Y. Nawa

Defective protective capacity of W/Wv mice against Strongyloides vatti infection and its reconstitution with bone marrow cells

Summary The susceptibility of congenitally anemic, and mast cell deficient W/Wv mice to infection with Strongyloides ratti was examined. After a primary infection, W/Wv mice showed greater and more persistent peak larval counts than did normal littermates. Worm expulsion was also slower in W/Wv mice than in +/+ mice. Furthermore, difference in susceptibility was expressed as early as 24 h after infection, suggesting not only that protective mechanisms of the gut but also of the connective tissue were defective in W/Wv mice. Reconstitution with bone marrow or spleen cells from +/+ mice was effective in restoring the protective response in W/Wv mice, whereas thymocytes or mesenteric lymph nodes had no effect. Both connective tissue and mucosal mast cells were repaired in W/Wv mice after marrow reconstitution and infection. Since relatively long incubation period was required for the expression of such reconstituting activities, bone marrow cells seem to contain precursor cells of the effector and/or regulator cells.

Strongyloides ratti: The role of enteral antigenic stimuli by adult worms in the generation of protective immunity in rats

Immunogenicity of adult Strongyloides ratti was studied in rats. Immunization of rats by intraduodenal implantation of adult worms could completely inhibit the egg production and hasten the expulsion of challenged worms which were developed from subcutaneously inoculated L3 or were implanted intraduodenally as adults. Enteral immunization by intraduodenal implantation of adult worms was, however, not able to affect the esophageal larval output of the challenge infection with L3. In contrast to enteral immunization with adult worms, immunization by full sequence of a primary infection or by a combination of drug-abbreviated infection and adult worm implantation could suppress the esophageal larval output of the challenge infection. The relationship between the host defense mechanism and the life cycle of S. ratti is discussed.

Inhibition by testosterone of immune reactivity and of lymphoid regeneration in irradiated and marrow reconstituted mice

Nachweis, dass die Behandlung letal bestrahlter und mit isologem Knochenmark regenerierter Mäuse mit Testosteron zu starker Herabsetzung der immunologischen Reaktivität und zu eindeutiger Reduktion des lymphatischen Gewebes führt.

IgE response inStrongyloides ratti-infected rats with special reference to the life cycle of the parasite

Parasite-specific IgE antibody response was examined inStrongyloides ratti-infected rats. The results showed that the parasite-specific IgE antibody response was generated after a primary infection. However, repeated infections rather depressed the level of parasite-specific IgE antibody in the serum. Immunization limited to specific stages of the parasite revealed that stimulation of parasite-specific IgE antibody was related to the intestinal adult stage. On the other hand, depression of IgE titers was related to the tissue-migrating larval stage. The capacity of the each stage of the parasite to induce specific IgE response may be related to the variable results of the IgE responses in human strongyloidiasis.

Effect of testosterone on the kinetics of the development of suppressor cells in adjuvant arthritis.

The induction of unresponsiveness to mycobacterial adjuvant took a longer time in male DA rats than in female rats. A shift in the induction time of unresponsiveness in males toward the female type was brought about by castration, but could be reverted to the male type by the application of testosterone. The transfer study revealed that cells capable of preventing arthritis required a longer incubation time for their development in males than in females. This suggests that testosterone inhibits the development of suppressor cells in adjuvant arthritis.

REGULATION OF B-CELL DIFFERENTIATION BY ANTIGENIC STIMULI ACROSS BURSAL EPITHELIUM IN NEONATAL CHICKEN

Publisher Summary The bursa of Fabricius is known as the major site for B-cell differentiation. It is well established that various antigenic materials derived from the gut or artificially introduced into the cloacal lumen are trapped into the bursal lumen by sucking movements. This chapter discusses a study to investigate the regulatory role(s) of specific and/or nonspecific stimuli across the bursal epithelium on B-cell differentiation in neonatal chicken by using two different systems. When neonatal chickens were intracloacally primed with sheep red blood cells (SRBC) and then intravenously challenged with the same antigen, markedly enhanced plaque forming cell (PFC) response in the spleen was observed. The bursal duct was ligated on the 19th day of incubation without any damage on the blood, and lymphatic vasculature, and subsequent development of the bursa, and of the immune reactivity was examined. The size of the bursal lymphoid follicles of these chickens was slightly smaller than those of controls. Neither necrotic changes nor severe involution of the bursal lymphoid follicles was observed at any age examined, and lymphopoiesis in the bursa gradually increased with age. It is found that when immune reactivity of these chickens was examined by anti-SRBC PFC response, marked suppression was observed, although the reactivity gradually increased with age. It is observed that when bursal duct ligation was performed one week after hatching, no or only very minor effect was observed in the development of the immune system.

Lymphocyte Emigration in Related to the Formation of Lymph Follicles

リンパ球には胸腺由来のTリンパ球と骨髄由来のBリンパ球がある。新生仔胸腺摘出C3Hマウスに致死量の放射線を照射。直ちに骨髄細胞を移入した動物(Bマウス)のリンパ組織を観察すると, T, Bリンパ球は末梢リンパ組織では違つた領域に分布することがわかる。Bマウスにリンパロ胞が形成されることは, リンパロ胞が主としてB(骨髄)依存であることを示している。しかしながら, 放射線照射後骨髄細胞を移入する時に, 胸腺細胞を加えて注射すると, リンパロ胞は骨髄細胞だけを注射した場合よりはるかに早く, はるかに多く形成される。このことから, 胸腺細胞はリンパロ胞の形成を促進することが分る。Tリンパ球の再循環として知られた後毛細管静脈はまたBリンパ球の通路でもある。そしてリンパロ胞の形成に重要な役割を果たしているに違いないと思われる。放射線照射後骨髄細胞を移入した動物にテストステロンの水性懸濁液を使用すると, リンパロ胞の発育が抑制され, 抗体産生細胞が減る。幹細胞のリンパ系への分化にたいするテストステロンの効果が討議された。