Yoshiyuki Murakami

Donor-specific prolongation of rat skin graft survival induced by rat-donor cells and cyclophosphamide under coadministration of monoclonal antibodies against T cell receptor alpha beta and natural killer cells in mice.

Because of the recent interest in human xenotransplantation, we investigated the possibility of inducing tolerance in a xenogeneic combination using cyclophosphamide (CP). Donor-specific prolongation of xenogeneic Fisher 344 (F344) rat skin graft survival for up to 60 days was induced in C57BL/6 (B6) mice by giving F344 bone marrow cells and spleen cells on day 0, CP on day 2, and monoclonal antibodies against murine TCR-alpha beta and NK1.1 on days--1 and 3. The inoculation of the xenogeneic cells brought accelerated repopulation of TCR-alpha beta+ T cells, even under the administration of anti-TCR-alpha beta mAb. The quick increase of the host TCR-alpha beta+ T cells caused by the xenogeneic cell injection was deeply suppressed by CP. Mixed lymphocyte reaction, CTL activity, and antibody production against donor F344 were profoundly suppressed for 50 days. Mixed xenogeneic chimerism was observed for 1 month after the inoculation of donor cells in the spleen and peripheral blood of the recipient B6 mice, but was never observed in the thymus. Moreover, when irradiated F344 cells were used in place of viable cells, chimerism was never detected and graft survival was only slightly prolonged. Clonal deletion of V beta 5- or V beta 11-bearing murine T cells was not observed on day 50 in the thymus or spleen of the recipient B6 mice. These results suggest that treatment with viable xenogeneic donor cells, CP, and mAbs against T and NK cells can induce a temporary peripheral mixed chimerism and donor-specific prolongation of xenogeneic skin graft survival. The destruction with CP of T and B cells that are xenoreactive and thus proliferating after antigen stimulation, followed by mechanism other than intrathymic clonal deletion, may be the mechanism of the hyporesponsiveness in the present system.

A case of CD56+ cutaneous aleukaemic granulocytic sarcoma with myelodysplastic syndrome

We describe a 70‐year‐old man with cutaneous granulocytic sarcoma who presented with numerous cutaneous nodules but without any leukaemic involvement of the peripheral blood. The tumour cells were positive for lysozyme, peroxidase, CD11a, CD11c, CD33 and HLA‐DR, and weakly positive for CD4 and CD14, suggesting granulocytic differentiation. The bone marrow at admission showed dysplasia of the erythrocytic and granulocytic lineage and complex chromosomal abnormalities in association with an increase in monocytes. The patient was diagnosed as having granulocytic sarcoma of monocytic lineage with concomitant myelodysplastic syndrome. In this case, tumour cells also expressed the neural cell adhesion molecule (CD56), which has been suggested as a possible risk factor for developing granulocytic sarcoma in acute myelogenous leukaemia.

CD1a+, CD3+, CD4+, CD8+, CD68+ and cutaneous lymphocyte-associated antigen-positive cells in Bowen's disease

Background Bowen’s disease (BD) is a squamous cell carcinoma in situ that rarely invades into the underlying dermis. However, little is known about its immunohistology.

Factor XIIIa expression in pseudo-Kaposi sarcoma.

A 39‐year‐old man had pseudo‐Kaposi sarcoma on his left foot. A biopsy specimen obtained from a cutaneous lesion showed increased numbers of vascular spaces, proliferation of fibroblast‐like spindle cells, and deposition of hemosiderin in the dermis. Immunohistochemically, proliferative fibroblast‐like spindle cells around the vessels were positive for anti‐factor XIIIa antibody. Excessive heat radiation was detected from the skin lesions by thermography.

