Chardès T, Velge-Roussel F, Mevelec P, Mevelec M N, Buzoni-Gatel D, Bout D
Equipe de Recherche Université de Tours-INRA d'Immunologie Parasitaire, UFR des Sciences Pharmaceutiques de Tours et Unité INRA de Pathologie Infectieuse et Immunologie, Nouzilly, France.
Immunology. 1993 Mar;78(3):421-9.
This study was performed to determine the T-cellular immune responses following Toxoplasma gondii oral infection and to assess further toxoplasma antigens on their ability to stimulate in vitro mucosal and systemic T-cell immunity. Parasite-specific cellular immune responses in Peyer's patches (PP), in mesenteric lymph nodes (MLN) and in spleen (SPL) were investigated using a lymphoblastic transformation test following oral infection of mice with strain 76K cysts of T. gondii. An early toxoplasma sonicate-induced mucosal T-cell proliferation occurred in MLN and PP with a peak responsiveness on day 6 post-infection (PI) and rapidly reached background levels on day 7 PI in PP and on day 8 PI in mesenteric lymph nodes. A later splenic cellular blastogenesis was observed from day 28 PI and persisted throughout the experiment (day 91). At the time of T-cell proliferation, FACS analyses revealed a decrease in the relative percentages of CD4+ and CD8+ T cells with a predominance of CD8+ lymphocytes which leads to an inversion of the CD4/CD8 ratios. We found that CBA/J is a high responder mouse strain in the induction of mesenteric and splenic T-lymphocyte blastogenesis compared to the intermediate responder BALB/c and low responder C57BL/6. Toxoplasma gondii antigens SAG1 (30,000 MW) and GRA4 (40,000-41,000 MW), which are known to induce locally IgA antibodies, are shown to stimulate primed mucosal T lymphocytes from CBA/J and BALB/c mice whereas no proliferation was demonstrated with C57BL/6 T cells. 229-242 peptide, derived from the deduced amino acid sequence of GRA4, only induces detectable proliferation of primed-CBA/J T lymphocytes. Following oral experimental infection, the in vitro mesenteric response to a toxoplasma sonicate is dominated by a Th2-type cytokine pattern whereas a predominant Th1 cytokine response is observed in the spleen. Finally, in vitro stimulation of mesenteric T cells with the three defined toxoplasma antigens resulted in secretion of interleukin-5 (IL-5) and IL-6 (except for SAG1) and interferon-gamma (IFN-gamma) whereas no detectable IL-2 or IL-4 was observed.
本研究旨在确定弓形虫口服感染后的T细胞免疫反应，并进一步评估弓形虫抗原刺激体外黏膜和全身T细胞免疫的能力。在用76K株弓形虫囊肿口服感染小鼠后，使用淋巴细胞转化试验研究派尔集合淋巴结（PP）、肠系膜淋巴结（MLN）和脾脏（SPL）中的寄生虫特异性细胞免疫反应。感染后第6天，早期弓形虫超声裂解物诱导的黏膜T细胞增殖在MLN和PP中出现，反应性达到峰值，在PP中感染后第7天迅速降至背景水平，在肠系膜淋巴结中感染后第8天降至背景水平。从感染后第28天开始观察到脾脏细胞的胚细胞形成，并在整个实验过程中持续存在（第91天）。在T细胞增殖时，流式细胞术分析显示CD4+和CD8+T细胞的相对百分比下降，CD8+淋巴细胞占优势，导致CD4/CD8比值倒置。我们发现，与中等反应性的BALB/c和低反应性的C57BL/6相比，CBA/J是诱导肠系膜和脾脏T淋巴细胞胚细胞形成的高反应性小鼠品系。已知能诱导局部IgA抗体的弓形虫抗原SAG1（30,000 MW）和GRA4（40,000 - 41,000 MW），能刺激CBA/J和BALB/c小鼠的致敏黏膜T淋巴细胞，而C57BL/6 T细胞未显示增殖。源自GRA4推导氨基酸序列的229 - 242肽，仅诱导致敏CBA/J T淋巴细胞的可检测增殖。口服实验性感染后，体外肠系膜对弓形虫超声裂解物的反应以Th2型细胞因子模式为主，而在脾脏中观察到主要的Th1细胞因子反应。最后，用三种确定的弓形虫抗原体外刺激肠系膜T细胞，导致白细胞介素-5（IL-5）和IL-6（SAG1除外）以及干扰素-γ（IFN-γ）的分泌，而未观察到可检测到的IL-2或IL-4。
