Abstract

The histocompatibility system exists for defence against viruses. It is responsible for the rejection of allograft. The immune system attempts to counter the explosive speed of viral replication by directing the defensive immune attack by cytotoxic T cells on to histocompatibility antigens on the infected cell’s surface. This enables destruction of the virus factories before the cytotoxic T cells are swamped by the myriad numbers of new virions, a thousand coming from each infected cell every 10 hours. The histocompatibility system mistakes alloantigen on grafts for virus-infected host cells that need swift destruction. For surgical transplantation, Henry Kaplan discovered that immune ablation of the recipient followed by inoculation with donor bone marrow prevents rejection of allogeneic grafts. Sykes has improved Kaplan’s technique by adding recipient bone marrow cells to the donor ones injected for reconstitution of the recipient after immune ablation. Kaplan’s technique, used on untreated pigs, should be the standard procedure for transplantation.

Highlights

  • Oncologists, wishing to study tumours by transplanting them from their source to another laboratory animal, found that the tumours were rejected

  • To emulate identical twins for acceptance of foreign grafts, oncologists used brother-sister mating of rodents to produce inbred strains. This led to discovery of the histocompatibility system, governed by a major genetic complex, named the major histocompatibility complex (MHC) [3]

  • In a famous experiment Zinkernagel and Doherty [5] found that a cell infected by a virus extrudes a viral peptide on to its surface histocompatibility antigens, where it can be attacked by a complementary cytotoxic T cell clone, if one exists

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Summary

Introduction

Oncologists, wishing to study tumours by transplanting them from their source to another laboratory animal, found that the tumours were rejected. Medawar [1] observed that the rejection of foreign skin grafts on a woman was accelerated on the second occasion, correctly concluding that an immunological process was involved. In 1952 the first successful kidney transplant was performed between identical twins [2], demonstrating the genetic basis of rejection. The genes involved will be described below

The Histocompatibility System
Functions of the MHC
Mechanism of Immune Tolerance
Chimera manufacture
The contestants Influenza virus Cytotoxic T cell
Improvement of Transplantation
False fear of pig tissues now gone
Unmodified pigs can be used
Full Text
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