332
4
INHIBITION OF IMMUNOGLOBULIN SYNTHESIS BY STEROID SENSITIZED THIAZOLOBENZIMIDAZOLE COMPOUND (WY-18,251, NSC 310633). H. Fc~ie;~e~, S. Dheer, and P. Sc~a~eck Research Division, Wyeth Laboratories,
HUMAN LYMPHOCYTES
P.O. Box 8299, Philadelphia,
PA.
19101,
BY A
USA
Pokeweed mitogen (PWM) stimulates immunoglobulin (Ig) synthesis in cultures of human peripheral blood lymphocytes, and we have found, in agreement with Cooper, et al. (Clin. Exp. l ~ u n o l . 37:145, 1979), that PWM + methylprednlsolone (P+P) further stimulates the synthesis of Ig. Wy-18,251 inhibits the P + P stimulated synthesis of IgG and IgM. This inhibition may be due either to the replacement of T suppressor cell functional activity by Wy-18,251, or to its interference with steroid stimulation of B lymphocytes.
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QUANTITATION OF HUMAN TUMOUR-REACTIVE LYMPHOCYTES IN BLOOD AND TUMOUR BY LIMITING FREQUENCY ANALYSIS. B.M. V o s e Department of Immunology, Paterson Laboratories, Christie Hospital & Holt Radium Institute, M a n c h e s t e r M~0 9BX. Antigen activated T lymphocytes can be maintained in conditioned media containing interleukln-2 (IL-2). Limiting dilution techniques dependent upon IL-2 allow the quantitation of tumour reactive lymphocytea at different sites by e n u m e r a t i o n o f c e l l s stimulated in mixed lymphocyte-tumour cultures (MLTC). Blood lymphocytes (PBL) and t h o s e i s o l a t e d from eight enzymatically dispersed l u n g and b r e a s t t~mou~e ( T I L ) w e r e p l a t e d u n d e r l i m i t i n g azlutlon conditions with irradiated autolosous tumour, blood mononuclear ceils a s f e e d e r s and I L - 2 and i n c u b a t e d f o r 7 - 9 d a y s . Microcultures were assayed for proliferation by u p t a k e o f (3H) t h y m i d i n e and c y t o t o x i c i t y agalnst autologous and a l l o g e n e i c t u m o u r and K562. Ttmour associated lymphocytes showed significantly higher frequencies o f 1) s p o n t a n e o u s l y IL-2 reactive cells ( I / 9 0 0 and 1 / 4 7 5 0 ) and 2 ) p r o l i f e r a t i v e ( 1 / 2 0 0 and 1 / 1 2 0 0 ) and c y t o t o x i c tumour reactive precursors than blood lymphocyteJ but lower frequencies o f NK ( 1 / 2 5 0 0 and 1 / 1 6 0 0 ) p r e c u r s o r s . Four to eight fold concentrations of tumour reactive cells were regulLrly f o u n d i n TIL. Phonetypic analysis revealed that although proportions of T cells i n PBL and TIL w a r e s i m l l L r ( 6 0 - 8 5 % ) TIL s h o w e d a m a r k e d i n c r e a s e i n t h e n u m b e r o f OKT8 ÷ ( c y t o t o x i c / s u p p r e s s o r ) cells,
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PHARMACOLOGICAL STUDIES ON A NITOGKN,
K. Imanishi and I. Suzuki Laboratory of Applied Immunology, 2-9-3 Zukei, Koriyama 963, Japan
ALOCTIN A.
The Koriyama
Institute of Medical
Immunology,
Aloctin A (Ale A) is a mitoEen isolated from Aloe arborescens Mill, has a mol wt of 18,000, consists of 2 subunits, ~ and 8, and exhibits various biolcEical activities, such as mitoEenic activity for T cells, cytoagElutination, bindin E reactivity for a2-macroElobulin and complement 3rd component activation via the alternative pathway. Ale A inhibits the growth of transplantable murine tumor in viv____o but not in vitro and also inhibits experimental models of inflammation in rats. To elucidate the mechanisms of these effects, immunoloical studies have been investigated. After i.v. administration of Ale A cytotoxic activity arose in mouse spleen cells and peritoneal cells but not lymph node cells, while after i.p. administration the activity arose in only peritoneal cells. The effector ceils in spleen were NK cells. The effector cells in peritoneal cells were not only NK cells but also other cells which seemed to be neutrophils. Macrophages i~iduced by i.p. injection of Ale A showed cytostatic activity and the intracellular level of B-Elucuronidase of these macrophaEes increased up to 4 times of the residents. The administration of Ale A caused marked increases of serum proteins such as hemopexin in mice.