group animals shows that the absolute number of AFC was statistically significant lower. It is found that the absolute number of all peritoneal leukocytes in the 1st rat’s group was 164.2±2,7 millions cells (p<0.05 towards the 2nd and 3rd group), the absolute number of all peritoneal leukocytes in the 2nd rat’s group was 104.0±8.9 millions cells (p>0.05 for group 3), and the number of all peritoneal leukocytes in the control group was 132.1 ± 15.6 millions cells. In the 1st group comparatively to the control group, increase of the peritoneal lymphocytes’ absolute number was revealed (p<0.05). At the animals of the 2nd group, the number of peritoneal lymphocytes did not differ from that in the control group (p>0.05). The absolute number of peritoneal mononuclear phagocytes, neutrophils and mast cells in animals with hyperthyroidism of varying heaviness degrees was not different from the same parameter of the control group (p>0.05). The phagocytic activity of peritoneal neutrophils in rats with thyrotoxicosis was not statistically significant in comparison with parameters of the 3rd group. The 1st group rats’ relative number of active phagocytic mononuclear phagocytes (that have captured two or more objects of phagocytosis) was less (25.67±2.22%) than in the control group (33.33±2.66%; p<0.05). Activation of mononuclear phagocytes was detected in the 2nd group of animals. Relative parameters of phagocytic activity, particularly activity of mononuclear cells that captured four or more fSRBC (data not shown; p<0.05 towards the control group) were increased. Evaluation of the phagocytosis absolute parameters revealed quantitative increase of the phagocytic active mononuclear cells that have seized more than five fSRBC (p<0.05). Changes among the parameters of mast cells’ phagocytic activity under a mild form of thyrotoxicosis were not revealed (p>0.05). Under a heavier form of thyrotoxicosis, the following changes were found: relative decrease in the number of cells that have captured one fSRBC, and increase of relative amount of cells that captured four or more objects (p<0.05), as well as relative decrease in the number of active phagocytic mononuclear phagocytes (in the 2nd group - 45.42±5.65%, in the 3rd group - 33.07±1.12%; p<0.05). Overall, by analyzing total phagocytic activity of peritoneal cells, it is pinpointed that changes of peritoneal leukocytes’ phagocytic activity in the 1st group are minimal in nature, and analyses in the 2nd group shows statistically significant increase in almost all relative indexes of peritoneal leukocytes’ phagocytic activity, and statistically significant increase in absolute indexes of white blood cells that have captured four or more objects. Conclusion. Thus, under experimental rat’s hyperthyroidism, the dose-dependent hormone influence on different parameters was revealed: on cell-mediated and humoral immune response, on peritoneal cells’ phagocytic activity. Under a milder form of hyperthyroidism, the following factors are observed: increasing expression of immune inflammation under the DTH reaction, quantitate increase of AFC in the lymph node, as well as increase of the peritoneal leukocytes’ total number with primary quantitate increase of lymphocytes and reduce of the relative number of active phagocytic cells that belong to monocyte-macrophage series. Under heavier hyperthyroidism, thyroxine suppressive effect on the indexes of immune response was detected, along with this, the total number of peritoneal cells did not change, but peritoneal cells’ phagocytic activity increased, particularly the number of cells that captured four or more objects.

References

1. Shilov Ju.I., Godovalov A.P. Immunomodulatory effects of adrenergic agent under experimental thyrotoxicosis // Russian Journal of Immunology. 2008. Vol. 2 (2-3). P. 153-153.
2. Forner M.A., Barriga C., Ortega E. Exercise-induced stimulation of murine macrophage phagocytosis may be mediated by thyroxine // European Journal of Applied Physiology. 1996. Vol. 80(3). P. 899-903.
3. Shilov Ju.I., Gein S.V., Chereshnev V.A. Influence of blockade of beta-adrenoreceptors and acute stress on antibody formation, delayed type of hypersensitivity, phagocytic cell activity in local immune response // Russian Journal of Immunology. 2001. Vol. 6(3). P. 301-308.

Keywords: experimental thyrotoxicosis, Phagocytic activity, peritoneal phagocytic cells, antibody-forming cells, Delayed-type hypersensitivity reaction

Conference: IMMUNOCOLOMBIA2015 - 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología, Medellin, Colombia, 13 Oct - 16 Oct, 2015.

Presentation Type: Poster Presentation

Topic: Immunotherapy

Citation: Shilov JI, Godovalov AP and Zenkov AL (2015). Changes of cell-mediated and humoral immune response, absolute cell number and their phagocytic activity in peritoneal cavity at experimental thyrotoxicosis in rats. Front. Immunol. Conference Abstract: IMMUNOCOLOMBIA2015 - 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología. doi: 10.3389/conf.fimmu.2015.05.00098

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Received: 15 May 2015; Published Online: 14 Sep 2015.

* Correspondence: Mr. Anatoliy P Godovalov, Acad. E.A. Wagner Perm State Medical University, immunology, Perm, Russia, AGodovalov@gmail.com

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