The Difference And Associated Mechanism Of Immunologic Reaction Caused By Different Stressor

Stress is unavoidable in our daily life. The common stressors includewound, heat, pressure of work, test and so on. A conclusion has been drawnthrough a lot of experiments and observations: A series of variance inphysiological function, psychological function, endocrine, neuro-biochemistry and immunological function will take place on the conditionof stress. These changes can keep the balance of internal environment.With the development of society, we have recognized that acute stressenhances, whereas chronic stress suppresses the immune function. It isreported that stress exposure induces changes in cellular and humoralimmunity in laboratory animals. A focus for investigating stress-inducedimmune compromise has been provided. On the other hand, chronic stressexposure led to a disruption of cellular immunity, a reducedmitogen-induced T-cell proliferation, a poor T-cell-dependent antibodyresponse and a disruption of cytokine secretion. The mechanisms by whichthese alterations occur have not been fully elucidated. Major histocompatibility complex (MHC) is a conglomerate of genesplaying an important role in recognition of self and non-self. These genesare under tight control. The MHC of the mouse, the H-2 complex, has themost plentiful polymorphism. Like the MHC of other species, the H-2complex represents a group of closely linked genes, among which the classI and class II genes are the most characteristic. These genes have thefunction of presenting antigenic peptides, and thereby controlantigen-specific, adaptive immune responses. The most importantantigen-presenting molecules are the class I and class II molecules of MHCwhich present polypeptides to T cell. The products of the class II genes (Aand E in the mouse) are heterodimers of heavy (α) and light (β)glycoprotein chains. Both of the chains are encoded in the I region of theMHC. The Ab and Aa genes encoded the β and α chains of the A molecule.The A molecules are much less polymorphic than the E molecule. Severalstrains of the mouse do not express the I-E antigen. However, no strain isknown that does not express I-A, which may mean that this antigen is vitalfor survival. Thus, we chose the I-A as the goal gene to analyze thedifference and correlated mechanism of body immunoreaction caused bydifferent stressor. To investigate the exact relationship between stress and immunology,we established the mouse restraint stress model (psychological stress model)and heat stress model (physiological stress model). And the production (U)of Immunoglobulin G (IgG) to the protein antigen (ovalbumin) duringsecondary immune response was measured by Enzyme-LinkedImmunosorbent Assay (ELISA). It showed that there was a great differencebetween the two groups (p<0.05=, the antibody of the restraint group waslower than that of the heat group. What is more, the content of cortisol inthe serum was measured by radioimmuneassy (RIA), the result showed thatthe cortisol (nmol/L) in restraint group (5.57±1.75) and heat group(4.20±1.36) was higher than that in control(3.91±0.99), which judged thestress intensity. Flow cytometry was used to test the expression of H-2 IAbin lymphocyte, the result (Mean.)of heat group(6.83±2.32)was muchhigher than that of restraint group(2.86±1.76), there was a significantdifference between the two groups (p<0.05=. Also, the H-2 IAb gene wasdetected with the technique of one step reverse transcription PolymeraseChain Response (RT-PCR), the electrophoregram showed that all of themice express the H-2 IAb gene, which correlated with the result of flowcytometry (r=0.649). At the same time, the ratio of mouse weight of therestraint, heat and control was -0.09±0.06, -0.01±0.05, 0.11±0.06, therewere a great differences among the three groups. However, there was nocorrelation between the immune response and the ratio of mouse weight. Aconclusion has been drawn: immunologic reaction caused by differentstressor is different. The effect of psychological stress may be stronger thanthat of physical stress to the immunologic system, the mechanism may bedifferent.