Delayed Tissue Necrosis Associated with Mitomycin‐C Administration

To the Editor: Mitomycin C (MMC), an antitumor antibiotic, is active in numerous tumors and has been well used for cutaneous squamous cell carcinoma in association with peplomycin. Although extravasation of MMC to the tissues at the time of administration is a well-known cause of ulceration and tissue necrosis, there have been only infrequent previous case reports of an unexplained, delayed cutaneous ulceration (1-5). Cutaneous ulceration from extravasation of MMC generally occurs one to two weeks after treatment and persists for one to four months (6). We report a case of a patient who developed cutaneous ulceration seven weeks after intravenous MMC infusion without symptoms of tissue injury. Case Report: A 71-year-old woman underwent a resection for perianal squamous cell carcinoma developed from Bowens disease (Bowen-carcinoma) onJune 20th, 1997. She underwent left inguinal lymph node dissection for metastasis in November of 1998 and following local radiation and chemotherapy including MMC and peplomycin in December. Peplomycin was intramuscularly used on the bilateral deltoid muscle from December 1 to December 9. On December 10, she received MMC injection into th left volar antebrachial region adjacent to anticubital fossa. The patient did not notice any pain or incongruity while receiving this MMC infusion. There was no evidence of erythema or infiltration noted at that time. Four days later, the infusion site on her left forearm was slightly inflamed. The symptoms disappeared in several days without any specific treatment. However, seven weeks after the MMC injection, she noted slight induration and burning just on the left anticuboital Letters to the Editor

Sensitization of T-cell receptor-αβ+ T cells recovered from long-term T-cell receptor downmodulation

Although the survival of fully allogeneic skin grafts was prominently prolonged by adult thymectomy in anti‐T‐cell receptor‐αβ monoclonal antibody (TCR‐αβ mAb)‐treated mice compared with that of non‐adult thymectomized (ATX) mice, the skin allografts were eventually rejected. In the anti‐TCR‐αβ mAb‐treated ATX mice, as shown in the present study, most of TCR‐αβ+ cells were promptly activated on day 2 and then rapidly disappeared by day 7, but some TCR‐αβ− Thy‐1+ cells remained at that time. These TCR‐αβ− Thy‐1+ cells which have downmodulated their TCR‐αβ expression may be refractory to depletion events by the mAb treatment. Although these downmodulated T cells re‐expressed their TCR‐αβ on day 50, they could not respond to stimuli via TCR such as TCR cross‐linking or alloantigens. However, they recovered the reactivity to donor antigens on day 85. These results indicate that the downmodulated T cells by anti‐TCR‐αβ mAb treatment are long‐lived and re‐express their TCR‐αβ at a late stage to be sensitized to donor antigen, which suggests that additional regimens may be required to get permanent, or very long‐term, graft acceptance.

Anti-CD4 Monoclonal Antibody Reduces the Dose of Cyclophosphamide Required to Induce Tolerance to H-2 Haplotype Identical Skin Allografts in Mice

Abstract Cyclophosphamide (CP)-induced tolerance which consists of a single i.p. injection of 200 mg/kg CP 2 days after priming with 1 × 10 8 donor spleen cells (SC), leads to long-lasting donor-specific skin allograft tolerance in H-2 compatible, multiminor antigen incompatible, murine strain combinations. In this system, the optimal dose of CP has been suggested to be 200 mg/kg, however, such a dose of CP causes strong myelosuppression. In the present study, we therefore attempted to reduce the dose of CP by administering anti-CD4 monoclonal antibody (mAb) before donor cell priming in this toleranceinducing system. When C3H/He (C3H; H-2 k , Mls-1 b ) mice were injected i.p. with 200 ltg anti-CD4 mAb on day -3, 1 × 10 8 AKR/J (AKR; H-2 k , Mls-1 a ) SC plus 3 × 10 7 bone marrow cells (BMC) i.v. on day -2 and then 100 mg/kg CP i.p. on day 0, a long-lasting donor-specific skin allograft tolerance was established; furthermore, the decreases in the number of leukocytes and the concentration of hemoglobin (Hb) in the peripheral blood were all less in the C3H mice treated with this new combined protocol than in the C3H mice injected with 200 mg/kg CP following the previous protocol. In the periphery of these tolerant mice, the number of donor-reactive Vβ6 + CD4 + T cells decreased and mixed chimerism was observed on both days 14 and 80. On the other hand, in the mice injected with AKR SC, BMC plus 100 mg/kg CP without anti-CD4 mAb, the number of Vβ6 + CD4 + T cells decreased on day 14, and then recovered by day 80 when the mixed chimerism disappeared. These results therefore suggest that the combined use of anti-CD4 . mAb with CP can reduce the dose of CP without affecting the efficiency of inducing donor-specific tolerance, probably due to the enhancement of the destruction effect of donor-reactive T cells by CP.