Description: Segment 1 Greaves speaks to the camera. He introduces his subject by saying that the antibodies produced when experimental animals are injected with antigen are of especial interest for this talk, and that he will be specifically focusing on the cellular basis of this antibody response. He describes how the process of antibody production involves cell collaboration between macrophages, T and B lymphocytes and that this collaborative process will be the main theme of his discourse. Greaves goes on to talk about two technical advances which have made the study of antibodies more viable: the availability of marker systems to make the differentiation of cell populations more visible, and the second is the refinement of tissue culture methods. To illustrate how these two techniques function, Greaves refers to charts detailing the Marbrook chamber, a popular method of tissue culture, commonly used to measure antibody responses. He describes its anatomy in depth and shows, through diagrams, how it works. Time start: 00:00:00:00 Time end: 00:05:19:00 Length: 00:05:19:00 Segment 2 Greaves describes the method of 'local haemolysis in gel', used also to detect antibody responses in tissue cells. He refers to a chart detailing the technique and describes some of the results one might expect to see from it. Greaves moves on to discuss the collaborative nature of cells leading to the production of antibodies. He describes how taken individually neither T nor B lymphocytes produce antibodies, but combinations of them do. He refers to work on bone marrow cells to illustrate this. Time start: 00:05:19:00 Time end: 00:10:38:00 Length: 00:05:19:00 Segment 3 Not only do T and B lymphocytes combine to produce antibody, Greaves now shows how macrophages are also an important factor. Exactly how this occurs, he admits, is not known, but he highlights one current hypothesis. Referring again to the charts showing the Marbrook chamber, Greaves outlines in much detail some experiments by Feldman to show the role of macrophages in T-B interactions. Time start: 00:10:38:00 Time end: 00:15:00:00 Length: 00:04:22:00 Segment 4 Greaves continues to discuss Feldman's research into different models of cell interaction in order to produce antibody. He shows further detailed diagrams to illustrate one of Feldman's experiments, then goes on to discuss a further experiment from 1969 by Mitchison and Rajewsky which looks at antibody responses to haptens - the small molecules that can elicit an immune response when attached to a protein. He shows diagrams detailing this experiment and compares the results with those of Feldman's research. Time start: 00:15:00:00 Time end: 00:20:49:00 Length: 00:05:49:00 Segment 6 Greaves explains how the three examples above can trigger T and B cells directly, a system called second signals one to trigger antigen responses and the second to stimulate antibody. He refers to research by Antonio Coutinho on this subject, although he admits that this research is, as yet, 'controversial.' Greaves ends the lecture in a somewhat apologetic manner, he apologises for the complicated nature of the systems he has been discussing. However, he stresses that as this is such a crucial mechanism it is worth the effort of further research. He ends by reminding us that with cell collaboration in antibody production one should think of the B cell is the producer cell and the T cell as the regulator cell controlling the B cell response. Time start: 00:26:57:00 Time end: 00:33:44:24 Length: 00:06:47:24